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  1. NSLS-II Friday Lunchtime Seminar

    "Bragg-case X-ray dynamical diffraction propagator in physical optics simulator SRW: thin crystal phase retarders"

    Presented by John P. Sutter, Diamond Light Source, United Kingdom

    Friday, December 18, 2020, 12 pm

    Hosted by: Ignace Jarrige

    John P. Sutter(a), Oleg Chubar(b), Alexey Suvorov(b), Christie Nelson(b) and Kawal Sawhney(a) (a)Diamond Light Source; (b)NSLS-II, Brookhaven National Laboratory, Abstract A Bragg-case X-ray dynamical diffraction propagator has already been integrated into the "Synchrotron Radiation Workshop" (SRW) physical optics simulation software package. Previous benchmarking tests on crystal monochromators assumed thicknesses many times the extinction length, for which transmission is negligible. This paper reports tests of this propagator applied to thin crystals in transmission. The chosen example is a phase retarder, which allows users to alter the polarization of an X-ray beam. Phase retarders are often applied to studies of solid-state materials with hard X-rays, which current medium-energy storage ring synchrotron sources typically produce only with linear polarization. Correct designs of phase retarders require the accurate determination of both the intensity and the phase of the diffracted wave in all polarization states. First, to approximate an incident plane wave, SRW is used to simulate the passage of a Gaussian beam of very large radius of curvature through the phase retarder. Then, the phase retarder's effects on a typical undulator beam are simulated and the results are compared. Because X-ray phase retarders are highly sensitive to angular alignment, tolerances in misalignment are also determined. SRW simulations are compared with experimental data from the Integrated In Situ and Resonant Hard X-ray Studies (ISR) beamline at NSLS-II. The design of phase retarders can therefore be optimized for X-ray beamlines that must combine variable polarization with focusing or other properties.

  2. NSLS-II Friday Lunchtime Seminar

    "Traversing the "Devil's Staircase": Dynamic behavior of a frustrated antiferromagnet"

    Presented by Adra (Tory) Carr, National High Magnetic Field Laboratory, Los Alamos National Laboratory

    Friday, December 4, 2020, 12 pm

    Hosted by: Ignace Jarrige

    In frustrated magnets, seemingly simple competition between spin interactions can create theoretically infinite complexity. The Axial Next-Nearest Neighbor Ising (ANNNI) model is a classic model of frustration in which frustration occurs between nearest-neighbor ferromagnetic (FM) interactions and next-nearest-neighbor antiferromagnetic (AFM) interactions along chains of Ising spins. When cooled below the Neel temperature, the system passes through a theoretically infinite number of 1st order phase boundaries, referred to as the "Devil's staircase" or "Devil's flower". In this talk, we will discuss experiments performed at CSX (23-ID-1) using X-ray Photon Correlation Spectroscopy (XPCS) to test the dynamic behavior of these Devil's Staircase systems and demonstrate how this technique is broadly useful to study the peculiar dynamics of frustrated antiferromagnets. In particular, the results and model support a counterintuitive result: with decreasing temperature, the dynamics become faster.

  3. NSLS-II Friday Lunchtime Seminar

    "Structural studies of SARS-CoV-2 viral fusion inhibition peptides at NSLS-II"

    Presented by Dale Kreitler, NSLS-II

    Friday, November 20, 2020, 12 pm

    Hosted by: Ignace Jarrige

    SARS-CoV-2 uses a common viral strategy for fusing the viral envelope with a host cell membrane. The resulting fusion event is paramount to the infection process and this common strategy is known as a type I viral fusion mechanism. The energetically unfavorable membrane fusion event is driven by a large conformational change of the spike protein that occurs when the spike protein comes into contact with its target receptor on the host cell surface. One possible way to prevent this viral fusion event involves disrupting this conformational change by blocking the formation of the 6 helix bundle complex formed by the spike protein with synthetic polypeptide inhibitors. In this talk I will discuss preliminary structures of these polypeptide inhibitors in complex with fragments of the SARS-CoV-2 spike protein that were obtained at NSLS-II during min-safe operations. These structures provide some insight into important design considerations for future generation of SARS-CoV-2 membrane fusion inhibitors.

  4. NSLS-II Friday Lunchtime Seminar

    "The role of hard X-ray synchrotron characterization of additively manufactured metal and composite structures: enhancing processes, materials and performance"

    Presented by Gary Halada, Stony Brook University, NY

    Friday, November 13, 2020, 12 pm

    Hosted by: Ignace Jarrige

    Focusing on current challenges in understanding the process/structure/properties/performance relationship in additively manufactured (3D printed) alloys and ceramics, this talk will outline the potential role of planned hard X-ray capabilities at NSLS II. In particular, the talk will include recent results from an ongoing study of the relationship of factors contributing to durability of laser powder bed fusion (LPDF) formed 316L stainless steel, the role of print-formed micro and nanostructural heterogeneities on surface and bulk properties, and recent X-ray studies of alloys designed for aerospace, energy infrastructure and biomedical applications. The potential for in situ and in operando studies of printing via laser melting/sintering and post-printing processing to decrease porosity, improve surface finish and mechanical properties, as well as in situ X-ray analysis during corrosion and thermomechanical testing, will enhance the value of AM for manufacturing and a wide variety of applications relevant to regional industry and commercial applications.

  5. NSLS-II Friday Lunchtime Seminar

    "Investigation of Aqueous Electrochemical Energy Storage Mechanisms Utilizing Advanced Characterization Techniques"

    Presented by Daniel Charles, University of New Hampshire

    Friday, November 6, 2020, 12 pm

    Hosted by: Ignace Jarrige

    Electrochemical energy storage (EES) has become prevalent in daily life for their use in mobile electronics and electric vehicles. More recently, the need for large-scale stationary energy storage to integrate clean and renewable alternative energy sources to the electric grid has arisen. Aqueous EES devices using beyond-lithium charge carriers offer an attractive solution to this problem because of their superior safety, lower cost, and excellent transport properties compared to their organic counterparts. However, improvements in energy density and cyclability are required for implementation. Fundamental research on the charge-storage mechanisms is critical to understanding the structure-function relationship and, thus, for the development of electrodes materials for aqueous EES. Characterization of these electrode materials using synchrotron and neutron techniques provide vital information on the crystalline and electronic structure. Furthermore, time-resolved in situ measurements offer detailed information on structural changes due to the intercalation/de-intercalation of cations and the evolution of the electronic state of metal components during redox reactions. This, coupled with half-cell and full-cell electrochemical measurements, provides valuable insight into the change-storage mechanisms that occur. In this work, advanced characterization techniques have been used to investigate the charge storage mechanisms of nanoscale transition metal oxide electrode materials for aqueous EES. Various types of electrochemical charge storage mechanisms (pseudocapacitive, intercalation, and phase-change) were studied. Numerous strategies for improving the energy density and cyclability have been employed, including; studying the promotional effects of structural water, inducing structural disorder, synthesizing materials with open frameworks, doping with more redox-active components, using multivalent cations as charge carriers, and expanding the available potential window. These results provide a pathway for designing the next generation of aqueous EES devices. ________________________________ Daniel S Charles, Xiaoqiang Shan, SaeWon Kim, Fenghua Guo, and Xiaowei Teng

  6. NSLS-II Friday Lunchtime Seminar

    "Understanding the Instability of the Halide Perovskite CsPbI3 Through Temperature-Dependent Structural Analysis"

    Presented by Daniel B Straus, Princeton University, NJ

    Friday, October 30, 2020, 12 pm

    Hosted by: Ignace Jarrige

    Daniel B. Straus, Shu Guo, AM Milinda Abeykoon, and R. J. Cava Despite the tremendous interest in halide perovskite solar cells, the structural reasons that cause the all-inorganic perovskite CsPbI3 to be unstable at room temperature remain mysterious especially since many tolerance factor-based approaches predict CsPbI3 should be stable as a perovskite. We use a solid-state method to synthesize single crystals of perovskite-phase CsPbI3 that are kinetically stable at room temperature, allowing us to characterize its bulk properties and rationalize its thermodynamic instability. Electronically, CsPbI3 does not behave like a conventional semiconductor because its optical absorption and joint density-of-states is greatest near the band edge and decreases beyond the band gap for at least 1.9 eV. Structurally, single-crystal X-ray diffraction measurements reveal that while Cs occupies a single site from 100 to 150 K, it splits between two sites from 175 to 295 K with the second site having a lower effective coordination number. This finding along with other structural parameters suggests that Cs rattles in its coordination polyhedron. Pair distribution function measurements reveal that on the length scale of the unit cell, the Pb-I octahedra concurrently become greatly distorted, with one of the I-Pb-I angles approaching 82° compared to the ideal 90°. The rattling of Cs, low number of Cs-I contacts, and high degree of octahedral distortion cause the instability of perovskite-phase CsPbI3. These results reveal the limitations of tolerance factors in predicting perovskite stability and provide detailed structural information that suggests methods to engineer stable CsPbI3-based solar cells.

  7. Virtual Symposium

    "National Virtual Biotechnology Laboratory Symposium"

    Wednesday, October 28, 2020, 11:30 am
    Virtual - Registration required

    Hosted by: John Hill

    The symposium is a virtual event to highlight the impact the U.S. Department of Energy's (DOE) National Virtual Biotechnology Laboratory (NVBL) has had utilizing the unique capabilities of the DOE to tackle the science and technology challenges associated with COVID-19, and to discuss areas in which the NVBL can have impact in the future. With perspectives from Chris Fall, Director, Office of Science, DOE, and William A. Bookless, Principal Deputy Administrator of the National Nuclear Security Administration, the event will feature presentations from lead investigators reporting progress in: • Epidemiological modeling • Therapeutics • Testing • Understanding transport of the virus • Solving issues around supply chain challenges In addition, keynote speakers from outside the NVBL will discuss the upcoming science and technology needs in computing, testing and surveillance, and vaccines.

  8. NSLS-II Friday Lunchtime Seminar

    "Local structural symmetry breaking at ambient conditions in FeSe superconductor"

    Presented by Robert Koch, Condensed Matter Physics and Materials Science Dept

    Friday, October 23, 2020, 12 pm

    Hosted by: Ignace Jarrige

    We report pair distribution function measurements of the iron-based superconductor FeSe above and below the structural transition temperature. Structural analysis reveals a local orthorhombic distortion with a correlation length of about 4 nm at temperatures where an average tetragonal symmetry is observed. The analysis further demonstrates that the local distortion is larger than the global distortion at temperatures where the average observed symmetry is orthorhombic. Our results suggest that the low-temperature macroscopic nematic state in FeSe forms from an imperfect ordering of orbital-degeneracy-lifted nematic fluctuations which persist up to at least 300 K.

  9. NSLS-II Friday Lunchtime Seminar

    "Structure-based drug development for COVID-19"

    Presented by Desigan Kumaran & Babak Andi, Biology & NSLS-II

    Friday, October 16, 2020, 12 pm

    Hosted by: Ignace Jarrige

    The recent outbreak of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 in December 2019 posed great threats to public health and attracted enormous attention around the world. The morbidity and mortality rates associated with COVID-19 in the United States and Europe are increasing exponentially. To date, there are no clinically approved vaccines or antiviral drugs available for these COVID-19 infections and hence there is urgent demand for effective therapeutics and vaccines to control and eradicate the pandemic. We are using structure-based drug discovery (SBDD) approach to develop anti-COVID-19 drugs by targeting multiple viral targets. In order to ramp up the discovery process, we are screening FDA approved drugs with special attention to other existing antiviral and pathogen-specific drugs. Indeed, we have identified few FDA approved drugs that can inhibit (with moderate potency) one of the SARS-CoV-2 viral protein, main protease (Mpro), which play a key role in the viral replication cycle. In this presentation, we will highlight our efforts on SBDD approach on Mpro as a representative target that includes viral protein production, molecular docking studies, in-vitro binding assay and the co-crystal structure determination.

  10. NSLS-II Friday Lunchtime Seminar

    "Provenance and workflow tools for multimodal experiments"

    Presented by Line Pouchard, Computational Science Initiative, BNL

    Friday, September 25, 2020, 12 pm

    Hosted by: Ignace Jarrige

    New data management techniques are needed to address the increasing volume and complexity of data produced by the latest generation of detectors at Scientific User Facilities such as NSLS-II. The experiments carried out by very diverse user communities produce data processed in many unique and highly customized scientific workflows. The facilities exhibit further complexity in large and adaptable collections of instruments, broad ranges of data rates, and data access patterns. In addition, multi-modal techniques that characterize samples with different imaging modalities are poised to further increase the heterogeneity of data processing and analysis methods. One particular challenge is the development of collections of well-annotated datasets for use with machine learning techniques, including provenance. Provenance is the detailed recording of data lineage and software processes operating on data that enable interpreting, validating and reproducing results. This seminar will describe provenance and workflow tools developed by a joint NSLS-II-CSI team under LDRD, including a text mining portal classifying scientific literature papers by XAS edges, and a graph-based provenance wrapper developed for XPD and recently matured to run with a 3D reconstruction code.

  11. NSLS-II Friday Lunchtime Seminar

    "Reversible Room-Temperature Fluoride-Ion Insertion in a Tunnel-Structured Transition Metal Oxide Host"

    Presented by Wasif Zaheer, Texas A&M University, TX

    Friday, September 18, 2020, 12 pm

    Hosted by: Ignace Jarrige

    An energy storage paradigm orthogonal to Li-ion battery chemistries can be conceptualized by employing anions as the primary charge carriers. F-ion conversion chemistries show promise but have limited cyclability as a result of the significant change in volume of active electrodes upon metal−metal fluoride interconversion. In contrast, the exploration of insertion chemistries has been stymied by the lack of hosts amenable to reversible F-ion insertion at room temperature. In this study, we showed reversible and homogeneous topochemical insertion/deinsertion and bulk diffusion of F ions within the one-dimensional tunnels of sub-micrometer-sized FeSb2O4 particles at room temperature. The insertion of F ions is evidenced by formal oxidation of the iron centers from Fe2+ to Fe3+ with a lattice volume contraction of

  12. NSLS-II Friday Lunchtime Seminar

    "Spin-charge Higgs mode in bilayer iridates"

    Presented by Mark Dean, CMPMSD / BNL

    Friday, August 28, 2020, 12 pm
    via Zoom - contact:

    Hosted by: Ignace Jarrige

    Spontaneous symmetry breaking at phase transitions is one of the richest topics in physics describing situations as diverse as magnetism, through freezing, to how elementary particles acquire mass. Phase transitions can be classified into two categories based on whether the phase or the amplitude of the order parameter softens at the transition. In particle physics, both types of transition are well-known and termed either Nambu–Goldstone modes or Higgs Bosons for phase and amplitude modes, respectively. In insulating magnets, order is overwhelmingly conceptualized in terms of phase (i.e. Nambu–Goldstone) softening. In this talk, I will describe our resonant inelastic x-ray scattering (RIXS) experiments which reveal a Higg's amplitudon mode in bilayer magnetic Sr3Ir2O7. We attribute this mode to spin-charge coupled excitations arising from the narrow Mott-gap in this insulator. The material's proximity to a quantum critical point softens the amplitudon to excitation energies only sightly above the phase mode, allowing an active engagement of the mode in the magnetic phase transition. Our work provides a new solid-state platform for research on the dynamics of the Higgs mode and a means to understand novel magneto-transport in moderately correlated magnets.

  13. NSLS-II Friday Lunchtime Seminar

    "Phyllosilicates and X-ray amorphous materials on Earth and Mars, characterization with synchrotron radiation"

    Presented by Michael T. Thorpe, NASA Johnson Space Center, Houston, TX

    Friday, August 21, 2020, 12 pm

    Hosted by: Ignace Jarrige

    Phyllosilicates and secondary X-ray amorphous materials have the unique ability to record a history of sedimentary processing and the environmental conditions during their formation. These materials are abundant in Martian sedimentary rocks, as identified from the CheMin instrument on the Curiosity rover. However, their atomic structures lack long-range order, making them difficult to characterize with CheMin and laboratory instruments. Synchrotron radiation provides a state-of-the-art technique to characterize the structure and composition of these juvenile alteration products. Using sediments from the basaltic terrains of Iceland , we seek to understand how the composition and short-range atomic order of secondary phases evolve from source to sink.

  14. Summer Sundays

    "National Synchrotron Light Source II"

    Sunday, August 16, 2020, 3:30 pm

    Tune in to get an up-close look at the "beamlines" where scientists use ultrabright x-ray light to see the atomic structure of batteries, proteins, and more. Then, viewers will have the opportunity to pose questions to a panel of scientists.

  15. NSLS-II Friday Lunchtime Seminar

    "Use of synchrotron X-ray footprinting to reveal allosteric changes in a key plant metabolic enzyme"

    Presented by Rohit Jain, Case Western Reserve University, OH

    Friday, August 7, 2020, 12 pm

    Hosted by: Ignace Jarrige

    X-ray footprinting (XFP) is a tried-and-true method for probing macromolecule structure in solution. In XFP, hydroxyl radicals produced by X-ray radiolysis covalently label protein side chains and cleave phosphodiester backbones of nucleic acids, providing insight into macromolecular structure and dynamics that complements data obtained from crystallography, cryo-EM, and small-angle X-ray scattering. XFP beamline (17-BM) at NSLS-II uniquely provides unmatched photon flux density and high level of automation to help resolve challenging biophysical questions, not obtainable by other structural probes. Recent developments in mass spectrometry have advanced the structural analysis and can provide detailed sub-peptide and residue level information for protein footprinting studies. In this talk, we will illustrate the use of synchrotron X-ray footprinting technique for studying structural changes in KIN10 enzyme, a key plant metabolic enzyme, after binding to its phosphorylated disaccharide ligand.

  16. NSLS-II Friday Lunchtime Seminar

    "Quantum materials meet coherent x-rays"

    Presented by Xiaoqian Chen, NSLS-II

    Friday, July 31, 2020, 12 pm
    Zoom Invitation

    Hosted by: Ignace Jarrige

    Quantum materials are a class of materials whose properties are deeply rooted in quantum mechanical processes. A few examples include unconventional superconductors and magnets, topological insulators, and multiferroics. Phase nonuniformity and dynamics in quantum materials play a crucial role in deciding their ground states. This calls for a microscopic tool that is also sensitive to a wide range of dynamical time scales. In this talk, I will discuss why synchrotron coherent x-rays are an ideal tool. I will review recent developments in this field with an emphasis on the speckle correlation analysis performed at NSLSII, and discuss some future topics to explore.

  17. NSLS-II Friday Lunchtime Seminar

    "New opportunities for IXS at the GALAXIES beamline, Synchrotron SOLEIL"

    Presented by J-P. Rueff, Synchrotron SOLEIL, France

    Friday, July 24, 2020, 12 pm
    Zoom Invitation

    Hosted by: Ignace Jarrige

    The GALAXIES undulator beamline at Synchrotron SOLEIL is dedicated to inelastic x-ray scattering (IXS) and high energy photoemission (HAXPES) spectroscopy in the tender x-ray range (2.3 – 12 keV) [1]. We will present recent scientific results illustrating the capabilities of the IXS endstation at GALAXIES with an emphasis on extreme conditions [2,3] and x-ray Raman spectroscopy [4]. Ongoing instrumental developments for improved energy resolution, faster acquisition scheme and larger collection angle will be discussed. Finally, we will explore the new possibilities offered by the future SOLEIL Upgrade program. [1] Rueff et al., J. Synchrotron Rad. 22 (2015), 175 [2] Lebert et al., PNAS 116 (2019), 20280 [3] Mazzone et al., Phys. Rev. Lett. 124 (2020), 125701 [4] Georgiou et al., Science Advances 5 (2019), eaaw5019

  18. NSLS-II Friday Lunchtime Seminar

    "Characterization of Lithium & Sodium Batteries using Synchrotron X-ray Techniques at NSLS II"

    Presented by Zulipiya Shadike, BNL / Chemistry Department

    Friday, July 10, 2020, 12 pm
    via Zoom - contact:

    Hosted by: Ignace Jarrige

    The utilization of anion redox reaction is opening a new approach to increase rechargeable capacities in alkaline ion batteries recently. It is important to understand the oxidation state and electronic structure of anion in the electrodes at different state of charge. Herein, we designed and synthesized the O3-NaCr2/3Ti1/3S2 (NCTS) material, which is delivering a high capacity of 190 mAh g-1 (0.95 Na+) as a cathode for sodium battery based on the cation and anion redox processes. To study the underlying nature of anionic redox chemistry in this layered chalcogenide, we investigated the charge compensation mechanism and structure evolution of NCTS electrode using multi-model synchrotron x-ray techniques and scanning transmission electron microscopy. Our experimental results provided core evidence to reveal various charge compensation mechanisms, involving the formation of electron holes, anionic dimers, and disulfide-like species. These results provide a new insight to clarify the nature of anionic redox process of layered chalcogenides, which is important for the development of novel cathode materials with high energy density.

  19. NSLS-II Seminar

    "Considerations of accelerator design for future NSLS-II upgrade"

    Presented by Timur Shaftan, NSLS-II, Accelerator Division Director

    Friday, June 19, 2020, 12 pm
    Zoom Invitation

    Hosted by: Ignace Jarrige

  20. NSLS-II Friday Lunchtime Seminar

    "Structural biology in drug discovery: Development of viral protease inhibitors"

    Presented by Scott Lovell, University of Kansas, KS

    Friday, June 12, 2020, 12 pm
    via Zoom - contact:

    Hosted by: Ignace Jarrige

    X-ray crystallography is a widely utilized technique to provide essential high resolution structural information for proteins and is particularly important to determine inhibitor binding modes for drug development. Modern advances in protein crystallization automation, synchrotron X-ray beamlines and crystallographic software development have enabled the rapid determination of crystal structures which has greatly facilitated drug discovery and development projects. Diffraction data for dozens of protein-inhibitor samples can be collected in a matter of hours and immediately analyzed for inhibitor binding using automated crystallographic software pipelines. As such, information regarding the binding modes of various inhibitors can be quickly obtained which facilitates subsequent optimization. Application of these modern structural biology techniques has been critical to the advancement of ongoing collaborative projects focused on the development of covalent inhibitors that target the 3CL proteases of Norovirus, MERS-CoV, SARS-CoV and SARS-CoV-2.

  21. NSLS-II Friday Lunchtime Seminar

    "Correlating microscopic materials properties with superconducting qubit performance"

    Presented by Anjali Premkumar, Department of Electrical Engineering, Princeton University

    Friday, June 5, 2020, 12 pm
    via Zoom - contact:

    Hosted by: Ignace Jarrige

    In recent years, evidence has emerged that superconducting qubit performance is limited by imperfections in constituent materials. To characterize the microscopic character of these imperfections, we performed measurements of qubit lifetimes in parallel with structural and electron microscopy of the niobium films used in qubit fabrication. Correlations were found between qubit relaxation times and several materials properties, including grain size, oxide composition on the surface and within grain boundaries, and residual resistance. These findings represent a novel approach to understanding sources of qubit decoherence, utilizing techniques such as hard x-ray photoelectron spectroscopy and transmission electron microscopy.

  22. NSLS-II Friday Lunchtime Seminar

    "Understanding the improved cycling performance of sulfurized polyacrylonitrile cathode in Li-S battery"

    Presented by Seongmin Bak, Chemistry Division, Brookhaven National Laboratory

    Friday, May 29, 2020, 12 pm
    via Zoom - contact:

    Hosted by: Ignace Jarrige

    The demands on low cost and high energy density rechargeable batteries for both transportation and large-scale stationary energy storage are stimulating more research toward new battery systems such as metal, metal-sulfur, metal-air, and multivalent batteries. Since sulfur is an earth-abundant material with low cost and has a high theoretical capacity, Li-S battery chemistry has attracted significant interest during the past decade. The Li-S battery utilizes electrochemical conversion of sulfur (S8) to lithium sulfide (Li2S), going through multiple electron transfer processes associated with long- and short-chain polysulfide (Li2Sx) intermediates. It is well known that the long-chain polysulfides can be dissolved into electrolyte with aprotic organic solvents and migrated to the Li anode side. This so-called "shuttle effect" is considered as the main reason for the capacity loss and low coulombic efficiency of the Li-S system. A lot of efforts have been made on how to overcome the problem of polysulfide dissolution through new sulfur-based material and electrolyte, as well as cell engineering. Sulfurized polyacrylonitrile (SPAN) is a promising material capable of suppressing polysulfide dissolution in Li-S batteries with carbonate-based electrolytes. However, undesirable spontaneous formation of soluble polysulfides may arise in the ether-based electrolyte, and the conversion of sulfur in SPAN during the lithiation/delithiation process is yet to be understood clearly. In this talk, our recent characterization study on the SPAN cathode material in Li-S battery using spatially-resolved X-ray fluorescence (XRF) microscopy combined with X-ray absorption spectroscopy (XAS) will be present. The morphology changes and the redistribution of sulfur and polysulfide in both the SPAN cathode and lithium metal anode were monitored through the XRF images, while the chemical state changes of SPAN and sulfur-containing interfacial layer (i.

  23. NSLS-II Friday Lunchtime Seminar

    "Catalysis with XAFS and XPS at the Brazilian synchrotron: examples and perspectives"

    Presented by Daniela Coelho de Oliveira, LNLS, Brazil

    Friday, March 6, 2020, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    In this talk, I will present some recent results of catalysts characterization obtained at the Brazilian synchrotron using XAS and/or XPS . I will show a brief perspective of the new capabilities that are planned to attend the catalysis community as well as other research areas.

  24. NSLS-II Friday Lunchtime Seminar

    "Probing the short-range spin correlations of CuGeO3 with time-resolved RIXS"

    Presented by Thorsten Schmitt, Paul Scherrer Institut, Photon Science Division, Swiss Light Source, Switzerland

    Friday, February 28, 2020, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Resonant Inelastic X-ray Scattering (RIXS) has become a versatile tool for probing quantum materials, allowing simultaneous access to charge, lattice, spin and orbital degrees of freedom. Much of its success in recent years has been driven by huge improvements in instrumentation, and with the recent advent of X-ray free electron lasers such as the LCLS, it has become possible to translate this technique into the time-domain. Given its ability to address multiple degrees of freedom at once, time-resolved RIXS (trRIXS) therefore has huge potential for investigating materials with cooperative dynamics. Nevertheless, it remains technically very challenging to perform such experiments. We performed trRIXS at the oxygen K-edge in order to probe short-range spin correlations in CuGeO3. This quasi-1D material formed of chains of edge-sharing CuO4 plaquettes, displays pronounced anti-ferromagnetic (AFM) nearest-neighbor spin correlations and transitions into a spin-Peierls phase below 14 K, highlighting a close relation between magnetic and lattice sub-systems. As a result of these AFM correlations a Zhang-Rice singlet (ZRS) exciton can develop during the RIXS process, resulting in a distinct energy loss peak within the charge transfer gap. The amplitude of this ZRS exciton directly reflects the nearest-neighbor AFM correlations [1]. By photoexciting CuGeO3 across the charge gap (~4 eV) we induce a sudden reduction of the intensity of the ZRS exciton within 1 ps, which rapidly recovers before gradually decreasing again towards a stable value after ~10 ps. Comparison to equilibrium measurements and a thermal model reveal that the longer time scale dynamics are dominated by heating of the lattice. However, the initial drop and recovery of the ZRS at short time scales clearly imply a non-thermal behavior. In comparison, lower fluence data shows only a thermal component, suggesting a threshold effect. By comparison with model Hamiltonian calculations we reveal

  25. NSLS-II Friday Lunchtime Seminar

    "Effect of Metal (Pt, Ir) Nuclearity in the Subnanometer Regime on CO Oxidation Activity"

    Presented by Ayman M. Karim, Department of Chemical Engineering, Virginia Polytechnic Institute and State University

    Friday, February 21, 2020, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Supported noble metal catalysts are extensively used in industry and their catalytic performance is strongly affected by particle size and shape. In the last decade, supported single atoms and clusters in the subnanometer size regime have attracted a lot of interest since they maximize the metal utilization and have also shown extraordinary catalytic properties for many reactions. However, to tailor the catalyst properties for specific reactions and determine possible limitations, there is a need to understand, on the atomic scale, the origin of reactivity in the subnanometer regime. In this seminar, I will present my group's efforts in understanding the role of metal nuclearity and electronic properties in catalyzing CO oxidation as a model reaction. Using a suite of advanced characterization techniques (aberration-corrected electron microscopy, microcalorimetry, in-situ and in-operando DRIFTS, XPS, EXAFS and HERFD-XANES) complemented by DFT calculations and detailed kinetics measurements, the catalyst structural and electronic properties are identified and correlated with the reaction kinetics. In the talk, CO oxidation on Ir and Pt single atoms and subnanometer clusters supported on MgAl2O4 and CeO2, respectively, will be presented. We identified the active Ir and Pt single atom complexes and show that the reaction follows a combination of Eley-Rideal and Mars-van Krevelen mechanisms. Moreover, we show that despite considered a non-reducible support, CO oxidation on MgAl2O4 supported Ir subnanometer clusters follows a similar mechanism as on a reducible oxide where O2 is activated at the metal-support interface. Finally, the role of metal-support interaction in O2 activation and effect of CO binding strength on the catalytic activity will be discussed.

  26. NSLS-II Colloquium

    "Subsurface Landscapes of Oxidation and Reaction in the Critical Zone"

    Presented by Susan Brantley, Pennsylvania State University, PA

    Thursday, February 13, 2020, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: John Hill

    The globally ubiquitous mineral pyrite oxidizes even at low oxygen concentrations. As the most common crustal sulfide, pyrite reactivity impacts sulfur, iron, oxygen, and carbon budgets globally. We discovered that pyrite oxidizes completely at tens of meters depth even in low-porosity rocks in catchments in humid climates. As erosion exposes the pyrite to near-surface conditions in low porosity rocks, pore and fracture development is the main control on the rate of oxidative weathering. Between fractures, oxygen diffusion limits the weathering and oxidation is inferred to be largely abiotic because bacteria cannot enter rock matrix pores. Oxygen concentrations and erosion rates together can explain pyrite-derived sulfate fluxes in rivers to the ocean and may account for the presence or absence of pyrite in detrital sediments over Earth history.

  27. NSLS-II Friday Lunchtime Seminar

    "Tracing Processes Involving the Reactive Intermediates of To Better Understand the Role of Sulfur Cycling on the Fate of Arsenic and Iron in Sediments; Using Reactive Intermediates to Document Extensive Cryptic Sulfur Cycling Affecting Arsenic Levels"

    Presented by BENJAMIN C. BOSTICK, Columbia University, Palisades, NY

    Friday, January 31, 2020, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Arsenic (As) groundwater contamination is thought to result from the reductive dissolution of As-bearing iron oxides by microorganisms. Our understanding of the how reactions occur commonly depends on observing the consumption and production of reactants and products respectively. This approach can be insufficient in environmental systems containing complex compositions and phases that can react through multiple and distinct coupled biological and chemical processes. We suggest it is more effective to study environmental processes by considering dissolved and mineral species as reactive intermediates in geochemical cycles where their concentration is controlled by the balance between their production, consumption and transport. Here, we apply this approach to elucidate a critical role of sulfur (S) cycling in iron reduction in sediments affected by As contamination. Arsenic (As) contamination in soil and groundwater is commonly associated with iron reduction because the concentration of dissolved As and Fe(II) increase together as Fe(III) minerals convert to Fe(II) minerals. In contrast, sulfate concentrations are usually low and stable in groundwaters affected by As. This stability is often interpreted as evidence for the minimal role of S cycling in Fe reduction; however, there is mounting biochemical and mineralogical evidence that sulfate reduction is active and critical to both Fe(III) reduction and As mobilization. Sediment iron mineralogies indicate that reactive Fe(III) minerals are present in most sediments and this Fe(III) is particularly susceptible to chemical and biological reduction. These Fe minerals were transformed to Fe(II) carbonate, green rusts, and, rarely, iron sulfides as the sediments became reduced. The microorganisms identified in sediments undergoing reduction were not iron reducers, and often were autotrophs involved in S cycling. This data suggests that sulfate reduction is active, and tightly coupled to the oxidation of sulfide and elem

  28. NSLS-II Friday Lunchtime Seminar

    "Real-space Local Correlated Motion in Liquids studied by using Inelastic Scattering"

    Presented by Yuya Shinohara, Oak Ridge National Laboratory

    Friday, January 17, 2020, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Liquids are critical to our daily life. A paramount example is water, which covers 70% of the Earth's surface and make up about 80% of our body. Liquids are also crucial to many current energy technologies. Despite their importance, our understanding of liquids at the atomic level is much poorer than that for crystalline solids. Particularly elusive is a detailed description of the correlated dynamics in liquids, which is the key to controlling the transport properties of liquids. Recent progress in inelastic X-ray/neutron scattering makes it possible to obtain inelastic scattering spectra over a wide energy transfer (E) and momentum transfer (Q) with a high E- and Q-resolution within a reasonable amount of time. This enables us to calculate the Van Hove correlation functions via Fourier transform. With this novel approach, we have determined spatial and temporal correlations of molecular motion of liquids. In this presentation, I will present our recent efforts in understanding the real-space local correlated motion in liquids.

  29. CSI Q Seminar

    "Probing quantum entanglement at the Electron Ion Collider"

    Presented by Dmitri Kharzeev, Stony Brook University and BNL

    Wednesday, December 18, 2019, 1:30 pm
    Training Room, Bldg 725

    Hosted by: Layla Hormozi

    The structure functions measured in deep-inelastic scattering are related to the entropy of entanglement between the region probed by the virtual photon and the rest of the hadron. This opens new possibilities for experimental and theoretical studies using the Electron Ion Collider. The real-time evolution of the final state in deep-inelastic scattering can be addressed with quantum simulations using the duality between high energy QCD and the Heisenberg spin chain.

  30. NSLS-II Friday Lunchtime Seminar

    "Operation at 500mA average current on the horizon"

    Presented by Alexei Blednykh, NSLS-II

    Friday, December 6, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Igna

    500mA average current achieved in NSLS-II. Limitations on the total average current will be discussed in details. Localized heating of the vacuum components was the major issue. Since the heating issues were resolved we were able to demonstrate 500mA during the beam study time. However, for the regular operation @500mA we need more power from the RF system to compensate the synchrotron radiation losses produced by the bending magnets, present and future insertion devices. To mitigate the heating issue and increase the beam stability, bunch lengthening will be beneficial for NSLS-II.

  31. NSLS-II Friday Lunchtime Seminar

    "In Situ & ACERT - The LANL-BNL Cathode Collaboration"

    Presented by John Smedley, Los Alamos National Laboratory

    Friday, November 22, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    The Applied Cathode Enhancement and Robustness Technologies (ACERT) capability at LANL and the in-situ x-ray analysis growth chamber at BNL are two of the premier tools available for development of photocathode technologies. We are following a model of innovation and collaboration to move cathodes from lab to application, guided by theory, modeling, and experimental validation. This presentation will focus on two recent technology advances – cathodes with "atomic armor", single monolayers of coatings to the cathode surface and/or substrate to improve lifetime and enable operating in inferior vacuum, and highly crystalline CsTe, providing evidence that better crystallinity can improve QE while supporting an ultra-smooth surface. We hope to engender both technical discussion in these areas and open the door to future collaborations. LA-UR-19-28272

  32. NSLS-II Friday Lunchtime Seminar

    "Local structures of Sn-doped BCZT lead-free ferroelectrics"

    Presented by Frederick Peter Marlton, Aarhus University, Denmark

    Friday, November 15, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

  33. NSLS-II Friday Lunchtime Seminar

    "Underpinning the nuclear fuel cycle with synchrotron and laboratory based X-ray absorption spectroscopy"

    Presented by Neil Hyatt, University of Sheffield, United Kingdom

    Friday, November 8, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Nuclear energy provides about 30% of the world's low carbon electricity supply, from more than 450 civil nuclear reactors. The supporting nuclear fuel cycle comprises a suite of industrial processes, which transform uranium ore into nuclear fuel, and support reactor operations, decommissioning, waste management, and geological disposal. This seminar will highlight three case studies in the application of X-ray absorption spectroscopy (XAS) in the nuclear fuel cycle, embracing environmental contamination, nuclear forensics, and radioactive waste management. In addition to exploitation of state of the art micro-focus multi-modal beamlines at synchrotron light sources, I will also show how we are using new developments in laboratory based XAS instrumentation, to probe element speciation in nuclear materials.

  34. CSI Q Seminar

    "Many-body physics with atoms and molecules under quantum control"

    Presented by Sebastain Will, Columbia University

    Thursday, November 7, 2019, 3 pm
    Conference room 201, Bldg 734

    Hosted by: Layla Hormozi

    Over the past decade, quantum simulators based on ultracold atoms have emerged as a powerful tool to address open questions in strongly interacting systems and nonequilibrium quantum dynamics that have relevance in all areas of physics, from strongly correlated materials to cosmology. Today, quantum simulators based on ultracold dipolar molecules are within experimental reach, which exploit long-range dipole-dipole interactions and will give access to new classes of strongly correlated many-body systems. In this talk, I will present our efforts towards quantum simulation with ultracold dipolar molecules. In trailblazing experiments we have demonstrated the creation of ultracold molecules via atom-by-atom assembly, which yields complete control over the molecular degrees of freedom, including electronic, vibrational, rotational, and nuclear spin states. Exploiting this control, we have observed long nuclear spin coherence times in molecular ensembles, which makes ultracold molecules an interesting candidate for the realization of a long-lived quantum memory. In addition, the dipole-dipole interactions between molecules can be flexibly tuned via external electrostatic and microwave fields. This motivates our current work towards two-dimensional systems of strongly interacting molecules, which promises access to novel quantum phases, will enable high-speed simulation of quantum magnetism, and points towards potential quantum computing schemes based on ultracold molecules. In the end, I will briefly present our new project on enhancing quantum coherence by dissipation in programmable atomic arrays. For this effort we will develop a novel nanophotonic platform that will enable trapping of individual atoms in optical tweezer arrays with unprecedented accuracy and high-speed tunability.

  35. NSLS-II Friday Lunchtime Seminar

    "Disentangling the nematode-microbiome interactions underlying long-term different crop rotation systems"

    Presented by Kaile Zhang, University of Florida

    Friday, October 25, 2019, 12:30 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Integrating two years of bahiagrass (Paspalum notatum) into conventional peanut (Arachis hypogea L.) and cotton (Gossypium hirsutum L.) cropping systems (bahiagrass-bahiagrass- peanut-cotton) improves soil quality and crop production compared with the conventional peanut-cotton-cotton rotation (CR). However, it is unclear if this system, known as a sod-based rotation (SBR), affects interactions within soil biota and if such interactions affect nutrient cycling and soil fertility. In this study, we collected soils from long-term plots under CR and SBR (located in Quincy, FL), before cotton planting. Our results showed that the metabolic activities of relative low trophic groups (i.e., bacterivores and herbivores) were positively correlated with r-strategists irrespective of cropping systems, but negatively with k-strategists only under CR. These demonstrated that microbial communities under higher rotational diversity contributed larger to C, energy, and nutrient flows in soil food webs relative to CR. Compared with SBR, one or more functional nematodes groups were entirely missing or showed few abundances, and less evenness of the microbial community was exhibited under CR in spite of no significant differences between these twoKo systems. These results imply that SBR with greater rotational diversity induced higher soil community diversity and consequently sustains the distribution of soil biological community, with positive effects on soil nutrient availability and the control of plant parasites.

  36. NSLS-II Friday Lunchtime Seminar

    "Plant-fungal symbiosis and their potential impacts on terrestrial biogeochemistry"

    Presented by Ko-Hsuan (Koko) Chen, University of Florida

    Friday, October 25, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Fungi are associated with all lineages of land plants. While plant-fungal symbiosis is common, many of their interactions, ranging from mutualism, commensalism, to parasitism are yet to be determined. As plant-fungal symbiosis are tightly linked to nutrient cycling, different interaction types have substantial impacts on biogeochemistry. Here, we will use two plant-fungal symbiosis examples: 1) Pine and their ectomycorrhizal fungi, and 2) mosses and their associated fungi, to illustrate how considering plant-fungal interaction and biogeochemistry together can further our understanding toward a better understanding of plant-fungal biology.

  37. NSLS-II Friday Lunchtime Seminar

    "Imaging antiferromagnetic domains using x-ray Bragg phase contrast at CSX beamline"

    Presented by Valery Kiryukhin, Rutgers University, New Jersey

    Friday, October 4, 2019, 10:30 am
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    We review our recent experiments on imaging antiphase antiferromgnetic domains at CSX-1. The technique utilizes interference effects revealing the domain boundaries. The measurements produce direct images, and are done in real time.

  38. NSLS-II Friday Lunchtime Seminar

    "Crystal Engineering of Lanthanide Metal-Organic Frameworks (Ln-MOFs): A Rational pproach to Designing Materials with Targeted Applications"

    Presented by Zeyar Min, Univ of the West Indies, Mona Campus, Jamaica

    Friday, September 27, 2019, 12:30 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Metal-organic frameworks (MOFs) are hybrid organic/inorganic structures with well-defined topologies which feature metal ions or clusters bridged by rigid organic linkers and have attracted immense interest for their catalytic, sensing, magnetic and adsorption properties among others. Their high porosity (surface areas of up to 7000 m2/g) can be exploited to encapsulate a wide variety of guest molecules and numerous possibilities for tunable characteristics arise from careful manipulation of both the organic and inorganic components. One of the crystal engineering approaches of MOFs is reticular synthesis and enables rational design and assembly of novel porous materials by utilizing building blocks with varying structures and functionalities to attain certain desired physical and chemical properties. However, reticular synthesis using lanthanide metals ions as building blocks is disinclined due to their high coordination numbers and unpredictable coordination chemistry. Herein, a new approach to the crystal engineering of Ln-MOFs, their ratiometric tunable luminescence properties and ability to sense metal ions and components of nitroaromatic explosives is presented.

  39. NSLS-II Friday Lunchtime Seminar

    "Quantum Computing on crystalline beams of ions: the concept and proof-of-principle experiments"

    Presented by Timur Shaftan, NSLS-II

    Friday, September 27, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    One of the promising directions in Quantum Computers (QC) is based on using ion traps. In a modern QC, several tens of ions are collected in an electromagnetic trap of a cm in size, with their motion cooled down to micro K temperature level, leading to entanglement of their quantum states, controlled by laser and RF fields. These ions = qubits then used to run quantum computations at unprecedent rate using specialized codes (check, for example, QuTip, Quantum Toolbox in Python). I will discuss a concept of a QC, which holds a promise to support 105 of qubits in contrast to the state-of-the-art devices. The idea is to use crystalline beams of ions in an accelerator as the medium for qubits. The crystalline beams were demonstrated in storage rings in 1980s when many protons, being cooled with electron beam formed a revolving ring with crystalline-like structure inside. Marrying this concept with that of the QC on a conventional ion trap, one might consider expansion of the QC to a large particle accelerator with high qubit capacity. The latter is important for expansion of QC capabilities, including the processing power and robustness against errors due to decoherence. In this presentation I will go over the concept and my analysis of a few challenges that require proof-of-principal experiments so that the some basic aspects of this interesting concept are validated.

  40. NSLS-II Friday Lunchtime Seminar

    "Non-trivial Spin Textures in Ferromagnetic Hetero-Interfaces"

    Presented by Ramesh C Budhani, Department of Physics, Morgan State University, Baltimore, MD

    Friday, September 20, 2019, 12:30 pm
    NSLS-II Bldg. 743 Room 156

  41. NSLS-II Friday Lunchtime Seminar

    "Towards Real Time Characterization of Grain Growth from the Melt"

    Presented by Christopher Wright, Department of Applied Physics and Applied Mathematics, Columbia University

    Friday, September 20, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Single crystal materials have unique properties which are endowed by their long ranging atomic order. Growing these crystalline materials can be difficult, as entropy favors disordered grains and the growth dynamics are poorly understood, leaving the process of making crystals prone to trial and error and limiting its application in the broader research community. In my talk I will discuss our work elucidating the microstructural dynamics of floating zone growth using x-ray scattering techniques. One focus of this work is building the computational infrastructure to process the large stream of heterogeneous data which results from these techniques. These pieces of infrastructure are then used to characterize the growth of Rutile crystals via a float zone furnace. Particular attention is paid to the competition amongst the grains, and how certain grains are selected from the plethora which are created at the beginning of the growth.

  42. NSLS-II Colloquium

    "Theoretical Understanding of Photon Spectroscopies in Correlated Materials In and Out of Equilibrium"

    Presented by Thomas Devereaux, SLAC

    Thursday, September 12, 2019, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: John Hill


  43. NSLS-II Friday Lunchtime Seminar

    "Coherent X-ray Scattering Studies of Surface Processes: Self-Organized Ion Beam Nanopatterning"

    Presented by Karl Ludwig, Boston University, MA

    Friday, August 23, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Karl Ludwig*, Mahsa Mokhtarzadeh*, Jeffrey Ulbrandt#, Peco Myint*, Suresh Narayanan+, and Randall Headrick# *Boston University / #University of Vermont +Advanced Photon Source, Argonne National Laboratory Enabled by the continued increases in brilliance available from synchrotron x-ray sources, our goal is to develop coherent x-ray scattering as a powerful new tool for the investigation of surface dynamics during growth and patterning processes. In particular, our research has been developed new approaches in X-ray Photon Correlation Spectroscopy (XPCS), using it to examine the dynamics of kinetic roughening in amorphous thin film growth, the step structure evolution in polycrystalline epitaxial growth and self-organized ion beam nanopatterning. Broad-beam low-energy ion bombardment can lead to the spontaneous formation of nanoscale surface structures, but the dominant mechanisms driving evolution remain controversial. Here I will describe our studies of the classic case of ion-beam rippling of SiO2 surfaces, in which we examine the relationship between the average kinetics of ripple formation and the underlying ?uctuation dynamics. In the early stage growth of ?uctuations we find a novel behavior with memory stretching back to the beginning of the bombardment. For a given length scale, correlation times do not grow signi?cantly beyond the characteristic time associated with the early-stage ripple growth. In the late stages of patterning, when the average surface structure on a given length scale is no longer evolving, dynamical processes continue on the surface. Nonlinear processes dominate at long length scales, leading to compressed exponential decay of the speckle correlation functions, while at short length scales the dynamics appears to approach a linear behavior consistent with viscous ?ow relaxation. This behavior is found to be consistent with simulations of a recent nonlinear growth model. In addition

  44. NSLS-II Seminar

    "2019 NSLS-II Summer Intern Mini-Symposium"

    Presented by John Hill, Welcome & will introduce 11 speaker, Interns with NSLS-II

    Thursday, August 1, 2019, 1 pm
    Large Seminar Room, Bldg. 510

    Hosted by: Lisa Miller

    Will forward flyer upon request (

  45. NSLS-II Friday Lunchtime Seminar

    "Quantum materials based on metamorphic InAsSb superlattices"

    Presented by Sergey Suchalkin, Stony Brook University, Stony Brook, NY

    Friday, June 28, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Recently proposed metamorphic InSbxAs1-x/InSbyAs1-y superlattices (SLs) manifest a new class of bulk materials where the bandgap can be tuned down to negative values [1,2]. Application of the virtual substrate approach relieves the limitation dictated by the substrate lattice constant and makes possible to grow materials with high crystalline quality in the entire range of alloy compositions. While remaining viable candidates to compete with the state-of-the-art mercury-cadmium-telluride (MCT) compound materials in the field of infrared detection and imaging, the new low-bandgap InAsSb SLs are new platform for investigation of intriguing physical phenomena such as the quantum spin Hall effect, and Majorana zero modes which has recently appeared in the searchlight of solid-state physics. I will present the latest results on experimental and theoretical analysis of carrier dispersion and band structure of short period metamorphic InSbxAs1-x/InSbyAs1-y superlattices, obtained in the Optoelectronics group of Stony Brook University. We demonstrate that the Dirac dispersion is realized in short period InAs1-x Sbx/InAs1-ySby metamorphic superlattices with the bandgap tuned to zero by adjusting the superlattice period and layer strain [3,4]. It was shown that the new material has anisotropic carrier dispersion: the carrier energy associated with the in-plane motion is proportional to the wave vector and characterized by the Fermi velocity vF, the dispersion corresponding to the motion in the growth direction is quadratic. Remarkably, the Fermi velocity in this system can be controlled by varying the overlap between electron and hole states in the superlattice [3]. We present a picture of modification of the energy spectrum due to variation of layer thicknesses, strain and composition of the SLs. The effects of dimensional quantization, tunneling and interface scattering on the SL band structure will be discussed. 1 - G. Belenky, D. Wang, Y. Lin, D. Donetsk

  46. NSLS-II Friday Lunchtime Seminar

    "Recent progress on the electronic structure study of the heavy-fermion Ce-115 compounds"

    Presented by Qiuyun Chen, Science and Technology on Surface Physics and Chemistry Laboratory, China

    Friday, June 21, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Here we performed a combined bulk-sensitive soft x-ray angle-resolved photoemission spectroscopy (ARPES) and Ce 4d-4f resonant ARPES studies of the three parent compounds of the Ce-115 system: CeCoIn5, CeRhIn5, and CeIrIn5. In CeCoIn5, we spectroscopically resolved the development of band hybridization and the Fermi surface expansion over a wide temperature region. Unexpectedly, the localized-to-itinerant transition occurs at surprisingly high temperatures, yet f electrons are still largely localized even at the lowest temperature. These findings point to an unanticipated role played by crystal field excitations in the strange metal behavior of CeCoIn5. In CeRhIn5, we have directly observed a weakly dispersive heavy quasiparticle band in this heavy fermion compound, whose f-electrons are considered most fully localized. Two of the three crystal-electric-field (CEF) split levels of the Ce 4f5/21 states have been observed at 2.5 and 10 meV above the Fermi energy, with distinctive symmetries. The hybridization mainly happens between these states and Rh 4d band near the Brillouin zone center, on the most three-dimensional Fermi pocket. Remarkably, the f electrons start to turn itinerant at the highest sampling temperature, 180 K, a high temperature scale that is known to be consistent with the CEF splitting. In this important heavy fermion compound with antiferromagnetic state, we paint a comprehensive picture of the dual nature of the f electrons. In CeIrIn5, we find similar behaviors of the f electrons with that of CeCoIn5, and the hybridization also starts at much higher temperature than Tk. We also provide the first experimental evidence for 4f7/21 splittings which, in CeIrIn5, split the octet into four doublets. Our results offer a comprehensive and in part, unanticipated experimental picture of the heavy fermion formation, setting the stage for understanding the emergent properties, including unconventional superconductivity, in this and related material

  47. NSLS-II Friday Lunchtime Seminar

    "High resolution strain measurements and phase discrimination in solid solutions using X-Ray Diffuse Multiple Scattering (DMS)"

    Presented by Gareth Nisbet, Diamond Light Source, United Kingdom

    Friday, June 14, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    DMS is a new high resolution scattering technique which manifests as diffraction lines impinging on the detector plane, similar to Kikuchi lines or Kossel lines. I will explain how multiple intersections from coplanar and non-coplanar reflections can be used for phase discrimination in multi-phasic systems by following a simple reductive procedure. The methods will be demonstrated using data from complex PMN-PT and PIN-PMN-PT ferroelectric solid solutions. I will also show how convolutional neural networks are being applied to DMS data for phase discrimination.

  48. NSLS-II Friday Lunchtime Seminar

    "Status and perspective of high-energy automotive batteries"

    Presented by Richard Schmuch, University of Munster, Germany

    Friday, June 7, 2019, 12:30 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    This presentation gives an overview of the materials, performance requirements and cost of current automotive traction batteries based on Li-ion technology. It also includes important aspects related to electromobility, such as its sustainability and energy efficiency. As current Li-Ion batteries with intercalation-type active materials are approaching their physicochemical energy density limit of roughly 300 Wh/kg or 800 Wh/L, alternative technologies such as lithium-metal based all-solid-state batteries (ASSBs) currently intensively studied, which promise an energy density of up to 1000 Wh/L. The potential and challenges of this and other post Li-ion batteries (e.g. Dual-Ion, Mg-Ion, Li-Sulphur) are discussed and also compared by systematic bottom-up energy density calculations. Through a step-by-step analysis from theoretical energy content at the material level to practical energies at the cell level, the individual advantages and shortcomings of the studied battery types are elucidated. Literature: (1) Schmuch, R.; Wagner, R.; Hörpel, G.; Placke, T.; Winter, M. Performance and Cost of Materials for Lithium-Based Rechargeable Automotive Batteries. Nat. Energy 2018, 3 (4), 267–278. (2) Betz, J.; Bieker, G.; Meister, P.; Placke, T.; Winter, M.; Schmuch, R. Theoretical versus Practical Energy: A Plea for More Transparency in the Energy Calculation of Different Rechargeable Battery Systems. Adv. Energy Mater. 2018, 1803170, 1803170. (3) Placke, T.; Kloepsch, R.; Dühnen, S.; Winter, M. Lithium Ion, Lithium Metal, and Alternative Rechargeable Battery Technologies: The Odyssey for High Energy Density. J. Solid State Electrochem. 2017, 1–26. (4) Meister, P.; Jia, H.; Li, J.; Kloepsch, R.; Winter, M.; Placke, T. Best Practice: Performance and Cost Evaluation of Lithium Ion Battery Active Materials with Special Emphasis on Energy Efficiency. Chem. Mater. 2016, 28 (20), 7203-7217

  49. NSLS-II Friday Lunchtime Seminar

    "Longitudinal Coupling Impedance and Single-Bunch Instability"

    Presented by Alexei Blednykh, NSLS-II

    Friday, June 7, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Several instability thresholds and special waveform beam pattern have been observed during measurements of the electron beam energy spread σ_δ versus single-bunch current I_0 in NSLS-II. The experimental data have been collected from: the synchrotron light monitor (SLM) camera installed in a low dispersion area of the NSLS-II storage ring, the Full-Width Half-Maximum size of the In-Vacuum Undulator harmonic, the stripline kicker as a part of the bunch-by-bunch transverse feedback system and the large gap dipole chamber of Optical Extraction Beamline in NSLS-II. With mentioned measurement techniques we were able to confirm, that the microwave beam pattern behavior as a current dependent effect. The numerical simulations of the Vlasov-Fokker-Planck (VFP) equation with the longitudinal impedance budget simulated by the GdfidL code for a 0.3mm bunch length and the total longitudinal wakepotential W_(||,tot)(s), allowed us to reproduce the energy spread dependence on the single bunch current numerically for different lattices, bare lattice and regular operational lattice with all insertion devices magnet gap closed, including 3 damping wigglers. The present talk will be based on the results published in the Scientific Reports, 2018: A. Blednykh, B. Bacha, G. Bassi, W. Cheng, O. Chubar, A. Derbenev, R. Lindberg, M. Rakitin, V. Smaluk, M. Zhernenkov, Yu-chen Karen Chen-Wiegart and L. Wiegart, "New aspects of longitudinal instabilities in electron storage rings", Scientific Reports volume 8, Article number: 11918 (2018).

  50. NSLS-II Friday Lunchtime Seminar

    "Microspectroscopy of Extraterrestrial Materials, or, The Universe Viewed Through a Microscope"

    Presented by Paul Northrup, Stony Brook University

    Friday, May 31, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Synchrotron X-ray absorption fluorescence spectromicroscopy is an essential tool for characterization of heterogeneous (and often very small) extraterrestrial materials. A NASA-funded research program utilizes the TES (8-BM) and XFM (4-BM) to study composition and chemistry of extraterrestrial materials, especially focusing on return-mission samples. Of particular interest are Phosphorus and Sulfur compounds that may be either a) organic evidence of life, or b) precursors or critical raw materials for development of life, on early Earth or elsewhere. Initial samples include meteorites, interplanetary dust particles, and Lunar materials. Current sample-return missions (NASA OSIRIS REx and Japan's Hayabusa2) will retrieve material from distant asteroids in a few years. Future missions will return samples from Mars.

  51. NSLS-II Friday Lunchtime Seminar

    "THz vortex beam as a spectroscopic probe of magnetic excitations"

    Presented by Andrei A. Sirenko, New Jersey Institute of Technology, NJ

    Friday, May 24, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Circularly polarized light with spin angular momentum (SAM) is one of the most valuable probes of magnetism. We demonstrate that light beams with orbital angular momentum (OAM), or vortex beams, can also couple to magnetic excitations exhibiting dichroisms in a magnetized medium. In our recent experiments with coherent THz beams we observed that resonant optical absorption in a ferrimagnetic crystal of Dy3Fe5O12 depends strongly on both the handedness of the vortex and direction of the beam propagation with respect to the sample magnetization. This effect exceeds the conventional dichroism for conventional circularly polarized light. Our results demonstrate the potential of the vortex beams with OAM as a new spectroscopic probe of magnetism in matter. A possibility to convert synchrotron radiation at the 22-IR-2 MET beamline into a vortex beam and use it for materials spectroscopy will be also discussed in this talk. In collaboration with T. N. Stanislavchuk1, P. Marsik2, C. Bernhard2, V. Kiryukhin3, S-W. Cheong3, and G. L. Carr4 1 Department of Physics, New Jersey Institute of Technology, Newark, New Jersey 2 Department of Physics, University of Fribourg, Switzerland. 3 Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University 4 NSLS-II, Brookhaven National Lab

  52. NSLS-II Friday Lunchtime Seminar

    "MAXPD: Multi-Anvil X-ray Powder Diffraction — COMPRES Partner User Program for High Pressure Studies at 28-ID-2-D"

    Presented by Matthew L. Whitaker, Stony Brook University

    Friday, May 17, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    MAXPD is the downstream endstation of XPD, an insertion device beamline at Sector 28 (28-ID-2-D) of NSLS-II. The MAXPD endstation and General User Program are sponsored by the COnsortium for Materials Properties Research in Earth Sciences (COMPRES). MAXPD has an 1100-ton hydraulic press installed, which is equipped with a unique DT-25 pressure module that can be swapped out for a more standard D-DIA module as desired. MAXPD makes use of the world-class monochromatic beam available at XPD (usually ~67 keV), with which we collect both angular dispersive X-ray diffraction data and X-radiographic imaging. The first General User experiments took place in March 2018. Final Science Commissioning beamtime took place in August of last year, and the full General User program for MAXPD began in the 2018-3 cycle. In this seminar, I will give an overview of the science drivers behind the development of the endstation, some of its unique capabilities, some representative results from recent experiments conducted over the last two cycles at MAXPD, and where we are looking to go as we look to the future.

  53. NSLS-II Friday Lunchtime Seminar

    "Self-assembly of anisotropic nanocrystals from crystalline to quasicrystalline structures"

    Presented by Ou Chen, Brown University, Rhode Island

    Friday, May 10, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Anisotropic nanocrystals with defined composition, shape and surface patchiness represent a unique class of building objects for constructing high-order architectural nanomaterials. When utilized in assembly, anisotropic nanocrystals can display strong asymmetric interactions induced by the patchiness that may complicate the formation of ordered structures compared to the assemblies of isotropic building blocks. In this talk, I will use several types of anisotropic 'patchy' nanocrystals as examples to demonstrate how they assemble into the unprecedented superstructures through the directional interactions among the building blocks under an enthalpy-driven condition. Both translational periodicities and orientational ordering of the final superstructural materials will be discussed. The dominating driving forces lead to the obtained architectures will be identified through molecular dynamics computer simulations and experimental results.

  54. NSLS-II Friday Lunchtime Seminar

    "In situ studies of Zr-based MOFs for nerve-agents capture and decomposition"

    Presented by Anna M. Plonka, Stony Brook University, Dept. of Mat. Sci. & Chem. Eng.

    Friday, May 3, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Effective filters for the rapid decomposition of chemical warfare agents (CWAs) are in high demand for protecting military and civilian populations. Although many new materials, such as metal-organic frameworks (MOFs), have been proposed to use as CWA filtration media, their eventual transition requires a detailed understanding of the atomic-scale reaction mechanisms. Zr-based MOFs were recently shown to be among the fastest catalysts of nerve-agent hydrolysis reaction in solution. We show the results of a detailed study of the adsorption and decomposition of a nerve-agent simulant, dimethyl methylphosphonate (DMMP), on Zr-based MOFs, that have different pore sizes and connectivities, using synchrotron-based X-ray powder diffraction, X-ray absorption and infrared spectroscopy, which reveals key aspects of the reaction mechanism. Further, we evaluate how battle-field contaminants such as CO2 can influence effective detoxification of CWAs by Zr-based MOF-808.

  55. NSLS-II Friday Lunchtime Seminar

    "Coherent X-ray measurement of local step-flow propagation during growth of polycrystalline organic semiconductor thin films"

    Presented by Randall Headrick, University of Vermont

    Friday, April 26, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Vacuum deposition of C60 on a graphene-coated surface is investigated with X-ray Photon Correlation Spectroscopy in surface-sensitive conditions. Local step-flow is observed through the observation of oscillatory correlations in the later stages of growth after crystalline mounds have formed. An important aspect of the work is that coherent X-rays do not average over complex structures, and this allows us to monitor the growth on polycrystalline surfaces without loss of information. The experimental results show that the step-flow velocity must be nonuniform, and we model the velocity of each step-edge as being a simple function of the lengths of the terraces above and below it. This model predicts that the steps become almost stationary near the edges of the mounds where the local terrace length is very small, and the average slope of the surface is large. It was not previously known that such nonuniform and disordered step arrays as we have observed would follow such a simple growth law. This work shows that the use of coherent X-ray scattering provides an approach to better understand surface dynamics and fluctuations during crystal growth.

  56. NSLS-II Friday Lunchtime Seminar

    "Wireless Sensors, and updates to areaDetector with Computer Vision"

    Presented by Kazimierz Gofron, NSLS-II

    Friday, April 12, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    by K. Gofron, M. Rolland, J. Wlodek, The series of brief talks that concentrate on EPICS controls 1. Wireless sensors controlled from EPICS 2. Improvements to Area Detector at NSLS2 A. Low Energy, Low Cost: The Nordic Thingy:52 Sensor Suite 1. Wireless technologies 2. EPICS controls of wireless sensors 3. ioc components 4. Integrated into CSS, and clients B. Improvements to Area Detector deployment and features at NSLS2 1. ADPluginBar/Dmtx – QR Code and data matrix code readers for EPICS Area Detector 2. ADLambda – Adding new features to an existing driver, and updating to build on newer OS 3. ADCompVision – Bringing Computer Vision to Area Detector 4. ADUVC – An area detector driver for USB Video Class devices 5. ADEmergentVision – An area detector driver for Emergent Vision Technologies 10 GigE and 25 GigE cameras

  57. NSLS-II Colloquium

    "NASA's Mars 2020 Mission – First Steps Towards Mars Sample Return"

    Presented by Kenneth Farley, Caltech

    Thursday, April 11, 2019, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: John Hill

    Scientists have advocated for the return of samples from Mars for decades. The quest has finally begun in earnest: the Jet Propulsion Laboratory is in the final stages of construction of the Mars 2020 mission. Mars 2020 builds on the highly successful design of the Mars Science Laboratory (Curiosity Rover) and is updated with new landing capabilities, scientific instruments, and a very sophisticated rock sample collection system. Mars 2020's chief goals are to unravel the geology of its landing site, seek evidence of potential Martian biosignatures, and prepare a cache of several dozen samples for possible return to Earth by a future element of a notional Mars Sample Return campaign. NASA recently selected the mission's destination: Jezero Crater. This crater once held a very deep lake comparable in size to Lake Tahoe. Key geologic targets at the site include ancient Martian bedrock, lake sediments and especially a remarkably preserved river delta, and unusual carbonate-bearing rocks possibly precipitated from lake-water. Mars 2020 will launch in the summer of 2020, land on February 18, 2021, and rove the surface for at least two years. I am Project Scientist for Mars 2020 and will describe the goals and development of this mission, and of Mars sample return.

  58. NSLS-II Friday Lunchtime Seminar

    "Towards studying dynamics over 18 decades with correlation spectroscopy – first XPCS results from European XFEL"

    Presented by Felix Lehmkuehler, Coherent X-ray Scattering Group, DESY, Germany

    Friday, April 5, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Many phenomena in soft matter physics and biology happen on microsecond timescales, e.g., folding kinetics of proteins, where the time scale is basically defined by the protein size. Despite of the importance of such processes, μs time scales are very difficult to access in X-ray scattering experiments at storage rings as well as in quasi-elastic neutron scattering. The time structure of the European XFEL with MHz pulse repetition rate in a bunch train enables for the first time structural studies of dynamics and kinetics at such time scales. A method to investigate such phenomena is X-ray photon correlation spectroscopy (XPCS), tracking changes of the coherent diffraction pattern, the so-called speckle pattern, over time. XPCS has become a well-established technique at modern storage ring sources studying timescales ranging from several 1000 s down to milliseconds. At FEL sources, the higher average flux and superior degree of coherence allow the access to shorter timescales down to femtoseconds using split-pulse techniques. On the other hand, sequential-pulse XPCS is limited by the repetition rate of the FEL pulses, i.e. about 8 to 50 ms at normal-conducting hard X-ray FEL sources such as LCLS (USA) and SACLA (Japan). The high repetition rate of the European XFEL enables dynamics measurement on sub-μs time scales, which is otherwise difficult to achieve at storage ring, neutron, pump-probe or lab-based experiments. In this talk, first dynamics measurements at FEL sources using correlation techniques will be introduced and recent results on prototypical soft matter samples as well as fs dynamics of liquid water will be discussed. Afterwards, results from our recent XPCS experiment at European XFEL will be discussed, where we successfully performed measurements of (sub-)µs dynamics of soft matter samples. Furthermore, special attention is paid on shot-to-shot and train-to-train fluctuations of coherence and beam pointing obtained by c

  59. NSLS-II Friday Lunchtime Seminar

    "X-ray holography correlation spectroscopy: How to probe stochastic dynamics on the nanoscale"

    Presented by Christopher Klose, Max Born Institute, Berlin, Germany

    Friday, March 29, 2019, 12:30 pm
    NSLS-II Bldg 744 Rm 156

    Hosted by: Ignace Jarrige

    Nanometer-scale spin configurations such as magnetic domains walls (DW) or skyrmions are attractive as information entities for spintronic applications as they can be generated and manipulated by electrical spin-polarized currents. Naturally, the function of such devices is crucially determined by the thermal stability of the magnetic configuration used for encoding the information. In our study, we have investigated thermally activated magnetic DW dynamics on timescales ranging from sub-seconds to hours under equilibrium conditions in a thin-film magnetic multilayer material based on 15 repetitions of Pt/CoFeB/MgO trilayers. Such multilayers were already successfully used to demonstrate the basic operation of a skyrmion-based racetrack memory [1]. For our investigations, we developed a new experimental approach combining real-space imaging via Fourier-transform holography [2] and x-ray photon correlation spectroscopy [3]. Both methods rely on detecting coherent far-field diffraction from a disordered sample —a pattern of magnetic up and down domains in our case. Magnetic contrast is achieved by tuning the wavelength of circularly polarized x-rays to the Co L3 absorption edge (1.6 nm). For slow timescales (> 3 min), the analysis is based on the difference of scattering patterns recorded with opposite x-ray helicity (Fig. 1a). On one hand, the Fourier inversion of this difference results in a real-space image of the domains in the field of view (FOV) defined by a circular optics mask on the sample (Fig. 1b). On the other hand, we use the difference as input for an adapted temporal correlation analysis. Already at slightly elevated temperatures (310 K), the resulting two-time correlation function of the magnetic configuration at times t1 and t2 (Fig. 1c) reveals time periods of high correlation, i.e., high stability interrupted by sudden extensive domain rearrangements as witnessed by the related images.

  60. NSLS-II Friday Lunchtime Seminar

    "Can We Make X-ray CT More Universal?"

    Presented by Jun Lim, Pohang Light Source-II, Korea, Republic of (South)

    Friday, March 29, 2019, 12 pm
    NSLS-II Bldg 744 Rm 156

    Hosted by: Ignace Jarrige

    Full-field transmission x-ray microscope (TXM) based on Fresnel zone plate is a promising and intuitive manner to take high quality phase contrast images with spatial resolution of tens of nanometers, applicable to both synchrotron radiation and laboratory source. In particular, computed tomography (CT) using hard x-rays of high penetration depth provides a high-resolution 3D image. However, the small field of view (FOV) of ~10 microns provides only a very limited volume (~10-5 mm3) of information. It primarily limits the application area of TXM. In this talk, I present a new type of TXM for CT that enlarge the FOV as large as diameter of the objective zone plate. With this method, sub-millimeter FOV can be realized while maintaining the nano-scale spatial resolution. Through experiment, we obtain more than 1000 times more volume (~10-2 mm3) of information than a typical TXM, at ~200 nm resolution. Its general applicability is demonstrated with integrated chips and Artemia cysts. We believe that this type of TXM can be particularly useful for industrial sample analysis where bulk properties are important.

  61. NSLS-II Friday Lunchtime Seminar

    "Selective Catalytic Olefin Epoxidation with MnII-exchanged MOF-5"

    Presented by Amanda Stubbs, MIT, Functional Inorganic & Organic Materials

    Friday, March 22, 2019, 9:30 am
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Partial substitution of ZnII by MnII in Zn4O-(terephthalate)3 (MOF-5) leads to a distorted all-oxygen ligand field supporting a single MnII site, whose structure was confirmed by Mn K-edge X-ray absorption spectroscopy. The MnII ion at the MOF-5 node engages in redox chemistry with a variety of oxidants. With tBuSO2PhIO, it produces a putative MnIV-oxo intermediate, which upon further reaction with adventitious hydrogen is trapped as a MnIII−OH species. Most intriguingly, the intermediacy of the high-spin MnIV−oxo species is likely responsible for catalytic activity of the MnII-MOF-5 precatalyst, which in the presence of tBuSO2PhIO catalyzes oxygen atom transfer reactivity to form epoxides from cyclic alkenes with >99% selectivity. These results demonstrate that MOF secondary building units serve as competent platforms for accessing terminal high-valent metal−oxo species that consequently engage in catalytic oxygen atom transfer chemistry owing to the relatively weak ligand fields provided by the SBU.

  62. NSLS-II Friday Lunchtime Seminar

    "Results to date on the elimination of Insertion Device Motion control problems by the NSLS-II Insertion device working group"

    Presented by John Escallier, NSLS-II

    Friday, March 15, 2019, 12 pm
    NSLS-II Bldg. 744 Room 156

    Hosted by: Ignace Jarrige

    Control of Insertion Device gap motion by the use of the Delta Tau control platform requires a good understanding of several disciplines simultaneously. Physics, magnetics, mechanics, electronics, software, and control theory are all specialties needed to establish full control of the gaps. The ID working group is comprised of individuals who specialize in one or more of these disciplines, and have been quite successful at attacking and solving multiple issues related to the IVU devices. Improvements in accuracy and control have exceeded close to two orders of magnitude, while simultaneously keeping focus towards the eventual use of step and fly scanning of the gap in synchronous motion with other devices. As work on the first vendor's devices begins to ramp to completion, the group effort is being directed towards work on EPU's. This seminar will detail several of the problems encountered, how they were solved, and where the future lies.

  63. NSLS-II Colloquium

    "Challenges of Future Very Short Wavelength X-ray Free-Electron Lasers"

    Presented by Bruce Eric Carlsten, Los Alamos National Laboratory

    Thursday, March 14, 2019, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: John Hill

    Future X-ray Free-Electron Lasers (XFELs) will produce coherent X-rays with energies greater than 20 keV, which will require electron beams with lower laboratory emittances and relative energy spreads than those in current XFELs such as LCLS or the European XFEL. To satisfy this requirement, electron beam energies will need to be higher than in current XFEL designs if conventional accelerator architectures are used, leading to increased construction and operation costs. To provide design margin for these future XFELs at the lowest possible electron beam energies, novel schemes may be employed to suppress or eliminate the present limitations in XFEL performance. This talk will describe the dominant electron-beam instabilities and other effects (coherent synchrotron radiation, undulator resistive wall wakes, microbunch instability, and intrabeam scattering) and will describe a novel accelerator architecture to suppress the worst effects from them. Design trades to improve performance at lower beam energies will also be described. The baseline parameters for the proposed XFEL at Los Alamos (the MaRIE XFEL, designed to have an X-ray energy of 42 keV) will be used to illustrate these effects.

  64. NSLS-II Friday Lunchtime Seminar

    "Dynamic Investigations of functional proteins using synchrotron radiation and gold nano-crystals at SPring-8"

    Presented by Hiroshi Sekiguchi, SPring8, Japan

    Friday, March 8, 2019, 12:30 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    In addition to the static crystallographic information regarding a 3D structure of proteins, dynamic information regarding a protein's conformational changes would be helpful in elucidating the molecular mechanisms that regulate protein functions, such as ion channel gating and ligand-induced receptor activation. Such local and dynamic information can be obtained using optical microscopy with recently developed single molecule techniques, and we think that the technique with synchrotron X-rays would be more powerful technique because of its brilliance, its short wavelength of light, and its transparency. Small-angle X-ray scattering (SAXS) is one of well-established technique to investigate the nanoscale structure of protein under physiological conditions and structural changes in response to various external conditions and we have probed a compact intermediate state of calmodulin in the process of target binding [1,2] etc. And we have proposed a single molecule technique that utilizes synchrotron X-rays to monitor the internal motions of a single protein. We call it diffracted X-ray tracking (DXT) and it can detect atomic-scale dynamic motion of the protein at the single molecular level with several tens of microseconds time resolution [3]. In DXT, a target protein is labeled with a nanocrystal with a size of several tens of nanometers and the motions of the nanocrystal coupled with the protein's motions are recorded as the trajectories of diffraction spots from the nanocrystal [4-6]. At the seminar, we will present recent progress of such investigation for biomolecules at SPring-8 [7].

  65. NSLS-II Friday Lunchtime Seminar

    "A "coherent" picture of (some) Quantum Materials"

    Presented by Claudio Mazzoli, BNL / NSLS-II

    Friday, March 8, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Quantum Materials are attracting an increasing level of attention in order to understand and fully exploit their peculiar properties for innovative potential applications. The investigation of their relevant electronic phases, their dynamics and their coherence length scales is key to produce a consistent microscopic picture of their functionalities and response to external stimuli. In my talk, I will present some recent investigation on quantum materials performed at CSX (23-ID-1), focusing on their electronic order parameters and interactions, inhomogeneity and time evolution. Examples will include charge ordering in cuprate HTSC, magnetic ordering in artificial patterned samples and nickelates, exotic magnetic phases in multilayers.

  66. NSLS-II Friday Lunchtime Seminar

    "Non-magnetic gap in the topological insulators"

    Presented by Turgut Yilmaz, NSLS-II

    Friday, March 1, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    In this talk, I will introduce the electronic structure of Cr-doped Bi2Se3 / pristine Bi2Se3 heterostructure grown by molecular beam epitaxial method. We realized that such heterostructure provides sharper electronic states in angle resolved photoemission experiments. This promotes a new strategy to study the impact of impurities on the surface states of topological insulators. Furthermore, I will show that the apparent gap at the Dirac point of topological insulators in the non-magnetic state is indeed formed by the resonant states. We confirm this by performing the first principle band structure calculation and angle resolved photoemission spectroscopy with on and off-resonant photon energies.

  67. NSLS-II Friday Lunchtime Seminar

    "Formation and dynamics of organo-mineral associations in redoximorphic soils"

    Presented by Selina Tenzer, University of Hohenheim, Germany

    Friday, February 22, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Dissolved soil organic matter (SOM) hinders the crystal growth of Fe and Mn oxides but promotes the formation of metal-OM complexes. The strength of the interactions between SOM and the Fe(O,OH)6-octahedra depends, besides pH and ionic strength, on the available functional groups. We investigate the formation of oxides under alternating redox conditions in the presence of two isotopically labelled organic model substances: vanillin (lignin component with a reactive phenol group) and alanine (amino acid with a carboxyl and an amino group). Combining XRF, µXANES and µXRD at 5-ID will allow to identify Fe and Mn oxides, describe their crystallinity and estimate the importance of organic forms of Fe and Mn. Later, we will study the spatial distribution of vanillin and alanine across mineral surfaces by NanoSIMS.

  68. NSLS-II Friday Lunchtime Seminar

    "Magneto-electric waves in f-electron magnets"

    Presented by Nicolas Gauthier, Stanford University & SLAC

    Friday, February 15, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    The intertwining of electric, magnetic and structural degrees of freedom in materials is at the heart of novel strongly correlated phases such as magnetoelectric multiferoicity, superconductivity and heavy fermion ground states. Isolating the contributions of di erent degrees of freedom and characterizing their interplay are fundamental aspects to understand such unconventional phases. The multipolar expansion of the electronic con guration provides a powerful framework to attain this objective. As an example, I will present how we can reveal the role of electric quadrupole moments by measuring magnetic dipolar waves with neutron scattering in the frustrated magnet SrDy2O4. Our results indicate that electric e ects of the 4f-electrons can dominate over the magnetism in insulators and this encourages a reassessment of the description of rare-earth based magnets with unconventional properties.

  69. NSLS-II Collquium

    "Resonant x-ray scattering from soft materials as a probe of molecular orientation fluctuations at the nanoscale"

    Presented by Noel A. Clark, University of Colorado, Boulder

    Thursday, February 14, 2019, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: John Hill

    Orientation fluctuations are ubiquitous features of soft materials on length scales ranging from nanometers in the rotational dynamics of single molecules, to the macroscopic deformation of local orientational order in liquid crystals, polymers, and biomaterials. Here we present the application of depolarized resonant soft x-ray scattering (DRSoXS) as a selective probe of molecular orientation fluctuations at the nanoscale. This technique is demonstrated by determination of the wavevector spectrum of thermally generated collective reorientations in a nematic liquid crystal using Carbon K??-edge resonant scattering (incident wavelength = 4.4nm). DRSOXS uniquely reveals transient, short-range heliconical molecular assemblies and their pretransitional development, as ordering into a chiral three-dimensional helical state is approached.

  70. NSLS-II Friday Lunchtime Seminar

    "Rechargeable Sodium-Ion Batteries"

    Presented by Kyung-Wan Nam, Dongguk University, Seoul, Korea, Republic of (South)

    Friday, February 8, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    Rechargeable sodium-ion batteries (SIBs) are now attracting special attention with a great cost advantage over rechargeable lithium-ion batteries (LIBs) especially in the field of large-scale applications. For the successful development of the SIBs, it is imperative to find new cathode and anode materials with high capacity, high power, and long cycle life. With this perspective, we have examined the electrochemical properties of O3-layer structured oxides, Na3M(II)2M(V)O6, with a honeycomb ordering of M(II) and M(V) in the metal layer for the cathode material in SIBs.[1] One of this class materials, Na3Ni2BiO6, can reversibly deliver specific discharge capacities of up to 109 mAh/g with very flat voltage plateaus ~3.5V vs. Na/Na+. Structural changes occurring during charging/discharging investigated by using in situ X-ray diffraction (XRD) are correlated with its long cycle life. Long and short-range structure changes at various state of (dis)charge have been also probed ex-situ using combined synchrotron-based high-resolution X-ray powder diffraction (HRPD) and extended X-ray absorption fine structure (EXAFS). Some of its derivatives with increased redox voltages will also be presented. For the anode materials, various compositions of transition metal oxides including Ti and Fe elements having tunnel based structures (single- and double- tunnels) are explored as rechargeable SIBs.[2] Detailed electrochemical results combined with structural characterization will be presented in the seminar. References: [1] D.S. Bhange, G. Ali, D.-H. Kim, D.A. Anang, T.J. Shin, M.G. Kim, Y.-M. Kang, K.Y. Chung, K.-W. Nam, J. Mat. Chem. A 5 (2017) 1300-1310. [2] D.S. Bhange, G. Ali, J.-Y. Kim, K. Y. Chung, K.-W. Nam, J. Power Sources 366 (2017) 115-122.

  71. NSLS-II Friday Lunchtime Seminar

    "Phase Transition Kinetics of Close-Packed Block Copolymer Micelles"

    Presented by Sangwoo Lee, Rensselaer Polytechnic Institute, Troy, NY

    Friday, February 1, 2019, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ignace Jarrige

    In the past decades, the structures of spherical particle packing have been intensively investigated to understand the origin of materials structures and associated properties. However, despite its equal importance, the phase transformation kinetics of spherical particles has been relatively poorly understood. We investigated close-packed structures of spherical block copolymer micelles induced by rapid cooling of disordered micelles using small angle X-ray scattering experiments conducted at the 11-CMS and 12-SMI lines. We found that depending on the depth of quenching, disordered block copolymer micelles self-assemble into three different close-packed structures: face-centered cubic (fcc), random stacking of hexagonal-close packed layers (rhcp), and hexagonal-close-packed (hcp) structures as the depth of temperature quenching increases. Cooling and heating of these close-packed micelle solutions reveal that the hcp and rhcp structures are long-lasting metastable structures that eventually transform to stable fcc. Close-inspection of the 2D small angle X-ray scattering patterns shows that the formation of these metastable structures is correlated with the size of crystallites. The Laplace pressure is attributed to the origin of the formation of the metastable structures.

  72. NSLS-II Friday Luncheon Seminar

    "EDRIXS: An open source toolkit for simulating spectra of resonant inelastic x-ray scattering"

    Presented by Yilin Wang, Condensed Matter Physics & Material

    Friday, January 25, 2019, 12 pm
    NSLS-II, Bldg. 743 Rm 156

    Hosted by: Ignace Jarrige

    In this talk, we present an open source toolkit (dubbed EDRIXS) to facilitate the simulations of RIXS spectra of strongly correlated materials based on exact diagonalization (ED) of certain model Hamiltonians. The model Hamiltonian can be from a single atom, small cluster or Anderson impurity model, with model parameters from density functional theory plus Wannier90 or dynamical mean-field theory calculations. The spectra of x-ray absorption spectroscopy (XAS) and RIXS are then calculated using Krylov subspace techniques. This toolkit contains highly efficient ED, XAS and RIXS solvers written in modern Fortran 90 language and a convenient Python library used to prepare inputs and set up calculations. We first give a short introduction to RIXS spectroscopy, and then we discuss the implementation details of this toolkit. Finally, we show several examples to demonstrate its usage.

  73. NSLS-II Friday Lunchtime Seminar Series

    "Computer Vision and new areaDetector features"

    Presented by Kazimierz Gofron, NSLS-II

    Friday, January 18, 2019, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: Ignace Jarrige

  74. NSLS-II Colloquium Series

    "Superconductivity: Where we are and where we are going"

    Presented by Prof. Robert Cava, Princeton University, NJ

    Thursday, December 13, 2018, 4 pm
    Hamilton Seminar Room, Bldg. 555

    Hosted by: John Hill

    The discovery of superconductivity, the transmission of electrical current with zero energy loss, recently passed its 100th anniversary. This truly remarkable property of matter, found at cryogenic temperatures, has made its way into a variety of important uses in modern society, but nature has not yet given us the ultimate practical material that will change the world through its lossless transmission of electrical energy over long distances. Research on this complex problem in materials science persists in the world at many levels, and progress is continuously made on both scientific and practical fronts, in spite of the impatience that is often displayed by both the scientific and lay public. In this talk I will briefly describe where we are in this field, and how we got here, and describe the vision that some have had for where we should be going. Because my personal research is in the discovery of new superconducting materials, only one facet among the larger set of fundamental and practical issues currently under study, the talk will be given from that perspective.

  75. NSLS-II Friday Lunchtime Seminar

    "Magnetic skyrmions at room temperature - statics, dynamics, and high resolution imaging"

    Presented by Dr. Felix Buttner, Dept of Mat Sci & Eng , MIT

    Friday, December 7, 2018, 12 pm
    NSLS-II Bldg 743 Room 156

    Hosted by: Ignace Jarrige

    Magnetic skyrmions are the smallest non-trivial entities in magnetism with great potential for data storage applications. These chiral and topological quasi-particles furthermore exhibit fascinating static and dynamical properties that render them the ideal candidates to study new physics in high spin-orbit coupling materials. In this talk, I will first give a general introduction to the field of skyrmionics and the fundamental properties of skyrmions that derive from their energetics. I will then discuss various ways of creating and stabilizing room-temperature skyrmions experimentally, as well as how we can move them and observe their topological dynamics via high resolution time-resolved x-ray imaging. I will conclude with perspectives of future research in this field and related areas.

  76. NSLS-II Friday Lunchtime Seminar

    "A Novel Stripe Phase in Bi-2212 Cuprate"

    Presented by Yang Ding, Center for High Pressure Science & Technology Advanced Research, China

    Friday, November 30, 2018, 12 pm
    NSLS-II Bldg 743 Room 156

    Hosted by: Ignace Jarrige

    High-temperature superconductivity (HTSC) is one of the most important discoveries at contemporary condensed matter physics. However, its mechanism is still unclear. One way to approach this problem is to search for the controlling parameters of HTSC transition temperature Tc. In this presentation, we will introduce a novel type stripe phase in Bi2212 that is revealed by nano-imaging technique. Intriguingly, the evolution of the stripe phase is in coincidence with the change of Tc, which implies a correlation between the Tc and the optimal inhomogeneity in the cuprate.

  77. NSLS-II Seminar

    "Structure/Properties of Thin Film Composite Membranes for Water Purification"

    Presented by Christopher M. Stafford, NIST, Gaithersburg, MD

    Tuesday, November 20, 2018, 11 am
    NSLS-II Bldg. 744

    Hosted by: Ben Ocko

    Access to sustainable sources of clean water is critical to manufacturing, agriculture, energy production, public health, and national security. One prominent technology for meeting this need is membrane-based separations of water and dissolved contaminants/solutes via nanofiltration and reverse osmosis. This field is dominated by polymer-based membranes and has relied on complex, empirically optimized chemistries and structures based on material selections made decades ago. The resulting processes are energy intensive and suffer from limited performance lifetimes. We are bringing our deep expertise in measurement science and polymer science to address this critical technology, specifically by establishing fundamental structure/property relationships that correlate membrane topology and dynamics to membrane performance. In this talk, I will describe our recent efforts in synthesizing model membrane materials based on molecular layer-by-layer deposition of aromatic polyamide networks, as well as our measurements of swelling, crosslink density and mechanics of both model and commercial membrane materials. This understanding will enable industry to develop and manufacture next generation, energy-efficient membrane materials.

  78. NSLS-II Friday Lunchtime Seminar

    "Delivering Focused, Rapidly Tunable, Stable Monochromatic X-Rays to the GSECARS APS 13-ID-E Microprobe Endstation"

    Presented by Peter J. Eng, CARS and JFI, University of Chicago

    Friday, November 9, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: Ignace Jarrige

    With the APS-U scheduled for 2023 GSECARS, is designing and testing enhancements to beamline instrumentation to optimize the benefits of this upgraded source. The sector 13-ID-E microprobe endstation studies a wide range of environmental, earth and planetary problems, requiring a rich array of techniques and instrumentation. Central to the success of this program is the insertion device and the x-ray optics that produce, monochromate and focus the beam on the sample. All aspects of this system are under review. Design efforts are focused on 1) managing the increased total power and power density of the APS-U undulator source; 2) improved beam and sample stability; 3) improved focusing optics; and 4) rapid and high duty cycle scanning of the incident beam energy. This is an ongoing development effort with a number of enhancements schedule to be installed in the 1st quarter of 2019. Other components are in the design or prototype phase, drawing on collaboration between universities, national labs and industry.

  79. NSLS-II Friday Lunchtime Seminar

    "Materials Tribology: An Application-Driven Field with Rich Opportunities for Fundamental Studies of Surface Chemistry, Physics, Structure"

    Presented by Brandon A. Krick, Department of Mechanical Engineering and Mechanics, Lehigh University

    Friday, November 2, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: Ignace Jarrige

    The significant economic (~3-6% of developed countries GDP) and environmental (several percent of our annual energy consumption) impacts of friction and wear make tribology is an important, application-driven field. However, there is an opportunity and need for inherently fundamental studies on surface chemistry, physics and structure to elucidate fundamental mechanisms for friction and wear. The non-equilibrium and transient nature of shear-induced changes caused by contacting surfaces in relative motion requires both in situ and ex situ advanced characterization techniques; many of these only available at the light source at Brookhaven. A brief overview of shear-induced (sliding friction/wear) alterations of surfaces will be presented for material systems including: - environmental and tribochemistry molybdenum disulphide based coatings for space applications - shear-induced band bending in GaN - mechanochemistry of polymer nanocomposites

  80. NSLS-II Friday Lunchtime Seminar

    "Thai heritage glasses studied by synchrotron radiation"

    Presented by Dr. Wantana Klysubun, Synchrotron Light Research Institute, Thailand

    Friday, October 26, 2018, 12 pm
    NSLS-II Bldg. 744 Rm 156

    Hosted by: Ignace Jarrige

  81. NSLS-II Friday Lunchtime Seminar

    "RIXS study of the charge and magnetic evolution in La2-xCexCuO4 combi-film"

    Presented by Xuerong Liu, Shanghai Tech University, China

    Friday, October 19, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: Ignace Jarrige

    Different from the simple one-band Hubbard model prediction, it has been recognized that the cuprate superconductors are electron-hole asymmetric. Recent RIXS work on the electron-doped Nd2-xCexCuO4 by K. Ishii et al. [1] and W. S. Lee et al. [2] reported a hardening of the spin excitations and the emergence of a charge excitation mode. Both these observations are in distinct contrast to that reported on the hole doped side, and brought attention again to the profound electron-hole asymmetry issue in the cuprates. Taking the advantage of a La2-xCexCuO4 combi-film, namely a film with large range doping gradient distribution, we studied the evolution of the charge and magnetic excitations from optimal- to over-doping systematically in fine steps. Our results establish the universality of the previous observation for the electron-doped cuprates. And more importantly, the doping dependent evolutions show that the magnetic and charge excitations are not the two faces of a coin. Rather, the spin-correlation roots in the short range correlation, and the charge-fluctuation stems from long range Coulomb interaction. [1] K. Ishii et al, Nat. Commun. 5, 3714 (2014). [2] W. S. Lee et al, Nat. Phys. 10, 883 (2014).

  82. NSLS-II Friday Seminar Series

    "Chasing Protons in Lithium Batteries"

    Presented by Zonghai Chen, Argonne National Laboratory

    Friday, October 12, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: Ignace Jarrige

    Nickel-rich lithium transition metal oxides have been recently considered as one of most promising cathode materials for high energy density lithium-ion batteries. However, the instability of the cathode electrolyte interface has been the major technological barrier for the development of nickel-rich cathodes. The early research has simply assigned this interfacial instability to the electrochemical oxidation of the commonly used carbonate solvents without much discussion on the nature of the parasitic reactions. A proprietary high precision electrochemical system was built in-house to quantitatively measure the rate and kinetics of the side reactions between the delithiated cathode and the non-aqueous electrolyte. Our results clearly indicated the dominant chemical reaction within the working potential window is the chemical, not electrochemical, reaction between the intermediate phase of cathode and the electrolyte, generating locally concentrated protons at the surface of the cathode materials. Figure 1 shows a generic mechanism of parasitic reactions occurring at the interface of cathode materials. Additional help from advanced characterization tools, such as synchrotron probes, will be also be discussed.

  83. NSLS-II Colloquium Series

    "Biophysical Studies of an RNA Virus particle and its Maturation: Insights into an Elegantly Programmed Nano-machine"

    Presented by John E. (Jack) Johnson, Department of Integrative Structural and Computational Biology, The Scripps Research Institute

    Thursday, October 11, 2018, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: John Hill

    Nudaurelia Capensis ? Virus (N?V) is a eukaryotic, quasi-equivalent, RNA virus, with a T=4 surface lattice, where maturation is dramatic (a change in particle size of 100Å) and is novel in that it can be investigated in vitro. Here we use X-ray crystallography, biochemistry, Small Angle X-ray Scattering, and electron cryo-microscopy and image reconstruction (CryoEM), to characterize maturation intermediates, an associated auto-catalytic cleavage, the kinetics of morphological change and to demonstrate that regions of N?V subunit folding are maturation-dependent and occur at rates determined by their quasi-equivalent position in the capsid. Matsui, T., Lander, G. C., Khayat, R., and Johnson, J. E. 2010. Subunits fold at position-dependent rates during maturation of a eukaryotic RNA virus. Proc Natl Acad Sci U S A 107:14111-5. Veesler, D., and Johnson, J.E. 2012. Virus Maturation. Annual review of biophysics 41:473-496. Doerschuk, P. C., Gong, Y., Xu, N., Domitrovic, T., and Johnson, J. E. 2016. Virus particle dynamics derived from CryoEM studies. Curr Opin Virol 18:57-63.

  84. NSLS-II Friday Seminar

    "Highly Active and Stable Carbon Nanosheets Supported Iron Oxide for Fischer-Tropsch to Olefins Synthesis"

    Presented by Congjun Wang, National Energy Technology Laboratory, Pittsburgh, PA

    Friday, October 5, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: Ignace Jarrige

    Light olefins production utilizes the energy intensive process of steam cracking. Fischer-Tropsch to olefins (FTO) synthesis potentially offers a more sustainable alternative. Here we show a promising FTO catalyst comprised of iron oxide nanoparticles supported on carbon nanosheets (CNS) fabricated from the carbonization of potassium citrate, which incorporates well dispersed K-promoter throughout the CNS support. This catalyst exhibits, to the best of our knowledge, the highest iron time yield of 1790–1990 μmolCO/gFe•s reported in the literature, 41% light olefins selectivity, and over 100 hours stable activity, making it one of the best performing FTO catalysts. Detailed characterization, including synchrotron X-ray spectroscopy, illustrates that the CNS support facilitates iron oxide reduction to metallic iron, leading to efficient transformation to the active iron carbide phase during FTO reaction. Since K is a commonly used promoter, our K-promoted CNS support potentially has broad utility beyond the FTO reactions demonstrated in the current study.

  85. NSLS-II Friday Lunchtime Seminar

    "Shape-Symmetry Incommensurate Polymer Crystals Directed by Liquid-liquid Interface"

    Presented by Prof. Christopher Li, Department of Materials Science and Engineering, Drexel University

    Friday, September 28, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: Ignace Jarrige

    Crystallization is ubiquitous in nature and semicrystalline polymers are of crucial importance in our daily life. Compared with small molecules, polymers crystallize via a more complex pathway because of their long chain nature and various metastable states associated with polymer crystals. In this talk, I will show that this complex conformational change of polymer chains upon crystallization can be employed to design and fabricate functional nanomaterials. We will focus on crystallization directed by liquid/liquid interface. Not only can this type of dynamic interface direct the crystallization pathway, it can also alter chain packing in the final crystals, leading to intriguing macroscopic properties. In particular, curved interface, which is incommensurate with the classical translation symmetry, frustrates chain packing, and induced defect formation, a topic that will be discussed in the context of recently reported spherical crystallography.

  86. NSLS-II Friday Luncheon Seminar

    "X-ray sparse-angle Bragg ptychography"

    Presented by Dr. Peng Li, Institut Fresnel (CNRS), Marseille, France

    Friday, September 21, 2018, 12:30 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: Ignace Jarrige

    X-ray Bragg ptychography is a scanning coherent diffraction imaging microscopy technique that can produce 3D maps of the crystalline structure of an extended nanostructured crystal at about 10nm resolution. With sparse-angle Bragg ptychography, the 3D maps can be extracted from an extremely undersampled data-set. This new strategy substantially reduces the acquisition time and mitigates problems, linked to radiation damage and instabilities, faced by conventional Bragg ptychography. However, the success of the image reconstruction is based on a good knowledge of the probe, whose uncertainties degrade the object reconstruction. In this talk, we solve this problem by proposing a simultaneous reconstruction of the probe and object functions. This is based on a strong but natural constraint of the probe properties. We demonstrate our approach on a He-implanted poly-crystalline Tungsten sample measured at ID01-ESRF. These findings open new possibilities for this imaging technique.

  87. NSLS-II Seminar

    "X-ray spectroscopy of transition metal oxides"

    Presented by Frank de Groot, Utrecht University, Netherlands

    Thursday, August 23, 2018, 11 am
    NSLS-II Building 744 Room 156

    Hosted by: Lisa Miller

    Some new developments in x-ray absorption (XAS) and resonant inelastic x-ray scattering (RIXS) will be discussed. An introduction is given of XAS, including the oxygen K edge, metal K edge and metal L edge [1,2]. The main part of the talk deals with resonant inelastic x-ray scattering (RIXS) In 2p3d RIXS one scans through the 2p XAS edge and measures the low energy excitations, including phonons, magnons, dd-excitations and charge transfer. The 100 meV resolved 2p3d RIXS spectra of ruby (Cr3+ in Al2O3), Fe3O4 and LaCoO3 will be discussed [3,4]. The present experimental resolution of 30 to 100 meV allows the detailed observation of the electronic structure, including the determination of crystal field parameters, covalency parameters and spin-orbit coupling, but also the momentum dependence of magnons and other low energy excitations. Related to the RIXS measurements is the analysis of Fluorescence yield (FY) detected x-ray absorption spectra (XAS), including the intrinsic deviations of FY-XAS spectral shape from the XAS spectrum that is important for measurements with x-ray free electron lasers [5,6]. [1] Core Level Spectroscopy of Solids Frank de Groot and Akio Kotani (Taylor & Francis CRC press, 2008) [2] Download the x-ray spectroscopy simulation software at [3] Huang et al. Nature Comm. 8, 15929 (2017). [4] Tomiyasu et al. Phys. Rev. Lett. 119, 196402 (2017) [5] F.M.F. de Groot, Nature Chemistry 4, 766 (2012) [6] Mitzner et al. J. Phys. Chem. Lett. 4, 3641 (2013)

  88. NSLS-II Colloquium Series

    "Mulling over Nanoemulsions: Interfacial Molecular Structure, Stabilization and Assembly"

    Presented by Prof. Geraldine (Geri) Richmond, University of Oregon

    Thursday, August 9, 2018, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: John Hill

    Nanoemlusions are finding numerous applications in the fields of pharmaceuticals, food production, materials synthesis and cosmetics. With the search for broader and improved usage of these unique droplets comes the need to better understand the molecular interactions at the surface that lead to their stabilization. This presentation will focus on our most recent efforts in measuring the molecular structure of the oil-water interface and the unique environment it provides for adsorption of molecules, surfactants and macromolecules at both planar and nanoemulsion oil/water interfaces. The studies are a combination of spectroscopic and thermodynamic measurements coupled with theoretical simulations.

  89. NSLS-II Friday Luncheon Seminar

    "Homoepitaxial growth of SrTiO3 by Pulsed Laser Deposition: energetic vs thermal growth"

    Presented by Jeff Ulbrandt, University of Vermont

    Friday, August 3, 2018, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  90. Summer Sundays

    "Brilliant Light, Dazzling Discoveries - National Synchrotron Light Source II"

    Sunday, July 29, 2018, 10 am
    Berkner Hall, Room B

  91. NSLS-II Friday Lunchtime Seminar

    "Manipulating sound propagation beyond the hypersonic range: recent IXS results"

    Presented by Alessandro Cunsolo, NSLS-II / BNL

    Friday, July 13, 2018, 12 pm

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, J. Thieme, G. Wang

  92. NSLS-II Friday Lunchtime Series

    "Investigating slow kinetic processes using synchrotron radiation: A case study of cement hydration in nuclear waste cements"

    Presented by Claire L. Corkhill, University of Sheffield, United Kingdom

    Friday, June 29, 2018, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, J. Thieme, G. Wang

  93. NSLS-II Friday Luncheon Series

    "The Helmholtz Imaging Platform (HIP): Imaging Sciences in Germany"

    Presented by Alexander Pichler, DESY Hamburg, Germany

    Friday, June 22, 2018, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  94. NSLS-II Seminar

    "Understanding microstructure evolution in lithium battery electrodes through coupled modeling and experiments"

    Presented by Ming Tang, Dept of Materials Science & NanoEngineering, Rice University, Houston, TZ

    Monday, May 7, 2018, 11 am
    NSLS-II Bldg. 744 Room 156

    Hosted by: Yong Chu & Jun Wang

    Like most materials, there exist very rich microstructure evolution phenomena in lithium battery electrode compounds during battery operation. Elucidating such phenomena through combined modeling and characterization including synchrotron-based techniques could yield valuable insights on how electrode structure should be designed and tailored at the mesoscale to enable stepwise improvement in battery performance. In this talk, I will first present our recent study on the unique aspects of phase transformation kinetics in Li-ion battery electrodes, using LiFePO4 as a model system. Through combined phase-field modeling and transmission x-ray microscopic observation of Li deintercalation process in LiFePO4 microrods, we discovered that intercalation-induced phase transformations can proceed in several distinct kinetic modes with varied electrochemical conditions and particle geometry. In particular, a hybrid mode, in which phase growth is surface-reaction-limited or bulk-diffusion-limited along different directions, is revealed for the first time. In the surface-reaction-limited transformation regime, we predict a surprising effect of antisite defects on accelerating phase boundary migration velocity by two orders of magnitude over defect-free LiFePO4 due to defect-induced increase in the surface reaction area. This finding suggests defect engineering as a fruitful approach to enhance the rate performance of intercalation compounds. The second part of this talk concerns the fundamental mechanism of dendrite growth on Li metal surface during electroplating, which presents a major challenge to the adoption of Li metal anodes in rechargeable batteries. Combining Li electroplating experiments and modeling, we obtained a key insight that Li dendrite growth is a stress-driven process, which is initiated by the compressive residual stress developed in deposited Li during battery cycling. Accordingly, elimination of the plating stress, e.g. via the use of soft substrate for Li

  95. Brookhaven Women In Science Speaker

    "The Exciting World of Molecules: An Image From Within Using Light Sources and Free Electron Lasers"

    Nora Berrah, University of Connecticut

    Thursday, April 26, 2018, 4 pm
    Large Seminar Room, Bldg. 510

    Professor Berrah, chair of the University of Connecticut Physics Department, will take us on a fascinating voyage through the molecular world. All that surrounds us is ultimately made of atoms and molecules; these materials are not static—they are dynamic and move. Berrah uses x-rays from light sources and free electron lasers (FELs) to study how they move, why they move, and what it means to us. During her talk, she will share her recent studies on fullerenes, a molecule that may be used for drug delivery systems to the body, in lubricants, and as catalysts. Nora is the recipient of numerous awards. She recently received the Davisson-Germer Prize from the American Physical Society. Nora is also an active member of COACh, an organization that is working to increase the number of women scientists and engineers, and the success of their careers, through innovative programs and strategies. Coffee and cookies will be available at 3:30 p.m.

  96. NSLS-II Friday Luncheon Seminar

    "Macromolecular Interactions in Polymer-based Complex Fluids"

    Presented by Sudipta Gupta, Louisiana Consortium for Neutron Scattering, Department of Chemistry, Louisiana State Univ, Baton Rouge, LA

    Friday, April 20, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  97. NSLS-II Friday Lunchtme Seminar Series

    "SMI Beamline Status Update"

    Presented by Mikhail Zhernenkov, NSLS-II

    Friday, April 13, 2018, 12 pm
    NSLS-II Building 743 Room 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  98. NSLS-II Friday Lunchtime Seminar

    "Interactive Ray-Tracing in XRT Code"

    Presented by Roman Chernikov, Canadian Light Source

    Friday, April 13, 2018, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  99. NSLS-II Colloquium Series

    "Sustainable chemical energy storage: critiques and crystallography"

    Presented by William (Bill) David, University of Oxford, United Kingdom

    Thursday, April 12, 2018, 4 pm
    Physics Bldg. 510 Large Seminar Room

    Hosted by: John Hill

    Our increasing dependence on intermittent renewable energy production places a greater focus on the development of novel, affordable energy storage. The recent emphasis on electrochemical storage, and on lithium batteries in particular, addresses a significant component of our future energy storage requirements but future low-carbon energy scenarios must utilise a broad range of storage options. This talk will focus on several examples the underline the role that synchrotron X-ray and neutron powder diffraction can play in the understanding of both electrochemical and chemical energy storage systems.

  100. NSLS-II Friday Lunchtime Seminar Series

    "ISR Beamline Status Update"

    Presented by Christie Nelson, NSLS-II

    Friday, April 6, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  101. NSLS-II Friday Lunchtime Seminar Series

    "ESM Beamline Status Update"

    Presented by Elio Vescovo, NSLS-II

    Friday, March 30, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  102. NSLS-II Friday Lunchtime Seminar Series

    "Automated robot based systems for crystallography on beamlines and in laboratories: developments performed on FIP-BM30A at the ESRF"

    Presented by Jean-Luc Ferrer, IBS, Grenoble, France

    Friday, March 30, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  103. NSLS-II Friday Lunchtime Seminar Series

    "Design and Initial Commissioning Results for SIX, the Soft Inelastic X-ray Scattering Beamline"

    Presented by Joseph Dvorak, NSLS-II

    Friday, March 23, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  104. NSLS-II Friday Lunchtime Seminar Series

    "SR tomographic imaging studies at the ESRF"

    Presented by Paul Tafforeau, ESRF, France

    Friday, March 9, 2018, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  105. NSLS-II Friday Lunchtime Seminar Series

    "Probing crystal structures of complex materials using the atomic Pair Distribution Function"

    Presented by Milinda Abeykoon, NSLS-II

    Friday, March 2, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  106. NSLS-II Friday Lunchtime Seminar Series

    "Using X-ray Fluorescence Microprobe to Elucidate the Chemistry of Trace Elements in Soils and Plants"

    Presented by Ryan Tappero, NSLS-II

    Friday, February 23, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  107. NSLS-II Friday Lunchtime Seminar

    "Tender-Energy Spectromicroscopy Applications to Natural and Engineered Materials: the Spectromicroscopy Paradox"

    Presented by Paul Northrup, NSLS-II

    Friday, February 16, 2018, 12 pm
    NSLS-II Bldg 743 Rm 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  108. NSLS-II Friday Lunchtime Seminar Series

    "Fabrication of rotating lattice single crystal - a novel form of solid"

    Presented by Himanshu Jain, Lehigh University

    Friday, February 9, 2018, 12 pm
    NSLS-II Bldg. 743 Room 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  109. NSLS-II Friday Lunchtime Seminar Series

    "Combining high energy x-ray diffraction techniques with laser-induced fluorescence in operando catalysis"

    Presented by Uta Hejral, Lund University, Sweden

    Friday, February 2, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: M. Abeykoon, S. Chodankar, B. Ocko, T. Tanabe, J. Thieme

  110. NSLS-II Friday Lunchtime Seminar Series

    "Revolutionizing synchrotron science: the National Synchrotron Light Source" and "Nanofabrication of Hard X-ray Optics for the APS and APS-Upgrade"

    Presented by John Hill and Michael Wojcik, NSLS-II at BNL and APS at ANL

    Friday, January 19, 2018, 12 pm
    NSLS-II, Bldg. 743 Room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  111. NSLS-II Seminar

    "Using X-Ray and Infrared Imaging to Understand How Fungus can be used to Grow Bigger Plants"

    Presented by Tiffany Victor, PhD, Photon Sciences

    Friday, January 12, 2018, 12 pm
    NSLS-II Bldg. 743 Rm 156

    Hosted by: Lisa Miller

  112. NSLS-II Colloquium Series

    "Development of insertion devices at SOLEIL"

    Presented by Marie Emmanuelle Couprie, SOLEIL, France

    Thursday, January 11, 2018, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: John Hill

    Insertion devices (undulators and wigglers) are essential components for accelerator based light sources, such as synchrotron radiation facilities implemented on storage rings and free electron lasers. The wide panoply of insertion devices developed at Synchrotron SOLEIL (electromagnetic, combined permanent magnet and electromagnetic for rapid switching of the polarization, permanent magnet APPLE-II, hybrid in-vacuum and cryogenic undulators, out and in-vacuum wigglers) enables to cover a very wide spectral range (from the UV to the hard X-rays), and to provide flexibility for the users of the SOLEIL third generation light source. Starting from the description of the developments carried out at SOLEIL on the different types of systems, some future perspectives will be given, considering the evolution of the specifications of the different light source types. The use of the undulator radiation for photon beam based alignment and adjustment (such as taper) will be discussed. Furthermore, undulator radiation can serve as an electron beam diagnostic and provide a further insight on the electron beam quality itself, as illustrated in the case of the COXINEL project, using laser plasma acceleration.

  113. NSLS-II Seminar

    "The Canadian Light Source – A Bright Light on the Prairies"

    Presented by Rob Lamb (CEO) and Dean Chapman (Science Director), Canadian Light Source, Canada

    Wednesday, December 13, 2017, 11 am
    NSLS-II, Bldg. 745

    Hosted by: Qun Shen

    The Canadian Light Source (CLS) began operations in 2005 with 7 beamlines. Now a dozen year later, the last of 22 beamlines are in the final stages of construction. The ring is now almost completely filled with only one straight remaining. As the second decade of the CLS begins and the CLS matures, a new strategic plan focuses on using our most precious resource – the staff – to be more engaged in helping solve problems of societal importance. Some aspects of this plan and unique highlights from the facility such as agricultural and medical imaging research will be discussed.

  114. NSLS-II Engineering Seminar Series

    "Introduction to NSLS-II Survey and Alignment"

    Chenghao Yu, Brookhaven National Laboratory

    Tuesday, December 12, 2017, 2 pm
    John Dunn Seminar Room, Bldg. 463

    Hosted by: Sushil Sharma & Steven Hulbert

    NSLS-II at Brookhaven National Laboratory is one of the newest and most advanced synchrotron facilities in the world. The accelerator and beamline components of this machine require very precise alignment to meet their performance requirements. For example, the alignment tolerance of magnets on a common girder of the storage ring is ± 30 µm and adjacent girders need to be aligned to within ± 100 µm. The precise alignment of the machine must be maintained throughout its lifetime. The alignment philosophy and processes, which are based on primary/secondary survey networks and modern laser trackers, will be discussed. The use of vibrating wire technique for a more precise alignment of the magnets will be described. Several "lessons–learned" examples will be presented to highlight good alignment practices and procedures. The Survey and Alignment group members, who are ready to support all survey and alignment requests across the lab, will be introduced.

  115. NSLS-II Seminar

    "Recent Infrastructure Developments in Materials Project"

    Presented by Patrick Huck, Lawrence Berkeley National Laboratory

    Tuesday, December 12, 2017, 11 am
    NSLS-II, Bldg. 743, Room 156

    Hosted by: Eli Stavitski

    Materials Project (MP, is harnessing the power of supercomputing together with state-of-the-art quantum mechanical theory and a scientific workflow stack driven by open-source Python software to compute the properties of all known inorganic materials and beyond, design novel materials and offer the data for free to the community together with online analysis and design algorithms. MP now also allows users to contribute and share new theoretical and experimental materials data with its community of more than 40,000 users via the MPContribs framework. The MPComplete service allows users to suggest new compounds for calculation by MP, thereby involving the community in the process of growing the available materials data. MPCite creates persistent citations and facilitates sharing amongst collaborators by assigning Digital Object Identifiers (DOIs) to all MP compounds. MPContribs, MPComplete and MPCite are important steps in MP's effort to deliver a next-generation collaborative platform for Materials (Data) Science.

  116. NSLS-II Friday Lunchtime Seminar Series

    "Synchrotron Radiation Calculations and Insertion Devices: Practical Examples from NSLS II Beamlines"

    Presented by Dean Hidas, Photon Sciences, BNL

    Friday, December 8, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  117. NSLS-II Colloquium Series

    "Imaging dynamics of radiation-sensitive molecules."

    Presented by John Spence, Physics, Arizona State University, Tempe, AZ

    Thursday, November 9, 2017, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: John Hill

    The possibility of out-running radiation damage by the "diffract-and-destroy method, using femtosecond pulses of either electrons or hard X-rays, opens completely new vistas for imaging molecular dynamics at atom resolution and sub-picosecond speeds (1). First, I'll compare high-energy electron beams for this purpose, and compare them in regard to damage mechanisms and time-scales with XFEL radiation. I'll suggest a fast mode of image formation which provides high resolution despite the use of the large incoherent photocathode. I'll then review our work using the hard X-ray pulsed laser at SLAC within our BioXFEL 6-campus NSF consortium (, aimed at the application of X-ray lasers (XFELs) to Structural Biology. I'll show molecular movies from light-sensitive proteins with 150 fs time resolution and near-atomic spatial , using both crystals and solution scattering obtained from the LCLS XFEL at SLAC, and very recent single-particle virus images (one virus per shot) showing dynamics. I'll discuss work in my lab on methods for hydrated sample delivery for an XFEL, and the compact IC XFEL under construction on the ASU campus, which uses a laser as an undulator. Finally, I'll review a recent proposal for the use of intensity interferometry to analyze the angular dependence of inner-shell X-ray fluorescence from a molecule. See Google Scholar for references and the many collaborators whom I thank. 1. J.Spence. XFELS for structure and dynamics in biology. IUCrJ 4, 322 (2017).

  118. NSLS-II Friday Lunchtime Seminar Series

    "Fast switching between 2D and direct, 3D XRF imaging using Collimating Channel Arrays and the Maia detector" and "Sirepo – an open-source cloud-based software interface for X-ray source and optics simulations"

    Presented by Arthur Woll and Maksim Rakitin, CHESS, Cornell University and NSLS-II, BNL

    Friday, October 27, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  119. NSLS-II Seminar

    "The Australian Synchrotron Imaging and Medical Beamline: Melting components, scanning rhinos and planning human imaging"

    Presented by Daniel Häusermann, Australian Synchrotron, Australia

    Friday, October 27, 2017, 10 am
    NSLS-II, Bldg. 743 Rm 156

    Hosted by: Andrew Broadbent

    The main characteristics of the Imaging and Medical Beamline (IMBL) are ? 150m long, 3 experiment enclosures ? 36kW X-ray power ? Water cooled monochromator, minimal optics ? Samples up to 1m x 1.2m ? Energies from 20 to 350keV ? Computed tomography ? In vivo imaging and CT ? Radiotherapy research ? Extensive support infrastructure ? Clinical programmes with human patients Total power, beam aspect ratio and beamline configuration flexibility present unique challenges and plenty of opportunity for destroying components. Despite this the IMBL reliability and science programmes are outstanding. Research ranges from palaeontology and materials to micro-beam radiotherapy (MRT) and world unique large animal in vivo imaging, including CT. Furthermore, preparation for clinical research with human patients has led the development of novel approaches to equipment and beamline safety. This presentation will cover technical features, accidents and their mitigation, science results and the preparation for human imaging and MRT trials, including the new beamline components and modifications these demand.

  120. NSLS-II Colloquium Series

    "From single atom magnets to ultrafast switching: Insights from x-ray absorption spectroscopy and microscopy"

    Presented by Pietro Gambardella, Department of Materials, ETH Zurich, Switzerland

    Thursday, October 12, 2017, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: John Hill

    What is the smallest possible size of a magnet? How fast can we switch the magnetization of a thin film? The answer to these simple questions reveals a fascinating world of interactions, which are largely dominated by interface effects. Understanding and controlling such interactions opens new perspectives for classical and quantum data processing technologies at the microscopic scale. Synchrotron radiation measurements exploiting x-ray dichroism at the L- and M-edges of the transition metal and lanthanide elements, respectively, provide a unique spectroscopic and microscopic tool to link the nanoscale properties of matter to the magnetic behavior of different classes of materials. In this talk, I will describe our studies of the evolution of magnetism from single atoms to nanoparticles and molecular magnets [1-4], focusing on the conditions required to achieve magnetic bistability in small systems [5,6]. I will further report on recent efforts to induce magnetization switching using electrical currents in materials characterized by strong spin-orbit interactions [7,8]. Current pump/x-ray probe experiments reveal the mechanism and time scale of magnetization reversal induced by the spin–orbit torques and spin Hall effect in thin film heterostructures, which has applications in ultrafast magnetic random access memories with high endurance [9,10]. [1] P. Gambardella et al., Phys. Rev. Lett. 88, 047202 (2002). [2] P. Gambardella et al., Science 300, 1130 (2003). [3] P. Gambardella et al., Nature Mater. 8, 189 (2009). [4] S. Stepanow et al., J. Am. Chem. Soc. 136, 5451 (2014). [5] I. G. Rau et al., Science 344, 988 (2014). [6] F. Donati et al., Science 352, 318 (2016). [7] I. M. Miron et al., Nature 476, 189 (2011). [8] K. Garello et al., Nature Nanotech. 8, 587 (2013). [9] M. Baumgartner et al., Nature Nanotech., in press (2017). [10] G. Prenat et al., IEEE Transactions on Multi-Scale Computing 2, 149 (2016).

  121. NSLS-II Friday Lunchtime Seminar Series

    "Complex Materials Scattering (CMS) beam line update and "Frontier Microfocusing Macromolecular Crystallography (FMX) beamline update"

    Presented by Masafumi Fukuto and Martin Fuchs, NSLS-II, BNL

    Friday, October 6, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  122. NSLS-II Seminar

    "Front Ends and Insertion Devices for APS Upgrade"

    Presented by Mohan Ramanathan, Argonne National Laboratory

    Thursday, October 5, 2017, 2 pm
    Bldg 744 Room 156

    Hosted by: Sushil Sharma

    The Advanced Photon Source (APS) Upgrade Project is a major redesign of the current operating machine to a new multi-bend low emittance lattice operating at 6 GeV with 200 mA of stored beam. To fully support the APS Upgrade (APS-U), the front ends and insertion devices (IDs) located inside the storage ring tunnel need to be upgraded. Most of the front ends at the APS were designed more than 20 years ago and have limitations in the power handling capability. As part of APS Upgrade all the ID front ends will be replaced to one of two types – capable of handling the full straight section of IDs or canted with two ID beams. At the current time, the APS has 54 IDs in operation over 33 beamlines. Most of the devices were optimized more than 20 years ago for 7-GeV operation, providing full energy tunability in the hard x-ray range. To maximize the brightness and flux for all the beamlines (also part of the APS-U), most of the IDs will be replaced. This seminar will provide an overview of the plans for the front ends and insertion devices for the APS-U.

  123. NSLS-II Friday Lunchtime Seminar Series

    "NSLS-II Beam Diagnostics"

    Presented by Weixing Cheng, NSLS-II, BNL

    Friday, September 29, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  124. NSLS-II Engineering Seminar Series

    "Bridging The Gaps Between Mechanical Engineering, Electrical Engineering, and Motion Control for NSLS-II"

    John Escallier, Brookhaven National Laboratory

    Tuesday, September 12, 2017, 2 pm
    John Dunn Seminar Room, Bldg. 463

    Hosted by: Sushil Sharma and Mary Carlucci-Dayton

    Mechanical design constraints in many cases can present difficult and unintended motion control challenges in many instruments such as frontend slits, insertion devices, mirrors and monochromators. Design decisions for meeting science requirements often times introduce control stability issues that seldom arise in non-scientific equipment. The Delta Tau motion system is an extremely versatile platform for this control, but also presents a severe learning curve as a result of the versatility. This presentation will demonstrate how subtle geometry effects can create large control problems, and how to look for those subtle "opportunities."

  125. NSLS-II Seminar

    "On the assessment of radiation damage and high temperature effects in novel nuclear materials using the BNL accelerators and synchrotrons"

    Presented by Nick Simos, Sr Scientist Emeritus, BNL

    Friday, September 8, 2017, 3 pm
    Large Seminar Room, Bldg. 510

    Hosted by: Ron Pindak

    In search for new and improved materials, composites and super-alloys capable of withstanding the anticipated extreme states associated fusion reactors; high temperature fast reactors and multi-MW particle accelerators, novel reactor steels, super-alloys and composites are continuously being explored to help meet both the challenge of the higher demand environments and the intended application. Higher fluxes and fluences of irradiating species (neutrons and/or protons), extreme temperatures and aggressively corrosive environments make up the new cocktail of operating conditions of the new array of material structures. One of the challenges in characterizing the effects that high radiation fluxes of neutrons and protons induce on these novel material structures in conjunction with high temperatures is the link between lattice induced damage and phase transformation and macroscopic physical properties which ultimately determine performance in the real environment. High energy X-rays at the BNL synchrotrons have offered a path in establishing this important connection between micro-scale effects and physical properties of novel material structures exposed to high radiation fluxes. Specifically, by integrating the unique capabilities of the BNL accelerator complex that includes, in addition to the NSLS and NSLS II, the proton accelerator and Tandem as well as those of CFN, the evolution and/or damage of materials ranging from classical structures such as graphite, beryllium and steels to novel super-alloys, such as those of Invar and "Gum" metal, and new composites have been characterized both at the two length scales. The pivotal role of high energy X-rays from NSLS to NSLS II in making the connection will be presented demonstrating the enormous potential of the NSLS II in answering fundamental questions in our path towards the next generation nuclear materials. Furthermore, first glimpses of the correlation of lattice effects or damage induced by differ

  126. NSLS-II Colloquium Series

    "Experiments, Analyses, and Manipulations with Particle Beam"

    Presented by Shyh-Huan Lee, Indiana University, IN

    Thursday, September 7, 2017, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: John Hill

    Progress on particle beam physics research have provided marked improvements in beam intensity, brightness, and stability advancing frontier research in applied and fundamental science. This talk will review some beam measurements and manipulation studies being undertaken to improve beam performance in storage rings. Hopefully, these studies will be relevant to the operation and improvement of National Accelerator User Facilities.

  127. NSLS-II Engineering Seminar Series

    "The Diamond Storage Ring: Recent Enhancements and Future Plans"

    Nigel Hammond, Diamond Light Source Ltd., United Kingdom

    Tuesday, August 15, 2017, 2 pm
    John Dunn Seminar Room, Bldg. 463

    Hosted by: Sushil Sharma & Mary Carlucci-Dayton

    Several recent improvements have been completed, or are in progress, for the Diamond Light Source Storage Ring. This presentation will summarise changes in respect of the lattice (The Double-Double Bend Achromat) and the practicalities of carrying out this change, vibration mitigation, and improved monitoring of dissolved oxygen in the cooling water. In addition the current plans for a complete upgrade of the Storage Ring will be outlined.

  128. NSLS-II Friday Lunchtime Seminar Series

    "Structural Characterization of Sulfhydrated Proteins Involved in Oxidative Stress"

    Presented by Ruth Pietri, University of Puerto Rico

    Friday, August 11, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  129. Brookhaven Lecture

    "516th Brookhaven Lecture: 'From NSLS to NSLS-II and Beyond: Accelerator Physics Challenges'"

    Tuesday, August 8, 2017, 4 pm
    Berkner Hall Auditorium

    Hosted by: Larry Carr

  130. NSLS-II Seminar

    "Physical Sciences Electron Microscopes"

    Presented by Dr. Cecilia Sanchez-Hanke, Diamond Light Source, United Kingdom

    Monday, August 7, 2017, 11 am
    NSLS-II Bldg 743 (LOB3), room 156

    Hosted by: Klaus Attenkofer

    Electron microscopes (EM) are getting more and more visibility at large facilities such as radiation sources. At Diamond, we have established a collaboration with the Industry and the University to install two high-end microscopes. The selected final location for the microscopes was the same building as I14 Diamond's Nano-probe beamline because of the similar mechanical stability specifications so that these aberration corrected Electron Microscopes can go beyond the atomic resolution. I will be talking about the advantages of having at Diamond these instruments, that in no doubt are complementary to the beamlines. And the challenge that we encounter to try to bring the photon based community into the electron microscopes and vice versa.

  131. NSLS-II Friday Lunchtime Seminar Series

    "From Particles to Patients: The Role of an Epoxide Hydrolase in P. Aeruginosa Virulence"

    Presented by Kelli Hvorency, 2017 Julian D. Baumert. PhD. Thesis Award Winner, Dartmouth College

    Friday, August 4, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  132. Summer Sundays

    "Brilliant Light, Dazzling Discoveries at the National Synchrotron Light Source II"

    Sunday, July 30, 2017, 10 am
    Berkner Hall, Room B

    Visit the National Synchrotron Light Source II

  133. NSLS-II Friday Lunchtime Seminar Series

    "Special Edition: Enjoy an hour of interesting science from our summer student interns."

    Presented by N. Hameed, A. Lowery, T. Solomon, P. Panica & A. MacGregor

    Friday, July 28, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme an

  134. NSLS-II Friday Lunchtime Seminar Series

    "Understanding Energy Storage Materials in Model Systems using X-ray Scattering" and "Development of Submicron Capillary Optics"

    Presented by Hans-Georg Steinrück and Benjamin Stripe, Stanford Synchrotron Radiation Lightsource and Sigray Inc.

    Friday, July 21, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  135. NSLS-II Friday Lunchtime Seminar Series

    "Bio-cryo Electron Microscopy: The Opportunity and Plan" and "Characterizing Self-Assembled Nanoparticles Employed in Drug Delivery Systems"

    Presented by Sean McSweeney and Kazuo Sakurai, NSLS-II, BNL and University of Kitakyushu

    Friday, July 14, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  136. NSLS-II Friday Lunchtime Seminar Series

    "In-situ Studies of the Reforming Reactions on Ceria-based Catalysts for the Production of Hydrogen"

    Presented by Zongyuan Liu, BNL, Chemistry Department

    Friday, June 16, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  137. NSLS-II Engineering Seminar Series

    "Thin Films for X-Ray Optics"

    Raymond Conley, Advanced Photon Source

    Tuesday, June 13, 2017, 2 pm
    John Dunn Seminar Room, Bldg. 463

    Hosted by: Sushil Sharma and Mary Carlucci-Dayton

    In order to produce high quality optics, deposition equipment must be designed with the utmost in stability and flexibility. Limitations encountered with the first generation of APS deposition systems led to new designs, including the NSLS-II MLL Deposition System and three machines at the APS. The goals for the latest machine, called the "Modular Deposition System" are not only to produce a wide variety of multilayer and other thin-film based x-ray optics, but also to allow the APS to initiate an ion-beam figuring (IBF) based mirror surface correction capability. Off-line surface metrology can be utilized for iterative feedback into the fabrication process, however, the prospect of obtaining surface figure information without the need to extract the substrate from the vacuum chamber provides a number of performance advantages such as increased throughput, quasi-real time deposition feedback, and the flexibility to work with reactive materials. By locating the interferometry transmission flat remotely within the UHV system, errors in the measurement induced by environmental factors such as air turbulence and humidity may be minimized. Provisions for a dynamically-actuated aperture will be used to explore methods for 3-D multilayer deposition intended to enable the use of new optical geometries and allow for higher efficiency and mirror figure correction. Multilayer deposition will be the first priority for the machine, while the other features related to metrology, figuring, and the dynamic aperture will be brought online later as they are developed.

  138. NSLS-II Friday Lunchtime Seminar Series

    "MEMS-based Dynamic X-ray Optics" and "Structural Studies of Energy Materials"

    Friday, June 9, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang

  139. NSLS-II Friday Lunchtime Seminar Series

    "Status of SSRF and the Shanghai X-FEL Projects, and Efforts in Single Particle Imaging and Whole Cell Imaging with X-FELs"

    Presented by Thomas Earnest, Shanghai Synchrotron Radiation Facility

    Friday, May 12, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  140. NSLS-II Friday Lunchtime Seminar Series

    "SAC Rerun: User Program Update"

    Presented by Lisa Miller, NSLS-II, BNL

    Friday, May 5, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  141. NSLS-II Friday Lunchtime Seminar Series

    "SAC Rerun: DAMA Update"

    Presented by Stuart Campbell, NSLS-II, BNL

    Friday, April 28, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  142. NSLS-II Friday Lunchtime Seminar Series

    "Meeting the Challenges and Expectations of Automated, Data Intensive Experiments at Diamond Light Source" and "Scientific Computing at the ESS"

    Presented by Alun Ashton and Jon Taylor, Diamond Light Source Ltd and European Spallation Source ERIC

    Friday, April 21, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  143. NSLS-II Friday Lunchtime Seminar Series

    ""Iridium Thiospinel - Orbital Parts Unknown" and "Graphene-Based Microfluidics for Serial Crystallography"

    Presented by Emil Bozin and Sarah L. Perry, CMPMS/BNL and University of Massachusetts Amherst

    Friday, March 31, 2017, 12 am
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  144. NSLS-II Friday Lunchtime Seminar Series

    "Revealing the Local Atomic and Magnetic Structure of a New Dilute Ferromagnetic Semiconductor by Pair Distribution Function Analysis" and "Resonant Scattering on T' cuprates""

    Presented by Benjamin Frandsen and Jonathan Pelliciari, Lawrence Berkeley National Laboratory and Massachusetts Institute of Technology (MIT)

    Friday, March 24, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  145. NSLS-II Friday Lunchtime Seminar Series

    "X-ray Amplification (XAMP) of Meso-scale Structures" and "Structure Solution and Refinement of Stacking Faulted NiCl(OH)"

    Presented by Julien Lhermitte and Sebastian Bette, CFN, BNL and Max Planck Institute for Solid State Research, Germany

    Friday, March 17, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  146. NSLS-II Friday Lunchtime Seminar Series

    "The NSLS-II Complex: From Commissioning to Operations"

    Presented by Guimei Wang, NSLS-II, BNL

    Friday, March 10, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  147. NSLS-II Engineering Seminar Series

    "High-Resolution Monochromator Development for Nuclear Resonant Scattering"

    Presented by Thomas Toellner, X-Ray Science Division,

    Tuesday, March 7, 2017, 2 pm
    John Dunn Seminar Room, Bldg. 463

    Hosted by: Sushil Sharma and Mary Carlucci-Dayton

    High-resolution monochromators (HRMs) are key components at nuclear resonant scattering beamlines, and their development at the APS has been ongoing for decades. They are used to resolve the frequency spectrum of isotope-specific atomic dynamics using nuclear resonant vibrational spectroscopy and to reduce the enormous electronic charge scattering that accompanies nuclear excitation using synchrotron radiation. The latter allowing the measurement of hyperfine fields using synchrotron Moessbauer spectroscopy. The narrow line-widths (neV) associated with nuclear resonances also offer an excellent diagnostic tool for the characterization of HRMs, and have greatly facilitated their development. HRMs with ultra-high energy-resolution exposed the need for greater energy-alignment stability and prompted the development of cryo-stabilization. A recent prototype sub-meV-bandwidth monochromator for hard X-rays that implements cryo-stabilization has been built that displays a 100-fold improvement in energy-alignment stability over other designs. This unprecedented level of control allows one to observe the intrinsic factors that limit the energy resolution obtainable with silicon. I will present the principle design aspects of this prototype along with its performance, and discuss what has been learned.

  148. NSLS-II Friday Lunchtime Seminar Series

    "Elemental Concentration and Size Apportionment of Combustion Particles from Wood-fired Appliances" and "Creating Methods for Material Design and Synthesis for Microporous and Mesoporous Materials"

    Presented by Monica Gray-Georges and Nicholas Brunelli, Lincoln University of Pennsylvania and Ohio State University

    Friday, March 3, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  149. NSLS-II

    "NSLS-II Town Meeting"

    Wednesday, March 1, 2017, 1 pm
    NSLS-II Building 745, Conference Room 156

    Hosted by: NSLS-II UEC

  150. NSLS-II Friday Lunchtime Seminar Series

    "Wide Bandgap Semiconductors: A Solution for Next Generation Radiation Detector"

    Presented by Anwar Hossain, Nonproliferation and National Security Department, BNL

    Friday, February 24, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  151. NSLS-II Friday Lunchtime Seminar Series

    "Soft X-ray Spectromicroscopy Beamline at the Canadian Light Source and Recent Developments"

    Presented by Jian Wang, Canadian Light Source

    Friday, February 17, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  152. NSLS-II Engineering Seminar Series

    "Hard X-ray Imaging with Sub-20 nm Spatial Resolution: Instrumentational Challenges and Solutions"

    Evgeny Nazaretski, NSLS-II, BNL

    Tuesday, February 14, 2017, 2 pm
    John Dunn Seminar Room, Bldg. 463

    Hosted by: Sushil Sharma and Mary Carlucci-Dayton

    The Hard X-ray Nanoprobe (HXN) beamline at NSLS-II has been designed and constructed to enable imaging experiments with unprecedented spatial resolution and detection sensitivity. The HXN x-ray Microscope is a key instrument for the beamline, providing a suite of experimental capabilities which includes scanning fluorescence, diffraction, differential phase contrast and ptychography utilizing Multilayer Laue Lenses (MLL) and zone plates (ZP) as nanofocusing optics. During this presentation, different phases of the X-ray microscope development process will be reviewed. Various prototype systems designed and constructed prior to completion of the HXN-microscope will be discussed. Experimental data demonstrating ~15 x 15 nm spatial resolution imaging using MLL optics will be presented. I will discuss instrumentational challenges associated with high spatial resolution imaging and will outline future development plans.

  153. NSLS-II Friday Lunchtime Seminar Series

    "X-ray Amplification of Mesoscale Structures" and "NSLS-II Fast Orbit Feedback System"

    Presented by Julien Lhermitte and Yuke Tian, CFN, BNL and Photon Sciences, BNL

    Friday, February 10, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  154. NSLS-II Friday Lunchtime Seminar Series

    Presented by Scott McCormack and Stephanie Laga, University of Illinois Urbana-Champaign and Yale University

    Friday, February 3, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  155. NSLS-II Friday Lunchtime Seminar Series

    "Recent Developments with Hybrid Photon Counting Detectors at Dectris"

    Presented by Stefan Brandstetter, Dectris, Switzerland

    Friday, January 27, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  156. NSLS-II Friday Lunchtime Seminar Series

    "Structural Exploration on Nanocelluloses from Non-wood Plants"

    Presented by Chengbo Zhan, Stony Brook University

    Friday, January 20, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  157. NSLS-II

    "NSLS-II Town Meeting"

    Friday, December 9, 2016, 1 pm
    Building 703, Large Conference Room

  158. NSLS-II Colloquium Series

    "Operando Spectroscopy of a Catalytic Solid: Towards a Molecular Movie"

    Presented by Bert Weckhuysen, Utrecht University Netherlands, Netherlands

    Wednesday, November 30, 2016, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: Eli Stavitski

    The search for new or more effective catalysts would benefit from a multiscale science approach bridging the molecular world with the macroscopic world. Such detailed information can be realized if we would have access to a very powerful camera shooting molecular movies of a catalytic solid at work. This is the field of operando spectroscopy and recent breakthroughs in chemical imaging techniques, based on optical, electron and X-ray methods, demonstrate that such molecular movie concept is within reach. This lecture discusses the recent advances in spectroscopy and microscopy of catalytic solids at different length scales, starting from single molecules and single atoms up to the level of individual catalyst particles and ensemble effects in a reactor bed. Special emphasis will be devoted to the exploration of mesoscale effects in catalytic solids.

  159. NSLS-II Friday Lunchtime Seminar Series

    "Thin Film Crystalline Stratification and Anisotropic Thermal Expansion investigated with Grazing Incidence X-ray Scattering"

    Presented by Eliot Gann, NIST

    Friday, November 11, 2016, 12 pm
    NSLS-II Bldg 744 (LOB 4), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  160. NSLS-II Friday Lunchtime Seminar Series

    "Energy Materials Research at SSRL"

    Presented by Michael Toney, SSRL/SLAC

    Friday, October 28, 2016, 12 pm
    NSLS-II Bldg 744 (LOB 4), room 156

    Hosted by: Ben Ocko and Shirish Chodankar

  161. NSLS-II Engineering Seminar Series

    "The NSLS-II Optical Metrology Laboratory"

    Mourad Idir, Optics and Metrology Group Leader, NSLS-II

    Tuesday, September 13, 2016, 2 pm
    John Dunn Seminar Room, Bldg. 463

    Hosted by: Sushil Sharma and Mary Carlucci-Dayton

    During the last decade, we have seen ultra-fast progress in X-ray optics performances. This enhancement is directly linked to the development of the necessary tools to control these optical components. In parallel to the design and construction of new synchrotron radiation sources quite important efforts are required to upgrade existing and develop new x-ray optics that is capable of conditioning powerful x-ray beams with minimum losses of brilliance. In the context of these research and development activities a well-equipped laboratory is absolutely vital. It is now necessary to characterize optical surface figures, slope errors and roughness on meter-long optics over spatial frequencies as short as 0.1 mm and with slope errors reaching less than 100 nrad rms or surface figure errors close to 1 nm to preserve the high brightness made available by third and fourth generation synchrotron/FEL sources like NSLSII or LCLS. The NSLS-II Optical Metrology Laboratory (NSLSII-OML) includes commercial instruments for measuring long spatial frequency figure errors, mid spatial frequencies and high frequency roughness and had developed new instruments to measure slope errors: This talk provides a brief description of the different instruments currently available in the laboratory and gives an overview of the active R&D efforts within the NSLSII-OML.

  162. Summer Sunday

    "Brilliant Light, Dazzling Discoveries: National Synchrotron Light Source II"

    Sunday, July 24, 2016, 10 am
    Berkner Hall for Information

    Visit the National Synchrotron Light Source II, where scientists use intense beams of light to see the inner structure of batteries, proteins, space dust, and more.

  163. NSLS-II Friday Lunchtime Seminar Series

    "Effect of Hydrophobic and Hydrophilic Silica Nano Particles on the Dynamics of Phospholipid Films, an XPCS Investigation"

    Presented by Luigi Cristofolini, University of Parma, Italy

    Friday, July 15, 2016, 12 pm
    NSLS-II Bldg 744 (LOB 4), room 156

    Hosted by: L. Carr, S. Chodankar and B. Ocko

  164. NSLS-II Engineering Seminar Series

    "Mechanical Stability Issues at BNL"

    Charles Spataro, NSLS-II, Accelerator Division, Instrumentation Group

    Tuesday, July 12, 2016, 2 pm
    John Dunn Seminar Room, Bldg. 463

    Hosted by: Sushil Sharma and Mary Carlucci-Dayton

    High performance goals of several facilities at BNL (NSLS-II, RHIC, CFN and future eRHIC) require high mechanical stability of their equipment such as magnets, BPMs, mirrors, monochromators, detectors, and microscopes. The mechanical stability of these components can be compromised by site-wide ground vibrations, local vibration sources (pumps, motors, etc.), and fluctuations in air and water temperatures. This presentation highlights the results of several studies that have been conducted at several BNL sites and facilities over the past five years to characterize the mechanical stability issues and to develop mitigation schemes.

  165. NSLS-II Friday Lunchtime Seminar Series

    Presented by Mark Sutton and David Sprouster, McGill University and BNL

    Friday, July 8, 2016, 12 pm
    NSLS-II Bldg 744 (LOB 4), room 156

    Hosted by: L. Carr, S. Chodankar and B. Ocko

  166. Brookhaven Lecture

    "515th Brookhaven Lecture: 'Structural Biology: Studying Living Things as They Jiggle and Wiggle'"

    Presented by Sean McSweeney, National Synchrotron Light Source II at Brookhaven Lab

    Wednesday, June 29, 2016, 4 pm
    Berkner Hall Auditorium

    Hosted by: Thomas Watson

  167. NSLS-II Friday Lunchtime Seminar Series

    "Two Informal Talks of Interest to the Synchrotron Radiation Community"

    Presented by Joe Dvorak | BNL, Suzannah Wood | University of Oregon

    Friday, June 10, 2016, 12 pm
    NSLS-II 744 (LOB4) rm 156

    Hosted by: L. Carr, S. Chodankar and B. Ocko

  168. NSLSII Friday Lunchtime Seminar Series

    Friday, April 15, 2016, 12 pm
    NSLS-II Bldg 744 (LOB 4), room 156

    Hosted by: L. Carr, S. Chodankar and B. Ocko

    Presented by Dr. Jie Deng Yale University "Absorption Spectra and their Applications in High Pressure Mineral Physics" and Dr. Larry Carr NSLS-II - Brookhaven National Laboratory "Near-Field Infrared Study of Plasmonic and Effective Medium Behavior in Nanoscopic Granular Gold Films"

  169. NSLS-II Friday Lunchtime Seminar Series

    "Spectrum-Based Alignment of an In-Vacuum Undulator"

    Presented by Oleg Chubar, NSLS-II / BNL

    Friday, April 8, 2016, 12 pm
    NSLS-II 744 (LOB4) rm 156

    Hosted by: L. Carr, S. Chodankar and B. Ocko

  170. NSLS-II Friday Lunchtime Seminar Series


    Friday, March 18, 2016, 12 pm
    744 (LOB4) rm 156

  171. NSLS-II Town Meeting

    Friday, March 11, 2016, 1 pm
    Bldg. 703 - Large Conference Room

    Hosted by: NSLS-II Users' Executive Committee

  172. NSLS-II Friday Lunchtime Seminar Series

    "'PI3 Kinase: Molecular Determinants of PIP2 Recognition' and 'X-ray Total Scattering Study of the Local Structure of Disordered, Zr Based Exchange Materials'"

    Presented by Dr. Sandra Gabelli and Dr. Maxwell Terban

    Friday, March 4, 2016, 12 pm
    NSLS-II 744 (LOB4) rm 156

  173. NSLS-II Friday Lunchtime Seminar Series

    "Novel Pressure-Induced Confined Metal from the Mott Insulator Sr3Ir2O7' and 'Reverse Monte Carlo / evolutionary algorithm approach for EXAFS data" Presented by Yang Ding and Janis Timosenko"

    Friday, February 19, 2016, 12 pm
    NSLS-II 744 (LOB4) rm 156

  174. NSLS-II Friday Lunchtime Seminar Series

    "'Control of Beam Vertical Size to Diffraction Limit' and 'Effect of Dynamical Diffraction in Bragg Diffractive Imaging'"

    Presented by Yonjun Li and Wen Hu

    Friday, February 12, 2016, 12 pm
    NSLS-II 744 (LOB4) rm 156

  175. NSLS-II Friday Lunchtime Seminar Series

    "Canceled due to snow"

    Friday, February 5, 2016, 12 pm
    NSLS-II 744 (LOB4) rm 156

  176. NSLS-II Friday Lunchtime Seminar Series

    Friday, January 29, 2016, 12 pm
    NSLS-II 744 (LOB4) rm 156

  177. NSLS-II Friday Lunchtime Seminar Series

    Presented by Bruce Ravel and Li Li

    Friday, January 22, 2016, 12 pm
    NSLS-II 744 (LOB4) rm 156

    Hosted by: Larry Carr, Ben Ocko and Shirish Chodankar

    Two informal seminars of interest to the synchrotron radiation community

  178. NSLS-II Friday Lunchtime Seminar Series

    Presented by Ray Fliller (NSLS-II) and Mengkun Liu (Stony Brook

    Friday, December 11, 2015, 12 pm
    NSLS-II 744 (LOB4) rm 156

  179. NSLS-II Town Meeting

    Friday, December 4, 2015, 1 pm
    Large Conference Room, Bldg. 703

  180. NSLS-II Friday Lunchtime Seminar Series

    "Two informal talks of interest to the synchrotron science community"

    Friday, November 20, 2015, 12 pm
    NSLS-II 744 (LOB4) rm 156

  181. Brookhaven Lecture

    "Synchrotron Science…and Bugs?"

    Presented by Wah-Keat Lee, NSLS-II

    Wednesday, November 18, 2015, 4 pm
    Berkner Hall Auditorium

    Hosted by: Tom Watson

    Mosquitos infect millions of people with diseases including life-threatening malaria and dengue every year. Other insects are blamed for billions of dollars of damage to crops across the United States. And while most people squirm, swat, and scratch at the sight of insects, othersâ€"albeit far fewer than mostâ€"look to research facilities like ultra-bright x-ray-producing synchrotron light sources for unprecedented views of these six-legged creatures

  182. NSLS-II Friday Lunchtime Seminar Series

    Friday, November 13, 2015, 12 pm
    NSLS-II 744 (LOB4) rm 156

    Informal seminars of interest to the synchrotron radiation community

  183. NSLS-II Friday Lunchtime Seminar

    "Addressing the Data Challenge in Small Angle Scattering"

    Presented by Alexander Hexemer, Advanced Light Source, Lawrence Berkeley National Lab

    Friday, November 6, 2015, 12 pm
    NSLS-II Bldg 744 (LOB 4) conf. room 156

  184. NSLS-II Friday Lunchtime Seminar Series

    Friday, October 30, 2015, 12 pm
    NSLS-II 744 (LOB4) rm 156

    Hosted by: Larry Carr, Ben Ocko and Shirish Chodankar

    Two seminars of relevance to the synchrotron radiation community Bring your lunch!

  185. Photon Sciences Seminar

    "In-situ XAS, TXM and RIXS experiments"

    Presented by Frank de Groot, Debye Institute of Nanomaterials Science, Utrecht University, Netherlands

    Thursday, October 1, 2015, 11 am
    CFN Seminar Room, 2nd Fl., Bldg 735

    New developments in in-situ x-ray absorption (XAS), transmission x-ray microscopy (TXM) and resonant inelastic x-ray scattering (RIXS) will be discussed. A brief introduction is given of x-ray absorption spectroscopy, including the multiplet interpretation of XAS spectral shapes [1,2]. Nanoscale chemical imaging of catalysts under working conditions is possible with transmission x-ray microscopy. We have shown that TXM can image a catalytic system under relevant reaction conditions and provides detailed information on the morphology and composition of the catalyst material in situ [3]. The 20 nanometer resolution combined with powerful chemical speciation by XAS and the ability to image materials under reaction conditions opens up new opportunities to study many chemical processes. I will discuss the present status of in-situ TXM, with an emphasis on the abilities of the 10+ nm resolution TXM technique in comparison with 0.1 nm STEM-EELS [4,5]. Hard X-ray TXM allows the measurement of chemical images and tomographs under more realistic conditions, using a capillary reactor at 10 bar Fischer-Tropsch conditions [6]. The second part of the talk deals with resonant inelastic x-ray scattering (RIXS), In 2p3d RIXS one scans through the 2p XAS edge and measures the optical excitation range. As an example, the RIXS spectra of CoO will be discussed. The experimental resolution of 100 meV at ADRESS allows the detailed observation of the electronic structure. First-principle theoretical modelling was performed for the ground state and multiplet analysis for the RIXS experiments. The implications for measurements on coordination compounds (cobalt carboxylates) and cobalt nanoparticles is discussed, in particular the comparison with optical spectroscopy [7]. Related to the RIXS measurements is the analysis of Fluorescence yield (FY) detected x-ray absorption spectra (XAS), including the intrinsic deviations of the FY-XAS spectral shape from

  186. NSLS-ll Town Meeting

    Wednesday, August 5, 2015, 1 pm
    Building 703, Large Conference Room

    Hosted by: NSLS-ll Users' Executive Committee

    The NSLS-II staff and user community are invited to a Town Meeting on Wednesday, August 5, from 1-3 p.m. in building 703, Large Conference Room. Watch webcast starting at 1 p.m.

  187. Photon Sciences Seminar

    "Crystal and protein structure modeling, software development and applications"

    Maksim Rakitin

    Thursday, July 30, 2015, 9:45 am
    Conference Room 156, Building 744

    Hosted by: Oleg Tchoubar

  188. Photon Sciences Seminar

    "Some thoughts on the Impact of Software on Beamline Use"

    Presented by Brian H. Toby Ph.D., Argonne National Laboratory, Advanced Photon Source, Argonne, IL 60439-4856

    Thursday, July 23, 2015, 11 am
    Building 744, Conference Room 156

    Hosted by: Paul Zschack

  189. Brookhaven Lecture

    "506th Brookhaven Lecture: ''NSLS-II: The New Synchrotron Light Source at Brookhaven Lab'"

    Presented by Ferdinand Willeke, National Synchrotron Light Source II

    Wednesday, June 24, 2015, 4 pm
    Berkner Hall Auditorium

    Hosted by: Thomas Watson

  190. C-AD Accelerator Physics Seminar

    "A Robinson Wiggler for Lifetime and Brilliant Improvement at the Metrology Light Source"

    Presented by Tobias Goetsch, Helmholtz-Zentrum, Germany

    Thursday, May 14, 2015, 4 pm
    Large Conf. Rm. Bldg. 911B, Rm. A202

    Hosted by: Wolfram Fischer

    "The beam lifetime in electron storage rings concerns machines running in decay mode as well as machines doing top-up. A standard procedure to increase the lifetime is via bunch lengthening as the lifetime depends on the electron density in the bunch. Bunch lengthening is typically achieved with higher harmonic (Landau) cavities. There are several advantages in using a different approach: it is possible to increase the bunch length by installing a transverse gradient (Robinson) Wiggler, which allows to transfer damping between the horizontal and the longitudinal plane. While increasing the bunch length, the horizontal emittance is being reduced yielding advantages regarding the source size depending on the magnet optics. At the Metrology Light Source, a primary source standard used by Germanys national metrology institute (Physikalisch-Technische Bundesanstalt), such a scheme is being investigated. The prospects are higher brilliance for the important beamlines together with a lifetime improvement in the order of 100 %."

  191. NSLS-ll Town Meeting

    Friday, February 13, 2015, 1 pm
    Building 703, Large Conference Room

    Hosted by: NSLS-ll Users' Executive Committee

    The NSLS-II staff and user community are invited to a Town Meeting on Friday, February 13, from 1-3 p.m. in building 703, Large Conference Room. Watch webcast starting at 1 p.m.

  192. Brookhaven Lecture

    "501st Brookhaven Lecture: Negative Particles for Positive Breakthroughs: Characterizing Electrons in Novel Materials at NSLS-II"

    Presented by Ignace Jarrige, Photon Sciences Directorate

    Wednesday, January 21, 2015, 4 pm
    Berkner Hall Auditorium

    Hosted by: Thomas Watson

    During the 501st Brookhaven Lecture, Ignace Jarrige will discuss different ways electrons behave and affect unique materials' properties. He will then explain how the new Soft Inelastic X-ray Scattering (SIX) beamline—an extra-long beamline he is developing at NSLS-II—will measure how x-rays excite atomic bonds in new materials researchers are inventing around the world. Jarrige and his collaborators will use this new tool to unravel mysteries of electrons' collective behavior with unprecedented accuracy as they witness emerging phenomena such as superconductivity—the ability to conduct electricity with zero resistance—magnetism, and other phenomena that could lead to faster trains, more powerful computer processors, and far more efficient electrical grids.

  193. Photon Sciences Town Meeting

    Tuesday, October 28, 2014, 1 pm
    Large Conference Room, Bldg. 703

    Hosted by: Photon Sciences Users' Executive Committee

    The Photon Sciences staff and user community are invited to a Town Meeting on Tuesday, October 28, from 1-3 p.m. in the Large Conference Room, Bldg. 703. Watch webcast at 1p.m. by clicking

  194. Instrumentation Division Seminar

    "Current x-ray detector projects for NSLS-II beamlines"

    Presented by Peter Siddons, Photon Sciences Directorate

    Wednesday, October 22, 2014, 2:30 pm
    Large Conference Room, Bldg. 535

    NSLS-II is building a suite of new instruments for a range of applications. The Photon Science Detector Group has been working with the beamline scientists to develop new detectors closely aligned with their experimental needs. The talk will briefly describe these projects and the scientific techniques for which they are intended.

  195. Photon Sciences Directorate Seminar

    "The Sirius Project"

    Presented by Dr. Harry Westfahl Jr., LNLS, Brazil

    Monday, August 11, 2014, 1 pm
    Bldg. 745, Room 156

    Hosted by: Dr. Qun Shen

    The Brazilian Synchrotron Light Laboratory has started the construction of Sirius, a 3 GeV and 0.28 nm rad emittance storage ring. In this talk, Dr. Westfahl will present some of the main aspects of this new storage ring and its first and second phase beamlines, as well as the current status of the project.

  196. Photon Sciences Town Meeting

    Tuesday, July 29, 2014, 1 pm
    Seminar Room, Bldg. 725

    Hosted by: Photon Sciences Users' Executive Committee

    The Photon Sciences staff and user community are invited to a Town Meeting on Tuesday, July 29, from 1-3 p.m. in the NSLS Seminar Room, Bldg. 725. Watch webcast at 1 p.m.

  197. National Synchrotron Light Source Seminar

    "New dimensions in phase contrast X-ray imaging: faster and clinically relevant"

    Presented by Marco Stampanoni, Institute for Biomedical Engineering of the ETH and University of Zürichand Head of the X-ray Tomography group of the Swiss Light Source at the Paul Scherrer Institut, Switzerland

    Tuesday, July 8, 2014, 11 am
    Bldg. 744, room 156

    Hosted by: Jun Wang

    High brightness is a fundamental property of third generation synchrotron facilities. Those deliver coherent beams, which intrinsically provide access to the phase information from a sample. The Swiss Light Source operates TOMCAT, a beamline dedicated to TOmographic Microscopy and Coherent rAdiology experimenTs. Our group develops cutting-edge equipment for non-destructive tomographic investigations and provides the necessary instrumentation for phase contrast imaging at spatial resolution ranging over four orders of magnitude as well as the acquisition of 3D volumes within a fraction of a second. This presentation will illustrate how phase contrast imaging can be implemented with applications in human radiology down to nanotomographic imaging of single cells. A brief review of the most advanced phase contrast imaging techniques will be provided, with particular emphasis on full-field Zernike microscopy, free-space propagation and grating-interferometry. Each of these methods has shown to be particularly suited for selected investigations. Applications criteria as well as limitations for each technique will be presented, with the illustrative support of examples taken from daily experiments carried out at modern, third generation synchrotron facilities. Particular emphasis will be devoted to applications involving the investigation of life sciences relevant material like cells (organelles identification), soft tissue biopsies (tumor visualization, Alzheimer plaques detection), bones (canaliculi detection and statistical nano-morphometry), insects (biomechanics of tethered flight) and breast tissue (early cancer detection

  198. National Synchrotron Light Source Lunch Time Seminar

    "Quantifying Bone Microarchitectural Anisotropy with Diffraction Enhanced Imaging"

    Presented by Dean M. Connor, Medical University of South Carolina

    Friday, May 2, 2014, 12 pm
    Bldg. 744 (LOB 4) Room: 4L 156

    Hosted by: Klaus Attenkofer and Sanjit Ghose

  199. Brookhaven Lecture

    "491st Brookhaven Lecture 'A Fast, Versatile Nanoprobe for Complex Materials: The Sub-micron Resolution X-ray Spectroscopy Beamline at NSLS-II'"

    Presented by Juergen Thieme, Brookhaven Lab's Photon Sciences Directorate

    Thursday, February 6, 2014, 4 pm
    Berkner Hall Auditorium

    Hosted by: Allen Orville

  200. Talk by Ignace Jarrige

    "SIX: A Looong Beamline at NSLS-II to Probe Electrons"

    Ignace Jarrige, SIX Beamline Group Leader, NSLS-II

    Thursday, January 9, 2014, 8 pm
    Berkner Hall, Room B

  201. NSLS-II Seminar

    "NSLS-II Early Experiment Workshop: Inelastic X-ray Scattering (IXS) Spectrometer"

    Tuesday, October 1, 2013, 7:30 am
    Berkner Hall, Room B

    The Photon Sciences Directorate is hosting a workshop about developing an inelastic x-ray scattering (IXS) spectrometer for the National Synchrotron Light Source II (NSLS-II). The workshop will be held in Berkner Room B on Tuesday, Oct. 1, beginning at 7:30 a.m.

  202. Annual Users' Meeting

    "2013 Joint NSLS/CFN Users' Meeting"

    Wednesday, May 22, 2013, 8:30 am
    Berkner Hall Auditorium

  203. NSLS Workbench

    "X9 SAXS Workbench - 2013 Session I"

    Saturday, April 20, 2013, 9:30 am
    Conferene Room C, Bldg. 725

  204. NSLS Workbench

    "X9 SAXS Workbench - 2013 Session I"

    Friday, April 19, 2013, 9:30 am
    Conference Room C, Bldg. 725

  205. NSLS Workbench

    "X9 SAXS Workbench - 2013 Session I"

    Thursday, April 18, 2013, 9:30 am
    Conference Room C, Bldg. 725

  206. Brookhaven Lecture

    "486th Brookhaven Lecture: 'The Hard X-ray Nanoprobe at NSLS-II: A Big Microscope to Tackle Challenges at the Nanoscale'"

    Presented by Yong Chu, Photon Sciences Directorate at Brookhaven Lab

    Wednesday, April 17, 2013, 4 pm
    Berkner Hall Auditorium

    Hosted by: Allen Orville

    During the 486th Brookhaven Lecture, Yong Chu of the Photon Sciences Directorate will illustrate unique challenges and innovative approaches for x-ray microscopy at the nanoscale—measured in billionths of a meter. He will also discuss measurement capabilities for the first science experiments at NSLS-II.

  207. National Synchrotron Light Source Workshop

    "XANES Short Course: Theory, Analysis, Applications"

    Thursday, November 8, 2012, 9 am
    Large Conference Room, Bldg. 490

  208. NSLS-II Seminar

    "High Speed Choppers for X-Ray or Light Pulse Selection"

    Presented by Bernd Eberhard Lindenau, Forschungszentrum Juelich GmbH ( FZJ ), Central Department of Technology ( ZAT), Magnetic Bearings and Drives, Germany

    Monday, July 9, 2012, 1:30 pm
    703 Large Conference Room

    Hosted by: Daniel Bacescu

    For experiments, which ask for light pulses with a sequence different from the bunch mode predominantly offered by the synchrotron source, high speed pulse selectors have been developed. A fast rotating triangular shaped disk with the beam channel grooved along one of the disk sides serves as shutter element in the beam line for hard x-rays. The maximum open sequence of about 1000Hz is limited by the tolerable rotation speed of the shutter rotor, which is machined from high strength titanium alloy. Open times of the beam channel in the range of 500ns and +/-2 ns phase stability with respect to the bunch clock are realized with the present systems, which are used in combination with a probing laser for time resolved experiments at ESRF, APS, SPring8 and PF-AR. A 1.25 MHz chopper for light pulses is currently under development for operation at BESSY. It is based on the same platform for magnetic rotor suspension and drive control. This chopper is equipped with a slotted aluminium disk to allow open periods of 140ns. The design criteria of these systems will be presented and technical feasibilities will be addressed.

  209. National Synchrotron Light Source Lunch Time Seminar

    "ID 10 beamline recent development for Coherent Diffraction Imaging"

    Presented by Yuriy Chushkin, European Synchrotron Radiation Facility (ESRF), Grenoble, France

    Friday, July 6, 2012, 11 am
    Seminar Room, Bldg. 725

    Hosted by: Andrei Fluerasu

  210. National Synchrotron Light Source Lunch Time Seminar

    "Thermal Expansion of Crystalline Materials from High Temperature Powder X-ray Diffraction"

    Presented by Waltraud M. Kriven, University of Illinois at Urbana-Champaign, Dept. of Materials Science and Engineering

    Friday, June 22, 2012, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  211. NSLS-II Seminar

    Frank Steinbruckner, Keller Technology Corporation

    Friday, June 15, 2012, 1:30 pm
    NSLS-II Seminar Room, Bldg. 817

    Keller Technology Corporation offers vacuum components, weldments, custom vacuum chambers, and fully integrated vacuum systems-manufactured to your specifications, or designed & built to your requirements. KTC specializes in stainless steel and aluminum chambers with large, complex geometries. Our dedicated staff is well versed in the proper manufacture of custom vacuum chambers - from initial design through final test and packaging protocol. Keller Technology provides custom design and build-to-print services including: • Precision 5 Axis Machining • Fabrications in stainless steel, aluminum, steel alloys, exotic metals • ASME Code Pressure Vessels • Electro-mechanical assemblies • Integrated System Testing • Assemblies or components up to 40 tons

  212. NSLS/CFN Users' Meeting Workshop

    "Unique Tools for Energy Research: Chemical Analysis of Nanostructures Using Electron Energy Loss Spectroscopy and Energy-Dispersive X-ray Spectroscopy"

    Wednesday, May 23, 2012, 8 am
    CFN Bldg 735, Seminar Room 2nd Floor Conference Ro

    Hosted by: Fernando Camino

  213. NSLS/CFN Users' Meeting Workshop

    "Workshop 2: Unique Tools for Energy Research: Chemical Analysis of Nanostructures Using Electron Energy Loss Spectroscopy and Energy-Dispersive X-ray Spectroscopy"

    Tuesday, May 22, 2012, 12:30 pm
    CFN, Bldg 735, Seminar Room 2nd floor

    Hosted by: Fernando Camino

  214. NSLS/CFN Users' Meeting Workshop

    "Unique Tools for Energy Research: Chemical Analysis of Nanostructures Using Electron Energy Loss Spectroscopy and Energy-Dispersive X-ray Spectroscopy"

    Monday, May 21, 2012, 12:30 pm
    Berkner Hall, Room A

    Hosted by: Fernando Camino

  215. 2012 NSLS/CFN Users' Meeting

    Monday, May 21, 2012, 8:30 am
    Berkner Hall Auditorium

    The Joint National Synchrotron Light Source (NSLS) and Center for Functional Nanomaterials (CFN) Users' Meeting provides a venue for scientists from diverse disciplines who use the NSLS and CFN facilities to share their work and discuss future directions for their research. New results and advances in experimental capabilities in synchrotron radiation and the nanoscale science research will be highlighted.

  216. National Synchrotron Light Source Seminar

    "Capabilities for High PRecision UHV Engineering and Design"

    Presented by Larry Gilbert, Vacuum Solutions

    Thursday, May 17, 2012, 10 am
    703 Large Conf Room

    Hosted by: Scott Coburn

    Reuter Technology will be presenting their capabilities for high precision UHV engineering and design, and manufacturing including laser welding, vacuum brazing of such materials as diamond to copper, stainless steel to copper, and ceramic to copper and stainless steel. Reuter provides assembly of mechanical as well as electrical components in an Class ISO-3 clean room, including bakeout and leak testing. Reuter has extensive experience working with European beam lines and accelerator facilities and welcomes the opportunity to work with BNL. Reuter Technology is represented locally by Larry Gilbert ( ) of Vacuum Solutions Group.

  217. National Synchrotron Light Source Seminar

    "QIAGEN Sample & Assay Technologies"

    Presented by QIAGEN Sample & Assay Technologies, QIAGEN Inc.

    Wednesday, May 9, 2012, 11 am
    Conference Room C, Bldg.725

    Hosted by: Vivian Stojanoff

    Differential Scanning Fluorimetry on Rotor Gene Q and QIAgility: Fast Screening Methods for Protein Analysis The method we will discussing is Differential Scanning Fluorimetry and below are some examples of where DSF can provide helpful information when studying proteins > 1. Generate stability data on proteins with different additives and buffers. > 2. Determine different protein interactions > 3. Test efficient Ligand binding. > 4. Run mutant screenings from protein to protein. The Rotor Gene provides extremely high uniformity; due to even temperature distribution they can detect small. fluorescence differences between samples or states, more efficiently than any block based system. In addition the Rotor Gene Q is a real time cycler which can also perform: Quantitation Melt Curve Analysis Two Standard Curve method Delta Delta CT method Comparative Quantitation HRM End Point PCR Allelic Discrimination Scatter Plots

  218. NSLS-II Seminar

    "simulation of electron injection and diagnostic of plasma electron density in laser-plasma accelerator"

    Presented by An He

    Friday, April 27, 2012, 9 am
    Large conference Room, Building 703

    Hosted by: LiHua Yu

    Laser plasma accelerator(LPA) is becoming one promissing advanced accelerator due to its high acceleration gradient.Although lots of progress has been made, there are still many theorical and experimental details need to further be studied.In my talk I will disscuss two kinds of electron injection methods: the external bunch injection and the optical colliding pulse injection in the LPA. An experimental proposal on the diagnostic of plasma density in capillary in LPA will also be disscussed.

  219. National Synchrotron Light Source Seminar

    "A newly developed transmission x-ray microscope and its applications"

    Presented by Jun Wang, Photon Sciences

    Thursday, April 26, 2012, 1:30 pm
    Seminar Room, Bldg. 725

    Hosted by: Ron Pindak

    A full field transmission x-ray microscope (TXM) has been developed with Xradia and commissioned at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL). The capabilities, which we developed in auto-tomography, local tomography, and spectroscopic imaging that overcome many of the limitations and difficulties in existing transmission x-ray microscopes, are described and experimentally demonstrated. Sub-50 nm resolution in 3-dimensions (3D) with markerless automated tomography has been achieved. Applications to energy storage research and other areas are presented.

  220. NSLS-II Seminar

    "Description of the complete process of manufacturing for a long mirror system: Design to Delivery"

    Wednesday, April 25, 2012, 10 am
    703 - Large Conference Room

    Hosted by: Sanjit Ghose

    WinlightX is a mirror vendor from France, visiting BNL as part of the NSLS II XPD beam line Vertical Focusing Mirror Procurement contract. WinlightX will be around for 3 days and the last day (27th) is a free day for discussion. Therefore, anyone interested in meeting with them should contact Sanjit K Ghose(

  221. NSLS-II Seminar

    "Accelerator and Beam Physics at the VEPP-4M Electron-Positron Collider"

    Presented by Victor Smalyuk, BINP, Russia

    Tuesday, April 24, 2012, 3 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Samuel Krinsky

  222. National Synchrotron Light Source Seminar

    "Spectroscopy at The Brazilian Light Source"

    Presented by Daniela Coelho, The Brazilian Light Source, Brazil

    Monday, April 23, 2012, 10:30 am
    Seminar Room, Bldg. 725

    Hosted by: Klaus Attenkofer (PSD)

    Three scientists from the National Laboratory of Synchrotron Light Source (LNLS) of Brazil, Dr. Daniela Coelho, Dr. Cristiane Barbieri Rodella, and Dr. Narcizo Marques de Souza Neto will visit Brookhaven National Laboratory to exchange ideas in the area of x-ray spectroscopy. The group will present an overview on the Sirius project, a state-of-the-art 3 GeV storage ring with significantly reduced operations cost. The talk will focus on the needs of the spectroscopic community and its implementations.

  223. National Synchrotron Light Source Lunch Time Seminar

    "Characterization of Calcrete-Hosted Uranium Ores: Challenges and Insights from Leach Columns, Synchrotron-based X-ray and Electron Microscopies"

    Presented by Markus Gräfe, Senior Research Scientist, CSIRO-Process Science & Engineering, Australian Minerals Research Centre, Australia

    Friday, April 20, 2012, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Ryan Tappero

  224. NSLS-II Seminar

    "The Future Brockhouse X-Ray Diffraction and Scattering Sector at the Canadian Light Source"

    Presented by Stefan Kycia, Department of Physics, University of Guelph, CANADA

    Thursday, April 19, 2012, 3:30 pm
    NSLS-II, Lg. Seminar Room (Bldg. 703)

    Hosted by: Qun Shen

    We are in the process of constructing the Brockhouse X-ray Diffraction and Scattering Sector at the Canadian Light Source. This project was funded as a national project that has attracted support and interest from 20 universities and research institutions across Canada. The sector will support a diverse, active and successful community of Canadian and international scientists spanning the dissimilar disciplines of physics, chemistry, geology, environmental science, biology and engineering. The instrumentation will meet the researchers' diverse needs by providing excellent performance over a broad x-ray energy range from 5 to 100 keV. To achieve this, three beamlines will be sourced by two complimentary insertion devices: a Small Gap Undulator (SGU) and a Superconducting Wiggler (SCW). The SGU will source a high brilliance, beamline (5-22 keV) that will be dedicated to resonant and inelastic scattering, SAXS/WAXS experiments, magnetic scattering and reciprocal space mapping. The divergent x-ray beam produced by the SCW will be split by two side-bounce monochromators into two independent diffraction beamlines. One of them will be a lower energy beamline (5-22 keV) and will be used for high-resolution powder diffraction, microcrystal crystallography and reciprocal space mapping. The second SCW beamline will be a high energy one (20-90 keV) and will be dedicated to diffraction and scattering under extreme conditions and for high-resolution pair distribution function measurements. Over the last several years the design has evolved and we have managed to form the priceless collaborations with the LNLS Brazilian Synchrotron, the SINAP (the Shanghai Synchrotron) and IBM. An overview of the collaboration, the designs, predicted performance and science will be presented.

  225. National Synchrotron Light Source Seminar

    "Resonant Scattering Experiments at P09/PETRA III"

    Presented by Joerg Strempfer, DESY, Germany

    Friday, April 13, 2012, 10:30 am
    Seminar Room, Bldg. 725

    Tuning the x-ray energy close to an absorption edge can cause resonance effects in the diffracted signal, which are dependent on the properties of the material. The resonance effects are due to an increased sensitivity to small changes in the electron distribution around the atom to the absorption edge of which the energy is tuned to. Since the resonant signal can originate from a variety of influences acting on the atom, the challenge in the experiment is often to disentangle or determine the origin of the resonant signal. This is done by varying parameters like polarization, temperature or applied fields. The new beamline for Resonant Scattering and Diffraction (RSD), P09 at PETRA III, is designed especially for the investigation multipolar ordering processes like charge, magnetic or orbital order. Two diffractometers are available to conduct experiments using the highly brilliant synchrotron beam available at PETRA III. The polarization of the incident x-ray beam can be varied arbitrarily through x-ray phase-plates and the polarization of the scattered beam is analyzed by a polarization analyzer. Low temperature cryostats and high magnetic fields of up to 14 T combined with variable incident x-ray polarization allow the investigation of the electronic properties of the materials under investigation.

  226. NSLS-II Seminar

    "Promising Tool for Nano Materials Science, SPring-8"

    Presented by Masaki Takata, RIKEN SPring-8 Center, Japan

    Monday, April 9, 2012, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Qun Shen

    Enhancement of outstanding light source characteristics of SPring-8 such as high brilliance, extremely narrow divergence and short pulse characteristics have brought an innovation to the time resolved experiment for Materials Science. Since 2005, the X-ray pinpoint structural measurement which is an elaborate coupling of the 40ps time resolved experiment with the 100nm beam diffraction technique, has been developed and applied to the rapid phase change mechanism of DVD materials1-4), photo-induced phase transitions5) etc. SPring-8 has also made further progress in development of the ultrafast pulse selector, which allows far higher performance in time resolved measurement by full-coverage of the bunch mode of SPring-8. This improvement of time resolved experiment technique has led to success in time resolved diffraction measurement of the tetragonal lattice strain in single crystal BaTiO3 under electric field6). In the talk, challenges and the prospects for SPring-8 nano application indispensable for time resolved experiment will be also presented.

  227. National Synchrotron Light Source Lunch Time Seminar

    "Documentary Film Screening of Out of the Shadows"

    Presented by Kevin Sullivan

    Friday, March 30, 2012, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Pete Siddons

    For hundreds of years the public has only seen the surface of famous masterpieces by artists such as Van Gogh and Rembrandt; as well as medieval religious treasures such as The Norfolk Triptych. Now, through a melding of innovative scientific techniques and art connoisseurship, completely different paintings and important clues about the artists themselves are being uncovered one layer at a time by members of Holland's Rembrandt Research Institute and scientists from the University of Delft. Non-invasive technology such as x-ray fluorescence and 3D imaging can reveal these "worlds within a world" of art. Researchers can calculate how and when an artist first began working on their composition by tracing fingerprints, brushstrokes and analyzing different layers of paint pigments. These elements, once fully uncovered, sometimes reveal completely different works of art underneath the surface that were abandoned by these great artists and painted over. To help answer the question of why their works were abandoned, Out of the Shadows<> focuses on a group of scholars, the renowned Dr. Ernst Van De Wetering and Joris Dik who have recently been able to digitally restore lost images under existing masterpeices. The group's attention is drawn to two paintings, in particular, that were once dismissed as being mere copies of Rembrandt and which have recently been attributed as authentic. Out of the Shadows explores just how closely science allows art historians to enter an artist's psyche. The question of why an artist would choose to paint over their own masterpiece is explored in this fascinating documentary that ultimately rewrites the foundations of art history.

  228. NSLS-II Seminar

    "X6A Workbench: Hands-on Synchrotron Structural Biology"

    Tuesday, March 27, 2012, 9 am
    Conference Room C, Bldg. 725

    Hosted by: Vivian Stojanoff

  229. National Synchrotron Light Source Seminar

    "The Status of SSRF and its User Experiments"

    Presented by Jianhua He, Shanghai Synchrotron Radiation Facility, China

    Monday, March 26, 2012, 9:30 am
    Seminar Room, Bldg. 725

    Hosted by: Qun Shen

  230. National Synchrotron Light Source Seminar

    "The SSRF Phase II Project"

    Presented by Tiqiao Xiao, Shanghai Synchrotron Radiation Facility, China

    Monday, March 26, 2012, 9:30 am
    Seminar Room, Bldg. 725

  231. NSLS-II Seminar

    "X-ray Nanovision"

    Presented by Oleg Shpyrko, University of California, San Diego

    Friday, March 23, 2012, 1:30 pm
    Stony Brook Physics Building, Room B131

    Hosted by: Peter W. Stephens

    Attempts to produce focusing x-ray optics date back to the days of Roentgen, however, it was not until the past decade that X-ray Microscopy has finally been able to achieve sub-100 nm resolution. We have used X-ray micro-diffraction in combination with X-ray Photon Correlation Spectroscopy to investigate slow relaxation dynamics of Charge Density Wave domains in antiferromagnetic chromium and TaS2. I will discuss similarities between dynamics in these charge- and spin-ordered condensates and dynamics in soft jammed materials. I will also introduce a novel x-ray microscopy technique developed in our group, which relies on coherent properties of x-ray beams, and eliminates the need for focusing optics altogether, replacing it with a computational algorithm. We have applied this Coherent X-ray Diffractive Imaging technique to image magnetic stripe domains in GdFe multilayer films, as well as to image the distribution of lattice strain and ferroelectic polarization in thin films, devices and nanostructures. I will discuss applications of these novel x-ray imaging methods in context of new generation of fully coherent x-ray sources.

  232. National Synchrotron Light Source Lunch Time Seminar

    "Magnetic Field Induced Color Change in a-Fe203 Single Crystals"

    Presented by Jan Musfeldt, Department of Chemistry, University of Tennessee Knoxville, TN

    Friday, March 23, 2012, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

    We investigated the magneto-optical properties of a-Fe203 in order to understand the interplay between charge and magnetism in a model transition metal oxide. We discovered that hematite appears more red in applied magnetic field than in zero field conditions, an effect that is amplified by the presence of the spin flop transition. Analysis of the exciton pattern on the edge of the d-d color band reveals C2/c monoclinic symmetry in the high field phase. These findings advance our understanding of magnetoelectric coupling away from the static limit and motivate spectroscopic work on other iron-based materials under extreme conditions.

  233. NSLS-II Seminar

    "Time-Resolved X-ray Studies of the Layer-by-Layer Growth Mode of Complex-Oxide Thin-Films During Pulsed Laser Deposition - Joint Photon Sciences Institute Seminar Series"

    Presented by Joel Brock, Cornell University

    Wednesday, March 21, 2012, 4 pm
    Stony Brook University Physics Building room S240

    Hosted by: Peter Stephens

    Performing simultaneous X-Ray Reflectivity and Diffuse X-ray Scattering measurements during the deposition process, we measure the time-dependent thickness, coverage, and in-plane structure of films in the layer-by-layer growth mode. These rich data sets enable us to extract both the intra-layer and the inter-layer kinetics. Our results on the SrTiO3/SrTiO3 〈001〉 homo-epitaxial system explicitly limit the possible role of island breakup, demonstrate the key roles played by nucleation and coarsening in Pulsed Laser Deposition, and place an upper bound on the Ehrlich-Schwoebel barrier. Using EuTiO3 and LaAlO3 on SrTiO3 〈001〉 as a model hetero-epitaxial systems, we demonstrate that the relaxation mechanism varies with both layer number and with thin-film material.

  234. NSLS-II Seminar

    "NSLS-II Injection System Pulsed Magnets."

    Presented by Eric Blum

    Wednesday, March 21, 2012, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Dick Hseuh

    Following a brief review of the major features of NSLS-II injection, the talk will examine the pulsed magnets used for injection. The design and current state of the booster pulsed magnets will be examined. This will be followed by a description of the storage ring injection septum, now beginning construction at Danfysik. The major emphasis of the talk will be the storage ring kicker magnets which are under construction by NSLS-II staff.

  235. National Synchrotron Light Source Seminar

    "Metal oxide solar water oxidation photoanodes and their characterization by soft X-ray"

    Presented by Coleman Kronawitter, Department of Mechanical Engineering, University of California at Berkeley

    Monday, March 19, 2012, 9:30 am
    Seminar Room, Bldg. 725

    The use of metal oxide films, nanomaterials, and heterostructures in photoanodes enabling the solar-driven oxidation of water and generation of hydrogen fuel (solar water splitting) is examined. A range of transition- and post-transition-metal oxide material systems and nanoscale architectures is discussed in order to provide an overview of the field and recent results from the authors’ laboratories. Electrode structures examined include thin films, nanorod arrays, and heterostructures comprised of oxides such as -Fe2O3, ZnO, TiO2, and SnO2. The electronic structures of key oxide-oxide interfaces, relevant to the operation of efficient photoanodes, are examined using soft X-ray spectroscopy. These studies indicate that the interfacial regions of electrodes possess distinct electronic structures, which deviate in terms of orbital character and occupancy from those of their constituent bulk oxides. These observations can inform methodology to address certain operational deficiencies associated with the use of metal oxides for solar energy conversion applications.

  236. National Synchrotron Light Source Lunch Time Seminar

    "How Inelastic X-ray Scattering Can Be Used To Unveil The Mysterious Dynamic Behavior Of Water"

    Presented by Alessandro Cunsolo, BNL/NSLS-II

    Friday, March 16, 2012, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Yong Cai

    Nearly two decades of thorough Inelastic X Ray Scattering (IXS) investigations on water will be reviewed. They evidenced an extremely reach phenomenology, which has been in the focus of a lively debate: from the so called “fast sound” phenomenon, revealing the presence of a structural relaxation, to the evidence of propagating shear waves. It will be shown how these effects are intimately related to the existence of a hydrogen bond network. Finally, the new scenarios opened up by the development of next-generation IXS spectrometers will be outlined.

  237. NSLS-II Seminar

    ""From Thermoelectrics and Iron-Based Superconductivity to Insertion Devices""

    Presented by Ivo Dimitrov

    Wednesday, March 14, 2012, 9 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Toshi Tanabe

    Brookhaven National Laboratory is at the frontiers of physics, materials research and light source development. The search for novel materials, especially when they hold the promise for energy harvest and/or storage presents a host of scientific and technological challenges. My talk will focus on (i) thermoelectric materials development at BNL with an emphasis on inelastic time-of-flight studies of Einstein modes in filled skutterudites, (ii) high magnetic field studies of iron-based superconducting thin films, and (iii) Radia-based simulation and optimization routine of a versatile Superconducting Magnetic Energy Storage (SMES) device, based on realistic superconducting materials’ properties. Prospects for future development will be presented.

  238. NSLS-II Seminar

    "X-ray Imaging in Real Life"

    Presented by Chris Jacobsen, Argonne National Lab / Northwestern University

    Tuesday, March 13, 2012, 4 pm
    Stony Brook Physics and Astronomy Colloquium, Harr

    Hosted by: Peter Stephens

    Hierarchical structures fill our body, our planet, and our devices. X-rays provide a unique tool to image this hierarchy: they can penetrate into real materials and environments, they can reveal trace elements, and they can measure chemical states and crystalline lattice rearrangements. There are interesting problems over many time and length scales, ranging from watching explosives at work to understanding the dynamics of zinc in oocyte fertilization. Future directions in nanoscale imaging look towards complexity: that of a material's environment, and that of the data, so that one can learn from x-ray imaging in real life.

  239. NSLS-II Seminar

    "Ancient Materials and Artworks Illuminated by Synchrotron Light - Worlds of Physics Seminar Series"

    Presented by Eric Dooryhee, Photon Sciences Directorate, BNL

    Friday, March 9, 2012, 7:30 pm
    Stony Brook University, Earth and Space Sciences R

    Hosted by: Peter Stephens

    Over the past 10 years, Eric Dooryhee has been using Synchrotron Radiation Diffraction (SRD) to examine ancient objects and artifacts from the Louvre museum collections. Nowadays he is concerned with SRD's future frontiers as group leader for the x-ray powder diffraction beamline at what will be the most advanced synchrotron light source in the world, NSLS-II at Brookhaven Lab. Dooryhee is a physicist who has specialized in powder diffraction at most of the research facilities where he has worked. These include the Synchrotron Radiation Source at Daresbury, UK; the Interdisciplinary Research Center with Ions and Lasers in Caen, France; the European Synchrotron Radiation Facility in Grenoble, France; and the Neel Institute, also in Grenoble. He has a master's degree in hard condensed matter physics and crystallography, and a Ph.D. in radiation physics, both from the University of Paris. Subsequently, Dooryhee's work has included studies on a range of artifacts: cosmetic products, ancient ceramics and fresco paintings of the Mediterranean from the Greco-Roman times, gilded medieval Islamic glazed ceramics and easel paintings of the Renaissance. More recently, he did more diffraction and spectroscopic work on the Maya Blue pigment, renowned for its remarkable resistance in the forests of Meso-America for the last centuries. Since 2005, Dooryhee has run a series of international conferences called SR2A, for Synchrotron Radiation in Art and Archaeology.

  240. National Synchrotron Light Source Seminar

    "The magnetic and chemical structural property of the epitaxially-grown multilayered thin film"

    Presented by Hwachol Lee, Department of Physics, MINT Center, The University of Alabama, Tuscaloosa, USA

    Friday, March 9, 2012, 10 am
    Conference Room A, Bldg. 725

    The magnetic materials such as L10 FePt and B2 FeRh have been of great concern and studied intensively due to the high magnetocrystalline anisotropy and magnetic phase transition property. Modification of the magnetic material property by 3rd element provides more potential and flexibility in search of the novel phenomena, or in the future application. In this work, the epitaxially-grown Rh-doped FePt and Pd-doped FeRh multilayered thin films are studied for the structural and magnetic properties. For FePtRh, the compositionally-modulated L10 FePtRh superlattice structure shows the well-defined interface between layers and magnetic structure in spite of the compositional, structural similarity and high growth temperature. For Pd-doped FeRh, the magnetically and structurally correlated features are revealed in the Fe46Rh48Pd6 epitaxial thin films prepared in the 111-orientational growth mode. Additionally, the property of Rh seed layer on sapphire will be discussed.

  241. NSLS-II Seminar

    "New Ideas for Radiation Therapy Based on Synchrotron Radiation - Joint Photon Sciences Institute Seminar Series"

    Presented by Avraham Dilmanian, Medical Department, BNL, and Departments of Radiation Oncology and Neurology, SUNY Stony Brook

    Wednesday, March 7, 2012, 4 pm
    Stony Brook University, Physics building room S240

    Hosted by: Peter Stephens

    It was shown in the early 1990s at the X17B1 superconducting wiggler beamline of the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory that array of parallel, thin (25 to 90-μm thick) planes of synchrotron x rays (called microbeams) are tolerated by normal tissues in rats at up to very high doses (Slatkin et al., PNAS 1995). Within the next ten years the effect was confirmed in several other animal models both at the NSLS and at the European Synchrotron Radiation Facility (ESRF). In the mid 2000s it was shown at the NSLS that a) arrays of microbeams as thick as 680 μm (called minibeams) still retain much of their tissue-sparing effect, and b) two arrays of parallel, horizontal minibeams aimed at the target from 90º angles can be “interleaved” to produce a solid radiation field at the target (Dilmanian et al, PNAS 2006). I will present our a) interleaved x-ray minibeam studies that successfully treated a high-grade glioma rat brain tumor model, and b) application of arrays of vertical microbeams to treat a model of rat spinal cord contusion injury.

  242. NSLS-II Seminar

    "Beam instrumentation for SuperKEKB Accelerators"

    Presented by Makoto Tobiyama, High Energy Accelerator Research Organization, KEK, Japan

    Tuesday, March 6, 2012, 11 am
    Building 817, Conf Rm 71

    Hosted by: Sam Krinsky

    Present status of the development of the beam instrumentation systems for SuperKEKB accelerators will be shown. The recovery status of the KEK accelerators from the earthquake on 11/Mar will also be shown.

  243. National Synchrotron Light Source Seminar

    "Title: Structure-Property Relationships in Perovskite Oxide Thin Films"

    Presented by George Sterbinsky, National Institute of Standards and Technology

    Tuesday, March 6, 2012, 9:30 am
    Seminar Room, Bldg. 725

    In thin films, the biaxial strain imposed by heteroepitaxial growth can cause the appearance of novel properties wholly different from those of the bulk material. Two interesting examples are lanthanum cobaltite (LaCoO3) and europium titanate (EuTiO3). In bulk form, LaCoO3 has a non-magnetic ground state. When synthesized as a thin film, the ground state of LaCoO3 becomes ferromagnetic with a Curie temperature near 85 K. EuTiO3 is a paraelectric-antiferromagnet that becomes a ferroelectric-ferromagnet under biaxial tensile strain. In order to examine the origins of these phenomena, we have examined the atomic and electronic structures of epitaxial LaCoO3 and EuTiO3 thin films using x-ray absorption fine structure (XAFS) spectroscopy and x-ray diffraction (XRD). Highly strained LaCoO3 deposited on SrTiO3 has a pseudomonoclinic structure with a large difference between in-plane and out-of-plane Co-O bond lengths, which strongly affects the Co-O orbital hybridization in the material. However, increased hybridization is not the cause of ferromagnetism in LaCoO3. Instead, strain induced distortions of the oxygen octahedra increase the population of unpaired spins beyond a stabilization threshold for ferromagnetic order. In EuTiO3 films deposited on DyScO3, a strong coupling between ordering of the oxygen octahedral rotations and the orientation of the ferroelectric polarization is observed.

  244. National Synchrotron Light Source Lunch Time Seminar

    "Structural Basis of MAP Kinase Regulation"

    Presented by Prof. WolfganG Peti, Brown University, Department of Chemistry

    Friday, March 2, 2012, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Marc Allaire

  245. National Synchrotron Light Source Seminar

    "The making of next generation of MX beamlines at NSLS-II"

    Presented by Dieter Schneider, Brookhaven National Laboratory

    Friday, March 2, 2012, 9:30 am
    Seminar Room, Bldg. 725

    The continuing success of structural biologists in deriving structure and function of increasingly complex macromolecular assemblies drives the continuing development of their primary experimental tool: the MX beamline at the synchrotron. Increasingly smaller, more perfect and more readily available crystals demand a high performance micro-focusing beamline, and the increasing size of molecular assemblies under study requires an intense mini-beam line. The ongoing integration of crystallographic methods into a biologist’s standard toolkit spurs the development of more complete automation of the diffraction experiment and structure solving methods. This talk will measure our plans for the new AMX and FMX beamlines at NSLS-II in this context and offer an occasional look back at their predecessors at NSLS.

  246. National Synchrotron Light Source Lunch Time Seminar

    "Effects of Fluoride Treatment on the Chemical, Mechanical and Structural Properties of Bone"

    Presented by Alvin Acerbo, Photon Sciences

    Friday, February 24, 2012, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  247. National Synchrotron Light Source Lunch Time Seminar

    "The "Soda-stone" Alchemists: Re-defining Zeolite Natrolite at PTX Space"

    Presented by Yongjae Lee, Department of Earth System Sciences, Yonsei University, Korea

    Friday, February 17, 2012, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

    While an ever-expanding variety of zeolites with a wide range of framework topology is available, it is desirable to have a way to tailor the chemistry of the zeolitic nanopores for a given framework topology via controlling both the coordination-inclusion chemistry and framework distortion/relaxation. This is, however, subjected to the ability of a zeolitic nanopore to allow the redistribution of cations-water assembly and/or insertion of foreign molecules into the pores and channels. Small-pore zeolites such as natrolite (Na16Al16Si24O80x16H2O), however, have been known to show very limited capacity for any changes in the confinement chemistry. We have recently shown that various cation-exchanged natrolites can be prepared under modest conditions from natural sodium natrolite and exhibit cation-radius/temperature-dependent volume expansions/contractions by up to 18.8% via converting the channel ellipticity. Here, we show that pressure can be used as a unique and clean tool to further manipulate the chemistry and geometry of the natrolite nanopores. Our recent crystallographic and spectroscopic studies of pressure-insertion of foreign molecules, trivalent-cation exchange under pressure, and pressure-induced inversion of cation-water coordination and channel geometry in various cation-exchanged natrolites will be presented. This work was supported by Global Research Laboratory Program of the Korean Ministry of Education, Science, and Technology.

  248. National Synchrotron Light Source Seminar

    "Development and experimental study of all-solid-state mediator supercapacitor"

    Presented by Juanjuan Zhou, University of Miami

    Tuesday, February 14, 2012, 10 am
    Seminar Room, Bldg. 725

    Supercapacitors (SCs) are energy storage devices with much higher specific power, much longer cycle-life, much greater charge/discharge rate, but lower specific energy than rechargeable batteries. It is desired to develop all-solid-state supercapacitors that are compact, light-weighted, flexible, environmentally benign, and suitable for use in a wide temperature range with a comparable specific energy to rechargeable batteries. However, conventional all-solid-state supercapacitors suffer from both very low specific power and energy mainly due to very limited access of ions to active sites and low conductivity of polymer electrolytes. This presentation describes a new type of supercapacitors, mediator supercapacitors. Introducing and dispersing mediator molecules into polymer electrolytes enable the ultimate accessibility of the ions in polymer electrolytes to the active sites of the active material, mediators, and greatly enhance charge transport in polymer electrolytes. Two series of all-solid-state mediator supercapacitors have been developed: one is based on Nafion separator and the other one is based on polyvinylidene fluoride (PVDF)/LiCF3SO3 separator. Both provide much greater specific power and energy than those for other solid-state electrolyte supercapacitors and greater than those for conventional liquid electrolyte supercapacitors. SEM/EDS, FTIR, XRD, and in situ XAS measurements using the BNL facility were conducted to characterize the physicochemical states of mediators in the electrodes and to elucidate the mechanisms of charge/discharge, ionic conduction, and cycle stability. In situ XAS demonstrate that the charge/discharge cycle correlate with the oxidation/reduction of the mediators and the majority of the charge capacity is provided by the mediators as the receivers or donors of electrons. As the sideline of this presentation, new developments and findings of atomistic simulation of polymer electrolyte/electrode interfaces and in situ electrochem

  249. National Synchrotron Light Source Seminar

    "Nanostructured Electrodes for High-performance Electrochemical Capacitors"

    Presented by Qi Lu, University of Delaware

    Friday, February 10, 2012, 10 am
    Building 703, Large Conference Room

    Despite significant progresses in the development for high-performance supercapacitors, it lacks techniques to realize the full potential of electrode material by achieving simultaneously tailored pore structure, electrode conductivity, and crystallinity. Moreover, the problem of being difficult for industrial scale manufacture still exists. For an attempt to address all these issues, we recently have developed a simple and cost-effective process, which is also scalable, for achieving supercapacitor electrodes with both high energy and power densities. The process starts with the production of nickel nanoparticles with a modified polyol method. A simple mechanical compaction of nanoparticles and a followed thermal treatment result in compact, stable, highly porous Ni/NiO electrodes that do not require a support. During the charging process, OH- electrolytic ions are bound to the NiO, giving off electrons. The process is reversed when the stored electrical energy is drawn off as current. The high granularity NiO provides a large inner surface area, and the conductive network of the metal particles is maintained. High energy density of about 60 Wh kg-1 and power density of 10 kW kg-1 were simultaneous achieved with a slow charge/fast discharge process.

  250. NSLS-II Seminar

    "Organic Devices: Insights Provided by Soft X-ray Characterization Methods"

    Presented by Harald Ade, North Carolina State University

    Wednesday, February 8, 2012, 4 pm
    Stony Brook University, Physics, S240 Room

    Hosted by: Peter Stephens,

    Conjugated, semi-conducting polymers have tremendous potential for use in cheap, flexible, light weight devices and have been widely studied in thin film transistors (TFTs), light emitting diodes (LEDs), and photovoltaics (OPVs). Such devices offer the potential to create cheap energy, consume less energy, or be simply cheaper and more practical. Despite great empirical advances during the recent past and a rapidly growing research community, fundamental understanding of device function is still lacking in many instances. The relationship, for example, between structure, processing, and device performance is still unclear in poly(2,5-bis(3-tetradecyllthiophen-2-yl)thieno[3,2-b]thiophene) (pBTTT) based TFT devices. Recent work at the Advanced Light Source has for the first time uncovered a fundamental relationship between the length-scale of the correlation of the polymer backbone orientation as measured with resonant scattering and the saturation mobility. I will discuss these results and a number of other important issues in organic devices that could be resolved. I furthermore delineate important questions that are raised by the soft x-ray experiments. The examples discussed exemplify the importance of the mesoscale structure, i.e. how the nano-scale is connected to the “real world”. The advanced characterization capabilities anticipated to be available at NSLS-II should further accelerate progress and understanding in this rapidly growing field.

  251. Photon Sciences Directorate Talk Announcement

    "Visit of ISP System to BNL"

    Presented by Gerard Guillemin, ISP Systems, USA/France

    Monday, February 6, 2012, 9 am
    Bldg. 817, Conference Room 4

    Hosted by: Andy Broadbent

  252. National Synchrotron Light Source Lunch Time Seminar

    "In Vitro Assessment of the Cellular Toxicity of Nanostructures"

    Presented by Lenke Horváth, Ecole Polytechnique Fédérale de Lausanne and University of Fribourg, Switzerland

    Friday, February 3, 2012, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

    A major contribution to nanotechnology is the controlled synthesis of a large variety of nanomaterials, the basis of future applications. Within the last decades we have seen the rapid development of nanotubes and nanowires, like TiO2 nanofilaments, boron nitride nanotubes (BNNTs), zinc-oxide nanowires and especially that of carbon nanotubes (CNTs). Recently, another family of carbon-based compounds, graphene and its derivatives have received worldwide attention due to its particular electrical, thermal, optical, and mechanical properties. All these structures are very promising for applications and there is a forecasted expansion of their manufacturing which makes likely that human and environmental exposure will exponentially increase in the near future. As a result, there is a growing worry related to their possible health hazards, as some of them strongly resemble to asbestos. We have studied the toxic effect of CNTs, TiO2, BNNTs and graphene oxide by assessing cell proliferation on several cell-lines and the modification of their metabolism and their morphology. We tried to unravel the role of local catalytic activity, the importance of structural defects, functional groups and the tortuosity of these nanostructures in their alteration of cell proliferation. Acknowledgement. The study was performed in close collaboration with Beat Schwaller, Arnaud Magrez and László Forró.

  253. National Synchrotron Light Source II seminar

    "PLS-II Storage Ring Vacuum Commissioning Status"

    Presented by Taekyun Ha and Chongdo Park, Pohang Accelerator Laboratory, Korea

    Friday, February 3, 2012, 9:30 am
    Building 902, Training Room #1

    Hosted by: Hsiao-Chaun Hseuh

    Pohang Light Source upgraded machine (PLS-II) has been on commissioning stage since installation completed on June 2011. PLS-II storage ring vacuum system is designed to maintain pressure of low 10-9 torr for the beam-gas scattering lifetime to be longer than 20 hours, and the vacuum components, especially photon absorbers are designed to endure 3 GeV and 400 mA beam operation of PLS-II. In this talk, the present commissioning status of PLS-II storage ring vacuum will be introduced.

  254. National Synchrotron Light Source Seminar

    "Design of Resilient Silicon-Carbon Nanocomposite Anodes"

    Presented by Benjamin Hertzberg, Georgia Institute of Technology

    Tuesday, January 31, 2012, 9:30 am
    Seminar Room, Bldg. 725

    Si-based anodes have recently received considerable attention for use in Li-ion batteries, due to their extremely high specific capacity – an order of magnitude beyond that offered by conventional graphite anode materials. However, during the lithiation process, Si-based anodes undergo extreme increases in volume, potentially by more than 300 %. The stresses produced within the electrode by these volume changes can damage the electrode binder, the active Si particles and the solid electrolyte interphase (SEI), causing the electrode to rapidly fail and lose capacity. These problems can be overcome by producing new anode materials incorporating both Si and C, which may offer a favorable combination of the best properties of both materials, and which can be designed with internal porosity, thereby buffering the high strains produced during battery charge and discharge with minimal overall volume changes. However, in order to develop useful anode materials, we must gain a thorough understanding of the structural, microstructural and chemical changes occurring within the electrode during the lithiation and delithiation process, and we must develop new processes for synthesizing composite anode particles which can survive the extreme strains produced during lithium intercalation of Si and exhibit no volume changes in spite of the volume changes in Si. In this work we have developed several novel synthesis processes for producing internally porous Si-C nanocomposite anode materials for Li-ion batteries. These nanocomposites possess excellent specific capacity, Coulombic efficiency, cycle lifetime, and rate capability. We have also investigated the influence of a range of different parameters on the electrochemical performance of these materials, including pore size and shape, carbon and silicon film thickness and microstructure, and binder chemistry.

  255. NSLS-II Seminar

    "Zeeko Corrective Polishing and Smoothing Processes with Illustrations of their use in “Large Science Projects”"

    Presented by Richard Freeman, ZEEKO Ltd

    Monday, January 30, 2012, 11 am
    Bldg. 703 Large Conference Room

    Hosted by: Mourad Idir

    The talk will present the background and development of the Zeeko “Precessions” corrective polishing process with details the principles of the process and of the way that its universal toolkit and supporting software can be used to develop polishing solutions for many essential but complex optics. Examples of artefacts processed in this way will be shown as will the details and development of on machine (and off machine) metrology that has been developed for the control of these surfaces. Specifically included will be the techniques used and the results obtained on the following key projects: 1. E-ELT (the European Extremely Large Telescope) and TMT (the US Thirty Meter Telescope) 2. The production of X-Ray Telescope Mandrels for the Japanese NeXt telescope and the European e-Rosita telescope 3. The direct polishing of an experimental glass shell for WFXT (Wide Field of View X-Ray Telescope) 4. Supporting Metrology and details of our polishing partner for making Synchrotron mirrors

  256. National Synchrotron Light Source Seminar

    "Accelerator based x-ray sources: Beyond the Optical Microscope"

    Presented by Jerome Hastings, SLAC National Accelerator Lab

    Monday, January 23, 2012, 10 am
    Seminar Room, Bldg. 725

    Hosted by: David Siddons

    The x-ray science community has enjoyed the exponential growth of sources and instruments that has developed over the past 30 plus years. As we look forward the challenges for the x-ray community are to justify billion dollar investments. The potentials and possibilities will be discussed from a perspective of imaging compared with optical microscopes. The presentation is a personal view.

  257. National Synchrotron Light Source Seminar

    "Processing of Polymer Thin Films Using Supercritical Carbon Dioxide"

    Presented by Peter Gin, Stony Brook University

    Friday, January 20, 2012, 10:30 am
    Large Conference Room, Building 703

    Tremendous amounts of research are currently in place to investigate alternatives to energy inefficient and environmentally harmful operations. One such novel route in the polymer industry is the utilization of supercritical carbon dioxide (scCO2) as a “green” solvent for polymer processes. Unfortunately, because of its chemically inert nature, few long-chained molecules are soluble in CO2, limiting its potential to be a vital industrial processing tool. However, we recently found that under a specific set of temperature and pressure conditions near the critical point (Tc = 31.3 °C and Pc =7.38), known as the density fluctuation ridge, anomalous adsorption of the molecules occurred in polymer thin films. In this talk, I would like to show that by exploiting this unique trait, density fluctuating scCO2 could be utilized as a valid polymer processing tool, and towards the fabrication of advanced materials: 1) low density polymer thin films with molecular scale porosity used for low-dielectric applications 2) polymer thin films with enhanced crystallinity 3) well-ordered block copolymer thin films with controllable orientations. Such advances can eventually play a key role in the transformation of industrial operations to meet evolving environmental standards.

  258. National Synchrotron Light Source Seminar

    "Developments at the GM/CA CAT beamlines at the APS"

    Presented by Craig Ogata, Argonne National Laboratory

    Wednesday, January 11, 2012, 9:30 am
    Seminar Room, Bldg. 725

    GM/CA CAT has continued to take advantage of the development of tools that enhance the capabilities of its mini-beam collimators and development of a focused one micron beam. These tools are rolled into the JBluIce Graphical User interface. It provides a convenient user-friendly interface that provides intuitive controls to search for crystals or the best regions in larger crystals, an automated procedure to move along a defined 3-dimensional vector to collect data, a strategy protocol for collecting data, and continued improvement in sample mounting automation and remote operations. A current status report and examples of applications will be presented.

  259. National Synchrotron Light Source Seminar

    "Measurements of solid oxide fuel cell electrode microstructure and correlation with electrochemical performance and degradation"

    Presented by Scott Barnett, Northwestern University

    Monday, January 9, 2012, 11 am
    Seminar Room, Bldg. 725

    Hosted by: Jun Wang

    Quantitative analysis of solid oxide fuel cell (SOFC) electrode microstructure is a key element in connecting materials processing with microstructure and electrode performance, as well as understanding degradation mechanisms. This paper will describe the application of focused ion beam – scanning electron microscopy (FIB-SEM) for analyzing electrodes using both two-dimensional images and three-dimensional image reconstruction. The analysis yields a number of structural parameters needed for use in electrochemical models, including solid and pore volume fractions, interface areas, three-phase boundary lengths, connectivities, and tortuosities. The discussion will focus on the widely-used SOFC electrodes Ni-YSZ and LSM-YSZ (YSZ = Y-stabilized Zirconia; LSM = (La,Sr)MnO3). The effect of varying the volume fractions of the electronically-conducting and ionically-conducting phases will be described. Effects of varying the firing temperature of LSM-YSZ will be described. Initial results on the time evolution of Ni-YSZ structure will be discussed.

  260. National Synchrotron Light Source Seminar

    "Probing the structure of membranes and membrane proteins using X-ray scattering"

    Presented by Lin Yang, Brookhaven National Laboratory

    Thursday, December 22, 2011, 9:30 am
    Seminar Room, Bldg. 725

    Structure determination of membrane proteins is one of the challenges in structural biology. While X-ray crystallography remains the workhorse technique in these efforts, innovative use of X-ray scattering could provide complementary information to help elucidate the structures and function of these proteins. I will summarize the scientific results and technical developments in past studies of membrane fusion and pore-forming peptides utilizing substrate-supported multi-layered lipid membranes. I will then describe the recent progress using substrate-supported single-bilayers, which promise a more versatile platform for structural biologists to explore the structure of membrane proteins in near native environments, and how they interact with each other and with the lipid membrane. Expected advances with the advent of the new beamlines at NSLS-II will also be discussed.

  261. National Synchrotron Light Source Seminar

    ""Two rings for folding: crystal structure of the mammalian chaperonin CCT in complex with tubulin""

    Presented by Ines Munoz, Spanish National Cancer Research Centre (CNIO), Madrid, Spain

    Friday, December 16, 2011, 11 am
    Seminar Room, Bldg. 725

    Hosted by: Vivian Stojanoff

  262. National Synchrotron Light Source Lunch Time Seminar

    Presented by Dmytro Nykypanchuk, BNL / CFN

    Friday, December 9, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  263. National Synchrotron Light Source Seminar

    "High resolution soft-RIXS: scientific results and technical challenges"

    Presented by Giacomo Ghiringhelli, Visiting scholar at SIMES-Dept. of Physics, Stanford University

    Wednesday, December 7, 2011, 2 pm
    Seminar Room, Bldg. 725

    Hosted by: John Hill

  264. NSLS-II Seminar

    "Overview of Magnetic Measurement Activities at the Sincrotrone Trieste"

    Presented by Marco Musardo, Sincrotrone Trieste, Basovizza, Italy

    Friday, December 2, 2011, 9 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Toshi Tanabe

    An overview of recent magnetic measurement activities performed on insertion devices at Sincrotrone Trieste is presented. This includes the magnetic characterization of an APPLEII Undulator Prototype, developed in order to test different field optimization methods, and the results of the final Undulators and Phase Shifters for FERMI@Elettra, a Free Electron Laser facility in the extreme ultra-violet and soft X-rays. The main results obtained so far will be described together with the techniques and instruments used for measuring the above devices.

  265. National Synchrotron Light Source Seminar

    "Creating a strong synchrotron program in Macromolecular Crystallography"

    Presented by Robert Sweet, Brookhaven National Laboratory, Biology Department

    Thursday, November 17, 2011, 9:30 am
    Seminar Room, Bldg. 725

    Knowledge of molecular structure is the cornerstone of life science, and macromolecular crystallography -- MX -- is the gold standard for structure determination. 74% of the 70,000 Protein Data Bank deposits depended on MX diffraction data measured at a synchrotron. And seven recent Nobel Prize winners in Chemistry required readily available synchrotron x-rays for their research. Three of them used X25. Right now one third of all NSLS users come here to do MX measurements, and NSLS beamline X29 is the second most effective in the world in the production of PDB depositions. To accomplish this wasn't easy. In this lecture I'll take you back to the early days when we used x-ray film and had no cryogenics, will tell you how we created the present system, and will describe what we have in mind for NSLS-II.

  266. Photon Sciences Town Meeting

    Thursday, November 10, 2011, 1 pm
    Seminar Room, Bldg. 725

  267. National Synchrotron Light Source Seminar

    "Challenges in MX beamline design and implementation"

    Presented by Julian Adams, FMB Oxford Beamlines Ltd

    Thursday, November 10, 2011, 9:30 am
    Seminar Room, Bldg. 725

    The design, construction, integration, commissioning and user operation of the current generation of highly automated; remotely operated MX beamlines holds many challenges. All the aspects of hardware and software integration must be of the highest specification and quality to achieve stable user operations with low levels of intervention from operations staff with high reliability. I will describe the many successes and few less successful aspects of the implementation of the two MX beamlines at the Australian Synchrotron from 2005 till 2009. I will then look at advances in the state of the art in beamline diagnostics and detectors as well as new ideas in software automation and integration. These will bring to the next generation of beamlines higher levels of automation and improve the stability of the beamline. This will enhance the user experience and result in higher quality data with less lost time.

  268. National Synchrotron Light Source Seminar

    "Protein folding and Stability Distinguishing folded from unfolded state effects"

    Presented by Shifeng Xiao, Stony Brook University, Dept. of Chemistry

    Tuesday, November 8, 2011, 10 am
    Conference Room A, Bldg. 725

    The interactions which stabilize the native state and control the folding of the villin headpiece subdomain (HP36) are examined. HP36 is an extremely popular model for computational and experimental studies because of its small size, simple three-helix topology and very fast folding. Proline-aromatic interactions involving P62 and W64 have been proposed to play a critical role in specifying the subdomain fold by acting as gatekeeper residues, i.e. as residues absolutely essential for specifying the fold. Using a stable variant of HP36 as the new background we show that proline-aromatic interactions are not required for specifying the subdomain fold. This work is important because it argues against the concept of specific gatekeeper residues. To probe denatured state ensemble (DSE) electrostatic interactions, the pH dependent stability of wildtype HP36 and two mutants, K48M and K70M, both of which significantly increase the stability of the protein were examined. The increased stability of the K48M mutant is due to the removal of favorable electrostatic interactions in the DSE, while the increased stability of the K70M mutant is due to the introduction of a new hydrophobic interaction between the methionine and the hydrophobic core in the native state. The results demonstrate that electrostatic as well as hydrophobic interactions can play an important role in the DSE, and illustrate an approach for distinguishing native state effects from DSE effects. This work also has interesting implications for studies which attempt to stabilize proteins by targeting surface electrostatics since it shows the mechanism of stabilization may be much more complicated than anticipated.

  269. National Synchrotron Light Source Lunch Time Seminar

    "Growth Mechanisms and Electronic Properties of Epitaxial Graphene"

    Presented by Graham Creeth, University of Leeds, United Kingdom

    Friday, November 4, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

    Epitaxial growth on SiC is a candidate for exploiting graphene's extraordinary properties in technological applications [1]. Growth is achieved by annealing at temperatures above 1200 C, causing Si to evaporate from the SiC preferentially to C; the resulting carbon-rich surface forms a graphitic layer with the structural and electronic properties extremely sensitive to annealing conditions [2]. We present electronic transport and low energy electron microscopy (LEEM) data for (0001) 4H SiC samples annealed under UHV at various temperatures. The evolution of coherent electronic transport occurs for samples annealed at higher temperatures, as the size of individual graphene domains increases from tens of nm to several microns. Using a two-stage annealing protocol, we show that the larger grain size is due to a coalescence mechanism, as opposed to faster propagation of single grains. Fitting Magnetotransport (MR) data to weak localisation or weak anti-localisation models [3,4] yields electron scattering rates for various processes, while subtraction of the ts from the measured data allows less dominant contributions to magnetotransport from electron-electron interations and mesoscopic phenomena to be discerned. This work was supported by the EPSRC and Intel Ireland. References [1] C. Berger, Z. Song, T. Li, X. Li, A.Y. Ogbazghi, R. Feng, Z. Dai, A.N. Marchenkov, E.H. Conrad, P.N. First, and W.A. deHeer. [2] Luxmi, N. Srivastava, Guowei He, R. M. Feenstra, and P. J. Fisher. [3] Xiaosong Wu, Xuebin Li, Zhimin Song, Claire Berger, and Walt A. de Heer. [4] E. McCann, K. Kechedzhi, Vladimir I. Fal'ko, H. Suzuura, T. Ando, and B. L. Altshuler.

  270. National Synchrotron Light Source Seminar

    "Small-angle Neutron Scattering Study of Lipid Bilayer and Protein in Solution"

    Presented by Shuo Qian, Oak Ridge National Laboratory

    Monday, October 24, 2011, 10 am
    Seminar Room, Bldg. 725

    Small-angle Neutron Scattering (SANS) has been used to study the structure, function and dynamics of complex biological systems. With the selective deuterium labeling and contrast variation techniques, SANS is capable of distinguishing one component of the complex from the rest of it without changing the structure and function of biomolecules in biological relevant solution condition. This talk will present two recent studies on lipid vesicle bilayer structure and protein structure under crowding conditions, respectively. In the first study, the result shows that two membrane-active peptides alamethicin and melittin induce asymmetric distribution of charged lipids, enriching the outer leaflet of bilayer with negatively charged lipid. It suggests that these peptides may have a secondary stressful effect on target cells at even low concentrations. In the second study, the structure and oligomerization state of green fluorescent protein (GFP) were investigated under crowded conditions created by another protein human serum albumin (HSA). By using perdeuterated GFP and hydrogenated HSA, I am able to probe only the GFP in the solutions by contrast matching HSA with an appropriate D2O/H2O buffer mixture. Analysis of the data indicates that GFP undergoes an HSA concentration-dependent transition that alters the way in which GFP oligomerizes in the solution.

  271. National Synchrotron Light Source Lunch Time Seminar

    "On-Axis Microscope for Sample and X-ray Beam Visualization with 2 um Resolution"

    Presented by Kazimierz Gofron, Brookhaven National Laboratory, NSLS-II

    Friday, October 14, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  272. NSLS-II Seminar

    "Undulator Development and Operation at BESSY II"

    Presented by Johanns Bahrdt, Helmholtz-Zentrum Berlin, Germany

    Monday, October 10, 2011, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Reuben Reininger

    All permanent magnet undulators have been constructed and built at BESSY. The major part of the BESSY user community needs variable polarization and, thus, 6 APPLE II undulators are installed. Furthermore, a 5m long APPLE II undulator has been built at HZB for PETRA III. The device has been installed and characterized with electron beam. The operation of APPLE II undulators in a low electron energy storage ring such as BESSY II requires specific compensation schemes and accurate symplectic tracking schemes are essential. Recently, the undulator development at HZB concentrated on cryogenic permanent magnet undulators. A 20 period 9mm period length PrFeB based hybrid undulator has been built, magnetically characterized at low temperatures and tested with electron beam at MAMI. The results of this prototype are valuable for a 1.5m cryogenic undulator to be built for BESSY II.

  273. National Synchrotron Light Source Seminar

    "Infrared Spectroscopy of Charge Recombination in Superconductors in a Magnet Field"

    Presented by Xiaoxiang Xi, University of Florida

    Monday, October 10, 2011, 10 am
    Seminar Room, Bldg. 725

    In a conventional superconductor, electrons of opposite spin and momentum form pairs and condense to the ground state. When a picosecond laser pulse is used to break the pairs, the relaxation process involves the recombination of two excess quasiparticles and the creation of a phonon. A magnetic field can suppress the pairing by coupling to the electron orbital motion or aligning the spin. Both effects influence the recombination of excess quasiparticles. In this presentation, I will discuss the magnetic-field-induced weakening of superconductivity observed in type-II superconductors by infrared spectroscopy. The consequence on the excess quasiparticle recombination is studied by laser-pump synchrotron-probe time-resolved spectroscopy. We find that a magnetic field significantly reduces the recombination rate. A recombination model is proposed to interpret our experimental findings.

  274. National Synchrotron Light Source Lunch Time Seminar

    "Magnetic order and frustrated spin dynamics on a triangular lattice - the magnetic behaviour of Li(NiCoMn)O2"

    Presented by Dr. Markus Wikberg, Research Scientist, Uppsala University, Uppsala, Sweden

    Friday, October 7, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

    Layered transition metal oxides of α-NaFeO2-type structure have been > of historical interest from both theoretical and experimental > point-of- views. For instance, LiNiO2 was initially predicted as being > the first realization of a spin liquid. Even though a spin liquid > state has not been realized in LiNiO2, the magnetic ground state (in > this and other equi-structural materials) has been controversial and > is currently under considerable investigation. > Interests in Li- > layered compounds have also prompted a tremendous research effort due > to their application in Li-ion batteries. Where one seeks to partially > or in full replace Co in the LiCoO2 cathode with other transition > metal (TM) ions while maintaining the structural stability and > increasing the capacity. The replacement is primarily motivated by > cost and environmental concerns regarding Co. > > The magnetic properties in several compounds of Li(NixCoyMnz)O2 have > been investigated through SQUID magnetometry, neutron diffraction and > muon-SR. > The materials show a ferrimagnetic re-entrant cluster glass behaviour > with spin frustration in both 2 and 3 dimensions. The magnetic > behaviour is believed to originate from the degree of cationic mixing > (Ni2+ in the Li-layer), the TM- distribution, as well as the magnetic > cluster size in the material. > Additionally, a > possible link between low temperature magnetic order and frustration > and cathode performance at room temperature will be presented. > > [1] J. M. Wikberg et al. Physics Procedia, in print (2011) [2] J. M. > Wikberg et al. J. Appl. Phys., 180 083909 (2010) [3] J. M. Wikberg et > al. Phys. Rev. B, 81 224411 (2010) > > > >

  275. National Synchrotron Light Source Lunch Time Seminar

    "Second Order Nonlinear Imaging of Chiral Crystals (SONICC)"

    Presented by Jeremy Stevenson, Formulatrix

    Friday, October 7, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Vivian Stojanoff

  276. NSLS-II Seminar

    "ITT Geospatial Systems & Sydor Instruments Capabilities Briefing"

    Presented by Sydor, Sydor Instruments

    Thursday, October 6, 2011, 9:30 am
    Seminar Room, Bldg. 725

    Hosted by: Andy Broadbent

    ITT Geospatial Systems and Sydor Instruments will present an overview of their company capabilities. Topics to be discussed include x-ray optics, precision structures, detectors, diagnostics, and high resolution imaging systems. Both ITT and Sydor have participated in a number of directed energy programs and critical scientific applications where the highest level of performance is required. Sydor is currently working with BNL to commercialize the HERMES x-ray strip detector and manufactures a portfolio of streak cameras specifically for the synchrotron and accelerator community. ITT is currently working on (amongst other high tech products and projects): Precision Optics solutions for various industries, including aerospace, astronomy, and microlithography. Our world-class facilities are capable of manufacturing and delivering a full range of precision optics and optical systems including: mirrors, mounts and metering structures for ground, sea, air and space-based platforms and systems. Sydor and ITT have formed a joint team to address the critical needs of next generation beam lines and end station instrumentation for NSLS II and programs around the world.

  277. National Synchrotron Light Source Lunch Time Seminar

    "Title: Development of X-Ray Holography Methods for Structure Determination: Application of High Speed Detectors and Novel Numerical Methods"

    Presented by Yuhao Wang, : Department of Physics, New Jersey Institute of Technology

    Friday, September 30, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  278. National Synchrotron Light Source Seminar

    "Water as a solvent: structure and dynamics of simple water solutions."

    Presented by Simone DePanfilis, Museo Storico della Fisica e Centro Studi e Ricerche “E. Fermi”.

    Friday, September 30, 2011, 9:30 am
    Seminar Room, Bldg. 725

    The hydration structure and thermodynamics of simple and complex polar or non-polar entities in water is central to a molecular understanding of many biological and chemical processes, including protein folding and the self-assembly of micelles or membranes. The peculiar interaction of water with solutes stems from the molecular nature of the solvent itself. Thus, to understand the water-induced conformational and behavioural changes in macromolecules, or the water power as solvent of ionic species, one has to study not only the effects of water on the solutes but also the reverse, i.e. the modified behaviour of water in the vicinity of these entities. Within this framework, we carried out several experiments on water solutions of simple molecules that made use of advanced x-ray and neutron techniques. We will present the results of these experimental campaigns and comment on our findings.

  279. National Synchrotron Light Source Seminar

    "Angle‐resolved photoemission using photons from several eV to several keV"

    Presented by Lukasz Plucinski, Peter Gruenberg Institute PGI‐6, Forschungszentrum Juelich

    Tuesday, September 27, 2011, 9:30 am
    Seminar Room, Bldg. 725

    I will present an overview of recent angle‐resolved photoemission (ARPES) studies performed using monochromatized laboratory sources (Xe hv = 8.44 eV and Kr hv = 10.06 eV), non‐monochromatized HeI (hv = 21.22 eV), synchrotron soft x‐ray (20 eV – 1keV, with added spin‐resolved capability), laboratory MgKa (1.26 eV), and synchrotron hard x‐ray (3‐6 keV) radiation. These techniques have been recently applied to several important material systems including W and GaAs single crystals [1, 2], thin films of the topological insulator Bi2Te3 grown on Si(111) [3], LSMO/STO multilayers [4], and thin films of Fe grown on Au(001) and W(001) [5]. Figure 1: High resolution ARPES results from 20 nm thick Bi2Te3/Si(111) films at 15K with HeI hv=21.22 eV radiation [3]. In addition, I will discuss the details and planned upgrades of several photoemission systems which we operate at PGI-6, including a laboratory-based one with extremely low energies using Kr, Xe, Ar, and He radiation [6], and another one, with added spin-polarized capability, based at a soft x-ray synchrotron beamline of DELTA/Dortmund [7].

  280. National Synchrotron Light Source Seminar

    "Ferrofliud-based two-dimensional magnetic nanostructures studied by grazing incidence neutron and x-ray scattering"

    Presented by Alexei Vorobiev, European Synchrotron Radiation Facility, Grenoble, France

    Tuesday, September 27, 2011, 9 am
    CFN, Bldg 735, 2nd Floor Large Seminar Room

    In view of increasing demands for new material with advanced physical properties, which should provide further progress in development of e.g. nano-electronic devices, novel magnetic nanostructures with well controllable parameters are highly requested. On the other hand, magnetic nanostructures are also of interest for fundamental science because they often reveal new physical phenomena having no analogies in bulk materials. We examined possibility to use field- and surface-induced ordering of ferrofluids [1] for production of thin magnetic heterostructures consisting of single-domain nano-units periodically embedded into non-magnetic matrix. Particularly we studied ordering of ferrofluid at the bottom interface with a solid substrate [2], at the top interface with gas [3] and ordering of magnetic nanoparticles in the Langmuir layers. From simultaneous treatment of reflectivity and grazing incidence diffraction data we found that interfacial structures of bulk ferrofluids are essentially inhomogeneous, depend on the liquid carrier and type of the surfactant and can be manipulated by the external magnetic fields. Langmuir technique is described as the most straightforward way to create desired mono- or multilayered systems of laterally ordered magnetic nanoparticles on solid substrates. 1. R. E. Rosensweig, Ferrohydrodynamics (Cambridge University Press, Cambridge, England, 1985). 2. A. Vorobiev, J. Major, H. Dosch, G. Gordeev, and D. Orlova, Phys. Rev. Lett. 93, 267203 (2004). 3. A. Vorobiev, G. Gordeev, O. Konovalov, and D. Orlova, Phys. Rev. E. 79, 031403 (2009).

  281. Photon Sciences 6th IXS BAT Meeting

    Monday, September 26, 2011, 8 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Yong Cai

    The 6th NSLS-II IXS Beamline Advisory Team Meeting Bldg 817, Room 4, Sept 26th, 2011 Participants: BAT members: Clement Burns (WMU) - Chair Alfred Baron (RIKEN/SPring-8), Sow-Hsin Chen (MIT), John Hill (BNL), Michael Krisch (ESRF), Ho-kwang Mao (Carnegie), Tullio Scopigno (Universita’ Roma), Stephen Shapiro (BNL), Yuri Shvyd’ko (APS). NSLS-II members: Qun Shen, Ron Pindak, Andy Broadbent, Yong Cai, Scott Coburn, Alessandro Cunsolo, Jeff Keister, Nalaka Kodituwakku, Alexey Suvorov, Yuriy Stetsko, Kaz Gofron Main Topics for Discussion: • Choice of high energy-resolution optics for baseline scope • Spectrometer design • Early Science and sample environments Agenda (8:00am – 5:00pm): 08:00 – 08:20 Breakfast 08:20 – 08:30 Opening remarks and agenda (Clem Burns) 08:30 – 08:45 NSLS-II update (Qun Shen) 08:45 – 09:30 Updates on the beamline development and optics R&D (Yong Cai) - Latest results of NSLS-II optics R&D - Choice of high resolution optics for baseline - Procurement status - Other updates 09:30 – 10:30 Discussion - Choice of high resolution optics for baseline 10:30 – 11:00 Coffee break 11:00 – 11:45 Spectrometer design and discussion (Scott Coburn) - Design concept and specifications 11:45 – 12:30 Initial experiments and discussion (Yong Cai) - Possible early experiments and sample environments 12:30 – 13:30 Lunch break (discussion continues during lunch) 13:30 – 15:00 Open discussion (Clem Burns) 15:00 – 15:30 Coffee break 15:30 – 16:30 BAT discussion (Clem Burns) 16:30 – 17:00 Close-out Summary (Clem Burns) 17:00 Adjourn

  282. NSLS-II Seminar

    "Motion and Positioning Systems for Specific Synchrotron Applications"

    Presented by Philip Wallington, Q-SYS

    Friday, September 23, 2011, 11 am
    Large Conf Room Build 703

    Hosted by: Mourad Idir

    Q-Sys BV was founded in 2007 by four senior managers from Anorad Europe to continue the tradition of supplying high performance bespoke positioning systems. Within our portfolio of past works are several systems supplied to synchrotrons around the world, together with many special purpose machines for industries as diverse as digital printing, semiconductor wafer metrology, holographic origination and laser machining. To date we have supplied systems to BESSY, Canadian Light Source, Diamond Light Source, ALBA (CELLS) and DESY. Our latest project is an optical metrology bench for NSLS II, the fourth derivative of this system.

  283. National Synchrotron Light Source Seminar

    "Upgrades of XAFS Beamlines for Higher Scientific Performance"

    Presented by Tao Liu, Institute for Synchrotron Radiation (ANKA), Germany

    Tuesday, September 20, 2011, 9:30 am
    Seminar Room, Bldg. 725

    X-ray absorption fine structure (XAFS) spectroscopy is a technique for exploring the details of how x-rays are absorbed by an atom in a matter at energies near the core-level binding energies. XAFS measurement provides a practical and straightforward way to determine the chemical state and local atomic structure for the selected atomic species. Over the past forty years XAFS has benefited largely from the development of synchrotron radiation science and technology, from high brilliant sources, novel beamline optics to high performance detectors and end station facilities. To a large extent, these were pushed by various challenging practical applications from basic research and industry. In this talk I will present a brief overview of these developments and some of my previous work to improve the performance of XAFS beamlines. These include the development and improvement of XAFS facilities at the 3W1B beamline (BSRF), detector development for thin film and near surface XAFS measurements at the XDD beanline (SSLS), and the design of a novel X-ray device for energy filtering and monochromatizing based on X-ray refractive lens at ANKA. Some scientific cases will be involved, such as dilute magnetic semiconductors, high performance catalysts for hydrogen storage and ferromagnetic gold nanoparticles, etc.

  284. National Synchrotron Light Source Seminar

    "Observing the Gaps in High-Tc Superconductors by Angle Resolved Photoemission Spectroscopy (ARPES)"

    Presented by Hongbo Yang, Brookhaven National Laboratory, CMPMSD

    Monday, September 19, 2011, 9:30 am
    Seminar Room, Bldg. 725

    An energy gap opening in the spectral function at the Fermi level is a signature of superconductivity. High-Tc cuprates not only has a d-wave superconducting gap, which has the zero gapped nodal points along the Fermi surface, but also has a pseudogap in the normal state above the critical temperature. These fascinating features complicate that quest of understanding the nature of high-Tc superconductivity. Our recent ARPES studies shed some light on the nature of the pseudogap in the underdoped cuprate-BSSCO, and potentially clear the path for reaching the goal of solving the puzzle of high-Tc superconductivity.

  285. National Synchrotron Light Source Lunch Time Seminar

    "Analysis of Organic Grain Coatings in Primitive Interplanetary Dust Particles: Implications for the Origin of Solar System Organic Matter"

    Presented by Professor George J. Flynn, SUNY Plattsburgh

    Friday, September 16, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  286. National Synchrotron Light Source Seminar

    "The Macromolecular Crystallography Beamline BL13-XALOC at the Synchrotron Alba"

    Presented by Jordi Benach, CELLS - ALBA Synchrotron Light Facility, Spain

    Wednesday, September 14, 2011, 2:30 pm
    Seminar Room, Bldg. 725

    Hosted by: Lonny Berman

    ALBA is a third generation 3-GeV synchrotron near Barcelona, Spain that is currently under commissioning. Out of the initial seven first-phase beamlines, BL13-XALOC is devoted to Macromolecular Crystallography (MX). The photon source of this beamline has been optimized to deliver the highest flux at the Se K-edge while keeping full tunability. The optics consists of a cryogenically cooled Si(111) channel-cut crystal monochromator and a pair of mirrors in a Kirkpatrick-Baez configuration. The end station includes a high accuracy single axis diffractometer and a removable mini-kappa mount. The end station is also equipped with an automated mounting robot that can deal with samples in cryo conditions or in crystallization plates. The main data collection detector is a photon-counting 6-Mpixel detector that offers outstanding capabilities like a very fast framing rate (12 images/second), a large dynamic range (20 bits, >10^6), and negligible dark current noise. Most of the components of BL13-XALOC have been installed and the control system is currently being finalized. The beamline is ready to start x-ray beam commissioning in October 2011 and it is expected to be opened to users during the first half of 2012.

  287. National Synchrotron Light Source Seminar

    "The Macromolecular Crystallography Beamline BL 13 - XALOC at the Synchrotron Alba"

    Presented by Jordi Benach, CELLS - ALBA, Synchrotron Light Facility, Spain

    Wednesday, September 14, 2011, 2:30 pm
    Seminar Room, Bldg. 725

    Hosted by: Lonny Berman

    ALBA is a third generation 3-GeV synchrotron near Barcelona, Spain that is currently under commissioning. Out of the initial seven first-phase beamlines, BL13-XALOC is devoted to Macromolecular Crystallography (MX). The photon source of this beamline has been optimized to deliver the highest flux at the Se K-edge while keeping full tunability. The optics consists of a cryogenically cooled Si(111) channel-cut crystal monochromator and a pair of mirrors in a Kirkpatrick-Baez configuration. The end station includes a high accuracy single axis diffractometer and a removable mini-kappa mount. The end station is also equipped with an automated mounting robot that can deal with samples in cryo conditions or in crystallization plates. The main data collection detector is a photon-counting 6-Mpixel detector that offers outstanding capabilities like a very fast framing rate (12 images/second), a large dynamic range (20 bits, >10^6), and negligible dark current noise. Most of the components of BL13-XALOC have been installed and the control system is currently being finalized. The beamline is ready to start x-ray beam commissioning in October 2011 and it is expected to be opened to users during the first half of 2012.

  288. National Synchrotron Light Source Seminar

    "Surface Induced Order at Liquid and Polymer Interfaces"

    Presented by Benjamin Ocko, Brookhaven National Laboratory

    Tuesday, September 13, 2011, 9:30 am
    Seminar Room, Bldg. 725

    Surface freezing, the formation of a one or two molecular layers thick crystalline film on the surface of a melt, occurs in long-chain hydrocarbons such as n-alkanes and alcohols over a range of temperature where the bulk remains molten. More recently, related phenomenon has also been observed at solid interfaces and at surfactant covered surfaces of water. I will provide an overview of surface freezing in a variety of systems and provide a basis for understanding this phenomenon. I will also report recent work on the ordering of conjugated polymers at the nanostructured interfaces. Work at Brookhaven National Laboratory is supported by US Department of Energy,

  289. National Synchrotron Light Source Seminar

    "Path from soft x-ray microscopy to inelastic scattering"

    Presented by Konstantine Kaznatcheev, Brookhaven National Laboratory

    Monday, September 12, 2011, 3 pm
    Seminar Room, Bldg. 725

    Soft x-ray microscopy at a SR source takes full advantage of soft x-ray specific interactions and provides chemical sensitivity based on a distinct x-ray absorption structure that is characteristic of each chemical species. The variation of x-ray polarization extends measurements to include dichroic signals, which permits one to derive molecular orientation or element-specific magnetic moments. Large penetration length provides “bulk sensitivity” and enables the study of buried interfaces under relevant conditions (magnetic and electrical fields; in a wet, pH controlled state; or under mechanical impact). Individual angular projections can be combined in a tomographic set and give 3D reconstruction at a spatial resolution approaching 25nm. Still, as with any other technique, x-ray transmission microscopy has limitations. I will use the research examples from the Canadian Light Source Spectromicroscopy beamline to illustrate them. In particular, the discussion will evolve around heterogeneous catalysis, where a variety of size-dependent structural, magnetic, electronic, and catalytic properties of nano-particles demands in situ fine characterization. Fischer-Tropsch synthesis provides an effective route to green, sustainable, clean bio-fuel production, but requires a development of a chemical reaction model for further improvement of catalytical activity. It is now possible (a) to construct enclosed reaction cells, (b) to identify the valence state of different nano-particles at reactive condition, and (c) to follow oxidation state variation through a chemical reaction. We can extend snap-shot imaging to sequential time evolution as reactive condition changes and, based on quantitative compositional analysis at a scale finer than 30nm, follow the chemical balance and flow of reactive products. Finer details of adsorbate–adsorbent interaction, or catalytical particle surface composition remain more obscure. The interaction of nano-particle (guest)

  290. NSLS-II Seminar

    "The Preliminary Application of Synchrotron Radiation Technique on Archaeology"

    Presented by Dr. Changsui Wang, Graduate University of the Chinese Academy of Sciences, China

    Monday, September 12, 2011, 1:30 pm
    Large Seminar Room, Bldg. 703

    Hosted by: Eric Dooryhee

    Two applications of Synchrotron Radiation Technique on Archaeology were introduced. First, the distribution of zinc and lead in the brass artifact of the fifth millennium BC and two kinds of brass produced by “melting” and “solid-state reduction” simulation experiments were analyzed by -X-ray fluorescence at the Shanghai Synchrotron Radiation Facility (SSRF). The results suggest that the archaeological brass artifact utilized alloy produced by a solid-state reduction process. This result is consistent with an indigenous origin in China. Second, as we knows, drilling is one of the most complex techniques for making stone implement during ancient times. In this report, virtual 3D reconstruction by using µCT was first applied to disclose drilling tool marks on the inner wall of one small perforation

  291. National Synchrotron Light Source Lunch Time Seminar

    "Droplet microfluidics technologies for single cell gene expression analysis"

    Presented by Professor Helmut H. Strey, Department of Biomedical Engineering, SUNY Stony Brook

    Friday, September 9, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  292. National Synchrotron Light Source Lunch Time Seminar

    "The realization of in situ approach in imaging and spectroscopy using SPEM, PEEM and SEM"

    Presented by Andrei Kolmakov PhD, Department of Physics, Southern Illinois University

    Friday, September 2, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  293. C-AD Accelerator Physics Seminar

    "Design of an ultimate storage ring for future light source"

    Presented by Dr. Yichao Jing, C-AD, BNL

    Friday, August 26, 2011, 4 pm
    Large Conference Room, Bldg. 911B

    Hosted by: Coordinator: Chuyu Liu

    An ultimate storage ring with natural emittance reaching diffractive limit is capable of producing transversely coherant synchrotron radiation. In this talk, speaker reports the progress of a 10 pico-meter storage ring design and dynamica aperture study. He will also talk about the study of instabilities which limit the ring's performance.

  294. Photon Sciences Seminar

    "Soft X-ray Spectromicroscopy on Environmental and Biological Samples"

    Presented by Julia Sedlmair, University of Gottingen, Germany

    Friday, August 26, 2011, 1:30 pm
    Seminar Room, Bldg. 725

    Hosted by: Juergen Thieme

  295. Instrumentation Division Seminar

    "Applications of spherically bent crystals and Pilatus hybrid pixel array detectors (PAD) for x-ray spectroscopic measurements of ion temperature and plasma flow velocity in ITER and NIF: Potential applications on x-ray light sources"

    Presented by Kenneth Hill and Manfred Bitter, Princeton Plasma Physics Laboratory

    Wednesday, August 24, 2011, 2:30 pm
    Large Conference Room, Bldg. 535

    Recently developed one-dimensionally imaging high resolution x-ray spectrometers using a single spherically bent crystal and Pilatus PAD arrays, or 2D multiwire proportional counters, have revolutionized Doppler spectroscopic measurements of plasma ion temperature and flow velocity in tokamak plasmas worldwide by providing, from a single instrument, measurements over the entire extended plasma cross section. We have collaborated with groups to install and operate such spectrometers on tokamaks and stellarators at MIT and in Japan, China, and Korea, and are presently developing the conceptual design for a set of such x-ray imaging crystal spectrometers (XICS) for the international tokamak, ITER, which is being constructed in Cadarache, France. This XICS instrument is also applicable for Doppler measurements of inertial confinement fusion (ICF) plasmas, such as the National Ignition Facility (NIF). Additional schemes have been developed which eliminate the astigmatism by use of specially matched pairs of spherically bent crystals and which provide 2D x-ray imaging with almost arbitrary angles of incidence over millimeter scales with potential spatial resolution of microns. These x-ray optical schemes may also have beneficial applications in other areas, such as x-ray lithography, x-ray microscopy for biological research on x-ray light sources, or x-ray beam steering, focusing, and monochromatization at synchrotron facilities. An overview of the 1D imaging Doppler spectroscopy on present tokamaks, performance simulations for the ITER spectrometers, and preliminary testing of the 2D imaging schemes in visible light will be presented, as well as planning and progress on testing the 2D imaging schemes with x rays.

  296. National Synchrotron Light Source Seminar

    "Research of electronic structure of transition metal dichalcogenides by methods of Soft X-ray Absorption, Photon Emission and Photoelectron spectroscopies"

    Presented by Mikhail Yablonskikh, Sincrotrone Trieste SCpA, Basovizza I-34012, Italy

    Wednesday, August 24, 2011, 9:30 am
    Building 703, Large Conference Room

    Layered dichalcogenides of Ti intercalated with transition metals TMxTiZ2 (TMDC's) where TM= Mn, Cr, Fe, Co, Cu or Ag and Z= S, Se, Te are low dimensional solids where monoatomic layers of TM atoms with a given density are separated by nonmagnetic slabs of the TiZ2 matrix [1]. Discovery of charge-denstity wave (CDW) to superconductive state transition in Cu dichalcogenides and promise of that for Fe and Cr TMDC's inspired a number of studies of their electronic structure [2] which are dedicated to understand the nature of superconductivity, the origin of magnetism and the formation of CDW. The formation of electronic band structure and the chemical bonding situation were examined for three classes of compounds: TiZ2 host-lattice materials, TM (Cr, Mn, Fe, Co) intercalates and Cr substitution compounds. Since electronic properties of TMDCs can be understood in terms of charge transfer and interlayer separation [3], Soft X-ray Absorption, Soft X-ray Photoelectron and Soft X-ray Emission spectroscopies were used. It was found that a strong hybridization between 3d orbitals of intercalated TM atom, Ti 3d and Z p orbitals plays a major role resulting in energy shifts of the conduction band, modi cations of the valence band and variations of the density of states at the Fermi level [4]. The interplay between the band structure, interlayer separation and the chemical bonding of TM atoms with a host lattice TiSe2 will be shown. Further opportunities for research of TMDCs and corresponding experimental challenges will be discussed.

  297. National Synchrotron Light Source Seminar

    "From X-ray standing waves to Borrmann Spectroscopy"

    Presented by Martin Tolkiehn, Deutsches Elektronen-Synchrotron (DESY)

    Thursday, August 11, 2011, 9:30 am
    Building 703, Large Conference Room

    The method of x-ray standing waves (XSW) is a well established technique for the determination of adsorbate or dopant atomic positions in single crystals. It is based on the interference of incident and Bragg reflected wave, which is calculated with the dynamical theory of x-ray diffraction. This means that highly perfect crystals are necessary. I will present an improvement of the classical XSW method, which allows application of the XSW technique to non-perfect single crystals. This is achieved by describing the standing wave field in the frame of the kinematical approximation. Recent results of such kinematical x-ray standing waves (KXSW) investigations of doped non-perfect crystals will be shown. Usually the XSW and KXSW techniques are used in Bragg geometry. However the application of both methods is also possible in Laue geometry. A particularly interesting phenomenon observed in the latter case is the Borrmann effect, which is caused by the standing wave field inside the crys- tal. For certain reflections the low electrical field intensity at the atoms leads to a low dipole absorption (anomalous transmission). At the same time the high field gradient results in an enhanced quadrupole absorption. Therefore the intensity of the reflected beam strongly depends on the quadrupole absorption cross section of the atoms at the nodes of the standing wave field. This effect can be used for the identification and investigation of quadrupolar features in the x-ray absorption near edge structure (XANES). I will present a theoretical model of this novel Borrmann Spectroscopy method and demonstrate its applicability to transition metal K edges and rare earth L edges.

  298. National Synchrotron Light Source Seminar

    "High Resolution Soft X-Ray RIXS in Quasi One-Dimensional Cuprates and Oxide Heterostructures"

    Presented by Thorsten Schmitt, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland

    Wednesday, August 10, 2011, 9:30 am
    Seminar Room, Bldg. 725

    Resonant inelastic X-ray scattering (RIXS) is a powerful bulk-sensitive photon-in/photon-out spectroscopic probe of the electronic structure with atomic and orbital sensitivity. It is an ideal method for studying excitations from the electronic ground state in correlated transition metal oxides, being directly sensitive to charge-, orbital- and spin-degrees of freedom. Ultra-high resolution instrumentation for RIXS is available at the ADvanced RESonant Spectroscopies (ADRESS) beamline of the Swiss Light Source at the Paul Scherrer Institut, being optimized for soft X-rays with variable polarization between 0.4 and 1.8 keV [1]. The SAXES (Super Advanced X-ray Emission Spectrograph) RIXS spectrometer of the ADRESS beamline has a resolving power of ca. 12000 for 1 keV. It allows varying the scattering geometry between incident and inelastically scattered X-rays in order to study low-energy excitations as a function of momentum transfer. In this talk I will give an overview on high-resolution and momentum dependent RIXS studies of magnetic and electronic excitations in quasi one-dimensional cuprate and oxide hetersotructure systems Sr2CuO3 is a quasi one-dimensional corner-sharing single-chain compound possessing the nearly ideal properties of the one-dimensional antiferromagnetic Heisenberg spin-1/2 model. The momentum transfer dispersion of the Cu L3-RIXS signal in Sr2CuO3 along the chain direction reveals that the main spectral weight follows the lower onset of the two-spinon (and higher order) continuum and probes the dynamical spin structure factor. Numerical calculations within the Bethe Ansatz allow a detailed line shape analysis of the RIXS response. The modes within the orbital excitation energy range show that the dd excitations in Sr2CuO3 are momentum dispersive and can be associated with orbitons, i.e. dispersive excitations mediated by the superexchange interactions. A spin-orbital superexchange model reproduces this orbiton dispersion and explains the lar

  299. National Synchrotron Light Source Seminar

    "Resonant inelastic x-ray scattering studies of the iron pnictides – a slow start but a strong finish?"

    Presented by Ignace Jarrigge, SPring 8

    Tuesday, August 9, 2011, 9:30 am
    Seminar Room, Bldg. 725

    For the past three years, photoelectron and optical spectroscopies have provided most of the momentum behind the tremendous research effort on the electronic structure of the new superconducting iron pnictides. In contrast, resonant inelastic x-ray scattering (RIXS) has yet to make a solid contribution to the research on this new class of superconductors. This is because the iron pnictides are metals, and hence have a very low Raman scattering cross-section. In this talk, I will present RIXS data recently obtained at both Fe-K and Fe-L edges on single-crystals of PrFeAsOx (x=0.7,1), which belong to the so-called 1111 family. Owing to a combination of high energy resolution and high incident flux, we were able to observe features corresponding to two types of charge excitations: dd interband transitions between 0.2 and 2.0 eV energy loss, and As4p-Fe3d charge transfer around 4 eV. A weak momentum dependence across the Fe-As plane is observed for the dd interband transitions. The knowledge of these excitations enables us to readily assess the strength of the electron correlation effects, believed to play a central role in the peculiar physics of the iron-based superconductors. Finally, I will discuss which other iron pnictide compounds are likely to be well suited to RIXS.

  300. National Synchrotron Light Source Lunch Time Seminar

    "Understanding the Aggregation of Cu, Zn Superoxide Dismutase in Amyotrophic Lateral Sclerosis"

    Presented by Daphne Meza, University of New Orleans

    Friday, August 5, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  301. National Synchrotron Light Source Lunch Time Seminar

    "The Effects of a High Fluoride Treatment on Osteoporotic Bone as Measured by Fourier Infrared Transform Imaging"

    Presented by Natalie Delpratt, Columbia University

    Friday, August 5, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  302. National Synchrotron Light Source Lunch Time Seminar

    "Analysis of Oil Production in Algae as a function of Visible Light Wavelengths"

    Presented by William Willis, Stony Brook University

    Friday, August 5, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  303. National Synchrotron Light Source Lunch Time Seminar

    "Understanding how Pollen Tube Germination is Affected in Plants Genetically Modified to Improve Biomass Production"

    Presented by Genevieve Kuczewski, Shoreham - Wading River High School

    Friday, August 5, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  304. National Synchrotron Light Source Lunch Time Seminar

    "Understanding how Pollen Tube Germination is Affected in Plants Genetically Modified to Improve Biomass Production"

    Presented by Maria Sirenko, Ridge High School, NJ

    Friday, August 5, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  305. National Synchrotron Light Source Seminar

    "Scanning photoemission microscopy in soft X-ray and VUV"

    Presented by Pavel Dudin, Sincrotrone Trieste, Elettra, Italy

    Friday, August 5, 2011, 9:30 am
    Seminar Room, Bldg. 725

    The talk is devoted to the use of scanning photoemission microscopies in material studies. The surface, electronic, chemical and structural sensitivity of photoemission makes it an instrument that is very useful for material studies like strongly electronically correlated systems, catalysts, superconductors, graphene, etc. With the photon spot of small size (less than 1 m) photoemission acquires spatial resolution, substantially extending research possibilities. For example, extremely small samples could be studied, like graphene flakes, polycrystalline domains, single crystals that couldn’t be grown to large sizes, etc. Another interesting possibility are the systems with intrinsic spatial inhomogeneties in electronic and/or chemical properties. The good examples are the domains in conductivity formed under the conditions of the metal to insulator transition. Further, the artificial structures with micron sizes could be studied. At Elettra the core level and VB/ARPES photoemission microscopies are developed at the beamlines of ESCA microscopy and Spectromicroscopy, respectively. The former is well known to provide mapping of surfaces with spatial resolution of 200 nm and highly relevant chemically, due to high sensitivity of core level lineshape to local environment of the atom. The beamline successfully used in studies of OLED, fuel cells, catalysts, nanotubes, semiconducting heterostructures, etc. The upgrade of SpectroMicroscopy beamline dedicated to the development of spatially resolved ARPES has been commissioned few years ago. Now it builds up the user community by offering the possibility of ARPES with spatial resolution less than 1 micron. Up to now, the spatially resolved ARPES has been already used in studies of various materials with strong electronic correlations: superconductors, graphene, CDW materials (TaS2 and TaSe2), vanadium oxides, etc. The correlated use of shallow core level (less than 70 eV in binding energy) and ARPES microsc

  306. National Synchrotron Light Source Seminar

    "Photoelectron Spectroscopy & Photoelectron Microscopy"

    Presented by Elio Vescovo, Brookhaven National Laboratory, Photon Sciences

    Tuesday, August 2, 2011, 9:30 am
    Seminar Room, Bldg. 725

    Ultrathin metal films – let’s say in the 1 to 10 monolayers range – exhibit characteristic physical and chemical properties with no counterpart in bulk materials. This behavior stems from the two-dimensional character of their electronic structure. Photoelectron techniques are therefore optimal tools to investigate these systems. In this talk, spin- and angular-resolved photoelectron spectroscopy (SP-ARPES) will be used to investigate the lifting of the spin degeneracy in the surface electronic states of a non-magnetic system: the 1-dimentionally modulated Bi monolayer on Ag(110). X-ray Photoelectron microscopy will instead be applied to study the low temperature mass transport during the separation of Fe70Ni30 martensite into the equilibrium bcc and fcc phases.

  307. NSLS-II Seminar

    "Coherent diffraction imaging with transmission and Bragg reflection geometries"

    Presented by Xiaojing Huang, ANL

    Monday, August 1, 2011, 2:30 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Dr. Yong Chu

    Coherent diffraction imaging (CDI) technique inverts far-filed diffraction pattern to real-space images using phase retrieval algorithms. Because CDI provides higher radiation dose efficiency compared with lens-based microscope system and has the potential to reach diffraction-limited resolution, it is favorable for image radiation sensitive biological samples. CDI applications on imaging freeze-dried, chemically dried and frozen hydrated yeast cells will be presented. Combined with resonant excitation process, CDI is capable to unravel magnetic domain structures. When operated in Bragg reflection geometry, Bragg CDI recovers real-space images of crystals, with magnitudes represent electron densities and phases represent strain distribution. Presenter will show Bragg CDI studies on silicon-on-insulator and zinc oxide crystals, and discuss the developments on extending Bragg CDI's capability to investigate specimens under extreme conditions, such as heavily strained and in high-pressure environment.

  308. National Synchrotron Light Source Seminar

    "The copper speciation studies in biological samples using X-ray Fluorescence Microprobe (XFM)"

    Presented by Naresh Kujala, Argonne National Laboratory

    Monday, August 1, 2011, 9:30 am
    Seminar Room, Bldg. 725

    Copper plays an important role in angiogenesis and tumor growth. The anti-growth action of copper chelators is mainly their induced inhibition of angiogenesis. Cu is considered as a target for novel cancer therapies that offer lower level of toxicity compared to current available chemotherapies. Although Cu oxidation state has not been directly implicated as being a characteristic of the tumor growth process, this can not be completed excluded as a potential role of Cu in tumor growth. As Cu concentration in tissue samples (prostate and breast cancer) has few parts per million. X-ray fluorescence microprobe (XFM) spectroscopy can detect very low metal concentrations with high efficiency and identify oxidation states and coordination chemistry using spectral lines that are normally unresolved by other techniques. This low metal concentration required a high flux incident beam capable to generate enough fluorescence x-rays to be detected. The main drawback in this configuration is the high intensity of the scattering signal from the supporting matrix. Measuring copper K fluorescence from tissue samples, for instance, can be critically masked by the strong scattering signal, reducing the sensitivity level and potentially saturating conventional solid-state photon-counting detectors. To overcome these limitations a high energy resolution and high efficiency compact, short focal distance Bent Crystal Laue Analyzer (BCLA) detection system has been developed for copper speciation in biological samples. The analyzer has energy resolution of 14 eV@ Cu Kα line and it has notable advantages to resolve the Cu Kα1, Kα2, and Kβ fluorescence lines while offering a very low background. The designed BCLA will be used on copper speciation studies in biological samples with specific applications to cancer biology.

  309. National Synchrotron Light Source Lunch Time Seminar

    "Characterization of Crystalline Structures in Organic Semiconductors for High Performance Organic Electronics"

    Presented by Professor Hoichang Yang, Inha University, Korea

    Friday, July 29, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

    Various organic thin film transistors (OTFTs) containing conjugated materials are now becoming commercially available in the form of light emitting diodes, and proto-type electronic polymer circuits of pi-pi conjugated polymers or oligomers. Successful uses of these devices are presently being demonstrated. Thin films for OTFT applications can be fabricated through various film processing techniques, such as vacuum deposition and solution casting. Since the performance of OTFT devices is inherently related to the local ordered structure of these semiconducting films, it is important to achieve a greater control of the self-assembly of semiconducting materials on functionalized dieletric substrates. Specifically, the desire to make nanometer scale devices for future electronic applications further emphasizes a preferential orientation of pi-pi conjugated crystal planes, as a hole-transporting path in p- or n-type semiconductor-based OTFTs. Herein, I introduce the effects of crystalline structures in pentacene, oligothiophene derivative, PTCDI-C13, TES-ADT, TIPS pentacene, F8T2, PQT12, and poly (3-alkyl thiophene) thin films, as organic semiconductors, on their charge-transport behaviors in OTFTs using two-dimensional grazing-incidence X-ray diffraction and atomic force microscopy (AFM). Interconnection between crystal grains, as a prerequisite for high performance OTFT applications, is highlighted via conducting-AFM characterization.

  310. National Synchrotron Light Source Seminar

    "Lipid-Mediated Assembly of Biomolecular Nano-objects at Liquid Interfaces."

    Presented by Masa Fukuto, Brookhaven National Laboratory, CMPMS

    Wednesday, July 27, 2011, 9:30 am
    Seminar Room, Bldg. 725

    Biomolecular nanoparticles (BNPs), such as proteins and viruses, bound to a lipid monolayer are well suited for investigating interface-directed assembly of nanoscale building blocks. Using the air-water interface as the assembly platform, we have recently demonstrated density-driven 2D crystallization of BNPs for two types of BNP-lipid interactions, one based on electrostatic interactions (type I) and the other based on specific ligand binding (type II). For type I, the assembly of icosahedral viruses (CPMV and TYMV) on a cationic lipid monolayer was studied as a function of pH and the monolayer charge density. In-situ grazing-incidence small-angle x-ray scattering (GISAXS) measurements show that 2D crystals of these virus particles are formed above a threshold monolayer charge density and only in a narrow pH range just above the virus' isoelectric point, where the net charge on the virus is weakly negative. For CPMV, the observed 2D crystal structure is analogous to the densest lattice plane within the known 3D crystals. By contrast, for TYMV, two new forms of 2D crystal structures have been found that are distinct from any lattice planes in the previously observed 2D or 3D assemblies. The roles of particle shape and patchiness, interface-induced particle orientation, and competing anisotropic inter-particle interactions in stabilizing these structures will be discussed. For type II, the 2D assembly of the protein streptavidin (SA) on a biotin-bearing lipid monolayer was studied as a function of the surface density of biotin, a protein-binding ligand. In-situ Brewster-angle microscopy, GISAXS, and x-ray reflectivity measurements were carried out to elucidate the relationship between the adsorption, 2D phase behavior, and binding state of SA. In particular, the threshold biotin density for inducing the 2D crystallization is found to be remarkably close to the density of the ligand-binding sites in the SA crystal. Moreover, the fully bound state of SA, correspo

  311. National Synchrotron Light Source Seminar

    "Magnetic Order in Multiferroic Rare Earth Ferroborates"

    Presented by Christie Nelson, Brookhaven National Laboratory, Photon Sciences

    Tuesday, July 26, 2011, 9 am
    Seminar Room, Bldg. 725

    Multiferroics are materials with more than one type of ferroic order, and have attracted recent interest due to potential device applications. Multiferroic rare earth ferroborates, RFe3(BO3)4, exhibit simultaneous antiferromagnetic and ferroelectric order, and strong coupling is indicated by the magnetic field dependence of the electric polarization. In order to shed light on the multiferroic mechanism in RFe3(BO3)4, x-ray scattering studies were carried out. A combination of resonant— at the rare earth L edges— and nonresonant magnetic x-ray scattering allows the behaviors of the rare earth and iron magnetic subsystems to be unraveled. For R = Gd and Nd, both commensurate and incommensurate magnetic phases are observed, and there is a correlation between the magnetic field-induced destruction of the incommensurate magnetic phases and the onset of electric polarization. In substituted ferroborates with rare earth species having different anisotropies, a decoupling between the rare earth subsystems is observed.

  312. NSLS-II Seminar

    "Performing magnet design and beam optics in an integrated framework"

    Presented by Shashikant Manikonda

    Monday, July 25, 2011, 11 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Toshi Tanabe

    Map methods are standard techniques used to design and optimize accelerator lattices. But for simulations with realistic electromagnetic fields computing transfer maps is a challenging problem. Recently new tools have been developed to do magnet design and perform beam optics simulations in an integrated framework. We will discuss the implementation, performance and advantages of these tools and show the utility for few practical cases.

  313. National Synchrotron Light Source Seminar

    "Core Level Spectroscopy at High Flux Beamlines"

    Presented by Klaus Attenkofer, Argonne National Laboratory

    Monday, July 25, 2011, 10 am
    Seminar Room, Bldg. 725

    Hosted by: Lisa Miller

    Recent developments in beamline design, detection technology, and data analysis has brought core level spectroscopy to a sophistication which allows one to probe “real materials under real conditions”. Many disciplines currently face the task to understand, tailor or optimize highly complex heterogeneous materials. Catalysis, battery development, organic solar cells or even the optimization of concrete are typical examples. All these examples have in common that the scientist needs to visualize morphology and microscopic structure during processing or operation of the devices. Modern X-ray absorption spectroscopy (XAFS) can play a key role for this exciting challenge. As a local probe, not requiring long-range order like most scattering techniques, XAFS explores the local structure and the electronic configuration around the absorber atom, making it to an exceptional instrument in the toolkit of the developer. The talk will give an overview how high flux beamline designs combined with modern detection technology will increase throughput and opens avenues to novel spectroscopic approaches.

  314. National Synchrotron Light Source Seminar

    "X-ray Views of Biological Mineralization"

    Presented by Elaine DiMasi, Brookhaven National Laboratory

    Monday, July 25, 2011, 9:30 am
    Building 703, Large Conference Room

    Mineralized tissues such as bone and tooth have a mysterious origin, from a physical chemistry point of view. Classical crystallization theory concerns energetic tradeoffs in the addition of molecules or ions to the surfaces of crystal nuclei. From these considerations the formation of less stable precursor phases and the concept of Ostwald ripening emerge. However, minerals produced by cells in live tissue are likely to emerge along a significantly different path. The observation and speculation of “electron dense granules”, “x-ray amorphous mineral”, matrix vesicles, calcium phosphate “Posners clusters”, and organic-mineral clusters such as lipid-calcium phosphate complexes have been mentioned in the literature for decades. These ideas connect to current thinking from biomimetic chemistry experiments, where polymer-induced liquid precursors and prenucleation clusters have been reported. This is the backdrop for experiments using synchrotron x-rays to make new observations of biological minerals. I will briefly mention achievements at the organic interface in model systems and, in more depth, discuss Ca L-edge absorption spectroscopy performed at the nanoscale at scanning transmission x-ray micro-spectroscopy beamlines.

  315. National Synchrotron Light Source Lunch Time Seminar

    "A Dense Monolayer of Ions at Soft Interfaces"

    Presented by Dr. Binyang Hou, University of Illinois at Chicago

    Friday, July 22, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

    An important unsolved problem in the study of ion distributions is the relationship of macroscopic electrochemistry measurements to the ion distribution determined by microscopic synchrotron x-ray scattering measurements. In this work, we present recent x-ray reflectivity and interfacial tension measurements of electrified oil/water interfaces as a function of interfacial electric potential for a series of interfaces between solutions of 10 mM alkali chloride (XCl, where X is the alkali metal ion of Li+, Na+, Rb+ and Cs+) in water and 5 mM organic supporting electrolyte BTPPATPFB in 1, 2-dichloroethane (DCE). The potential is established by the use of electrodes and supporting electrolytes in the bulk phases. Interfacial tension as a function of interfacial electric potential was measured to determine the potential of zero charge (PZC) and the capillary wave roughness of each interface. The interfacial excess charge was determined from the tension measurements as well. X-ray scattering experiments were carried out at the ChemMatCARS beamline 15-ID at the Advanced Photon Source (Argonne National Laboratory, USA). Large changes in reflectivity occur from intermediate potentials for each sample. These results disagree with predictions of the Gouy-Chapman (GC) theory. A Poisson-Boltzmann (PB) calculation that incorporates a potential of mean force (PMF) to describe the role of liquid structure on the ion distributions agrees well with the x-ray reflectivity data. These results confirmed a layer of TPFB- ion formed at the interfaces at high positive electric potentials. In addition, we calculated the excess interfacial charge from the ion distributions determined by the x-ray measurements analysis for each interface. These calculated excess interfacial charges from the PB-PMF method are in good agreement with the tension measurement results. These agreements make a direct connection between the molecular level x-ray measurements and macroscopic interfacial tensi

  316. National Synchrotron Light Source Seminar

    "Evidence of high metal tolerance in seeds of hyperaccumulator plants revealed by X-ray fluorescence microprobe"

    Presented by Ryan Tappero, Brookhaven National Laboratory, Photon Sciences

    Friday, July 22, 2011, 9:30 am
    Seminar Room, Bldg. 725

    Metal hyperaccumulator plants are used in commercial phytoremediation and phytomining operations to recover metals of economic value from enriched soils or sediments. Information regarding the distribution and speciation of metals at the micron scale is needed to locate the phenomena of hyperaccumulation in tissues, cells, and organelles in order to understand the mechanism of (hyper)tolerance and ultimately improve phytoextraction efficiency. Metal (hyper)tolerance in mature plants occurs via chemical binding of metals (i.e., chelation) and intracellular compartmentalization. X-ray fluorescence microprobe was used to investigate metal localization and speciation in situ because standard sample preparation methods (e.g. embedding) cause re-distribution of metals or alter their speciation. In seeds of nickel (Ni) hyperaccumulator Thlaspi goesingense, Ni was preferentially localized in the embryonic tissue with the greatest enrichment in the cotyledons (leaves), radicle (root), and hypocotyl (stem); nickel was nearly absent from the testa (seed coat). Nickel within the embryo was spatially correlated with sulfur (S) and closely associated with manganese (Mn). For intact seeds, fCMT revealed preferential localization of Ni in the epidermis of the rudimentary plants. High-resolution images of seed cross-sections showed Ni compartmentalized preferentially within the single layer of epidermal cells. In cotyledons, epidermal cells contained circa 8-fold more Ni than immediately adjacent palisade cells and circa 6-fold more Ni than (spongy) mesophyll cells. Nickel K-edge XAS measurements on (oriented) seeds and single epidermal cells exposed in cross-section revealed the storage form of Ni was a nickel-sulfur nanocluster resembling alpha nickel sulfide (-NiS). Intracellular compartmentalization and chemical binding of Ni in the seed embryo provides evidence that these rudimentary plants have developed a (hyper)tolerance mechanism for metal homeostasis. Ne

  317. National Synchrotron Light Source Seminar

    "In situ experiments in Synchrotron X ray Tomography"

    Presented by Prof. Eric Maire, Université de Lyon and Havard University

    Wednesday, July 20, 2011, 3 pm
    Seminar Room, Bldg. 725

    Hosted by: Jun Wang

    The microstructure of heterogeneous materials such as multiphase alloys, composites, cellular materials, etc... has sometimes a very complicated nature. The complexity of this microstructure can nowadays be imaged in 3D using different methods at different scales (FIB/SEM, Atom Probe Tomography, TEM tomography, etc.). The most commonly used of these methods is probably X-Ray Computed Tomography (XRCT) because of its multimaterial, multiscale and non destructive character. 3D imaging (if non destructive like it is the case for XRCT) can also be coupled with in situ loading (1) of the sample (in situ tension or compression, in situ heating, in situ freezing, etc.). The observation of the evolution of the microstructure under load in 3D allows to understand the microscopic mechanisms involved during the transformation/ deformation of these heterogeneous materials as illustrated in Fig. 1 in the case of a dual phase steel. The 3D image of the initial microstructure of the sample can, in a final analysis stage, be used as a direct input for a numerical simulation of the response of the material to the load, the results of which being directly comparable to the in situ experiments. This presentation will illustrate this combination of techniques and how we have used it in recent studies in order to understand the deformation of heterogeneous materials.

  318. NSLS-II Seminar

    "Modeling study of SPEAR3 nonlinear dynamics"

    Presented by Xiaobiao Huang, SLAC

    Wednesday, July 20, 2011, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Samuel Krinsky

    Lattice modeling is studied to understand the nonlinear dynamics of the SPEAR3 ring, using data from magnet modeling, magnetic field measurements and alignment requirements. The gradient dipoles are modeled with an analytic magnetic field profile and a numeric integration pass method in Accelerator Toolbox (AT). Linear and nonlinear effects of quadrupole fringe field are included with a new AT pass method. Linear and nonlinear parameters from the modeling are compared to experimental measurements.

  319. National Synchrotron Light Source Lunch Time Seminar

    "Electronic Structure and Surface Characterization of Semiconducting Nanocrystals Using Synchrotron Radiation"

    Presented by Professor Robert Meulenberg, University of Maine

    Friday, July 15, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  320. National Synchrotron Light Source Seminar

    "Synchrotron full field x-ray imaging: APS experience and outlook"

    Presented by Wah-Keat Lee, Argonne National Laboratory

    Thursday, July 7, 2011, 9:30 am
    Large Conference Room, Building 703

    Hosted by: Lisa Miller

    The advent of synchrotrons have led to a renewed interest in x-ray imaging, in particular, various forms of phase-contrast imaging. In 2005, the APS upgraded an existing beamline into a dedicated full field imaging facility that houses three separate instruments: a white beam micron-resolution instrument, a monochromatic beam micron-resolution instrument and a 40 nm resolution transmission x-ray microscope. The first part and bulk of the talk will focus on a few applications using the micron-resolution instruments, namely insect physiology, ferrofluids and fuel injection systems. These systems involve very complex fluid dynamics, where for the first time, direct experimental data can be collected. The second part of the talk will discuss some of the current technical developments, challenges and general outlook.

  321. National Synchrotron Light Source Lunch Time Seminar

    ""A Mechanism for S-adenosyl methionine Assisted Formation of a Riboswitch Conformation: A Small Molecule with a Strong""

    Presented by Wei Huang, Department of Biological Science, Louisiana State University

    Friday, July 1, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  322. National Synchrotron Light Source Seminar

    "Femtosecond Carrier Dynamics and Nonlinear Effects in Quantum Cascade Lasers"

    Presented by Sheng Liu, University of Maryland Baltimore County

    Tuesday, June 28, 2011, 2 pm
    Large Conference Room, Bldg 703

    Hosted by: Dr. G. Larry Carr

    Quantum cascade lasers (QCLs) are semiconductor lasers based on intersubband transitions, resonant tunneling and phonon scattering, emitting Mid- to far-IR light. In order to understand the ultrafast carrier dynamics in QCLs, pump-probe technique has been extensively employed to investigate the electron transport dynamics and coupled light-matter interactions. Moreover, people have observed giant optical nonlinearity in quantum well structures and QCLs by taking advantage of the large dipole-matrix elements of intersubband transition. The talk will focus on studying the carrier dynamics of ultrastrong-coupling designed QCLs using degenerate Mid-IR pump-probe technique. Second harmonic generated pulses were also obtained from the QCLs pumped by femtosecond Mid-IR pulses through front facet illumination. Furthermore, other experiments related to Mid-IR such as supercontinuum generation in chalcogenide fiber, photoluminescence of type-II detector will be briefly discussed.

  323. National Synchrotron Light Source Lunch Time Seminar

    "Screening Effect of Highly Compressible supercritical Carbon Dioxide on Attractive Polymer/Substrate Interactions"

    Presented by Peter Gin, Department of Materials Science and Engineering, Stony Brook University

    Friday, June 17, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  324. National Synchrotron Light Source Lunch Time Seminar

    "Thermoelectric and Structual Properties of the Cu Doped Ca3Co409 System"

    Presented by Tao Wu, Department of Physics, New Jersey Institute of Technology

    Friday, June 17, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  325. NSLS-II Seminar

    "NSLS II injection system"

    Presented by Guimei Wang

    Thursday, June 16, 2011, 10 am
    Large Conference Room, Building 703

    Hosted by: Timur Shaftan

  326. National Synchrotron Light Source Lunch Time Seminar

    "Vector Potential Photoelectron Microscope (VPPEM)"

    Presented by Raymond Browning, R. Browning Consultants, Shoreham, N.Y.

    Friday, June 10, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

    A new class of electron microscope has been developed for the chemical microanalysis of a wide range of real world samples using photoelectron spectroscopy. Highly structured, three dimensional samples, such as fiber mats and fracture surfaces can be imaged, as well as insulators, and magnetic materials. The new microscope is unique in using the magnetic vector potential field as a spatial reference for imaging. The very different properties of the imaging method open up many opportunities for novel experiments such as the high resolution imaging of in situ chemical reactions on highly textured surfaces. A prototype instrument on U4A has demonstrated imaging of uncoated silk, magnetic steel wool, and micron sized single strand tungsten wires. This demonstration suggests that the microscope will have a major impact in many fields including: the study of catalysis, biological and organic thin films, battery technologies, and geology. This work has been funded by several NIST SBIR awards with the support and encouragement of Dan Fischer and the NIST Synchrotron Methods Group at NSLS.

  327. Science Cafe Book Reading & Discussion

    "Forensics at Brookhaven Lab's Light Source: The Truth and the Fiction Behind Red Herring"

    Presented by Archer Mayor, author & 2004 New England Booksellers Association award-winner

    Thursday, June 9, 2011, 7 pm
    Berkner Hall Auditorium

    Hosted by: Marsha Belford

    In a open-to-the-public evening mixing fiction and science, author Archer Mayor will first read excerpts from Red Herring, his 21st novel featuring Joe Gunther of the fictional Vermont Bureau of Investigation. In Red Herring, single drops of blood are found at the scene of three seemingly unrelated murders -- and the blood is not that of any of the victims. When conventional forensics only leads Joe Gunther to a dead end, the investigator takes a detour to the National Synchrotron Light Source at Brookhaven National Lab on Long Island. Here, the high-intensity beams of the NSLS shed light upon the culprit of these dastardly deeds and enable Joe Gunther and his fellow gum-shoes to track down not only the perpetrator of these crimes, but also the villainous master-mind. Following the reading, researchers from the NSLS will explore how tomorrow's forensics capabilities are being developed through research at the Light Source today. And, finally, the author will discuss what inspired him to make the NSLS a pivotal character, as it were, in Red Herring before answering questions from the audience. After the auditorium presentation, free refreshments will be served, and the author will autograph copies of his books, which will be offered for sale by Borders of Stony Brook. All are invited. Age 16 and over, bring photo ID.

  328. Photon Sciences Directorate Seminar

    "Nanoparticle Behavior in Environmental and Test Media: Conclusions from Static and Dynamic Stability Testing"

    Presented by Frank Von Der Kammer, University of Vienna, Austria

    Friday, June 3, 2011, 11 am
    Seminar Room, Bldg. 725

    Hosted by: Juergen Thieme

    The appearance and behavior of engineered nanoparticles in the environment determine their distribution, their fate and the exposure of organisms. This behavior is governed by several well-known parameters as surface potential of the particles, particle size and shape and of course the water chemistry. However a detailed understanding how the inter-connected processes of aggregation, transport, settling and transformation are influenced by these parameters is still missing. From the perspective of risk assessment it would be essential to be able to predict behavior, fate and transformation, but meaningful predictions derived from first principles remain difficult, even in fairly simple systems. For certain engineered nanoparticles like citrate stabilized Gold-NPs for example, which come with a fairly simple surface chemistry, the prediction of reactions may be more straight forward than for others, especially metal-oxide particles. Hence as long as process understanding remains underdeveloped empiric approaches will be necessary. We have addressed this issue by developing a testing approach to generate empiric data for the dispersion stability of nanoparticles in a wide variety of conditions. The testing procedure itself and the comparison of conditions and materials will be presented and discussed with respect to the application to real world conditions including analytical challenges in real surface waters and soils, limitations due to reduced complexity of the set-up, and the problem of heterogeneity and property distributions of the nanoparticles.

  329. NSLS-II Seminar

    "Roughness-induced Scattering of EUV/Soft-X-ray Optical Components"

    Presented by Sven Schroeder, Fraunhofer Institute for Applied Optics and Precision Engineering (IOF), Jena, Germany

    Wednesday, June 1, 2011, 1:30 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Mourad Idir

    The unrelenting demand for computer processors and memory with higher speed and capacity is directly connected to higher integration densities and, consequently, the printing of smaller feature sizes. Optical lithography at 193 nm is the current state of the art for manufacturing semiconductor structures. One key to enhance the resolution is to decrease the lithography wavelength. Extreme ultraviolet (EUV) lithography at 13.5 nm is expected to be the next generation lithography. The great leap to the Soft-X-ray spectral range, however, leads to tremendous requirements on the surface roughness of optical components. Roughness-induced light scattering may drastically reduce the throughput, the resolution, and the contrast in lithographic systems. The measurement and modeling of EUV light scattering are essential for improving the performance of EUV optical components. Furthermore, characterizing the relevant roughness properties even at very early stages in the manufacturing chain of optical components ensures that the desired performance can in fact be achieved. The talk first provides a brief overview of the EUV/Soft-X-ray related activities at IOF in general including multilayer coatings and diffraction gratings. Special emphasis will be placed on the modeling and measurement of roughness-induced light scattering. An instrument for EUV light scattering measurements at 13.5 nm developed at IOF will be presented. Results of angle resolved scattering measurements of Mo/Si multilayer mirrors for 13.5 nm will be analyzed using simple roughness and light scattering models. Furthermore, a laser light scattering method will be presented that enables the roughness of large collector mirrors for laser-produced plasma EUV sources to be characterized and the performance to be predicted before coating. If you would like to meet with this speaker please contact the host ( or Peter Takacs ( to cordinate a time.

  330. NSLS-II HXN BAT Meeting

    Wednesday, June 1, 2011, 8:30 am
    Large Conference Room, Bldg. 703

    Hosted by: Dr. Yong Chu

  331. Photon Sciences Seminar

    "New Improvements in Figuring of X-Ray Substrates"

    Presented by Deborah Dahan, SESO

    Tuesday, May 31, 2011, 10 am
    Bldg 703, Large Seminar Room

    Hosted by: Andy Broadbent

    SESO will present the company’s facilities and describe its x-ray products. Being aware of the scientific needs for nanofocusing mirrors, the company has developed new technologies and processes (including new mirror benders, Ion Beam Figuring and deterministic polishing) to manufacture micro to nanofocusing mirrors from 150mm to more than 600 mm length. The technological improvements in manufacturing and measuring X-ray mirrors are such that the company can now produce mirrors with slope errors down to 0.1µrad rms.

  332. NSLS-II Seminar

    "Monte Carlo Simulation of Neutron Powder Diffraction at Spallation Source"

    Presented by LI LI, Columbia University

    Friday, May 27, 2011, 2:30 pm
    Large Conference Room Building 703

    Hosted by: Enju Lima

    Measured powder diffraction patterns contain contributions from the sample examined in the study and the instrument used for the measurement.  Most available data analysis software operate on the measured data to extract sample parameters. However, there are few programs that can take sample parameters and rigorously simulate the expected diffraction profile for a given instrument. In this work Monte Carlo methods, within the framework of McStas software, were used for the simulation of neutron diffraction at SMARTS diffractometer in Los Alamos Neutron Science Center. Simulations included all machine components, such as the moderator, guide system, collimator, sample (kernel) and detector banks. The simulation yielded information on the line broadening introduced into the diffraction profile as a function of energy and was used to predict the size limit above which line broadening studies cannot be performed on this instrument. This work provides an example of how rigorous scattering theory can be used to design optimal diffraction instruments.

  333. NSLS-II Seminar

    "Mapping Structure from Microns to Atomic Length Scales with Coherent Diffraction."

    Presented by Stephan Hruszkewycz

    Thursday, May 26, 2011, 2:30 pm
    Large Conference Room, Building 703

    Hosted by: Enju Lima

    Coherent x-ray diffraction techniques that utilize speckle can be designed to provide reciprocal space information encoded with complex structural information ranging from unit cell to micron length scales. With two decades of development and an increased emphasis on coherence at light sources around the world, these techniques are maturing to the point of being useful as tools for exploring complex structural issues in materials science. This talk will focus on recent efforts to understand, develop, and apply novel coherent Bragg diffraction techniques to materials with complex local non-periodic structure. I will discuss experiments designed to use the coherent beams at the Advanced Photon Source(APS) and at the Linac Coherent Light Source (LCLS) as well as the simulation tools we designed to clarify the interaction of these beams with complex atomic structures. Specifically, our goals include 3D imaging of non-ideal oxide nanocrystals at the APS with both plane wave and focused coherent beams as well as measuring femtosecond dynamics in atomic glasses at LCLS using coherent speckle.

  334. Users' Meeting

    "Free Plenary Session, 2011 NSLS/CFN Users' Meeting"

    Tuesday, May 24, 2011, 8:30 am
    Berkner Hall Auditorium

    Hosted by: NSLS and CFN Users' Executive Committees

  335. NSLS-II Workshop

    Wednesday, May 18, 2011, 1 pm
    Berkner Hall

    Hosted by: Doon Gibbs

  336. NSLS-II - Beamline Development Workshop

    "BDP Workshop - Medical Imaging and Radiation Therapy (MIRT)"

    Presented by Various Speakers, Different Affiliations

    Monday, May 9, 2011, 8 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Avraham Dilmanian

    We propose the development of a state-of-the-art medical imaging and radiation therapy beamline for the NSLS-II, building on the experience and success to date at NSLS. The justifications for such a facility are a) the local expertise in medicine and technology in support of the ideas and demands of a diverse user community, and b) the specifications of the NSLS-II, making it one of the most suitable facilities anywhere for use in medical applications. These specifications include the facility’s 3.0 GeV ring energy, 500 mA top-off ring current and low emittance, the possibility of a high field superconducting wiggler source for full field, wide fan-beam imaging, and prospects for having a long beam line for imaging of large animals and potentially human subjects. Both basic research and preclinical studies in a wide range of applications will be conducted at the beam line. The facility will attract a large number of investigators from the immediate neighborhood, from the rest of the United States, and from other countries. The beamline will be competitive with the similar existing and planned facilities, globally.

  337. National Synchrotron Light Source Lunch Time Seminar

    "Measuring the dynamics on the go: X-ray photon correlation experiments under continuous flow"

    Presented by Andrei Fluerasu, NSLS-II BNL

    Friday, April 29, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  338. Workshop

    "Synchrotron X-ray Studies of Advanced Nuclear Energy Systems at NSLS II"

    Friday, April 29, 2011, 8:30 am
    Large Conference Room, Bldg. 490

    In order to gather and hear the scientific community opinion we are organizing a workshop on Synchrotron X-ray studies of advanced nuclear energy systems at NSLS II to be held on April 28-29, 2011, at Brookhaven National Laboratory. Sponsored by Brookhaven National Laboratory, this workshop will focus on the use of synchrotron X-rays techniques for investigating advanced nuclear structural materials and fuels, radioactive materials, materials of interest to the nuclear forensics and national security, and fabrication of materials using ion implantation

  339. Photon Sciences Beamline Development Workshop-Trends in Structural Biology

    "Beamline Development Workshop - All Day Event"

    Presented by Various Speakers, Various Institutions see below

    Thursday, April 28, 2011, 8 am
    Seminar Room, Bldg. 725

    Hosted by: Patrick Loll (Drexel) and Vivian Stojanoff (PS)

    With the advent of the NSLS-II, it is a good time to take stock of the current state of the art in structural biology, and to look forward to what the future will bring. This meeting is intended to survey current research and develop a perspective on future themes in structural biology. Discussions will focus both on current methods and methods currently under development, with the goal of identifying advances that are most likely to benefit the field.One and half day event. Confirmed speakers Mario Amzel (John Hopkins), Bert van den Berg (UMASS), Gino Cingolani (Thomas Jefferson), Roger Fourme (SOLEIL), James Holton (ALS), Veijo Honkimaki (ESRF), XianPeng Kong (NYU), Dean Madden (Dartmouth), Enrique Rudino (UNAM), Peter Siddons (PS), Gyorgy Snell (Takeda), Yong Tang (Wistar), Michael Wiener (UVa), Ji-Fang Zhang (Thomas Jefferson), Ming-Ming Zhou (MSSM).

  340. National Synchrotron Light Source Seminar


    Presented by Yevgeny Lifshitz

    Wednesday, April 27, 2011, 1 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

    Preparation of organic layers on liquid surfaces has been a topic for the scientific curiosity for more than hundred years. By this low–cost production method the variety of materials with important electrical, optical, structural and chemical properties can be made. However, in spite of the relatively good investigation of structure and properties of Langmuir films (LF), their use still did not become commercial. The main obstacle is the pure stability of organic layers on liquid sub phase. One way to overcome this problem is to use the organic molecule with ability to be polymerized after arrangement on the liquid surface. For this purpose in the present work the amphiphilic molecules containing either the diacetylene (PDA) or thiol part (TDT), which can be easily initiated for the polymerization, were used. The main idea of current research was to investigate the promising systems of ultra – thin organic layer on the gas – liquid interface and find the external parameters, which can control their basic properties such as crystal structure and morphology and advance the realization of the potential applications of this type of materials.

  341. National Synchrotron Light Source Lunch Time Seminar

    "Complexity behind Metal Organic Frameworks’ Chemistry"

    Presented by Jorge Gascon, Delft University of Technology, Catalysis Engineering – Chemical Engineering Dept, The Netherlands

    Friday, April 22, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

    During the last decade, Metal Organic Frameworks (MOFs) have attracted a great deal of attention in the field of nanostructured materials. The combination of organic and inorganic subunits in these crystalline porous materials has led to vast chemical versatility. In spite of initial skepticism owing to poor stability of the first MOF generation, impressive progress has been made during the last few years, yielding promising results in very different technological disciplines, such as, adsorption and heterogeneous catalysis. MOFs are indeed among the most sophisticated nano-structured solids: not only they possess high surface area and pore volume, but their chemical environment can be fine-tuned by selecting the appropriate building blocks, or by post-synthetic functionalization. In spite of the plethora of publications on the topic, very little is known about the factors that rule both the performance and the formation of this new class of materials. During this lecture, using two amino functionalized aluminum terephthalate based frameworks (NH2-MIL-53(Al)[1] and NH2-MIL-101(Al)[2]) as example, the reasons for the excellent CO2 capture ability and the step-by-step mechanism behind the competitive formation of these two MOF phases will be unraveled with the help of several in situ synchrotron based techniques. [1] a) A. Boutin, S. Couck, F.-X. Coudert, P. Serra-Crespo, J. Gascon, F. Kapteijn, A. H. Fuchs and J. F. M. Denayer, Microporous and Mesoporous Materials 2011, 140, 108-113; b) S. Couck, J. F. M. Denayer, G. V. Baron, T. Remy, J. Gascon and F. Kapteijn, Journal of the American Chemical Society 2009, 131, 6326-6327; c) S. Couck, T. Remy, G. V. Baron, J. Gascon, F. Kapteijn and J. F. M. Denayer, Physical Chemistry Chemical Physics 2010, 12, 9413-9418; d) E. Stavitski, E. A. Pidko, S. Couck, T. Remy, E. J. M. Hensen, B. M. Weckhuysen, J. Denayer, J. Gascon and F. Kapteijn, Langmuir 2011, 27, 3970-3976. [2] P. Serra-Crespo, E. V. Ramos-Fernandez, J. Gascon

  342. Instrumentation Division Seminar

    "New Detectors with Novel Electrode Configurations for Applications in Extremely Harsh Radiation Environments (sLHC), RHIC-Upgrade and Photon Sciences"

    Presented by Zheng Li, Instrumentation Division, BNL

    Wednesday, April 20, 2011, 2:30 pm
    Large Conference Room, Bldg. 535

  343. National Synchrotron Light Source Lunch Time Seminar

    "The role of heparin in APP dimerization"

    Presented by Dr. Ya Ha, Yale School of Medicine

    Friday, April 15, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Vivian Stojanoff

  344. National Synchrotron Light Source Lunch Time Seminar

    "Structure and Mechanism of the UvrA-UvrB DNA Damage Sensor"

    Presented by Danaya Pakotiprapha, Department of Molecular and Cellular Biology, Harvard University

    Friday, April 8, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: LinYang

  345. National Synchrotron Light Source Seminar

    "Low dimensional superconductivity and proximity effect of Pb nano-islands"

    Presented by Jungdae Kim, University of Texas at Austin

    Wednesday, April 6, 2011, 11 am
    Large Conference Room, Bldg 703

    Hosted by: E. Nazaretski

    Low-dimensional superconductivity has been the subject of intense interest for decades. One of the key open questions in superconductivity concerns its detailed properties in confined geometries at the nanoscale, particularly the size limits for which a real physical system can maintain global and local superconducting phase coherence. I will systematically address this fundamental issue via a detailed scanning tunneling microscopy/spectroscopy (STM/STS) study of Pb superconducting islands with different thicknesses and lateral sizes supported on Si(111). As the lateral dimension of an island is reduced, suppression of the superconducting gap D depends to a good approximation only on the volume of the island, being largely independent of its shape. We have discovered an intriguing lateral proximity effect on Pb nano-islands; an island with a higher transition temperature can induce superconductivity in a nearby island with a lower transition temperature. By measuring the spatial mapping of the local superconducting gap, we also experimentally determine a lateral “proximity” length. When an island is smaller than the proximity length, it is found that superconductivity within the island is rather uniform, indicating the rigidity of the order parameter on the scale of proximity length.

  346. National Synchrotron Light Source Seminar

    Christian Broennimann, Dectris, Switzerland

    Tuesday, April 5, 2011, 1 pm
    703 Large Conference Room

    Hosted by: Lutz Wiegart

    The PILATUS pixel detectors, large area modular two-dimensional hybrid pixel array detectors, have revolutionized protein crystallography and biological SAXS/WAXS by combining noise-free counter properties with highest data acquisition rates. These features enable optimized data acquisition modes and new experimental techniques. The PILATUS 6M detector was developed at the Paul Scherrer Institut specifically for protein crystallography. The PILATUS 1M and 2M detectors are becoming common at synchrotron SAXS facilities. Optimal data collection strategies for protein crystallography will be discussed in terms of oscillation angle, data redundancy and beam focusing properties as well as dose rate effects in room temperature data collection. Diffraction based alignment and grid scanning is ideally supported by virtue of the high framing rate (Aishima et al Acta Cryst. D66, 1032, 2010). Besides static and time-resolved biological SAXS, these detectors enable previously impossible data acquisition protocols such as scanning-SAXS and X-ray ptychography (Bunk et al, New J. Phys. 11 123016, 2009). Time resolved SAXS/WAXS experiments are enabled by the gating possibility of the detectors. The MYTHEN detector is a one-dimensional strip detector (Bergamaschiet al, J. Synchrotron Rad. 17, 653, 2010) widely used for a number of techniques as powder diffraction, surface diffraction and reflectometry. DECTRIS is further developing the detector technology. The large area detectors are now available with a factor of 2 higher frame rates. We are investigating the influence of synchrotron bunch structure effects on count rate corrections. A new concept to increase the count rate capability is presented. The most important development however concers pixel detectors with smaller pixels and higher frame-rates. Most recent results from the EIGER detector, currently developed at PSI and to be commercialized by DECTRIS, will be shown.

  347. National Synchrotron Light Source Seminar

    "Protein-protein interactions - some dynamic features"

    Presented by David Cowburn, Albert Einstein College of Medicine

    Monday, April 4, 2011, 3 pm
    Seminar Room, Bldg. 725

    Hosted by: Marc Allaire

  348. National Synchrotron Light Source Seminar

    "X-ray microdiffraction for the microstructural studies at micron/submicron scale"

    Presented by Kai Chen, Lawrence Berkeley National Laboratory

    Monday, April 4, 2011, 10:30 am
    Seminar Room, Bldg. 725

    Hosted by: Evi Nazaretski

    Beamline 12.3.2 at the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory is a newly commissioned beamline dedicated to x-ray microdiffraction. It operates in both monochromatic and polychromatic radiation mode. The facility uses a superconducting bending magnet source to deliver an x-ray spectrum ranging from 5 to 24 keV. The x-ray beam is focused down to about 1 μm size at the sample position using a pair of Kirkpatrick–Baez (KB) mirrors enclosed in a vacuum box. The sample placed on high precision stages can be raster-scanned under the microbeam while a diffraction pattern is taken at each step. The arrays of diffraction patterns are then analyzed to derive distribution maps of phases, orientation, and strain/stress inside the sample. It has demonstrated wide applications in the investigations of materials, earth, and environmental sciences, combining with other advanced techniques such as FIB, TEM, and so on.

  349. National Synchrotron Light Source Lunch Time Seminar

    "Extracting vibrational information from crystallographic data"

    Presented by Enrique Rudino-Pinera, Instituto de Biotecnologia Universidad Nacional Autonoma de Mexico

    Friday, April 1, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Vivian Stojanoff

  350. National Synchrotron Light Source Seminar

    "Theory and Practice of Scattering Techniques in the Elastic and Quasi-Elastic Regimes"

    Presented by Yimin Mao, SUNY Stony Brook

    Thursday, March 31, 2011, 11 am
    Seminar Room, Bldg. 725

    Scattering is a complicated process which, depending on the form of the sample and the detection scheme, can generate abundant structural and dynamic information for a broad range of systems such as solid state crystal, amorphous liquid, semi-crystalline polymer, polymer/colloidal/biomacromolecular solution, etc. A consistent description of scattering phenomena, focusing on aspects of spatial and time correlation will be presented, based on the author’s scattering theory understanding and experimental practice. In classic X-ray scattering experiment, time-averaged measurements are performed, we seek the spatial correlation in the detected signal, in both wide- and small-angle X-ray scattering(WAXS/SAXS) geometry . An ex- ample of crystallization behavior of propylene-1-butene(P-B) random copolymer under external field will be given, illustrating how advanced X-ray scattering data analysis can help to understand polymorphism, morphology and preferred orientation. On the other hand, laser source demonstrates excellent coherence property which can be used to perform time-dependent measurements such as dynamic light scattering (or photon correlation spectroscopy). In this case, we focus on intensity fluctuation induced by particle dif- fusion. Recent progress on theory and instrumentation on a new technique, the photon cross-correlation spectroscopy aimed at solving multiple scattering problem will be introduced. The presentation is based on the research projects during the author’s graduate study. No attempt will be made to introduce all specific details as individual case study, but the interrelationship among various experimental phenom- ena will be stressed, demonstrating that many important concepts can be interpreted coherently under a concrete framework.

  351. National Synchrotron Light Source Lunch Time Seminar

    "Molecular assembly of metal-organic frameworks as studied by X-ray scattering"

    Presented by Eli Stavitski, PhD, NSLS, BNL

    Friday, March 25, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  352. NSLS-II Seminar

    "Structure and Dynamics of Lipid Membranes — An x-ray and neutron study"

    Presented by Dr. Gang Chen

    Wednesday, March 23, 2011, 10 am
    Large Conference Room, Building 703

    Hosted by: Dr. Enju Lima

    The model phospholipid membranes are of considerable scientific and practical interest because they provide a window into understanding the thermodynamics for phase separation of membrane components in a living cell. Within this framework, intense debate currently surrounds the understanding of the fundamental basis for the formation and dynamics of the so called raft micro-domains, which have been broadly implicated in many membrane functions. Here we report an unusual consequence of a physical property of the membrane-substrate interface in influencing phase separation in supported bilayers. The planarity of the interface constrains the head-groups of the lower leaflet to organize in a single topologically-defined plane. As a consequence, we find that the topology of the outer leaflet becomes strongly corrugated in multicomponent bilayers. Influences of such imposed physical topology on phase separation are also discussed. The effect of the membrane-substrate interaction is further demonstrated in a multi-stack bilayer system. Off-specular diffuse scattering shows a kink which corresponds to the cutoff wave vector of surface capillary waves. In order to circumvent the substrate proximity effect and fully lift the dynamics of lipid membranes, we studied lipid membrane multilayers in humidity. Both x-ray and neutron scattering techniques are applied to study their phase transition. Below the phase transition temperature, a new phase which is related to the raft formation appears with distinct bilayer spacing and pops off from the lipid mixture. We also observed for the first time the dynamics of lipid membrane multilayers in humidity with X-ray Photon Correlation Spectroscopy (XPCS).

  353. National Synchrotron Light Source Lunch Time Seminar

    "High kinetic energy photoemission in basic and applied research"

    Presented by Olof Karis, Department of Physics, Uppsala University

    Friday, March 18, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  354. National Synchrotron Light Source Lunch Time Seminar

    "Applications of XAS/XMCD to Magnetic Oxide Thin Films"

    Presented by Dario Arena, NSLS, BNL

    Friday, March 18, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  355. National Synchrotron Light Source Seminar

    "From growth of multilayers to multilayer Laue lenses nanofabrication"

    Presented by Nathalie Bouet, Brookhaven National Lab

    Thursday, March 17, 2011, 2:30 pm
    Bldg 703, Large Conference Room

    Hosted by: Raymond Conley

    In spite of the widely recognized importance of WSi2/Si multilayer coatings for X-ray nanofocusing [1, 2], little work has been done to explore the different possibilities to prepare Multilayers Laue Lenses (MLL) from the as-grown films. The current technique to section the multilayers [3] is based on TEM cross-section like preparation. Despite the good results provided by this method, it has the disadvantage of being highly time and material consumptive, as well as imparting mechanical stress on the MLLs being sectioned which leads to a very poor yield rate and inherent limitation on sectioning thickness for the latest MLLs which have an unprecedented growth thickness. Reactive ion etching is actively being explored as a technique of choice to achieve a high-quality sectioning of the multilayers with preservation of the as-grown qualities of the samples. In addition, this preparation technique would provide access to more exotic shapes, which may provide greater mechanical stability of the MLL during actual use in synchrotron applications. This presentation will discuss the growth of multilayers, the associated metrology controls and our recent experimental investigations on reactive ion etching and inductively coupled plasma reactive ion etching of WSi2/Si multilayers [4] to fabricate usable Multilayer Laue lenses.

  356. NSLS-II Seminar

    "Development of sub-20nm Hard-x-ray Microscopy and Applications in Microangiogenesis and Nanomedicine"

    Presented by Yeukuang Hwu, Institute of Physics, Academia Sinica, Taipei, Taiwan

    Monday, March 14, 2011, 10 am
    Large Conference Room, Bldg. 703

    Hosted by: Yong Chu

    Using state-of-the-art nanofabrication, phase zone plates suitable for hard-x-rays, sub-20 nm resolution can now be obtained with ease. Ongoing developments in the instrumentation and reconstruction algorithms continue to improve the nanometer scale resolution x-ray imaging in 3D and non-destructive way. Review of this advent of this technology, its application to various domains in science, the relevance to the nanoscience and nanotechnology will be presented. Specifically, an effort to take full advantage of the power of x-ray imaging to look into deep and fine structures, such as the study of the microvascular structure in details and in different aspects relevant to the tumor angiogenesis. The high lateral and temporal resolution of x-ray microscopies are exploited in an optimal way to achieve the detailed understanding of the microangiogenesis process and benefit the drug development based on the anti-angiogenesis strategy. The key factors enable such capability are the effective integration of research community in biology, medicine, physics and chemistry. In particular, the proper animal handling, the selection of relevant animal models, the application of nanomedicine as labeling and contrast agents attributed to the first successful exploration of the imaging capability offered long ago by SR x-ray microscopy. This presentation will focus on course of the development in the instrumentation and experiments with special emphasis on the nanomedicine, nanofabrication and nanosynthesis made possible by synchrotron x-rays.

  357. National Synchrotron Light Source Lunch Time Seminar

    "In-Situ X-Ray Studies of Lithium Battery Electrodes"

    Presented by Michael Lowe, Cornell University

    Friday, March 11, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  358. National Synchrotron Light Source Seminar

    "Tomography and In situ time-resolved Imaging of Structural Evolution in Nanoporous Gold during Dealloying and Coarsening by Transmission X-ray Microscopy"

    Presented by Yu-chen Karen Chen, Northwestern University

    Monday, March 7, 2011, 10:30 am
    Seminar Room, Bldg. 725

    Nanoporous gold has attracted great attentions due to its numerous potential applications in sensors, actuators and catalytic materials. Dealloying of silver-gold alloys result in a sponge-like porous gold structure with 5-20 nm pore size. In order to change the optical and mechanical properties of the materials, their pore size can be further coarsened by post-annealing. To fully understand the underlying mechanisms of the dealloying and coarsening processes, we characterized the structural evolution of nanoporous gold using the transmission x-ray microscope at Advanced Photon Source. The microscope offers tomography capability and a 30-40 nm 2D resolution. Dealloying of silver-gold was imaged in-situ, within a custom designed chemical reaction cell. Coarsening of nanoporous gold was studied by 3D tomography as function of annealing time and temperatures. The structural evolution and kinetics in dealloying and coarsening will be discussed. Furthermore, many research fields can potentially benefit from this cutting edge imaging technique, especially with the higher time resolution achievable at third generation synchrotron x-ray sources, which provide high x-ray flux. A few new possible future applications using TXM for time-resolved imaging and nano-tomography will also be discussed.

  359. National Synchrotron Light Source Lunch Time Seminar

    "Full spin polarization of the surface state on a topological insulator Bi2Se3."

    Presented by Zhihui Pan, MSCMD, BNL

    Friday, March 4, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  360. National Synchrotron Light Source Seminar

    "Magnetic Soft X-Ray Microscopy: A Path Towards Imaging Magnetism Down to Fundamental Length and Time Scales"

    Presented by Peter Fischer, Lawrence Berkeley National Laboratory

    Friday, February 25, 2011, 10:30 am
    Seminar Room, Bldg. 725

    Hosted by: Dario Arena

    One of the scientific and technological challenges in nanomagnetism research is to image magnetism down to fundamental magnetic length and time scales with elemental sensitivity in advanced multicomponent materials. Magnetic soft X-ray microscopy is a unique analytical technique combining X-ray magnetic circular dichroism (X-MCD) as element specific magnetic contrast mechanism with high spatial and temporal resolution. Fresnel zone plates used as X-ray optical elements provide a spatial resolution down to currently 10nm thus approaching fundamental magnetic length scales such as magnetic exchange lengths. Images can be recorded in external magnetic fields giving access to study magnetization reversal phenomena on the nanoscale and its stochastic character with elemental sensitivity. Utilizing the inherent time structure of current synchrotron sources fast magnetization dynamics such as current induced wall and vortex dynamics in ferromagnetic elements can be performed with a stroboscopic pump-probe scheme with 70ps time resolution, limited by the lengths of the electron bunches. With a spatial resolution approaching the <10nm regime, soft X-ray microscopy at next generation high brilliant fsec X-ray sources will make snapshot images of nanosclae ultrafast spin dynamics become feasible.

  361. NSLS-II Seminar

    "Extreme Precision Optics manufacturing capabilities at Zygo Corporation"

    Presented by Marc Tricard, Zygo Corporation

    Tuesday, February 22, 2011, 1 pm
    Bldg. 703, Large Conference Room

    Hosted by: Mourad Idir

    Zygo Corporation, a leading provider of high precision optical components and optical metrology instruments, has recently acquired all the assets of ASML US Richmond Optics facility. Zygo has also hired key managements and employees working at ASML's Richmond facility to become part of Zygo's Optical Systems Division - Extreme Precision Optics (EPO) Group. In this presentation we will give an overview of Zygo’s overall capabilities for high end precision optics manufacturing with particular emphasis on these newly acquired capabilities. Of direct relevance to BNL’s optics needs will be various deterministic finishing techniques (including Computer Controlled Polishing - CCP, Ion Beam Finishing - IBF and Magneto-Rheological Finishing – MRF) capabilities now available at Zygo and of course the associated metrology to drive these processes.

  362. National Synchrotron Light Source Lunch Time Seminar

    "Structural Characterization of Aromatic-Solute Binding Proteins from Rhodopseudomonas palustris"

    Presented by Ruth Pietri, Ph.D, NSLS, BNL

    Friday, February 18, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  363. National Synchrotron Light Source Lunch Time Seminar

    "Electronic Structure of Zinc Tetraphenyl Porphyrins adsorbed on wide band gap semiconductors"

    Presented by Dr. Sylvie Rangan, Rutgers University

    Friday, February 11, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  364. National Synchrotron Light Source Lunch Time Seminar

    "Membrane Protein Folding Conformations and Interactions"

    Presented by Karen G. Fleming, Ph.D., Johns Hopkins University

    Friday, February 4, 2011, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  365. NSLS-II Seminar

    Dr. Paul Zschack, Argonne National Laboratory

    Tuesday, January 25, 2011, 3 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Qun Shen

    Knowledge of atomic arrangements and composition at surfaces in complex environments and at buried interfaces is fundamental to our understanding and control of fabricated thin-film structures and of complex interfaces found in nature. Indeed, many critical processes are controlled by interfacial structure and chemistry. Because of favorable cross sections, x-rays offer a unique opportunity to penetrate through gas, liquid, or solid thin-films to probe this structure on the atomic length scale. The hard x-ray brilliance of the Advanced Photon Source (APS) enables these in-situ studies and permits real-time investigations. In this talk, I will illustrate several important x-ray scattering and imaging techniques that are presently used at the APS for the study of interface structure. One area includes materials synthesis where in-situ, time-resolved crystal truncation rod scattering has been used to demonstrate that Pulsed Laser Deposition (PLD) is a two-layer growth process, largely governed by extremely fast non-equilibrium interlayer transport. In other studies, new x-ray imaging techniques have been used to characterize surface and buried interface structures with excellent spatial resolution. For example, X-ray Reflection Imaging Microscopy (XRIM) is a promising new full-field imaging technique that exploits phase contrast in interface scattering and has been used at the APS to characterize the step/terrace structure at solid-solid and solid-fluid interfaces. In addition to an overview of these current research capabilities, plans to expand Interface Science research at the APS through development of a dedicated, comprehensive facility will also be presented.

  366. NSLS-II Seminar

    "Compact ERL Project Status at KEK"

    Presented by Takashi Obina, High Energy Accelerator Research Organization, KEK, Japan

    Wednesday, January 12, 2011, 1:30 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Sam Krinsky, Weixing Cheng

  367. NSLS-II Seminar

    "SuperKEKB Status"

    Presented by Makoto Tobiyama, High Energy Accelerator Research Organization, KEK, Japan

    Tuesday, January 11, 2011, 1:30 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Sam Krinsky, Weixing Cheng

  368. NSLS-II Seminar

    "First Light at I13: News about the Imaging and Coherence Beamline at Diamond"

    Presented by Christoph Rau, Diamond Light Source, Didcot, United Kingdom

    Monday, January 10, 2011, 10:30 am
    Large Seminar Room, Bldg. 703

    Hosted by: Yong Chu

    The coherence and imaging beamline I13L is dedicated to hard X-ray microscopy either in direct or reciprocal space. For both, lens and lensless imaging, two inde-pendent stations will be operated at a distance of 250m from the source. The coherence length can be adjusted over a large range by a modification of the electron beam in the storage ring and slits in the fron-end. The imaging branch will perform In-line phase contrast imaging and tomography over a large field of view in the 6-30keV energy range. In addition it will be possible to switch to full-field microscopy with 50nm spatial resolution. Projection microscopy will be developed, as it is dose efficient and therefore particular suitable for radiation sensitive samples. Resolution beyond the limitations given by the detector and X-ray optics may be achieved with techniques working in the far field. For crystalline samples Coherent X-Ray Diffraction allows not only to reconstruct the shape of nano-crystals but also to provide 3D information about parameters such as internal stress. Other Coherent Diffraction Imaging techniques such as ptychography will be also implemented on the same 'coherence branch'. The electron optics have been modified in August 2010 and the new operation of the storage ring has been successfully implemented in user operation mode. We recently took a first image of a test pattern, the stations will be operational from October 2011. Reference: The Diamond Beamline I13L for Imaging and Coherence, C. Rau, U. Wagner, A. Peach, I. K. Robinson, B. Singh, G.Wilkin, C. Jones, SRI 2009, AIP Conference Proceedings Vol. 1234, pp. 121-126, (2010). Double Mini-Beta y plus Virtu7al Focusing Optics for Diamond Storage Ring, B. Singh, R. Bartolini, R. Fielder, E.C. Longhi, I.P. Martin, U.H. Wagner, C. Rau, PAC09 proceeding.

  369. NSLS-II Seminar

    "Next generation optics for high-resolution inelastic x-ray scattering: Principles, challenges, and progress"

    Presented by Yuri Shvyd'ko, Argonne National Laboratory, Advanced Photon Source

    Thursday, January 6, 2011, 2:30 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Yong Cai

    Principles and optical schemes of angular-dispersive backscattering monochromators and analyzers will be presented. The novel x-ray optics has a potential of achieving sub-meV energy resolution, spectral functions with sharper tails, and better momentum transfer resolution in inelastic x-ray scattering (IXS) experiments, as compared to the state of the art IXS optics. Optical and mechanical designs of the in-line angular-dispersive backscattering monochromators/analyzers, termed CDDW, will be introduced. Results of the first tests, at the APS, of the CDDW monochromators for 9.1 keV x-rays will be presented, in which a 0.4 meV resolution, and 16% average spectral efficiency have been demonstrated. If you would like to meet with this speaker after this presentation, please contact the host @ prior to this presentation to coordinate a time slot.

  370. NSLS-II Seminar

    "MAX-IV: Status, Schedule and Technical Challenges"

    Presented by Jonas Modeer, MAX-Lab, Sweden

    Monday, December 20, 2010, 11 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Samuel Krinsky

  371. National Synchrotron Light Source Lunch Time Seminar

    "Functional transport properties in complex transition metal oxides"

    Presented by Dr. Hee Taek Yi, Rutgers Center for Emergent Materials, Rutgers University

    Friday, December 17, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Larry Carr

  372. National Synchrotron Light Source Lunch Time Seminar

    "News from PETRA III"

    Presented by Wolfgang Caliebe, DESY

    Friday, December 10, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Steven Hulbert

  373. NSLS-II Seminar

    "Advanced R+D at the Advanced Light Source"

    Presented by Anthony Warwick, LBL

    Thursday, December 9, 2010, 8:30 am
    Bldg. 817, Conference Room 4

    Hosted by: Qun Shen

    After 15 years of operation there are many vigorous development programs at the ALS, some to develop new beamlines, some to radically improve instrumentation. This talk features a few examples, in the context of this mature and productive facility.

  374. Photon Sciences (United Way) Craft & Bake Sale

    Wednesday, December 8, 2010, 1 pm
    NSLS Lobby

    Hosted by: Betsy Hanson, Tammy Stein, Mary Anne Corwin

  375. NSLS-II Seminar

    "The bio-imaging and diffraction beamline P11 at PETRA III"

    Presented by Dr. Alke Meents, HASYLAB - DESY, Germany

    Monday, December 6, 2010, 10:30 am
    NSLS-II Large Conference Room, Bldg. 703

    Hosted by: Yong Chu

    Petra III is the new German 6 GeV synchrotron source with an emittance of only 1 nm rad. This makes PETRA III ideally suited for experiments requiring nanometer beam sizes in the harder X-ray regime. 14 different endstations cover experiments from material- to life sciences. The storage ring has reached its full performance and 3 beamlines have started regular user operation already. Beamline P11 is dedicated to the structure determination of biological objects in two different modalities. A Scanning Transmission X-ray microscope (STXM) operated at X-ray energies between 2.4 and 10 keV will allow structural investigations of aperiodic objects such as single cells and also small tissue sections. The STXM will allow cryo-cooling of the samples and will be operated in vacuum. A crystallography endstation will provide beamsizes down to 1 micron for the investigation of micro crystals and also a parallel beam option for large unit cell systems. The experiment will be equipped with a Pilatus 6M detector and an automatic sample changer. The first part of the presentation will provide a general introduction to the PETRA III facility and its beamlines. In the second part, beamline P11 will be presented in more detail with emphasis on different high precision hardware components developed by our group.

  376. National Synchrotron Light Source Lunch Time Seminar

    "Diboride Thin Films: Growth, Structure and Surface"

    Presented by Yukiko Yamada- Takamura, Japan Advanced Institute of Science and Technology (JAIST), Ishikawa, Japan

    Friday, December 3, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  377. National Synchrotron Light Source Lunch Time Seminar

    "Review of the present technology of the radiation source for Extreme Ultraviolet Lithography"

    Presented by Prof. Dr. Akira Endo, Japan

    Friday, December 3, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  378. National Synchrotron Light Source Lunch Time Seminar

    "Diboride Thin Films: Growth, Structure, and Surface"

    Presented by Yukiko Yamada-Takamura, Japan Advanced Institute of Science and Technology (JAIST), Japan

    Friday, December 3, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Jurek Sadowski

    Metal diborides, which have a simple crystal structure consisting of alternating hexagonal close-packed metal layers and honeycomb boron layers, have superior hardness and high melting temperature, together with high electrical and thermal conductivities. In the form of thin films, they could be integrated with other materials more easily, and become even more attractive. For example, zirconium diboride (ZrB2), which has a very good lattice matching to a wide-gap semiconductor, GaN, has a lot to offer in the form of epitaxial thin film: buffer layer, light reflector, heat-resistant electrode, etc. Here, I will present our recent results on the hetero-epitaxial growth of highly pure ZrB2 thin films using ultrahigh vacuum chemical vapor epitaxy method. Their surface structure and electronic properties were studied using scanning tunneling microscopy and angle-resolved ultraviolet photoelectron spectroscopy, and the similarities and differences between epitaxial thin film and single crystal will be discussed.

  379. NSLS-II Seminar

    "The Photon Transport System and Diagnostic for the FERMI at Elettra FEL Project"

    Presented by Daniele Cocco, Sincrotrone Trieste ScpA, Photon Transport and Beamlines Area, Mechanical Vacuum and Optics Group, Italy

    Friday, December 3, 2010, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Ruben Reininger

    The FERMI at Elettra project, a VUV and Soft X-ray Free Electron Laser (FEL), located in Trieste, Italy, is ready to deliver the first photons.This new machine is placed side by side to the 3rd generation SR source ELETTRA to extend the scientific capabilities of the Laboratory. In this seminar, after a brief introduction to the machine, the photon transport system of the FEL will be described, including diagnostic instrument and metrology issues. The first part of it, called PADReS, is dedicated to the photon diagnostic, intensity control and beamline selection. The second part is formed by four beamlines dedicated to four different kinds of experiments. Some solution will be described together with the preliminary results.

  380. National Synchrotron Light Source Workshop

    "CTM4XAS Charge Transfer Multiplet Course"

    Presented by Frank DeGroot, University of Utrecht, Netherlands

    Thursday, December 2, 2010, 1 pm
    Large Conference Room, Bldg 703

  381. National Synchrotron Light Source Seminar

    "In-Situ STXM and RIXS"

    Presented by Frank de Groot, Utrecht University, Netherlands

    Thursday, December 2, 2010, 10 am
    Seminar Room, Bldg. 725

    Hosted by: Steve Hulbert

    This talk deals with in-situ experiments that make use of Scanning Transmission X-ray Microscopy (STXM) and Resonant Inelastic X-ray Scattering. First, a brief introduction is given of x-ray absorption spectroscopy, including the multiplet interpretation of XAS spectral shapes. (The atomic multiplet, crystal field and charge transfer effects will in detail be explained in the afternoon course). With the recent developments in nanoreactors, soft X-ray STXM experiments make it possible to follow metal L edges at 1 bar and 500 C, with a spatial resolution of 20 nm. This allows the in-situ spectroscopic study of a single nanoparticle (in action). Recent STXM results show the spatial distribution of the degree of reduction of iron-oxide nanoparticles. A comparison is made with electron microscopy and some future directions of spectromicroscopy of nanomaterials are given. The second part of the talk deals with the role of Resonant Inelastic X-ray Scattering (RIXS) to unravel the nature of the states that are visible in the pre-edge region of the 3d metal K edges. Using the 1s2p RXES of LiCoO2 as example, the presence of a 1s4p dipole pre-edge next to the traditional 1s3d quadrupole pre-edge is explained. A recent development is the combination of hard x-ray RIXS with XMCD, allowing the possibility to measure magnetic properties under extreme conditions. Soft X-ray RIXS allows the detection of charge transfer and dd-excitations. Recent improvements in energy resolution allow the detection of spin-orbit and magnetic excitations. Potential new applications for in-situ nanoparticle research are indicated.

  382. National Synchrotron Light Source Lunch Time Seminar

    "How Electrons are Emitted from the [100] Negative Electron Affinity Surface of Boron Doped Diamond"

    Presented by Jonathan Rameau, BNL, Physics

    Friday, November 19, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  383. National Synchrotron Light Source Lunch Time Seminar

    "Folding of RNA in crowded solutions"

    Presented by Duncan Kilburn, Johns Hopkins University

    Friday, November 12, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  384. National Synchrotron Light Source Lunch Time Seminar

    "Electronic Structure of Strained Vanadium Dioxide Thin Films Using Soft X-ray Spectroscopy at X1b"

    Presented by Louis Piper, PhD, Assistant Professor, Physics, Applied Physics & Astronomy, Binghamton University, State University of New York

    Friday, November 5, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  385. National Synchrotron Light Source Seminar

    "Rigaku Osmic Capabilities"

    Presented by William Bowman, Rigaku Osmic

    Monday, November 1, 2010, 1:30 pm
    Conference Room A, Bldg. 725

    Hosted by: Lonny Berman

  386. National Synchrotron Light Source Lunch Time Seminar

    "One-dimensional hard-x-ray field retrieval using a moveable structure"

    Presented by Kenneth Evans-Lutterodt, BNL, PS

    Friday, October 29, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  387. NSLS-II Seminar

    "Spatially-resolved analysis of Element Distribution and Speciation in Soils and Soil Aggregates by by (mu)-XRF and (mu)-XANES"

    Presented by Joerg Prietzel, Techncial University of Munich, Germany

    Thursday, October 28, 2010, 9 am
    Seminar Room, Bldg. 725

    Hosted by: Juergen Thieme

    In recent decades, novel techniques of synchrotron-based X-ray spectroscopy and spectromicroscopy have emerged as powerful methods to study the biogeochemistry of nutrient as well as toxic elements in environmental samples, such as soils and sediments. The evaluation of element-specific or species-specific X-ray fluorescence or absorption patterns [X-ray Fluorescence Spectroscopy, XRF; X-ray Absorption Near-Edge Spectroscopy, XANES] enables environmental scientists to reveal patterns of element distribution and element speciation in environmental samples (e.g. soils) at different scales (from the m- or km-scale in landscapes or watersheds down to the micron- or submicron-scale in soil aggregates. Even spatial correlations between elements and/or element species can be addressed by analyzing the same sample at different element specific X-ray energies. The application potential of synchrotron-based spectroscopy and spectromicroscopy in soil science will be demonstrated by several examples. Furthermore, technical limitations as well as future prospects of the application of XAFS and (mu)-XAFS techniques for the analysis of soils and important biogeochemical interfaces in soils will be addressed.

  388. National Synchrotron Light Source Lunch Time Seminar

    "Structure-Property Relationships to Enable Plastic Electronics"

    Presented by Joe Kline, National Institute of Standard and Technology

    Friday, October 22, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  389. NSLS-II Seminar

    "Textured Dysprosium Poles for High-field, Short-period Cryogenically-cooled Hybrid Permanent-magnet Undulators"

    Presented by Slowa Solovyov, CMPD MSD, BNL

    Friday, October 22, 2010, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Oleg Chubar

    In the presentation we discuss feasibility of enhancement of the peak field in a short-period cryogenically-cooled hybrid permanent-magnet undualtor by using pole inserts with the saturation inductance Bsat over that of iron ( 2 - 2.5 Tesla). Magnetic simulations performed by RADIA magnetostatics code for the magnet material (PrFeB) and geometrical parameters of cryogenically-cooled permanent-magnet undulators considered for the development at the NSLS-II, demonstrate that the peak field continues to increase as Bsat of the pole is increased, reaching saturation at Bsat = 3.5 Tesla. Dysprosium metal, with the saturation inductance of 3.4 Tesla below 90 K, appears as a good candidate for the optimized pole material. However, due to high magnetic anisotropy of Dy, such a high level of magnetization can only be realized when the external field lies in the basal plane. This implies that the pole has to be single-crystalline or highly textured. Considering that the growing of large, >10 mm, Dy single crystals is difficult, we propose secondary re-crystallization as a method to induce the required texture in thin Dy foils. The textured foils can be stacked to produce pole inserts of the desired geometry and orientation. Results of small-scale processing and magnetic measurements of thin (20-60 microns) foils prove that the required texture quality can be achieved by relatively simple sequence of heat-treatment and rolling.

  390. National Synchrotron Light Source Lunch Time Seminar

    "Morphology of Phthalocyanine blends in thin film organic solar cells"

    Presented by Matthew Jurow, Hunter College, CUNY

    Friday, October 15, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  391. NSLS-II Seminar

    "Fourteen Years of Synchrotron Radiation for Museums: from Egyptian Cosmetics to Mona Lisa"

    Presented by Philippe Walter, Director, Laboratory - Centre Of Research and Restoration of the French Museums, France

    Tuesday, October 12, 2010, 11 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Eric Dooryhee

  392. National Synchrotron Light Source Lunch Time Seminar

    "The stability of nanoimprint induced molecular orientation in polymer nanostructures"

    Presented by Htay Hlaing, Stony Brook, BNL Condensed Matter Physics

    Friday, October 8, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  393. NSLS-II Seminar

    "PETRA III - Commissioning, First User Runs, Collective Effects"

    Presented by Rainer Wanzenberg, DESY, Germany

    Tuesday, October 5, 2010, 1:30 pm
    Large Conference Room, Bldg. 703

    Hosted by: Samuel Krinsky

  394. National Synchrotron Light Source Lunch Time Seminar

    "Determining the spin polarized unoccupied electronic structure of organic based magnetic system M[TCNE] using UV-Vis MCD by Saad Janjua"

    Presented by Saad Z. Janjua, NSLS, BNL

    Friday, September 24, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  395. NSLS-II Seminar

    "Optics, Sources and Systems for Laboratory X-ray Micro- and Nano-Imaging"

    Presented by Hans Hertz, Department of Applied Physics, Royal Inst. of Technology, Stockholm, Sweden

    Thursday, September 16, 2010, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Juergen Thieme

    Progress in laboratory-scale x-ray micro- and nano-imaging is reviewed. In the soft x-ray regime we demonstrate laboratory water-window microscopy with <25-nm-resolution, 3D microtomography of cryo-fixed biological samples, and aqueous-state imaging of environmental colloids. The progress relies heavily on our developments in diffractive optics, for resolution (13 nm Ni zone plates, compound zone plates), efficiency (Ni-Ge zone plates, now also at 13 nm) and for new contrast mechanisms (DIC and Zernike zone plates). In hard x-rays (10-30 kV) we discuss diffractive optics for high-brilliance synchrotron sources as well as phase-contrast x-ray imaging with few-µm detail based on a high-brightness laboratory electron-impact liquid-metal-jet-anode x-ray source.

  396. NSLS-II Seminar

    Mark Sutton, McGill University

    Wednesday, September 15, 2010, 11 am
    703 - Large Conference Room

    Hosted by: Andrei Fluerasu

    Intensity fluctuation spectroscopy (IFS) is an ideal way to study fluctuations in the microstructure of materials. For the last three decades or so, it has been extensively used with light scattering to study a large variety of transparent systems. Extending IFS to x-rays allows us to study opaque materials and to probe much shorter length scales, as required for example by binary alloys and carbon black in polymers (rubber). Recently, we have demonstrated how to make heterodyne measurments allowing measurements of relative phase information. In this talk, I will describe XIFS and discuss some of our recent results on a set of model rubbers.

  397. NSLS-II Seminar

    "JBluIce-EPICS: a modern control system with classical look for macromolecular crystallography at the Advanced Photon Source"

    Presented by Sergey Stepanov, ANL

    Wednesday, September 8, 2010, 9:30 am
    Bldg. 703 Large Conference Room

    Hosted by: Dr. Qun Shen

    The trio of macromolecular crystallography beamlines constructed by General Medicine and Cancer (GM/CA) Institutes at the APS has been in growing demand due to their outstanding micro crystallography capabilities. To raise the efficiency of these beamlines a significant effort has been put into designing fast, convenient, intuitive and robust beamline controls that could easy accommodate new beamline developments and provide high level of automation. This resulted in a system combining the widely praised user interface of SSRL BluIce as a frontend and the industrial power of EPICS as a backend. While the GM/CA controls have the look and feel of BluIce, their software design is very different making them faster, simpler and more flexible than most similar systems. The report will reveal the key design solutions implemented in JBluIce and discuss some automations making JBluIce highly praised by the crystallographic community: one-click change between 5, 10 and 20μm beam sizes; one-click beamline energy change that may involve switching undulator harmonics, mirrors lanes and beam realignment; automated diffraction rastering for finding small crystals and 'sweet' spots on poorly diffracting crystals with automated scoring of raster cells by the number of reflections; data collection along a vector; automated on-the-fly fluorescent rastering, a faster and lower-irradiation compliment to the diffraction rastering; fully automated fluorescence measurements for MAD that include signal optimization, fast on-the-fly energy scanning and automated adaption of scan range to chemical shifts; fly-scan minibeam realignment; automated loop and crystal centering, controls for sample automounter, automated screening, data collection auditing, remote access and a lot more.

  398. NSLS-II Seminar

    "Non-destructive characterization of microstructures utilizing the 3DXRD technique - an overview of software and applications"

    Presented by Soren Schmidt, RISOE, Denmark

    Friday, September 3, 2010, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Qun Shen

    The 3DXRD (Three Dimensional X-ray Diffraction) methodology for non-destructive characterization of individual grains in polycrystalline materials has been around for more than a decade. The first implementation, the 3DXRD microscope, is situated at beamline ID-11 at the European Synchrotron Radiation Facility (ESRF) developed in collaboration between Risoe and ESRF. A wide range of algorithms has been developed to facilitate new data analysis procedures. The ability to monitor the evolution in the local microstructure in materials has proven successful in studying recovery, recrystallization, grain growth as well as deformation mechanisms. The talk will give an overview of the 3DXRD software along with current and future scientific activities.

  399. NSLS-II Seminar

    "Hummingbird: active vibration isolation technology"

    Presented by Johan van Seggelen, MECAL, Netherlands

    Thursday, September 2, 2010, 10:30 am
    NSLS-II Large Conference Room, Bldg. 703

    Hosted by: Evgueni Nazaretski

    The high-tech industry constantly requires improvement of the accuracy of mechatronic systems. Floor vibrations around 1 Hz are a limiting factor in the performance of these systems. The Dutch engineering company MECAL ( developed a solution to suppress these vibrations significantly. - Suppression of floor vibrations of at least 30 : 1 - Low noise at low frequencies (around 1 Hz) as a result of direct position sensing - No stiff floor required as a result of voice coil actuation MECAL is a leading supplier of high-end active vibration isolation technology in the semiconductor and related high-tech industry. With their engineering competences they can carry out dedicated design-in projects and deliver customized platforms. Dr. Ir. Johan van Seggelen MBA (Business Development Manager at MECAL) will give a presentation on the technical details of the hummingbird technology and show performance measurement results. If you would like to meet with this speaker after this presentation, please contact the host @ prior to this presentation to coordinate a time slot.

  400. NSLS-II Seminar

    "The Design of the ALS Top-Off Mode Beam Interlock System -- from Requirements to Operation"

    Presented by Kenneth Baptiste, ALS/LBNL

    Tuesday, August 31, 2010, 1:30 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Samuel Krinsky

    ALS has been upgraded recently by adding a new mode of operation, the Top-Off Mode, which is in addition to the existing modes of Fill and Stored Beam. The Top-Off Mode permits injection of 1.9GeV electron beam into the Storage Ring, with the safety shutters open, once certain strict conditions are met and maintained. Top-Off Mode enables User operation without an interruption caused by mode switching between the Stored Beam Mode when safety shutters are open, to the Fill Mode with the safety shutters closed and back. The conditions necessary to permit Top-Off Mode are; stored beam is present, the energies are matched between the injector and storage ring, a select set of storage ring lattice magnets are operating at the correct current levels, and radiation losses are minimized. If certain combinations of these conditions are not met, a potentially dangerous condition of injecting electrons down a users beam line can exist. Therefore in addition to the configuration controlled beamline apparatus, a system of mode control, energy match, lattice match and stored beam interlocks are needed to actively control the injected beam prohibiting potentially dangerous conditions. In this talk I will present the Top-Off Mode Beam Interlock system requirements, specification, design, implementation and the operational experience from the first two years of operation.

  401. NSLS-II Seminar

    "An Overview of Science and Software Infrastructure at HPCAT"

    Presented by Dr. Arun Bommannavar, Carnegie Institution of Washington

    Friday, August 27, 2010, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Dr. Qun Shen

    An overview of science and software infrastructure at HPCAT is presented. Science at extreme conditions and instrumentation to accomplish the measurements is discussed with an emphasis on computer infrastructure and data acquisition software deployed. Planned APS upgrade adds additional requirements for data storage and user friendly operation. Java based softwares developed and deployed currently at HPCAT are shown . Current capabilities and future needs for data acquisition is presented.

  402. NSLS-II Seminar

    "Methods, related to ptychography used to reconstruct a hard X-ray beam waist"

    Presented by Cameron Kewish, Synchrotron SOLEIL, France

    Thursday, August 26, 2010, 1:30 pm
    Large Conference Room, Bldg. 703

    Hosted by: Ray Conley

    When coherent diffraction patterns are measured from overlapping regions in an extended sample it is possible to reconstruct not only the optical transmission function of the sample, but also the full complex-valued wavefield that was incident upon it. In this talk I will discuss the methods, related to ptychography, that we have used to reconstruct a hard X-ray beam waist created by nanofocusing K-B mirrors. Beyond characterizing the focus, the reconstructions provide us with a quantitative map of the aberrations in the mirror surface, and allow us to calculate corrections for astigmatism and misalignment. Ptychography provides an answer to the question "could the mirrors be re-aligned to produce a better focus?", even when the performance is close to the diffraction limit.

  403. NSLS-II Seminar

    "A New Beamline for Surface and Interface Science at Diamond Light Source"

    Presented by Dr. Tien-Lin Lee, Principal Beamline Scientist, Diamond Light Source, Oxford, UK

    Wednesday, August 25, 2010, 2 pm
    Large Conference Room, Bldg. 703

    Hosted by: Joe Woicik and Cecilia Sanchez Hanke

    A new beamline for studying surfaces and interfaces is currently being constructed at Sector 9 at Diamond Light Source and is scheduled to have its first light in November 2011. It is designed to be a dedicated facility for high-resolution investigations of atomic structures and electronic properties of a wide range of surfaces and buried interfaces, under ultra-high vacuum or ambient conditions, using photoelectron spectroscopy (PES), x-ray standing waves, x-ray absorption spectroscopy, photoelectron diffraction and x-ray reflectivity. To apply the different techniques to the same sample, and to access a wide range of absorption edges, which can be highly beneficial for studying complex systems, the beamline will provide both soft and hard x-rays with two canted undulators installed in a modified long straight section, and is designed to have one end-station where a spot on the sample can be probed by both beams. Such a combination also offers a unique opportunity for hard x-ray PES experiments over a wide energy range. This presentation will be focused on the technical design, scientific cases and current status of the beamline, with an overview of the research activities of other beamlines in the Surface and Interface Village at Diamond.

  404. NSLS-II Seminar

    "Numerical Simulations of X-ray Optics"

    Presented by Alexey Suvorov, SPring-8, Japan

    Tuesday, August 24, 2010, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Dr. Yong Cai

    In the talk I will demonstrate several algorithms to perform numerical evaluation and simulation of basic optical elements, namely planar x-ray mirrors, high resolution monochromators and crystal based focusing optics. In particular, first, I will discuss a problem of one-dimensional surface profile retrieval of x-ray mirror from grazing incidence images under coherent x-ray illumination. Three different approaches (analytical, iterative and a one based on the neural networks) to the problem will be analyzed and compared to each other. Next, a generalized solution to the problem of multi-beam dynamical x-ray diffraction from single and layered crystals will be presented. The new formalism embraces all possible diffraction geometries, including extreme cases of grazing and normal incidence and emergence. Finally, a focusing performance of cylindrically bent crystal in symmetric back diffraction geometry will be analyzed using wave-optical formalism. I will demonstrate a numerical simulation of a double-crystal setup which allows one to achieve a linear focal spot size of 2.8 nm.

  405. National Synchrotron Light Source Lunch Time Seminar

    "Synchrotron-based infrared research at Spring-8"

    Presented by Hidekazu Okamura, Physics Department, Kobe University, Japan

    Friday, August 13, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  406. National Synchrotron Light Source Lunch Time Seminar

    "Glimpses of Electronic Structure Peculiarities from Soft and Hard X-ray Absorption Studies: Lessons from Graphene and Vanadium Oxide Nanostructures"

    Presented by Sarbajit Banerjee, Assistant Professor, Department of Chemistry, University at Buffalo

    Friday, August 13, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  407. NSLS-II Seminar

    "Canadian Light Source and the REIXS Beamline"

    Presented by Feizhou He, Canadian Light Source, Saskatoon, Canada

    Friday, August 13, 2010, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Ruben Reininger

    Canadian Light Source, located at the University of Saskatchewan in Saskatoon, is Canada's national synchrotron research facility. Since the commencement of the operation in 2004, it now has 13 operational beamlines, and 6 more under construction. The REIXS beamline at CLS is a new soft X-ray scattering facility for elastic and inelastic x-ray scattering experiments. With two elliptical polarizing undulators (EPU) in the same straight section, the REIXS beamline can produce photons of various polarizations, and is capable of rapidly switching the polarizations. In the commissioning tests, the beamline has demonstrated high energy resolution, good beam flux, and excellent reliability. The REIXS beamline has two permanent endstations. The Resonant Soft X-ray Scattering (RSXS) endstation has started to generate very good scientific data since November 2009, and is now accepting general user proposals. The X-ray Emission Spectroscopy (XES) endstation is in the final stage of assembling and will start commissioning soon.

  408. National Synchrotron Light Source Lunch Time Seminar

    "The Effects of Sodium Fluoride on Human Embryonic Fibroblast Cells"

    Presented by Lauren Carlson, LeMoyne College

    Friday, August 6, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  409. National Synchrotron Light Source Lunch Time Seminar

    "Designing a Water Chamber to Generate Relative Humidity"

    Presented by Peter Ghali, NYIT

    Friday, August 6, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  410. National Synchrotron Light Source Lunch Time Seminar

    "Assessment of Skin Disease Diagnosis and Treatment with Infrared Light"

    Presented by William Willis, SBU

    Friday, August 6, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  411. National Synchrotron Light Source Lunch Time Seminar

    "Spontaneous Ferroelectric Order in a Bent-Core Liquid Crystal Phase of Orthorhombic Smectic Layers"

    Presented by Chenhui Zhu, Colorado

    Friday, July 30, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  412. National Synchrotron Light Source Lunch Time Seminar

    "Application of x-ray absorption spectroscopy in electrocatalysis"

    Presented by Minhua Shao, UTC Power

    Friday, July 30, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  413. NSLS-II Seminar

    "Multilayer optics at the (ESRF)"

    Presented by Christian Morawe, European Synchrotron Radiation Facility (ESRF), Grenoble, France

    Monday, July 26, 2010, 2 pm
    Bldg. 703, Large Conference Room

    Hosted by: Ray Conley

    The general mission of the ESRF Optics Group is to perform research and development of x-ray optical elements and systems. The group assists ESRF scientists in the conception of their beamline optics, and designs, fabricates, and tests optical elements. The group members operate a Crystal Laboratory, a Metrology clean room facility, a Multilayer Laboratory, and dedicated beamline instrumentation for rapid experimental access. In addition, they participate in development programmes on refractive lenses and on diamond crystals. The Multilayer Team is in charge of the development and fabrication of multilayer coatings for x-ray optical applications. The Multilayer Facility has been operational for about 15 years. During this period, more than 100 multilayer based optical elements were delivered to ESRF beamlines, some of which representing the workhorse in the optics hutch. A few years ago a new deposition system was designed, installed, and commissioned. Since 2008 the new laboratory is operational and has produced its first optical elements for ESRF beamlines. This talk will recall some fundamental properties of multilayer optics, discuss design and fabrication aspects, highlight the most prominent applications, and outline ongoing developments.

  414. NSLS-II Seminar

    "Multi-Axis Positioning with a Hexapod system and the advantages of a using Parallel Kinematics"

    Presented by Rainer Gloess, PI (Physik Instrumente) L.P.

    Monday, July 26, 2010, 10:30 am
    NSLS-II Large Conference Room, Bldg. 703

    Hosted by: Evgueni Nazaretski

    Dr. Rainer Gloess accompanied by Mark Wood: Talk will cover different hexapod designs and special designs for high vacuum and nonmagnetic applications. Measurement results, error budget, load capacity and thermal effects. Also using simulation tools and collision prevention software. If you would like to meet with the speaker after this presentation, please contact the host @ prior to this presentation to coordinate a time slot.

  415. NSLS-II Seminar

    "Data Management and Analysis Computing for LCLS"

    Presented by Alf Wachsmann, SLAC National Accelerator Laboratory

    Monday, July 26, 2010, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Qun Shen

    Overview of the online and offline data management and computing system for SLAC's LCLS free-electron X-ray laser the DAQ system to illustrate the data flow from the various experiments and then talk about the offline data management system and the analysis computing facility.The entire system is fully operational now for a few month and I will report on first experiences.

  416. National Synchrotron Light Source Lunch Time Seminar

    "Resonant x-ray studies on novel liquid crystal structures"

    Presented by Zengqiang John Liu, Assistant Professor of Physics, Department of Physics, Astronomy and Engineering Science St. Cloud State University WSB

    Friday, July 16, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  417. National Synchrotron Light Source Lunch Time Seminar

    "Slow dynamics in an azopolymer molecular layer studied by XPCS"

    Presented by Luigi Cristofolini, Physics Department, University of Parma, Parma, Italy

    Friday, July 16, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  418. NSLS-II Seminar

    "Lattice dynamics at ultra-high pressures: Quantification of phonon energies using high-resolution inelastic x-ray scattering"

    Presented by Daniel L. Farber, Lawrence Livermore National Laboratory - Earth Science Division

    Thursday, July 15, 2010, 11 am
    NSLS-II Large Seminar Room, Bldg. 703

    Hosted by: Yong Cai

    Over the past few years our group has focused a large experimental and theoretical effort on quantifying the vibrational energies in metals at high-pressures and high-temperatures. Our interest in the high-pressure properties of these elements is motivated both by their importance as constituents in the cores of many planetary bodies and by the rich variety of intriguing phenomena displayed by their lattice dynamics at room pressure. While IXS has addressed a number of phenomenological problems of great importance, such as the nature of the acoustic anisotropy of the Earth’s inner core by direct measurements on the high-pressure hcp-phase of iron, as well as by proxy experiments on cobalt; we have also pursued more general studies of condensed matter at high-pressure aimed at understanding many fundamental physical properties in systems as varied as Fe, Co, Mo, Ta, V, Ce, and even Pu. Indeed, with the application of pressures approaching 100 GPa, we are able to perturb the energy of condensed systems on the order of ~1 eV. Thus, performing lattice dynamics measurements under these conditions allows us to probe systems that have undergone fundamental changes the energetics of the chemical bonds. Most recently, we have determined the phonon dispersions across the isostructural gamma- to alpha-cerium transition, one of the most intriguing elemental phase transitions. Our new data together with first principals calculations place important thermodynamical and theoretical constraints on the underlying physics of this important transition. Such experiments have now begun to shed light on important magneto-elastic interactions, electron-phonon coupling and have the singular potential to provide critical data on the newly observed elastic perturbations across pressure induced spin-transitions. If you would like to meet with these speakers after this presentation, please contact the host at prior to this presentation to coordinate a time slot.

  419. NSLS-II Seminar

    "Instruments and methods for high-energy-resolution x-ray diffraction characterization of diamond crystals."

    Presented by Stanislav Stoupin, Argonne National Laboratory

    Monday, July 12, 2010, 10 am
    Large Conference Room, Building 703

    Hosted by: Yong Cai

    To date, silicon is the primary material for x-ray crystal optics. Well-established silicon crystal growth methods and processing techniques offer high quality diffracting elements with customizable crystallographic orientation. This flexibility is the key towards realization of millielectronvolt-resolution x-ray monochromators and analyzers for x-ray spectroscopy. However, silicon is inferior to diamond in terms of thermal conductivity, radiation hardness and thermal expansion. These are key aspects for high-heat-load applications of diamond in x-ray crystal optics, which become increasingly important at fourth-generation synchrotron sources. Furthermore, recent studies have shown that diamond is indispensable for realization of x-ray free-electron laser oscillator (XFELO), a highly anticipated future source of fully coherent x-rays of the highest brightness. Diamond crystals can play the role of high-reflectivity x-ray mirrors of the XFELO optical cavity. Realization of the XFELO requires x-ray diffraction studies of diamond crystals with millielectronvolt resolution. This talk, presents an overview of recently developed x-ray optical instruments and methods for routine characterization of diamond x-ray mirrors. Several schemes are discussed which enable measurements of diamond reflectivity for different Bragg reflections and ultraprecise measurements of thermal expansion

  420. National Synchrotron Light Source Seminar

    "Superconductivity under pressure in the iron-arsenides: The peculiar case of CaFe2As2"

    Presented by Alan I. Goldman, Ames Laboratory, U.S. DOE, and Department of Physics and Astronomy, Iowa State University

    Thursday, July 8, 2010, 1:30 pm
    Seminar Room, Bldg. 725

    Hosted by: Lawrence Margulies

    The discovery of pressure-induced superconductivity in the AFe2As2 (A=Ba, Sr, Ca) family opened an exciting new avenue for investigations of the relationship between magnetism, superconductivity, and lattice instabilities in the iron arsenide family of superconductors. At ambient pressure, the undoped parent phases undergo a tetragonal-to-orthorhombic distortion accompanied by antiferromagnetic order at lower temperatures. CaFe2As2 is unusual since, under modest pressures (< 1GPa), a new non-magnetic “collapsed tetragonal” (cT) phase emerges from the antiferromagnetically ordered low-temperature orthorhombic phase. Superconductivity in the parent AFe2As2 compounds, under applied pressure, has been reported by several groups using liquid-media pressure cells. Measurements under hydrostatic pressure conditions, however, found that superconductivity, if present at all, occurs over a very narrow range close to the reported orthorhombic-to-cT transition. I will discuss neutron and x-ray diffraction measurements under uniaxial and hydrostatic pressure conditions that have elucidated the nature of the phase responsible for superconductivity in this system.

  421. National Synchrotron Light Source Lunch Time Seminar

    "Ferroelectric thin films and superlattices: At Stony Brook and X21"

    Presented by Matthew Dawber, Assistant Professor, Dept. of Physics and Astronomy, Stony Brook University

    Friday, July 2, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  422. NSLS-II Seminar

    "High Quality Crystal Optics Fabrication for the IXS beamline at NSLS-II"

    Presented by Chaminda (Nalaka) Kodituwakku

    Thursday, July 1, 2010, 2 pm
    Large Conference Room. Building 703

    Hosted by: Yong Cai

    High quality crystal optics fabrication is one of the greatest challenges for synchrotron based x-ray beamlines. Specially, high resolution inelastic x-ray scattering requires very high quality crystal optics to achieve the required resolution and efficiency. One of the key breakthrough in x-ray optics is the development of Germanium (733) analyzer at sector 9 of APS. This medium resolution spherical diced analyzer designed for Cu K-edge resonant experiments, which gives ~120 meV resolution. Similar work has been done in many places including the set of high resolution analyzers of HERIX spectrometer at sector 30 of APS. These are made from Si (12 12 12) and gives 2-2.5 meV resolution at 21.657keV. The new NSLS-II sub meV resolution IXS beamline requires a state-of-the-art crystal optics to deliver required 0.1meV resolution. In contrast to these requirements I will demonstrate the preliminary work done at the IXS R&D lab of NSLS-II. Lastly I will discuss studies related to steady lattice parameters of diamond and silicon.

  423. NSLS-II Seminar

    "Recent X-ray Optics Projects at Diamond: Polychromator and Mirrors"

    Presented by John Sutter, Diamond Light Source, United Kingdom

    Tuesday, June 29, 2010, 10:30 am
    NSLS-II Large Conference Room, Bldg. 703

    Hosted by: Yong Cai

    The Optics and Metrology group at the Diamond Light Source undertakes a variety of projects both theoretical and experimental, both to support Diamond's own beamlines and to advance the knowledge of X-ray optics throughout the scientific community. The modeling of a bent-crystal polychromator for the X-ray absorption spectroscopy beamline I20 is one example. Such a device permits a full absorption spectrum to be collected in one shot. Both ray-tracing and wave-optical calculations have been performed on a silicon (1 1 1) polychromator diffracting 7 keV X-rays. These have yielded the instrumental resolution and the optimal sample-detector distance. The inspection and optimization of focusing Kirkpatrick-Baez mirrors is also of great practical importance. To perform these tasks, the Optics and Metrology group have developed both "ex-situ" techniques applied in a metrology cleanroom and "in-situ" techniques applied under beamline conditions. Slope error measurements obtained from both techniques show good agreement. The in-situ method has improved the focusing quality of Diamond's mirrors and permits deliberate defocusing.

  424. National Synchrotron Light Source Lunch Time Seminar

    "Soft X-ray Spectroscopic Study of Strontium-doped Lanthanum Manganite (La0.8Sr0.2MnO3) Cathodes for Solid Oxide Fuel Cell Applications"

    Presented by Dr. Louis Piper, Assistant Research Professor, Department of Physics, Boston University

    Friday, June 25, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

    Solid oxide fuel cells (SOFCs) are electrochemical devices characterized by a ceramic electrolyte - typically yttria stabilized zirconia (YSZ) - that enables the conduction of negative oxygen ions at elevated temperatures (i.e. > 800°C). At present the drive is to maintain high performance at intermediate operating temperatures (i.e. 500-700°C), which are more suitable for small-scale applications. As the temperature drops, reaction kinetics at conventional cathodes, such as strontium doped lanthanum manganite (La0.8Sr0.2MnO3), slow down considerably. This has led to various attempts to improve performance. The most notable being associated with the “burn-in” phenomenon or activation, where an applied bias improves the performance of the cathode over time. Various mechanisms have been proposed ranging from: Sr segregation; removal of Mn (Sr) oxide; nanopore formation; Mn2+ migration to the interface; and, La0.8Sr0.2MnO3/YSZ intermixing. However its origin still remains unclear. In this talk, I will report our recent results regarding the chemical composition and electronic structure of LSMO films at various stages of operation. By rapidly quenching and sealing in vacuum, we were able to directly compare the pristine (as-fabricated) La0.8Sr0.2MnO3 with both "heat-treated" (800°C in air, and no bias) and "burnt-in" (800°C in air, -1 V bias) La0.8Sr0.2MnO3 cathodes. This circumvented issues regarding 1) surface preparation (i.e. Mn reduction) and 2) use of soft x-ray techniques (i.e. ultra-high vacuum). Using a combination of core-level X-ray photoemission spectroscopy, X-ray emission/absorption spectroscopy, resonant inelastic X-ray scattering and resonant photoemission spectroscopy, we observed La-deficiency (severest near the surface) and an increased Mn4+ contribution (i.e. corresponding to hole doping > 0.55) of the cathode prior to activation. In addition we also observed dramatic changes in the oxygen environment before the application of a

  425. National Synchrotron Light Source Lunch Time Seminar

    "Order in Artificial Spin Ice: Real and Reciprocal Space Studies"

    Presented by Jason Morgan, PhD Student, School of Physics & Astronomy, University of Leeds

    Friday, June 25, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  426. NSLS-II Seminar

    "Latest Developments for Ultra-precision Mirrors and Benders (reaching the nm scale)"

    Presented by Philippe Godefroy, WINLIGHT, France

    Thursday, June 24, 2010, 11 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Andy Broadbent

    WINLIGHT is a supplier of mirrors, benders and KB mirrors. We will present our last developments in terms of polishing and surface inspection to reach the nm scale for large mirrors. As a supplier of complete systems, WINLIGHT will also present its bending technology. Results on the inspection machine and on beamlines will be presented.

  427. National Synchrotron Light Source Seminar

    "Accelerator Aspects of APS Upgrade"

    Presented by Michael Borland, APS/ANL

    Thursday, June 24, 2010, 10:30 am
    Seminar Room, Bldg. 725

    Hosted by: Samuel Krinsky

  428. National Synchrotron Light Source Lunch Time Seminar

    "Soft x-ray beamline optics"

    Presented by Ruben Reininger, BNL, NSLS-II

    Friday, June 18, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  429. NSLS-II Seminar

    "Synchrotron Radiation in Art and Archaeology"

    Presented by Joris Dik, Delft University, Netherlands

    Tuesday, June 15, 2010, 4 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Eric Dooryhee

  430. NSLS-II Beamline Development Proposal Workshop

    "NSLS-II BDP Time-resolved X-ray Diffraction and Spectroscopy Under Extreme Conditions Workshop"

    Presented by Various Speakers

    Tuesday, June 15, 2010, 8:30 am
    Bldg. 703, Large Conference Rm

    Hosted by: Alex Goncharov, and Vitali Prakapenka

  431. National Synchrotron Light Source Lunch Time Seminar

    "Far-infrared Mueller matrix ellipsometer at U4IR and its application for multiferroic materials and materials with the negative index of refraction."

    Presented by Andrei Sirenko, Associate Professor, Department of Physics, New Jersey Institute of Technology

    Friday, June 11, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

    We present the far-IR spectroscopic ellipsometer at U4IR beamline of the National Synchrotron Light Source (NSLS) in Brookhaven National Laboratory (BNL). This Ellipsometer is designed to measure a full-Mueller matrix of the sample by using compensators and wire-grid linear polarizers. With the exceptional brightness of synchrotron radiation and the Fourier-transform infrared (FT-IR) spectrometer, we measure ellipsometric data at multi-wavelengths between 10 and 4,000 cm-1. Studies of the phase transitions in multiferroic crystals are available using the close-cycle cryostat for temperatures between 4.2 K and 450 K. The wide range of -2 rotation, angle adjustment, and X-Y-Z translation of sample stage enables high accuracies in the alignment, calibration, and ellipsometric measurement. With the Labview program interface, the automated experiments with the pre-programmed measurement schedules are performed by controlling the motors, temperature, and FT-IR spectrometer. The ellipsometric data analysis is based on the Berreman’s 4×4 propagation matrix formalism to extract dielectric permittivity and magnetic permeability tensors for bulk and thin film samples from the Mueller matrix measured at variable incidence angles and sample orientations across the broad far-IR spectral range. Applications of this far-IR ellipsometry for multiferroic materials with ≠1 and for metamaterials with the negative index of refraction will be discussed. This development effort is supported by NSF-MRI-0821224.

  432. National Synchrotron Light Source Lunch Time Seminar

    "Modern High-resolution photoemission: an overview"

    Presented by Tony Valla, BNL- Condensed Matter Physics & Materials Science Dept.

    Friday, June 4, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  433. Beamline Development Proposal Workshop

    "Full-Field Imaging Beamline at NSLS II"

    Presented by Several Speakers

    Friday, June 4, 2010, 8:30 am
    Bldg. 817 Room 4

    Hosted by: Wah Keat Lee (APS-ANL)

  434. Beamline Development Proposal Workshop

    "X-ray Scattering for Biological Applications at NSLS-II"

    Presented by Several Speakers

    Wednesday, June 2, 2010, 8:30 am
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang (BNL)

    Workshop held June 2nd & 3rd, 2010

  435. NSLS-II Beamline Development Proposal Workshop

    "Time-resolved full field x-ray microscopy at nano and micro scale"

    Presented by Jun Wang, Organizer, NSLS

    Wednesday, June 2, 2010, 7:30 am
    Bldg. 703, Large Conference Rm.

    Hosted by: Jun Wang

    We will be holding a Workshop on time-resolved full-field transmission x-ray microscopy at nano and micro scales. The purpose of the workshop is to provide a forum to discuss the beamline development proposal to build a time-resolved full field imaging beamline at both nano and micro scale on an insertion device source at NSLS-II. The beamline will support scientific research benefiting from 2D and 3D x-ray imaging with high spatial resolution down to 30nm, high energies (5-25 keV) for larger penetration depths, high sensitivity using differential-absorption and phase-contrast, and faster imaging for investigation of dynamics. The main focus of this workshop is (a) to identify strong scientific cases in the areas of energy storage, biofuels, nano-electronics and materials, and geo and environmental

  436. National Synchrotron Light Source Seminar

    "From Scattering to Imaging, Recent Activities at the cSAXS Beamline"

    Presented by Andreas Menzel, Swiss Light Source, Switzerland

    Tuesday, June 1, 2010, 3 pm
    Seminar Room, Bldg. 725

    Hosted by: Lin Yang

  437. Beamline Development Proposal Workshop

    "X-ray Absorption Spectroscopy and Related Techniques at NSLS-II"

    Presented by Several Speakers

    Tuesday, June 1, 2010, 8:30 am
    Bldg. 703 Large Conference Room

    Hosted by: Bruce Ravel (NIST)

  438. NSLS/CFN Users' Meeting Plenary Session

    Presented by Dr. William F. Brinkman, Director, Office of Science US Department of Energy

    Tuesday, May 25, 2010, 8:30 am
    Berkner Hall Auditorium

  439. NSLS/CFN Joint Users' Meeting

    Monday, May 24, 2010, 7:30 am
    Berkner Hall Auditorium

  440. National Synchrotron Light Source Seminar

    "Electrostatically Self-assembled amphiplexes: A combinatorial X-ray diffraction approach"

    Presented by Vesna Stanic, Department of Biomedical Engineering, Stony Brook University

    Friday, May 21, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  441. National Synchrotron Light Source Seminar

    "Confinement Induced Phase Transition in a DNA-Lipid Hydrated Complex"

    Presented by Laurence Navailles, Universite de Bordeaux, Centre de Recherche Paul-Pascal, France

    Thursday, May 20, 2010, 1:30 pm
    Seminar Room, Bldg. 725

    Hosted by: Ron Pindak

    We study the effect of the soft confinement by fluid lipid bilayers on the spatial organization of DNA molecules in a DNA/zwitterionic lipid hydrated lamellar complex. The confinement is increased by dehydrating the complex in a controlled way, which leads to a decrease of the water channel thickness separating the periodically stacked bilayers. Using grazing incidence small-angle x-ray scattering on an oriented thin film, we follow in situ the structure of the DNA-lipid complex as dehydration proceeds. A structural phase transition is evidenced, where the 'classical' 2D nematic phase of DNA rods embedded within the one-dimensionally ordered lipid lamellar phase observed at high hydration is replaced by a new 2D hexagonal structure of DNA molecules intercalated between the lipid bilayers. In order to correlate the structural and diffusive properties of the system, we started 'surgical' FRAP (Fluorescence Recovery after photobleaching) experiments, using a confocal microscope (CLSM) on oriented samples. We have identified three modes of DNA diffusion: an isotropic diffusion, where the molecules in each layer are randomly distributed and randomly orientated, a noncorrelated nematic anisotropic diffusion, with a directional order in each layer but no correlation between neighbouring layers, and finally a correlated nematic anisotropic diffusion with correlation between neighbouring layers. Further we present a method of data analysis that allows distinguishing between isotropic and anisotropic diffusion, when averaging over several layers of a lamellar phase in homeotropic orientation.

  442. NSLS-II Seminar

    "Nanopositioning techniques development for hard x-ray nanoprobe with nanometer scale resolution"

    Presented by Deming Shu, Argonne National Laboratory - Advanced Photon Source (APS)

    Tuesday, May 18, 2010, 3:30 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Evgueni Nazaretski

    At modern synchrotron radiation sources and beamlines, high-precision positioning techniques present a significant opportunity to support state-of-the-art synchrotron radiation research. Meanwhile, the required instrument positioning performance and capabilities, such as resolution, dynamic range, repeatability, speed, and multiple axes synchronization are exceeding the limit of commercial availability. This talk presents the current nanopositioning techniques developed for the Argonne CNM/APS hard x-ray nanoprobe and the CNM/APS/NSLS-II test-bed of the multilayer Laue lenses (MLLs) based hard x-ray nanoprobe. Future nanopositioning techniques to be developed for the NSLS-II project will also be discussed. This work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-06CH11357. If you would like to meet with this speaker, please contact the host @ prior to this presentation to coordinate a time slot.

  443. NSLS-II Seminar

    "Energy Dispersive Detectors by Ketek"

    Presented by Richard Varall, Andreas Pahlke, and Jurgen Knoblo, Ketek, Germany

    Thursday, May 6, 2010, 10:30 am
    NSLS-II Large Seminar Room, Bldg. 703

    Hosted by: Yong Chu

    Presentation of the semiconductor company KETEK/Germany and it's Silicon Drift Detector (SDD) product portfolio including complete ED-XRF acquisition systems and KETEK's upcoming 7 chanel large area SDD array. Duration of the presentation will be about 45min plus time for questions/discussions.

  444. NSLS-II Seminar

    "Probing Migration of Magnetic Impurities at Sub-Nanometer Depth Resolution and Understanding Ion Beam Induced Magnetism in Nonmagnetic Multilayers"

    Presented by Professor B. Dev, Department of Materials Science Indian Association for the Cultivation of Science, Kolkata, India

    Wednesday, May 5, 2010, 10 am
    Bldg. 703, Large Conference Room

    Hosted by: Sanjit Ghose

    X-ray standing wave fields, excited in periodic nanostructured multilayers during Bragg diffraction, have been used to probe atomic migration in multilayers. Ion beam induced migration of Fe impurity atoms from the C layers to the Pt layers in a Pt(Fe)/C(Fe) multilayer, where each layer is about 2 nm thick, has been detected. With a depth resolution better than 0.2 nm, the change of Fe concentration in C (also Pt) layers has been determined as a function of fluence of 2 MeV Au ions, which the multilayers were irradiated with. Magneto-optical Kerr effect measurements show ferromagnetism and an increase of coercive field in the ion-irradiated multilayers with increasing ion fluence. Magnetic force microscopy also shows the evolution of ferromagnetic domains. Further investigations with X-ray diffraction and transmission electron microscopy reveal the formation of FePt nanoparticles, as a consequence of Fe migration from C-layers into Pt-layers. In view of the availability of focused ion beams with beam spots of a few nanometer diameter, possible applications of this ion beam induced ferromagnetism in nanoscale fabrications will be discussed.

  445. National Synchrotron Light Source Lunch Time Seminar

    "X-ray excited optical luminescence in InGaN/GaN MQW structures"

    Presented by Andrei A. Sirenko, Associate Professor, Department of Physics, New Jersey Institute of Technology, Newark, NJ

    Friday, April 30, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

    Synchrotron-based x-ray radiation at Cornell High Energy Synchrotron Source (CHESS - A2 beamline) was used to excite luminescence spectra in InGaN/GaN multiple quantum well (MQW) structures for optoelectronic devices. Both, cw and time-resolved techniques have been performed in detecting the x-ray excited optical luminescence (XEOL) signal. The peak of XEOL for GaN layers coincides with that for conventional PL obtained with a laser excitation, while the XEOL peak for the InGaN active region has a 50 nm shift compared to spectra measured with laser-based PL and cathode-luminescence. Time-resolved measurements were done on XEOL spectra using a streak camera. The temporal structure of the x-ray synchrotron beam at CHESS permits exciton life-time measurements in a broad range from 0.5 ns up to a few microseconds. We determined that GaN exciton lifetime varies between 1.3 and 4.5 ns in different structures, while the InGaN exciton lifetime is on the microsecond scale due to higher defect density. Our experimental approach has been extended to the use of x-ray micro-beams. Using this approach a micron-size spot can probe InGaN/GaN device structures simultaneously measuring: (i) x-ray diffraction, (ii) photoluminescence spectra, and (iii) exciton life-times. Work is in collaboration with S.M. O'Malley (Rutgers University - Camden), P. Revesz and A. Kazimirov (CHESS)

  446. National Synchrotron Light Source Lunch Time Seminar

    "Soft xray fluorescence high angular collection optics"

    Presented by Joseph Dvorak, NSLS, BNL

    Friday, April 30, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  447. NSLS-II Seminar

    "High Perfromance Synchrotron Components from Industry: The Reliable Bruker ASC Way"

    Presented by Riccarado Signorato and Wolfgang Diete, Bruker ASC/ACCEL, Germany

    Wednesday, April 28, 2010, 1 pm
    Bldg. 703 Large Conference Room

    Hosted by: Andrew Broadbent

    Bruker ASC is continuing and expanding the X-ray beamlines and components business of former ACCEL Instruments GmbH, capitalizing on the vast amount of experience gathered by key ACCEL personnel over more 10 years of successful deliveries of full beamlines and components to synchrotron radiation facilities worldwide. Thus, the current Bruker ASC portfolio includes all developments and technologies mastered by former ACCEL and is complementing them with additional capabilities in Insertion Devices and Endstations. Our X-ray activity can then be traced back to our first beamline installed in year 2000 and since then ACCEL, now Bruker ASC, has a clear track record of successfully completed projects, as proven by our large number of satisfied references worldwide. Bruker ASC operates on projects that are often technically demanding, innovative and at the current limits of state-of-the-art technology and they are generally developed and finalized in a collaborative way with our scientific counterparts. This talk will give an overview of our current activities and products and will present a few selected results especially focused towards the challenging specifications needed to match the extremely high brilliance of future NSLS II sources

  448. NSLS-II Seminar

    "High Energy X-rays for Materials Science-New Trends"

    Presented by Veijo Honkimanki, European Sychrotron Radiation Facility, France

    Tuesday, April 27, 2010, 10 am
    NSLS Conference Room Am, 725

    Hosted by: Eric Dooryhee

  449. NSLS-II Seminar

    "Bent Crystal Optics for High Energy Diffraction"

    Presented by Veijo Honkimaki, European Synchrotron Radiation Facility (ESRF), France

    Monday, April 26, 2010, 11 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Eric Dooryhee

  450. National Synchrotron Light Source Lunch Time Seminar

    "Mith and Realities about protein crystallography under magnetic fields"

    Presented by Dr. Abel Moreno, Professor Biological Chemistry, Institute of Chemistry, UNAM

    Friday, April 23, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  451. NSLS-II Seminar

    "Development of a Fluorescence‐type Monochromatized X‐ray Beam Position Monitor with Sub‐micron Spatial Resolution for NSLS‐II Beamlines"

    Presented by Phil Yoon, Brookhaven National Laboratory

    Thursday, April 22, 2010, 1:30 pm
    NSLS-II Larege Conference Room, Bldg. 703

    Hosted by: Hanfei Yan

    A new enhanced prototype (Prototype‐II) of a Monochromatic X‐ray Beam‐Position Monitor (X‐BPM) has been developed for end‐station users at the future NSLS‐II beamlines. A new design of a ring array of multi‐segmented Si photodiodes as a photon sensor has a larger solid angle than the previous design. Backscattering mode of operation is realized by utilizing custom‐made bi‐ASIC chips in a new electronic readout design. Cooling module and UHV operation are selected to reduce inherent noise and background events. As a result of unprecedented and detailed modeling, characterization, and various calculations, the new X‐ray BPM is capable of achieving sub‐micron spatial resolution and even higher. I will present the novel methodology of developing a fluorescence‐type X‐ray detector in an ultra high spatial resolution regime.

  452. NSLS-II Seminar

    "Nanopositioning: Technology and Applications"

    Presented by Katerina Moloni, VP of Product Development at nPoint, Inc.

    Thursday, April 22, 2010, 10:30 am
    NSLS-II Large Seminar Room, Bldg. 703

    Hosted by: Evgueni Nazaretski

    The talk will present design choices when nanopositioning devices are used while focusing on application requirements. If you would like to meet with this speaker after this presentation, please contact the host at prior to this presentation to coordinate a time slot.

  453. Brookhaven Lecture

    "456th Brookhaven Lecture: 'Getting More From Less: Correlated Single-Crystal Spectroscopy and X-ray Crystallography at the NSLS'"

    Presented by Allen Orville, Ph.D., Biology Department, BNL

    Wednesday, April 21, 2010, 4 pm
    Berkner Hall Auditorium

    Hosted by: Stephen Musolino

    <p>By integrating different techniques to collect complementary data at beam line X26C of the National Syncrotron Light Source (NSLS), Allen Orville and his colleagues of the Macromolecular Crystallography Research Resource are providing new insights into the structures of macromolecules.</p> <p>During the 456th Brookhaven Lecture, on Wednesday, April 21st, Orville will describe his approach and his findings in a talk entitled "Getting More From Less: Correlated Singe-Crystal Spectroscopy and X-Ray Crystallography at the NSLS," beginning at 4 p.m. in Berkner Hall. Refreshments will be offered before and after the lecture.</p> <p>During his talk, Orville will discuss his field of protein crystallography, reviewing its landmark discoveries and explaining new ways of using the NSLS and, in the future, the NSLS-II, to build on those discoveries.</p> <p>Allen Orville took his Ph.D. in biology from the University of Minnesota in 1997. After completing a postdoc with the Howard Hughes Medical Institute at the University of Oregon, 1997-2000, he began an assistant professor at the Georgia Institute of Technology. Orville joined BNL's Biology Department in 2006 as an associate biophysicist and was promoted to biophysicist in 2008.</p> <p> To join the lecturer for dinner at an off-site restaurant following his talk, please contact Kathy Folkers, or Ext. 3415.</p>

  454. National Synchrotron Light Source Lunch Time Seminar

    "Nanofabrication for x-ray science a case study"

    Presented by Ming Lu, Ph.D., Center for Functional Nanomaterials, Brookhaven National Laboratory

    Friday, April 16, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  455. National Synchrotron Light Source Lunch Time Seminar

    "Back-diffraction in HPHT diamond single crystals"

    Presented by Marcelo Honnicke, NSLS-II

    Friday, April 16, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  456. NSLS-II Seminar

    "Opto-mechanical Design Considerations for the LCLS X-ray Mirror System"

    Presented by Tom McCarville, Lawrence Livermore National Laboratory

    Thursday, April 15, 2010, 1:30 pm
    Large Seminar Room, Bldg. 703

    Hosted by: Kon Kaznatcheev

    Coherent X-rays present interesting challenges for the opto-mechanical system. They are not only imposes stringent requirements on mirror surface figure, but due the large distances mirror pointing resolution and stability requires new approach to the mechanical design. Pointing resolution of LCLC mirror system must be within 100 nano-radians, and must be stable throughout the experiment duration of several hours. This presentation describes the opto-mechanical system being designed for LCLS, and how it rises to these challenges. The design approach and supporting analysis are described, along with experimental results from prototypes and final installation.

  457. NSLS-II Seminar

    "Impedance and Collective Effects Studies for the TPS Storage Ring."

    Presented by Andriy Rusanov

    Monday, April 12, 2010, 10:30 am
    Large Conference Room (Lower Level), Building 703

    Hosted by: Sam Krinsky

    Taiwan Photon Source (TPS) is a new third generation synchrotron storage ring which will be built at the present site of the NSRRC (Taiwan). The talk summarizes results of the impedance and collective effects studies for the TPS storage ring. Wake potentials and impedances for each component of the storage ring have been simulated with a 3D electromagnetic code GdfidL. Collective effects in the TPS storage ring have been simulated with tracking code ELEGANT (quasi-Green's function for the entire ring and coherent synchrotron radiation (CSR) have been taken into account). Thresholds of the longitudinal microwave instability and the CSR induced instability have been estimated.

  458. Light Sources Directorate Seminar

    "Synchrotron SOLEIL: Present status and future plans"

    Presented by Steve Dierker, Light Sources Directorate

    Monday, April 12, 2010, 9:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Steve Dierker

  459. National Synchrotron Light Source Lunch Time Seminar

    "In situ characterization of atomic layer deposition using synchrotron radiation"

    Presented by Christophe Detavernier, In situ characterization of atomic layer deposition using synchrotron radiation

    Friday, April 9, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  460. National Synchrotron Light Source Seminar

    "3DXRD: A Tool for Grain Mapping And For Studying Grain Dynamics"

    Presented by Henning Friis Poulsen, Riso National Lab for Sustainable Energy, Denmark

    Thursday, April 8, 2010, 1 pm
    Seminar Room, Bldg. 725

    Hosted by: Chi-Chang Kao

    Three-Dimensional X-Ray Diffraction (3DXRD) microscopy is an emerging methodology for in situ studies of mm-sized polycrystals (metals, ceramics, rocks). In favorable cases, the position, volume, orientation, stress-state and dislocation densities of hundreds of grains can be determined simultaneously and sufficiently fast to enable in situ studies of e.g. phase transformations, coarsening and plastic deformation. 3D movies of the changes in grain boundary topology of samples with > 1000 grains have been obtained with a spatial resolution of 1 mu. In addition, the approach allows for structure solution and refinement of multigrains. Examples of work will be shown, with a bias towards basic studies in metallurgy, and the prospect of combined 3DXRD-tomography work highlighted. Ideas for generalizing 3DXRD microscopy to the nano-scale will be presented. Focus will be on R&D in the so called nanodetector: a single photon counting imaging detector for 5-200 keV x-rays with specifications of 100 nm resolution, 1 mm^2 active area and a throughput of 10^9.

  461. NSLS-II Seminar

    "Some scientific computer tools for spectroscopy and diffraction developed at ESRF"

    Presented by Manuel Sanchez del Rio, European Synchrotron Radiation Facility (ESRF), France

    Thursday, April 8, 2010, 11 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Eric Dooryhee

    A fundamental part in a synchrotron radiation experiment is related to the analysis of data, usually done in two phases, i) on-line (at the beamline) for improving the measurements and extracting as much of results as possible, and ii) off-line (careful detailed analysis at home). In a first part I'll discuss the requests and interest in data analysis means for users working on beamlines that produce massive amount of data. Then, I'll present some developments available in XOP for x-ray diffraction using 2D detectors and X-ray Absorption spectroscopies. Finally, I will first present a short overview of some tools developed and maintained at ESRF and distributed worldwide for different applications in X-ray spectroscopies (fluorescence, reflectivity, absorption) and ab-initio calculations.

  462. NSLS-II Seminar

    "X-ray optics simulations and beamline modeling for the ESRF Upgrade Programme"

    Presented by Manuel Sanchez-del Rio, European Synchrotron Radiation Facility (ESRF), France

    Wednesday, April 7, 2010, 2 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Eric Doorhee

    The challenging ESRF Upgrade Programme foresees the reconstruction of about one third of the beamlines. The new beamlines will be very long (more than 100 m) to use routinely micro- and nano-beams. This requires a very high demagnification of the ESRF source, which makes beamline optics design a fundamental concept for the future availability of bright and small beam. At present, during the concept phase, an intense use of computer tools for x-ray optics is necessary, in particular ray-tracing, which has demonstrated to be the most reliable tool for designing and optimizing synchrotron beamlines. A substantial effort has already been invested at the ESRF in developing optics tools and facilitating their use. I will summarize our existing tools, based on XOP and SHADOW. Some examples of recent simulations will be presented, including all kind of synchrotron optics (reflective, refractive and diffractive). An important issue is to understand what are the conditions required (figure shape and figure errors) for the maximum allowed demagnification, and what are the limits. In parallel, an ambitious project for the upgrade of the existing software and development of new tools has been planned.

  463. National Synchrotron Light Source Lunch Time Seminar

    "Superconducting thin films of FeSe0.5Te0.5 and FeTe:Ox by Pulsed Laser Deposition"

    Presented by Weidong Si, Condensed Matter Physics and Materials Science Department, BNL

    Friday, April 2, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  464. National Synchrotron Light Source Lunch Time Seminar

    "Detector Development and Charge Transport Studies in Diamond at Surrey University"

    Presented by Annika Lohstroh, Surrey University, United Kingdom

    Friday, April 2, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  465. NSLS-II Seminar

    "Recent Developments in X-ray Refractive Optics at the ESRF"

    Presented by Anatoly Snigirev, European Synchrotron Radiation Facility, ESRF, France

    Monday, March 29, 2010, 10:30 am
    Bdlg. 703, Large Conference Room

    Hosted by: Oleg Chubar

    The presentation is intended to review the most recent developments of hard X-ray micro- and nano- focusing optics at the ESRF. The main emphasis will be given to the performance of refractive optics. As in-line optics, compound refractive lenses do not change the direction of x-ray beam. They can be easily incorporated at almost any beamline providing collimating or focusing option. X-ray transfocators as energy tuneable refractive optical systems were recently developed at the ESRF. The transfocator is a lens assembly whose focal length can be continuously adjusted by the mechanical movement of one or more groups of individual parabolic lenses. These devices are simple to align, allow good working distance between the optics and the sample, and are becoming standard elements in synchrotron beamlines instrumentation. In the last few years a rapid progress in the fabrication of X-ray refractive optics using MEMS micro-electronics technology has opened the possibility of developing planar nanofocusing lenses. Driven by the requirements of new 100 m-long beamlines at the ESRF we have designed, manufactured and tested planar parabolic lenses made of silicon that have a short focal distance in the energy range of 10 and 100 keV. In addition to nanofocusing lenses each lens-chip contains a set of bi-lens interferometers enabling on-line coherence characterization of the incoming beam. The optical tests of the new lenses were performed at the Instrumentation Test ID6 beamline using the Micro-optics test bench (MOTB). The MOTB is a versatile instrument capable of high resolution X-ray optics characterization, coherence and stability measurements. The current status of the MOTB end station will briefly be described.

  466. National Synchrotron Light Source and Materials Science Department Seminar

    "High-Throughput Science: the Electronic Structure of All Known Inorganic Materials and Beyond"

    Presented by Anubhav Jain, Massachusetts Institute of Technology

    Monday, March 29, 2010, 10:30 am
    Seminar Room, Bldg. 725

    Hosted by: Vivian Stojanoff

    Accelerating discovery in science and technology is a goal we all share. This talk discusses the Materials Genome project at MIT, which has as its goal to compute properties of all inorganic materials with known crystal structures using Density Functional Theory (DFT). We have completed over 60,000 DFT calculations, encompassing most of the materials reported in the Inorganic Crystal Structure Database (ICSD) as well as many newly predicted compounds. We describe how such rapid computational screening has led to the discovery of several interesting new materials for use as Li ion battery cathodes. Statistics collected from screening were used to address the inverse problem of designing materials satisfying constraints on cathode voltage and stability. Finally, we present work in the field of crystal structure prediction through data mining of crystal structure databases. Our approach has predicted several novel ternary oxide materials, providing a path forward to the rapid discovery of promising new materials.

  467. National Synchrotron Light Source Lunch Time Seminar

    "Experiments with geometrically frustrated magnets - a quantum spin liquid and a valence bond glass"

    Presented by M. A. deVries, E.C. Stoner Laboratory, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK

    Friday, March 26, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  468. NSLS-II Seminar

    "Megapixels per hour: Ultrafast X-ray Fluorescence Microscopy at the Australian Synchrotron"

    Presented by David Paterson, Austrailian Light Source, Austraila

    Wednesday, March 24, 2010, 1 pm
    Large Seminar Room, Bldg. 703

    Hosted by: Andy Broadbent

    A hard x-ray micro-nanoprobe [1] has been constructed at the Australian Synchrotron to provide versatile X-ray fluorescence microscopy across an incident energy range from 4 to25 keV. Two X-ray probes are used to collect µ-XRF and µ-XANES for elemental and chemical microanalysis: a Kirkpatrick-Baez mirror microprobe for micron resolution studies; and a Fresnel zone plate nanoprobe with laser interferometer encoding of sample position and capable of 60 nm resolution. Some unique aspects of the XFM beamline design, including a horizontal bounce DCM, and some lessons learned will be discussed. The beamline is commissioning an advanced energy dispersive x-ray fluorescence detection scheme named Maia developed by BNL [2] and CSIRO Australia [3]. The Maia detector employs an annular geometry of 384-element planar silicon array to create a large acceptance solid-angle and handle count rates greater than 107/s. On-the-fly scanning combined with event mode data acquisition enables sub-ms per virtual pixel dwell with real-time elemental deconvolution and image projection. A 96-element Maia prototype used on the KB mirror microprobe has created high definition elemental maps with over 100 megapixels on a range of geological, materials and biological samples in practical time frames. Ultrafast X-ray fluorescence acquisition realises high definition elemental mapping, and creates the opportunity for fluorescence tomography and XANES imaging within practical time frames.

  469. National Synchrotron Light Source Lunch Time Seminar

    "Growth of electrochemically deposited ZnO nanostructures: in situ synchrotron experiments and modelling"

    Presented by Bridget Ingham, Industrial Research Ltd., Lower Hutt, New Zealand

    Friday, March 19, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  470. NSLS-II Seminar

    "Two-dimensional Mean Field Treatment of Coherent Synchrotron Radiation Effects with Application to Microbunching Instability in Bunch Compressors"

    Presented by Gabriele Bassi, University of Liverpool and Cockcroft Institute

    Thursday, March 18, 2010, 1:30 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Sam Krinsky

    Bunch compressors, designed to increase the peak current, can lead to a microbunching instability driven by an increased coherent synchrotron radiation (CSR) at wavelengths shorter than the bunch length, with detrimental effects on the beam quality. This is a major concern for free electron lasers (FELs) where very bright electron beams are required, i.e. beams with low emittance and energy spread. We have developed a parallel code based on a two-dimensional mean field treatment of CSR effects. The two-dimensional charge/current distribution is represented by a Fourier series in beam frame, with coefficients determined through Monte Carlo sampling over an ensemble of tracked points. This method, used in statistical density estimation, gives a globally smooth distribution with low noise. The field equations are solved accurately in the lab frame using retarded potentials and a novel choice of integration variables that eliminates singularities. We will discuss our algorithm and its application to the microbunching instability for the bunch compressor system of the FERMI@Elettra FEL.

  471. NSLS-II Seminar

    "Experimental Observation of Optical Aharonov-Bohm Effect in Stacked ZnTe/ZnSe Type-II Quantum Dots"

    Presented by Igor L. Kuskovsky, Department of Physics, Queens College of CUNY

    Wednesday, March 17, 2010, 10 am
    Bldg. 703, Large Conference Room

    Hosted by: Hanffei Yan

    The Aharonov-Bohm (AB) effect is typically discussed for a quantum charged particle moving along a closed trajectory in a magnetic field. There, however, exists a possibility of the AB effect associated with an overall neutral quasi-particle that possesses a radial electric dipole moment, such as excitons in cylindrical type-II quantum dots (QDs). The AB phase reveals itself in photoluminescence (PL) properties of type-II QDs since, due to the cylindrical symmetry, the exciton ground state initially has a zero orbital angular momentum, which changes to higher values with increasing magnetic field. This transition of the angular momentum to a non-zero value influences the optical properties in two ways: (i) the ground state energy will oscillate as the orbital angular momentum states cross and (ii) the PL intensity will change from strong (bright exciton with zero angular momentum) to weak (dark excitons with non-zero angular momentum) with increasing magnetic field. We present experimental studies on type-II magneto-excitons in stacked ZnTe/ZnSe type-II QDs. Results show strong AB oscillations in both the energy and intensity of the PL from the same structure. This is the only system for which the oscillations in both energy and intensity have been reported. In addition, we find that the AB oscillations are remarkably robust against temperature, with the AB signature visible up to 180 K. We believe this to be the highest temperature at which the AB effect, and therefore quantum coherence, has been observed in semiconductor ring-like structures. To explain the observations, we evoke an idea of the QD stacking, which ensures that the electron's wave-function is "pushed" to the side of the dot due to electron-electron interaction, independent of stress, whereas cylindrical geometry nicely defines the ring-like trajectory for an electron. In our model, an electron moves around an entire stack of QDs, one of which is occupied by a hole.

  472. National Synchrotron Light Source Seminar

    "Imaging soft tissue structures with high energy x-rays: Contrast mechanisms and applications of diffraction enhanced imaging"

    Presented by Dean Connor, University of North Carolina at Chapel Hill

    Wednesday, March 10, 2010, 10:30 am
    Seminar Room, Bldg. 725

    Hosted by: Zhong Zhong

    Diffraction enhanced imaging (DEI) is an x-ray-based imaging modality that yields image contrast from the absorption, scattering, and refraction of x-rays. Particularly because of its ability to extract refraction contrast, even from low-density materials, it has proven to be a powerful tool for the imaging of soft tissue features. DEI has already shown significant contrast-to-noise ratio gains over conventional radiography for the imaging of soft tissue in mammography and cartilage, and, most recently has shown the ability to image amyloid beta plaques in the excised brains of a transgenic mouse model of Alzheimer’s disease. Dr. Connor will discuss the contrast mechanisms of DEI, summarize the existing research, and point towards future developments in both synchrotron-based and x-ray-tube-based DEI systems.

  473. NSLS-II Seminar

    "The Electronic Structure and Morphology of Organic Semiconductors ---- A Case Study of Rubrene"

    Presented by Huanjun Ding, University of Rochester

    Monday, March 8, 2010, 10:30 am
    NSLS-II Seminar Room, Bldg. 703

    Hosted by: Evgueni Nazaretski

    Rubrene, a tetraphenyl derivative of tetracene, has demonstrated strong potential for organic electronic applications. The recent studies suggest that the field-induced hole mobility of rubrene single crystal is over 20 cm2/Vs at room temperature, which is among the highest in organic semiconductors and is comparable to that of poly-Si. Despite of the exciting achievements in the device application, the current understanding about the relationship between the molecular structure and the electronic properties is limited by several factors. In this talk, I will present, to our knowledge, the first band structure measurement of an bulk rubrene single crystal with angle-resolved photoemission spectroscopy (AR-PES). The high quality of the crystal surface was confirmed with atomic force microscopy (AFM) and scanning tunneling microscopy (STM). Highly reproducible dispersive features were observed with nice symmetry about the Brillouin zone center and boundaries. The energy dispersion of the highest occupied molecular orbital (HOMO)-derived bands show strong anisotropic behavior in the a-b plane of the unit cell. The measured band structure is compared to the density functional theory (DFT) calculations. Furthermore, the energy level alignment at the interfaces between rubrene thin film and different metal substrates are studied with ultraviolet and x-ray photoemission spectroscopy (UPS and XPS). The charge injection barriers at these interfaces are discussed. Finally, the morphology of the thermally evaporated rubrene thin film is studied with AFM for various sample preparation conditions.

  474. National Synchrotron Light Source Lunch Time Seminar

    "Diffraction Enhanced Imaging: Recent Progress Towards the Clinic"

    Presented by Zhong Zhong, NSLS, BNL

    Friday, March 5, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  475. NSLS-II Seminar

    "Beam Diagnostics and Detectors from FMB Oxford"

    Presented by Nigel Boulding, Managing Director and Scott Mowat, FMB OXFORD, United Kingdom

    Thursday, March 4, 2010, 9 am
    Conference Room A, Bldg. 725

    Hosted by: Andy Broadbent

    Since 1994 FMB Oxford has designed and manufactured synchrotron beamline systems for facilities around the world, first as Oxford Instruments ATG, as Oxford Danfysik from 2001 and in its latest incarnation from October 2007. Since that time we have successfully delivered around $150M of equipment operating primarily in 3rd generation sources. We have marketed, licenced and developed a range of products for use in beamlines. The focus of recent licences has been that concerning the in-situ measurement of beam position and intensity. These measurements can then be used to stabilize the beam via the control of the upstream beamline elements. The designs of various detectors and diagnostics, along with their associated electronics, are presented and discussed

  476. NSLS-II Seminar

    "FMB Oxford Capabilities in Beamlines and Components"

    Presented by Nigel Boulding, Managing Director and Scott Mowat, FMB OXORD, United Kingdom

    Wednesday, March 3, 2010, 10 am
    Bldg. 703 Large Seminar Room

    Hosted by: Andy Broadbent

    Since 1994 FMB Oxford has designed and manufactured synchrotron beamline systems for facilities around the world, first as Oxford Instruments ATG, as Oxford Danfysik from 2001 and in its latest incarnation from October 2007. Since that time we have successfully delivered around $150M of equipment operating primarily in 3rd generation sources. The recent years have been characterized by the success of full beamline projects in Australia (4) including software and controls and full beamline optics packages on the CLAESS beamline at ALBA, the NANO beamline at ANKA and the ROBL beamline at the ESRF. Advances in performance and stability of monochromators and mirror systems are continuing in response to the ever-increasing search for the perfect beam. The designs of various components are presented and discussed

  477. National Synchrotron Light Source Lunch Time Seminar

    "Probing the Electronic Structure of Metal Vanadates Using Hard and Soft X-rays"

    Presented by Christopher J. Patridge, Department of Chemistry, University at Buffalo, The State University of New York

    Friday, February 26, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  478. National Synchrotron Light Source Lunch Time Seminar

    "Diffraction Enhanced Imaging: Recent Progress Towards the Clinic"

    Presented by Zhong Zhong, BNL, NSLS

    Friday, February 26, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  479. National Synchrotron Light Source-II Seminar

    "The X-ray Optics Metrology Laboratory at APS: Status and Future Plans"

    Presented by Jun Qian, Argonne National Lab, X-ray Science Division

    Thursday, February 25, 2010, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: R. Conley

    The APS X-ray optics metrology laboratory has been serving the APS users community since its commissioning in 1994. The laboratory houses four instruments: a long trace profilers, a 150 mm aperture laser Fizeau interferometer, a dual phase shifting/white light vertical scanning microscope interferometer, and an atomic force microscope. In this talk, the metrology laboratory will be described and the instrument performance and capabilities will be discussed along with future plans and upgrades. * This work is supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

  480. National Synchrotron Light Source Town Meeting

    Wednesday, February 24, 2010, 1 pm
    Seminar Room, Bldg. 725

    Hosted by: NSLS Users' Executive Committee

  481. NSLS-II Seminar

    "Control-Systems Based Analysis and Design Methods for Scanning Probe Microscopy"

    Presented by Dr. Chibum Lee, University of Illinois, Urbana-Champaign

    Monday, February 22, 2010, 10:30 am
    Bldg. 703, NSLS-II Large Seminar Room

    Hosted by: Evgueni Nazaretski

    Recent demonstrations of nanoscience provide ample evidence indicating the feasibility of rational control, manipulation and interrogation of matter at the atomic scale. A class of devices, with micro-sized sensor probes, called Scanning Probe Microscopes (SPMs) are in the forefront of the technology that have demonstrated imaging and manipulation of sample properties. However, this technology is still far from realizing the promise of routinely tailoring matter at the atomic scale. Such ability, once realized, will have far reaching impact and revolutionize every area of science and technology, especially the areas of material science, biology, medicine, and manufacturing. This talk presents control systems theoretic analysis and synthesis of new modes of operations that significantly expand the range of performance specifications and capabilities of SPMs. In particular, the focus is on the two main requirements of SPMs, the precision positioning of the matter with respect to the probe and the obtaining of the surface topography from the probe data. A characterization of the inherent fundamental trade-offs between resolution, tracking-bandwidth, and reliability specifications on the positioning capability of these devices. A series of control designs which exploit these trade-offs appropriately to achieve pre-specified feasible performance objectives is discussed. These designs have two degrees of freedom (2DOF), that is, have the feedforward and the feedback components, and are obtained using the optimal control framework. Implementations and experimental results on the application of these designs show over 100-300% improvement over competing existing designs. For imaging, control systems tools have been used to model and analyze probe-sample (matter) interactions and design signals that estimate the sample topography. The central concept in this design is to view sample-topography signals as disturbance signals and use system theoretic tools to estimate

  482. National Synchrotron Light Source Lunch Time Seminar

    "Is there a Dirac cone in the iron-based superconductor?"

    Presented by Hongbo Yang, CMPMSD, BNL

    Friday, February 19, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  483. National Synchrotron Light Source Lunch Time Seminar

    "Infrared Spectroscopy of GaAs"

    Presented by Stephanie Gilbert, Vanderbilt University

    Friday, February 19, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

  484. National Synchrotron Light Source Lunch Time Seminar

    "CO adsorption on Ru(0001) and PtRu/Ru(0001) near surface alloys using ambient pressure photoemission spectroscopy"

    Presented by David Starr, Center for Functional Nanomaterials, Brookhaven National Laboratory

    Friday, February 12, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  485. National Synchrotron Light Source Lunch Time Seminar

    "Origin of the magnetoelectric coupling in PZT/LSMO multiferroic structures"

    Presented by Carlos A. F. Vaz, Department of Applied Physics and CRISP, Yale University, New Haven, CT 06520

    Friday, February 12, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

    By using a combination of electric, transport, magnetic and spectroscopic techniques, we shed light on the origin of the magnetoelectric coupling recently observed in LaSrMnO3/PZT heterostructures. A modulation in the Mn valence state as a function of the PZT polarization is found from x-ray absorption near edge spectroscopy measurements, demonstrating the electronic origin of the magnetoelectric coupling effect. By correlating the changes in valency with the changes in magnetic moment, we conclude that a change in the spin configuration of LaSrMnO3 takes place at the interface. This effect is attributed to changes in the electron occupancy of the Mn 3d orbitals and the competing super-exchange and double exchange interactions that are a hallmark of these strongly correlated oxides.

  486. National Synchrotron Light Source Seminar

    "Non-Destructive 3-D Structural Imaging and Characterization of Heterogeneous Functional Materials (HeteroFoaMs) for Energy Systems"

    Presented by Wilson Chiu, Department of Mechanical Engineering, University of Connecticut

    Monday, February 8, 2010, 10:30 am
    Seminar Room, Bldg. 725

    Hosted by: Jun Wang

    Fuel cells, batteries, capacitators, electrolyzers, solar cells, combustion devices, fuel processing devices, and membranes and coatings all consist of heterogeneous functional materials (HeteroFoaMs) that exhibit functional behavior in a manner that controls their collective performance as an energy system. There is a critical need to understand the role of a HeteroFoaM’s structure, morphology, and composition on system performance. This seminar presents a non-destructive approach to image and characterize HeteroFoaMs using a transmission x-ray microscope at the Advanced Photon Source 32-ID-C. Three-dimensional structures within the sample volume are tomographically reconstructed at 38 nm spatial resolution. Multi-component lattice Boltzmann methods are used to analyze mass transfer, heat transfer, ionic/electronic charge transfer, and chemical/electrochemical reaction rates in the HeteroFoaM. To demonstrate this technique, chemical elements, chemical bonding, and phase- and pore-network structures in a solid oxide fuel cell are examined to provide fundamental insight into the origins of transport-related losses during operation. This work is supported by an Energy Frontier Research Center on Science Based Nano-Structure Design and Synthesis of Heterogeneous Functional Materials for Energy Systems (HeteroFoaM Center) funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences (Award DE-SC000106).

  487. NSLS-II Seminar

    "Ketek GMBH Silicon Drift Detectors"

    Presented by Richard Varall, KETEK Creative Detector Solutions, Munich, Germany

    Friday, February 5, 2010, 1:30 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Andy Broadent

    Ketek has been the leading manufacturer of SDD's since the early to mid 90's. As many are aware, much of the development of the silicon drift detector was done at BNL. However, the production rights and patents eventually came under the control of the Max Plank Institute who sold the rights to Ketek. Ketek is located in Munich, Germany. The first devices were 5 mm sq. surface area devices. Improvements in crystal size, count rate capability, energy resolution and peak to background followed with the primary emphasis of development geared towards the microanalysis and XRF commercial markets. Ketek and the few other manufacturers have over the years virtually eliminated the Si(Li) detector from the commercial markets and Ketek is now developing the product more for the synchrotron market. The enhanced capabilities of the SDD in the areas of energy resolution, high count rate and ease of use will be discussed. Ketek now has crystal sizes up to 100 mm sq. It is Ketek's intention to deliver a 7 element array to the APS by September of 2010. I am hoping the discussion can include NSLS input on how the multi-element array product can be designed to fit the applications of the NSLS and NSLS II.

  488. National Synchrotron Light Source Lunch Time Seminar

    "The Magnetic Field Dependence of Quasiparticle Dynamics in a Superconductor Studied by Time-Resolved Far-Infrared Spectroscopy"

    Presented by Xiaoxiang Xi, University of Florida

    Friday, February 5, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  489. National Synchrotron Light Source Lunch Time Seminar

    "A bi-prism based coherometer for hard x-rays"

    Presented by Kenneth Evans-Lutterodt, NSLS/NSLS-II

    Friday, February 5, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  490. NSLS-II Seminar

    "Energy of the Quasi-free Electron in Atomic and Molecular Fluids (Queens College & SRC) & The Optical Design of the X-ray Powder Diffraction Beamline (NSLSII - BNL)"

    Presented by Xianbo Shi, Queens College

    Friday, February 5, 2010, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Eric Dooryhee

    Part I: My graduate work focused on the systematic study of perturber critical point effects on the quasi-free electron energy in atomic and molecular supercritical fluids, which involved obtaining vacuum ultraviolet photoionization spectra at various electric fields for a myriad of dopant/perturber systems. I will show these experimental results and the theoretical modeling. Part II: Since July 2009, I have been participating in the optical design of the XPD beamline. The beamline characteristics are studied theoretically and simulated using third party ray tracing softwares (e.g., SHADOW). I will present the results on the energy resolution, the beam size and the reflectivity of the bent Laue and Bragg crystals. I will then discuss the integration of the analytical theory results with the SHADOW ray tracing, which is used in the simulation of the sagittal bent double-Laue monochromator. Finally, I will talk about the combination of the monochromator and the vertical focusing optics (e.g., multilayered mirrors, bent crystals and CRLs).

  491. NSLS-II Seminar

    "Persistent Superconductivity in Ultrathin Pb Films: An STM/S Study"

    Presented by Daejin Eom, Columbia University

    Wednesday, February 3, 2010, 10:30 am
    Bldg. 703, Large Conference Room

    Hosted by: Evgueni Nazaretski

    I will present the measurements of the superconducting energy gap of epitaxially grown Pb films as a function of the layer thickness. Ultrathin Pb films (5 – 18 ML) on Si(111) were grown by low temperature deposition followed by room temperature annealing. A home-built, low-temperature scanning tunneling microscope (STM) was used to probe the relevant electronic and geometric properties. The layer-dependent energy gap and transition temperature (Tc) show persistent quantum oscillations down to the lowest thickness without any sign of suppression. Moreover, by comparison with the quantum-well states measured above Tc and the theoretical calculations, we found that the Tc oscillation correlates directly with the density of states oscillation at the Fermi level (EF). The oscillation is manifested by the phase matching of the Fermi wavelength and the layer thickness, resulting in a bilayer periodicity modulated by a longer wavelength quantum beat.

  492. NSLS-II Seminar

    "Optical and At wavelength Metrology development at SOLEIL synchrotron"

    Presented by Mourad Idir, Synchrotron SOLEIL, France

    Tuesday, February 2, 2010, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Qun Shen

    Generalization of specific optical metrology and systematic testing of all delivered components has yield in the last decade to a significant improvement of the optical surfaces installed on synchrotron radiation (SR) beamlines around the world. Surface roughness is classically characterized by phase-shift interferential microscope, sometimes AFM. Long trace profiler (LTP), which measures the local slope along a line profile, has been the choice instrument to measure figure errors of large size components. Controlling optical components (mirrors, crystals, gratings) is an essential task in order to predict the properties of a beamline and optimize its alignment and final performances. Synchrotron center around the world have developed the appropriate equipment and in the last ten years have accumulated a large expertise and moreover, the ability of measuring reliably small departure from the ideal shape has generated a continuous improvement of the quality of the optics deliver by the main synchrotron mirror manufacturers. In this talk, I will focus on the development of Metrology capabilities develop at SOLEIL Synchrotron both in the optical metrology laboratory and using the Metrology and Tests Beamline. I will report also on some R&D activities develop during the last years:  Design, development, test and use of active x-ray optics coupled with wavefront analyser.  2 D stitching system based on Shack Hartmann wavefront I will then concluded describing some new ongoing development in order to be able to measure the optical component needed to achieve diffraction limited focal spot on new Nanoprobe beamlines

  493. National Synchrotron Light Source Seminar

    "Advanced Optical Systems For Basis Science Research"

    Presented by Michael Pivovaroff, Lawrence Livermore National Laboratory

    Monday, February 1, 2010, 1:30 pm
    Seminar Room, Bldg. 725

    Hosted by: Chi-Change Kao

    Lawrence Livermore has a long history of developing innovative optical systems for basic science applications. In this talk, I will discuss two such efforts: the X-ray offset mirror systems for the Linac Coherent Light Source, the recently commissioned X-ray free electron laser, and the Gemini Planet Imager, an adaptive optic-based instrument capable of direct detection of nearby extra-solar planets. The capabilities LLNL has developed in X-ray and adaptive optic design and modeling, precision metrology and engineering and thin-film and multilayer deposition, coupled with expertise from other DOE laboratories, could be used to develop the novel X-ray optics for the next generation of national light sources.

  494. National Synchrotron Light Source Seminar

    "Integrating X-ray solution scattering and computation: Multimeric assembly of the Src-kinase Hck"

    Presented by Sichun Yang, Ph.D., Dept. of Biochemistry and Molecular Biology, University of Chicago

    Monday, February 1, 2010, 11 am
    Seminar Room, Bldg. 725

    Hosted by: Wuxian Shi

    This presentation will introduce an integrative framework that combines small-angle X-ray scattering (SAXS) and computer simulations for the study of structural assemblies of multimeric complexes. I will first propose the procedure of integrating SAXS data and molecular simulations and a newly developed computational method – Fast-SAXS – for high-throughput scattering computing. The integrative approach uses a Monte Carlo scheme to minimize the differences between theoretical and experimental SAXS profiles and provides the ability to derive structural descriptions of multimeric complexes in solution. Then, I will describe the application of this integrated approach to unravel assembly mechanisms of a multidomain Hck signaling complex under various conditions of ligand binding and mutation. Finally, I will outline the use of this integrated approach for a future exploitation on the long-standing unsolved problem of multidomain assembly of nuclear estrogen receptors (ERs) and its application to high-throughput drug screening for ER-positive and hormone-sensitive breast cancer treatments.

  495. National Synchrotron Light Source Lunch Time Seminar

    "Structural characterization of disordered states of proteins"

    Presented by Veronika Csizmok, University of Toronto

    Friday, January 29, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  496. National Synchrotron Light Source Lunch Time Seminar

    "Structural Biology of Rap-mediated Competence Development in Bacillus Subtilis"

    Presented by Melinda Baker, PhD., Dept. of Microbiology and Molecular Genetics, Univ. of Medicine and Dentistry of New Jersey (UMDNJ)

    Friday, January 29, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  497. National Synchrotron Light Source Lunch Time Seminar

    "Electrostatic 2d assembly of nanoparticles on lipid monolayers at air-water interface"

    Presented by Sumit Kewalramani, Condensed Matter Physics and Materials Sciences Dept.

    Friday, January 22, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  498. National Synchrotron Light Source Lunch Time Seminar

    "Study of low temperature oxygen mobility and related properties in non stoichiometric oxides."

    Presented by Andrea Piovano, University of Torino, Italy

    Friday, January 22, 2010, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  499. NSLS-II Seminar

    "High-Energy X-Ray Optics Development (50-150 keV) at the APS"

    Presented by Sarvjit Shastri, APS, Argonne National Laboratory

    Thursday, January 21, 2010, 10:30 am
    NSLS-II, Bldg. 703 Large Conference Room

    Hosted by: Yong Cai

    Due to its high electron beam energy (7 GeV) and small source size/divergence, the Advanced Photon Source (APS) is a brilliant source of high-energy x-rays, which are often the scattering probe of choice for various types of investigations in materials and condensed matter systems. The APS beamline 1-ID is dedicated to this photon energy range in regard to research applications and beam-delivering optics. The high-energy x-ray optics at 1-ID and its performance will be primarily presented, including monochromatization to various energy resolutions (using bent and flat crystals), refractive lenses for focusing and collimation, brilliance preservation, stability issues, and ongoing development. Applications enabled by the optics will be mentioned, such as materials deformation studies, pair distribution function measurements, high-pressure diffraction, high-energy fluorescence, and resonant diffraction at heavy element K edges. Optics upgrades at other APS high-energy beamlines will also be discussed.

  500. NSLS-II Seminar

    "Capabilities and advances in x-ray mirror manufacturing"

    Presented by Helge Thiess

    Tuesday, January 12, 2010, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Qun Shen

    Applications such as FEL and recent 3rd generation synchrotron sources imply further improvement of the achievable beamline optics quality. Here the level for the residual slope errors can be as small as 0.1 µrad. In addition beam quality preservation in the scattering process frequently demands height errors in the order of 0.5-1nm rms over the clear aperture combined with surface roughness about 0.1 nm rms. These new challenges are out of reach without proper profiling, interferometric and/or stitching methods. However the process technology for the manufacturing of surfaces in desired quality range cannot be achieved without close interaction of metrology and figuring. Collaboration of mirror manufacturers and optics groups at the user facilities on topics such as figuring iterations with external surface data and metrology cross comparison is mandatory.

  501. National Synchrotron Light Source Seminar

    "Combined in situ Micro-Spectroscopic Approach to Study Catalytic Solids in Action"

    Presented by Eli Stavitski, Utrecht University, Netherlands

    Monday, January 11, 2010, 10 am
    Conference Room A, Bldg. 725

    Hosted by: Lisa Miller

  502. National Synchrotron Light Source Seminar

    "Electric field control of magnetism and ferroelectricity in single crystals of multiferroic BiFeO3"

    Presented by Valery Kiryukhin, Rutgers University

    Monday, January 11, 2010, 10 am
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

    Abstract: BiFeO3 is a room-temperature multiferroic combining large electric polarization (P) with long-wavelength spiral magnetic order. Significant efforts have been devoted to studies of thin-film BiFeO3 model multiferroic devices, and local control of magnetization by an electric field has been demonstrated recently. However, the extant thin films consist of a poorly controlled patchwork of ferroelastic domains severely impeding experimental work. We report growth of mm-sized single crystals consisting of a single ferroelectric (FE) domain. The obtained crystals were studied using optical microscopy, PFM, and neutron diffraction. Switching between two (out of 8) unique directions of P by an electric field is demonstrated. Magnetic moments are strongly coupled to the lattice, and rotate together with P when the field is applied. Within a single FE domain, electric field can be used to control the populations of the 3 equivalent magnetic domains with different directions of the spiral wave vector. In particular, a FE monodomain with a single-wave-vector magnetic spiral can be prepared. The spiral has the same helicity in the entire sample. These effects are reversible. Thus, electric field can be used to control the ferroelectric and magnetic states, and even the magnetic helicity of the sample. This level of control makes single-crystal BiFeO3 a promising object for investigation of physics of magnetoelectric coupling in multiferroics, as well as for model multiferroic device research. Based on these results, we demonstrate a novel device, a switchable FE diode, and also report observation of a photovoltaic effect in semiconducting BiFeO3 samples.

  503. Light Sources Seminar

    "The Jefferson Lab Amplifier - JLAMP - a next generation light VUV/Soft X-ray light source proposal"

    Presented by Gwyn Williams, Jefferson Lab

    Friday, January 8, 2010, 11 am
    Large Seminar Room, Bldg. 703

    Hosted by: Steve Dierker

  504. NSLS-II Seminar

    "Diffraction of focused x-ray beams from perfect crystals: first experimental results and possible applications"

    Presented by Alexander Kazimirov, CHESS, Cornell University, Ithaca, NY

    Wednesday, January 6, 2010, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Yong Cai

    Modern focusing optics is able to deliver x-ray beams of the size of 100 nm and smaller for a variety of applications based on scattering and diffraction techniques. Meanwhile, diffraction of focused beams from crystals requires detail theoretical and experimental analysis. Theory predicts that a focused x-ray beam Bragg diffracted from a perfect crystal has a fine structure which depends on the size of the beam, thickness of the crystal and diffraction conditions. In this talk, I will present first experimental results allowing for a detailed comparison with theory and outline possible practical applications. Experiments were performed at the APS and the ESRF by using zone plates and refractive lenses as focusing optics. New experimental setup in which high-resolution detector is placed in the focus and crystal is positioned between the focusing optics and the focus was proposed and utilized. The broadening of the focused beam by crystals due to extinction effect and the evolution of fine spatial structure with angle were experimentally observed and analyzed. Experimental images recorded from real crystals and semiconductor structures demonstrate that this experimental setup can be used as a new imaging technique that combines spatial locality and depth sensitivity.

  505. National Synchrotron Light Source Seminar

    "A Salt and Batteries: Applications of Nonresonant Inelastic X-ray Scattering to Model and Applied Systems"

    Presented by Ken Nagle, University of Washington

    Monday, January 4, 2010, 2:30 pm
    Seminar Room, Bldg. 725

    Hosted by: Bruce Ravel

    The rational design of improved battery electrodes for Li-ion batteries faces many barriers, not the least of which is a correct, fundamental understanding of the changes in local electronic structure that accompany insertion and removal of lithium. For this reason, the DOE report “Basic Research Needs for Electrical Energy Storage” singled out nonresonant inelastic x-ray scattering (NIXS) as a promising technique for in situ studies of these basic electrochemical processes. NIXS at ~1 eV energy resolution provides a bulk-sensitive alternative to x-ray absorption spectroscopy for studies of low-energy (<1.5 keV) electronic transitions. Furthermore, at sufficiently high momentum transfers NIXS is sensitive to dipole-forbidden transitions, providing additional information about electronic structure. After illustrating these issues with a study of Na 1s core excitons in NaCl and NaF, I will discuss the application of NIXS to ex situ and in situ studies of lithiation of transition metal oxide compounds.

  506. NSLS-II Seminar

    "Multiple-Wave X-ray Diffraction: Fundamentals and Application"

    Presented by Yuriy Stetsko, Davron Staffing

    Wednesday, December 23, 2009, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Yong Cai

    Abstract Multiple-wave x-ray diffraction takes place when more than one set of atomic planes is simultaneously brought into position to diffract an incident beam. As a result of the scattering of x-rays from periodic two- or three-dimensional structures, the multiple-wave diffraction reflects structural crystal information that cannot be obtained from single two-wave diffraction. However, due to the comparably large number of waves involved in the multiple-wave diffraction process, generally, the correspondent wavefields and diffracted intensities cannot be resolved analytically. For this reason, we have developed several approaches for numerical solution of the multiple-wave dynamical x-ray diffraction equations for bulk crystals and crystalline multilayers in a plane-wave approximation of the incident beam. We also proposed several approximations, including the iterative Born and resonance perturbation Bethe approximations, for the explanation of the fundamental behavior of three-wave x-ray diffraction. Among such behavior we have theoretically predicted and experimentally studied some new phenomena of a multiple-wave interaction of x-rays with matter: the indirect excitation of polarization-forbidden x-ray reflections, the polarization suppression of the detour-excited waves, the anomalous behavior of multiple-wave x-ray interaction at atomic resonance, the coherent multiple-wave x-ray interaction in charge-density wave materials. Due to the sensitivity to the phases of the structural factors, the multiple-wave diffraction has found its unique application for the solution of the phase problem of x-ray optics, diffraction physics and crystallography. We have proposed some theoretical approaches to explain the phase sensitivity of multiple-wave diffraction, as well as developed the experimental techniques for quantitative determination of reflection phases for bulk crystals, surface layers, macromolecular crystals, charge-density waves, and phase shifts at at

  507. NSLS-II Seminar

    "The Facility for Rare Isotope Beams Project"

    Presented by Thomas Glasmacher, FRIB

    Friday, December 18, 2009, 11 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Diane Hatton

    The Facility for Rare Isotope Beams (FRIB) will be a DOE-SC national user facility supporting the mission of the Office of Nuclear Physics. Michigan State University designs and establishes FRIB on its campus in East Lansing, MI. FRIB will be centered around a 200 MeV/nucleon superconducting-rf heavy-ion driver linac and create rare isotope beams by projectile fragmentation followed by in-flight separation. FRIB will provide experimenters with fast, stopped and reaccelerated rare isotope beams. This seminar will present an overview of the FRIB project and the science it enables.

  508. NSLS-II Seminar

    "Vacuum R&D Related to CesrTA and ERL-based Light Sources"

    Presented by Yulin Li, Cornell University

    Thursday, December 17, 2009, 11 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Dick Hseuh

    Over the past 3 years, a prototype DC photo-cathode injector was designed and constructed at CLASSE, as a key initial step toward the Energy Recover Linac (ERL) based light sources at Cornell. The prototype injector includes a DC photo-cathode electron gun, a 10-cell superconducting radio-frequency cavity cryo-module, electron beam transport beamlines equipped with a suit of beam instrumentation and electron beam dumps… In the meantime, we have also successfully re-configured the Cornell Electron Storage Ring (CESR) vacuum system to convert it into a test accelerator (CesrTA), as a part of the Globe Design Efforts (GDE) of the International Liner Collider Damping Ring. In this talk, highlights of the vacuum R&D efforts related to these two research programs are discussed.

  509. NSLS-II Seminar

    "Transition from Anisotropic Magneto-Resistance to Giant Magneto-Resistance in Tape Drives"

    Presented by John Nibarger

    Monday, December 14, 2009, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Toshi Tanabe

    This talk will investigate the transition of Anisotropic Magneto-Resistance (AMR) to Giant Magneto-Resistance (GMR) in tape drives. Although GMR was introduced in the late 90’s in disk drives, tape drives are just beginning to implement this technology. To provide a context for this seemingly late adoption, an introduction of magnetic recording head fundamentals will be given followed by scaling issues that has governed the magnetic data storage industry. These scaling issues provide the motivation for the transition from AMR to GMR in tape drives as well as the transition to Tunneling Magneto-Resistance (TMR) in disk drives.

  510. National Synchrotron Light Source Lunch Time Seminar

    "Charge accumulation at La2CuO4 - La2-xSrxCuO4 interfaces studied with resonant soft x-ray scattering ...and other recent goings on at beam line X1B"

    Presented by Peter Abbamonte, Physics Dept., University of Illinois at Urbana-Champaign

    Friday, December 4, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Steve Hulbert

    Several groups have recently reported that the onset temperature of superconductivity in certain copper oxides may be enhanced - perhaps even exceeding the bulk maximum - at interfaces in artificial structures fabricated by atomic layer-by-layer deposition techniques [1,2]. A key question is whether this effect is purely structural, i.e. arising from cation interdiffusion between the layers, or arises from something more fundamental like the formation of a carrier accumulation region, such as occurs at a metal-on-semiconductor interface. To address this issue we used resonant soft x-ray scattering (RSXS) to quantify the hole distribution in a superlattice of insulating La2CuO4 (LCO, x=0) and overdoped, nonsuperconducting La2-xSrxCuO4 (LSCO, x=0.36). Despite its nonsuperconducting constituents, this structure is superconducting with Tc = 38 K. We found that the conducting holes redistribute electronically from LSCO to the LCO layers, indicating the existence of an electronic, charge accumulation region. The LCO layers were found to be optimally doped, suggesting they are the main drivers of superconductivity. Our results demonstrate that nontrivial electronic effects take place in oxide heterostructures, and may be observed with RSXS.

  511. NSLS-II Seminar

    "Smart Magnetic Shape Films To Improve X-ray Optics Performance"

    Presented by Mel Ulmer, Dearborn Observatory - Northwestern University

    Thursday, December 3, 2009, 1:30 am
    Large Seminar Room, Bldg. 703

    Hosted by: Qun Shen and Peter Takacs

    The goal is to demonstrate that shape modification can be successfully applied to thin walled (~100-400 micron thickness) replicated optics or slumped glass optics to improve the near net shape of the mirror as well as the mid-frequency ripple. The proposed process involves sputter deposition of a magnetic smart material (MSM) film onto permanent magnetic material. The permanent magnetic material would be the mirror substrate in the case of electroformed optics and would be plated onto the back of glass optics. The MSM material exhibits strains about 400 times stronger than ordinary ferromagnetic materials. The deformation process involves a magnetic write head which traverses the surface, and under the guidance of active metrology feedback,locally magnetizes the surface to impart strain where needed. Because of the hard magnetic material, the localized shape change remains until actively demagnetized. The following tasks will be performed. Upgrade of a sputtering chamber to enable coating 10 cm and larger diameter pieces. Make sputtering targets of our baseline MSM called KelvinAll(TM). Make substrates onto which to sputter the MSM. Sputter onto both electroformed and and plated glass substrates. Model the magnetostrictive response for various substrate and MSM thickness combinations. Finite element modeling of the mirror based on all materials, thicknesses, boundary conditions, and magnetic field magnitude and location. The final step in year 3 will be to show that both free standing cylinders of revolution, mounted glass, and mounted cylinders can be shaped with a goal of 1" half-power diameter encircled energy as demonstrated primarily by ray tracing. The Argonne Advanced Photon Light Source will be used as well. In addition to changes in the macro figure, determine what is the smallest length (goal 100 microns) scale over which the substrates, particularly glass can be smoothed.

  512. NSLS-II Seminar

    "An Ultra-Stable Platform for the Study of Nanowires and Single-Atom Chains"

    Presented by Douglas T. Smith, National Institute of Standards and Technology (NIST), Gaithersburg, MD

    Monday, November 23, 2009, 10:30 am
    Large Conference Room, Bldg. 703

    Hosted by: Evgueni Nazaretski

    If you would like to meet with the speaker afterwards, please contact the host, prior to this presentation to coordinate a time slot. Accurate measurement of mechanical and electronic properties at length scales approaching atomic dimensions often requires the ability to measure and control displacement between, for example, a probe tip and a surface with resolution and stability finer than those atomic dimensions. We have developed a new instrument we call a feedback-stabilized break junction (FSBJ) based on a fiber-optic Fabry-Perot interferometer that has been optimized for DC stability. The FSBJ allows us to accurately measure and control the motion of a probe tip relative to a surface with long-term stability better than 10 % of a typical atomic radius. In this talk, I will describe the design and performance of the interferometer system in detail, and will also show how we are using the FSBJ to study the electronic and mechanical properties of gold nanowires and single-atom chains formed between a probe tip and a surface.

  513. NSLS-II Seminar

    "Development of short period high field undulators at the ESRF and SOLEIL"

    Presented by Charles Kitegi

    Monday, November 23, 2009, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Toshi Tanabe

    In synchrotron radiation sources, Planar Polarized Undulators (PPUs) and Elliptically Polarized Undulators (EPUs) produce high energy photon beams with controlled polarization. As far as PPUs are concerned, In Vacuum Undulator is the existing technology to build small period high field undulator. In such devices, Neodymium-Iron-Boron (NdFeB) or Samarium Cobalt (SmCo) permanent magnets maintained at ambient temperature are enclosed in the vacuum where the multi GeV electron beam is stored. IVU requires the use of magnets with high resistance against demagnetization. This constraint limits the use of magnets with a remanence below 1.3T. In particular NdFeB magnets with remanence higher than 1.4T cannot be used. However below 150K these magnets have similar resistance to SmCo magnet. Thus since 2004, several Cryogenic Permanent Magnet Undulators (CPMU) are under development in radiation sources. A first CPMU was installed in the storage ring at the ESRF in 2008. Two other CPMU are under development at the ESRF and SOLEIL, there are planned to be installed in 2010. Specificities relevant to such devices such as the operation temperature, the impact of thermal gradient will be presented. In-vacuum magnetic measurement bench developed at the ESRF and SOLEIL are discussed. Among EPUs, Advanced Planar Polarized Light Emitter-II (APPLE-II) is the device which produces the strongest helical field. APPLE-II consists in two planar undulators side by side; the adjustable shift between girders sets the polarization. At SOLEIL, 9 APPLE-II with period ranging from 80 mm down to 44 mm have been successfully assembled and installed in the storage ring. An APPLE-II with 36 mm period and 0.8 T peak field is under development. At such low period and high field, magnetic force introduces mechanical deformation leading finally to systematic error in the undulator field. The investigations done to point out the deformation are presented. Solutions to minimize systematic errors are dis

  514. National Synchrotron Light Source Seminar

    "Computing on Adaptive 2-D Graphitic Nanostructures"

    Presented by Bin Yu, SUNY @ Albany, College of Nanoscale Science & Engineering

    Friday, November 20, 2009, 2:30 pm
    Seminar Room, Bldg. 725

    Hosted by: Chi-Chang Kao

    2-D graphitic nanostructures (mono- and bi-layer graphene) have been the subject of intense research due to unique structure and associated quantum phenomena which can be exploited to implement novel electronic and quantum devices for information processing. We seek to develop new device operation principle on an “electronically flexible” and “optically active” 2-D graphitic material platform to achieve energy efficiency, scalability, and potential heterogeneous integration between electronics and photonics for information processing. The central task is to explore electronic and quantum properties of these materials, serving as the ground for further device research. In this seminar, recent research activities in related topics will be presented.

  515. National Synchrotron Light Source Lunch Time Seminar

    "Imaging Interfacial Structures by Phasing Coherent Bragg Rod: Total and Element-Specific Structure Factors"

    Presented by Hua Zhou, NSLS, BNL

    Friday, November 20, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  516. National Synchrotron Light Source Lunch Time Seminar

    "X-ray Crystallography: Guiding Drug Discovery and Development"

    Presented by Robert Suto, Xtal BioStructures, Inc.

    Friday, November 20, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  517. National Synchrotron Light Source Seminar

    "Zone plate based scanning photoemission imaging and spectromicroscopy at Elettra"

    Presented by Luca Gregoratti, ELETTRA, Italy

    Friday, November 20, 2009, 10 am
    Seminar Room, Bldg. 725

    Hosted by: Elio Vescovo

    With respect to the other photoelectron microscopy techniques a Scanning PhotoEmission Microscope (SPEM) uses the most direct approach to photoelectron spectromicroscopy which is the use of a small focused photon probe to illuminate the surface. The SPEM at the Elettra synchrotron light source can operate in two modes: imaging and spectroscopy. In the first mode the sample surface is mapped by synchronized-scanning the sample with respect to the focused photon beam and collecting photoelectrons with a selected kinetic energy. The second mode is photoelectron spectroscopy from a microspot. The SPEM on the ESCAmicroscopy beamline at Elettra has a lateral resolution of 120 nm; and an overall energy resolution which is now better than 200 meV. Samples can be heated, cooled (liquid N2) and biased during the measurements. The beamline is open to the public and private research community; two call for proposals of experiment are available per year together with the possibility of dedicated collaborations on specific projects. Some recent achievements in the chemical, physical and electronic characterization of nano- and micro-structured surfaces and interfaces will be presented providing an overview of the capabilities of this powerful technique. Metallic adsorbate interaction, oxidation and supporting properties of multiwall carbon, semiconducting and metal-based nanotubes will be presented, showing how even dynamic phenomena such as mass transport along the nanotube surface can be monitored by the SPEM. A special design of the samples allows for the investigation of single nanotubes with diameter down to 60nm. Finally an overview of the limits in the applications of the x-ray photoelectron microscopes imposed by the operation principles will be given together with the future developments allowing the investigation of materials at mbar and even ambient pressure.

  518. NSLS-II Seminar

    "Accelerator magnets: from low to high field in approximately 45 minutes"

    Presented by Mauricio Lopes

    Thursday, November 19, 2009, 1 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Toshi Tanabe

  519. NSLS-II Seminar

    "X-Ray Multilayer Mirrors for Synchrotron Application"

    Presented by Yuriy Platnov and James Wood, Rigaku Innocative Technologies

    Wednesday, November 18, 2009, 11 am
    Large Conference Room, Bldg. 703

    Hosted by: Andy Broadbent

    The presentation includes the following: • Multi layer deposition facility at RIT • LTP,Interferometric microscope, AFM,Talysurf profiler for surface roughness testing of substrates and multilayer mirrors • X-Ray performance characterization • Sizes, materials, uniformity, d-accuracy • The lowest d-spacing multilayer structures • Structures with highest and lowest spectral resolution • Experimental reflectivity in 5keV to 60keV range • Striped DMM • Radial d and gamma graded structures • Multilayer Fresne Zone Plates

  520. National Synchrotron Light Source Seminar

    "Kinoform Refractive X-ray Optics Lenses for Nanofocusing and Prisms for Interferometry and Coherence Measurements"

    Presented by Abdel Isakovic, NSLS

    Tuesday, November 17, 2009, 2 pm
    Seminar Room, Bldg. 725

    Hosted by: K. Evans-Lutterodt

    In the past two decades X-ray community witnessed an increase in the use of refractive optics. Following the demonstrations that allow refractive lenses to focus down to 1 micron spot size, a logical step is to explore the possibility of nanofocusing tests. The NSLS refractive optics program has explored two different materials (silicon and diamond), and I will show in this talk how nanofocusing can be performed at the spot size near 30 nm with Si lenses, and how diamond lenses can be further advanced to reach the same or better result. In the second part of the talk, I will demonstrate a novel method of controlling the X-ray photons for the purpose of measuring the degree of synchrotron X-ray coherence, and for potential future interferometric applications. The method uses microfabricated bi-prism arrays that lead to X-ray interference in the mode of Young's double slit experiment and allows for easy measurements and applications in the Fresnel regime. The talk will showcase various useful technical details, including a brief review of nanopatterning and etching solutions we developed, and the use of X-ray fluorescence in detection of nanoscale focal spot size, and in quantification of X-ray interference patterns. Lastly, some applications of our optics in various collaborative efforts will be shown.

  521. NSLS-II Seminar

    "The Advanced Photon Source Upgrade Project Status"

    Presented by Yeldez Amer, ANL

    Tuesday, November 17, 2009, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Diane Hatton

    Overview of the technical, funding and planning activities associated with the proposed APS Upgrade.

  522. NSLS-II Seminar

    "Nanoscopium: a Scanning Hard X-ray Nanoprobe Beamline at Synchrotron Soleil (France)"

    Presented by Andrea Somogyi, Synchrotron Soleil, France

    Friday, November 13, 2009, 1:30 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Juergen Thieme

    . Nanoscopium is the single scanning hard X-ray nano-probe beamline planned at SOLEIL. This ~155 m long beamline will exploit the high brilliance and coherence characteristics of the X-ray beam both for diffraction limited focusing and for contrast formation. It will offer imaging techniques in multimodal mode in the 30 nm to 1 µm spatial resolution range and will be a research tool for a wide user community working in the fields of earth-, environmental-, and life-sciences. The beamline will cover the 5-20 keV energy range. The stability of the nanobeam will be ensured by horizontally reflecting beamline optics (a sagitally and a tangentially pre-focusing mirror, horizontally reflecting monochromators) in front of the overfilled secondary source. Trade-off between high energy resolution (E/E~10-4) and high flux (1011 ph/s with E/E~10-2) will be achieved by two interchangeable monochromators (a double crystal and a double multilayer one). KB mirror and FZP lenses will be used as focusing devices. The beamline is in the design and construction phase. It is foreseen to be open for users at the beginning of 2013

  523. National Synchrotron Light Source Lunch Time Seminar

    "The Band Gap Controversy of Indium Oxide"

    Presented by David Payne, University of Oxford, UK

    Friday, November 13, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  524. National Synchrotron Light Source Lunch Time Seminar

    "Environmental Significance of Bauxite Residues"

    Presented by Markus Grafe, Commonwealth Scientific Industrial Research Organization, Australia

    Friday, November 13, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  525. National Synchrotron Light Source Seminar

    "Prospects for Adaptive X-ray Optics"

    Presented by Ali Khounsary, Argonne National Laboratory, Advanced Photon Source

    Thursday, November 12, 2009, 10:30 am
    Seminar Room, Bldg. 725

    Hosted by: Ed Haas

  526. NSLS-II Seminar

    "Study of Ion Effects in the ILC Electron Damping Ring"

    Presented by Dr. Guoxing Xia

    Thursday, November 12, 2009, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Sam Krinsky

    Ion effects are one of the very high priority issues in the damping ring R&D for the Technical Design Phase of the International Linear Collider (ILC). Ions produced from the processes like collision ionization, tunnel ionization and synchrotron radiation ionization of the residual gas in the vacuum pipe couple the beam motion and cause the two-stream instabilities in the machine. For the low-emittance storage rings with multi bunch operation, like the ILC electron damping ring, the single passage instability so-called fast ion instability is prominent and potentially deleterious to the machines performance. In this talk, ion effect issues are overviewed, followed by a detailed introduction to the simulation study of the fast ion instability in the ILC damping ring. Possible cures are proposed as well. In addition, the latest experimental results on the fast ion instability at KEK ATF damping ring are also presented.

  527. National Synchrotron Light Source Lunch Time Seminar

    "In situ HT Synchrotron Studies of Phase Transformations in Oxide Ceramics"

    Presented by Waltraud Kriven, University of Illinois at Urbana-Champaign

    Friday, November 6, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  528. National Synchrotron Light Source Lunch Time Seminar

    "Investigation of L-Ta2O5 to H-Ta2O5 Phase Transformation using HTXRD"

    Presented by Pankaj Sarin, University of Illinois at Urbana-Champaign

    Friday, November 6, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  529. NSLS UEC Town Meeting

    Wednesday, November 4, 2009, 1 pm
    Seminar Room, Bldg. 725

  530. NSLS-II Seminar

    "X-ray mirror surfacing, on-line metrology and nanofocusing: challenges, achievements and perspectives"

    Presented by Dr. Luca Peverini, European Synchrotron Radiation Facility, France

    Wednesday, November 4, 2009, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Qun Shen

    Present and future world-leading radiation sources are being designed and optimized to enable the routine production of coherent X-ray nanobeams of great interest in X-ray spectroscopy, diffraction and imaging applications. X-ray beams with sizes as small as a few tens of nanometers have been recently obtained in dedicated experiments. There is now an evergrowing demand to make nano-beams accessible to a wider community. Along this line a surfacing station for X-ray mirrors was recently developed and installed at the metrology beamline BM5 of the ESRF. The instrument allows to eventually realize and control strongly aspheric mirrors for X-ray nanofocusing using an on-line at-wavelength metrology. This seminar will review some recent achievements in the field along with pertinent examples of on-line diagnostics for which X-rays prove to be a unique probe. A set of novel experimental techniques will be presented to describe: a) the use of real time diffuse X-ray scattering to study the scaling behaviour of roughness in growing/eroded surfaces. b) An exact solution to the classical phase retrieval problem in X-ray reflectometry and its application to obtain the depth density distribution of an evolving thin film. c) The use of shearing X-ray interferometry and of the near field X-ray scattering to infer the wave front and the coherence degradation of radiation in X-ray optical systems and, finally d) the development of a fast and robust ion beam profiling process to realize nanofocusing mirrors. The proposed integrated approach promises to be a valuable and complementary alternative to the existing technologies for realizing the next generation of reflective X-ray optics for synchrotron and FEL radiation sources.

  531. National Synchrotron Light Source Lunch Time Seminar

    "The Oxidation State of Earth's Mantle"

    Presented by Elizabeth Cottrell, National Museum of Natural History, Smithsonian Institution

    Friday, October 30, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  532. National Synchrotron Light Source Seminar

    "Photo-induced structural dynamics studied by x-ray diffraction with time resolution 200 fs"

    Presented by Dr. Gerhard Ingold, Laboratory for Synchrotron Radiation, PSI Switzerland

    Thursday, October 29, 2009, 3 pm
    Seminar Room, Bldg. 725

    Hosted by: Chi-Chang Kao

    The design and performance of the FEMTO laser slicing source operated at the Swiss Light Source [1] is presented. The spatiotemporal stability of the source allows to perform pump-probe grazing incidence x-ray diffraction with time resolution 200 fs. Options to increase the flux at the experimental station by 1-2 orders of magnitude are discussed. We report on experiments where the photoinduced non-equilibrium carrier and structural dynamics in Peierls distorted systems (Bi, Te) has been studied [2[. In a recent experiment we measured the structural response to ultrafast melting of charge and orbital order in a manganite (LCMO) [3]. We find that in addition to Angstrom spatial resolution a time resolution of ultimately 10 fs will be needed to follow the coupling between different degrees of freedom (i.e. charge, orbital, spin and lattice) and the dynamics of phase transitions between different competing phases in such strongly correlated materials. For this we pursue to extend our present experiments to resonant and non-resonant scattering experiments both in the soft and hard x-ray range at existing FEL facilities [4]. [1] P. Beaud et al., PRL 99 (2007), 174801. [2] S.L. Johnson et al., PRL 100 (2008), 155501 and PRL 102 (2009) 175503. [3] P. Beaud et al., submitted. [4] G. Ingold et al., Z. Kristallgr. 223 (2008) 292.

  533. NSLS-II Seminar

    "Spectro-microscopy at the ID21 beamline: Recent Developments and Applications to Cultural Heritage"

    Presented by Marine Cotte, Centre of Research and Restoration of the French Museums and ESRF, France

    Monday, October 26, 2009, 10:30 am
    Large Conference, Room, Building 703

    Hosted by: Eric Dooryhee

    The ID21 beamline at the ESRF is dedicated to X-ray micro-spectroscopy. The scanning X-ray microscope has a tunable energy ranging from 2.1 to 7.2 keV and is optimized for very low background and low detection limit. It has been recently refurbished to give enhanced functionalities. As an example, the microscope can now host two different optical focusing configurations: either zone plates (ZP) or a Kirkpatrick-Baez mirror system (KB). A compact X-ray wavelength dispersive spectrometer achieving a few tens of eV energy resolution has also been implemented for highly selective fluorescence detection. A load-lock system allows fast exchange of samples under vacuum, and greatly facilitates operation under cryogenic conditions. The microscope enables identification down to few ppm and localization with a submicron beam of various elements. These elemental mappings can be completed with spectroscopic analyses, performed on single points or as 2D images as well. Typical scientific questions concern the co-localization and/or speciation of trace elements in heterogeneous matrices at the micron scale. Therefore, the submitted proposals are mainly in the field of Environmental Science and Biology. Besides, since a few years, applications in the field of Cultural Heritage are increasing. Generally speaking, the non-invasive character, low detection limit, high lateral resolution and high chemical sensitivity of SR-based X-ray techniques are highly relevant properties for the chemical characterization of art materials, which are usually precious, heterogeneous and complex. The chemistry involved in both the past history of the objects, i.e. during their fabrication, and in their future life, i.e. during preservation and restoration treatments, can be addressed by such techniques. A particular focus will be made on recent applications of XAS (at the ESRF, but more generally on synchrotron facilities) in art conservation.

  534. National Synchrotron Light Source Lunch Time Seminar

    "3He Opalescence as Seen by Neutron Transmission"

    Presented by Timothy Charlton, Rutherford Appleton Laboratory, United Kingdom

    Friday, October 23, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  535. NSLS-II Seminar

    "Successful Completion of the Top-off Upgrade of the Advanced Light Source"

    Presented by Christoph Steier, LBNL

    Wednesday, October 21, 2009, 10:30 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Samuel Krinsky

  536. National Synchrotron Light Source Lunch Time Seminar

    "Photo-active Ceramic Membranes for the Control of Biofouling"

    Presented by Shannon Ciston, University of New Haven

    Friday, October 16, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  537. National Synchrotron Light Source Seminar

    "Perspectives on X-Ray Coherent Diffraction Imaging"

    Presented by Malcolm Howells, Senior Physicist Emeritus, Advanced Light Source Division, Lawrence Berkeley National Laboratory

    Friday, October 9, 2009, 3 pm
    Seminar Room, Bldg. 725

    Hosted by: Lonny Berman & Andrei Fluerasu

  538. National Synchrotron Light Source Lunch Time Seminar

    "Quantification of Organochlorine Concentrations by X-ray Absorption Spectroscopy with Environmental and Public Health Applications"

    Presented by Alessandra Leri, Marymount Manhattan College

    Friday, October 2, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  539. National Synchrotron Light Source Lunch Time Seminar

    "Study of the structure of starch and biomass materials by small-angle and wide-angle X-ray scattering techniques in relation to their enzyme digestibility"

    Presented by Yong-Cheng Shi, Kansas State University

    Friday, October 2, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  540. Physics Colloquium

    "How NSLS Came to Brookhaven"

    Presented by Robert Crease, Stony Brook University

    Tuesday, September 29, 2009, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: William Morse

  541. National Synchrotron Light Source Lunch Time Seminar

    "Real-Time Studies of Surface Nanostructure Development during Ion Bombardment"

    Presented by Karl Ludwig, Dept. of Physics; Boston University

    Friday, September 25, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

    The ion bombardment of surfaces is of considerable scientific and technological interest. Theoretical and experimental work has shown it to be a complex process, in some cases leading to surface instabilities that produce self-assembled nanostructures while leading in other cases to nanoscale surface smoothening. However, important questions remain about the fundamental processes acting on the surface during the bombardment. Using real-time GISAXS we’re able to make detailed comparisons of observed kinetics with theory that are difficult or impossible with other methods. Our primary focus has been on surface morphology development of Si during low-energy (< 1000 eV) Ar+ ion bombardment, both the native development of the surface and the formation of nanodots via Mo “seeding” during bombardment.

  542. National Synchrotron Light Source Lunch Time Seminar

    "Simultaneous XAFS Measurements of Multiple Samples"

    Presented by Bruce Ravel, NIST

    Friday, September 25, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  543. National Synchrotron Light Source Seminar

    "Modeling Effects that Accelerate Aluminum Corrosion: A Kinetic Study of the Copper-Aluminum Displacement Reaction"

    Presented by Sabrina Sobel, Professor & Chair, Hofstra University, Dept. of Chemistry

    Thursday, September 24, 2009, 10:30 am
    Seminar Room, Bldg. 725

    Hosted by: Lisa Miller

    Aluminum corrosion is an important industrial concern. Studies have indicated the aluminum corrodes more quickly in sea water, and when in contact with copper, either metallic or as Cu(II) in solution. Since Cu is a more noble metal than Al, a Galvanic cell can be established easily, promoting aluminum oxidation. The ‘chloride acceleration effect’ is well established, and is the major reason for accelerated aluminum corrosion in sea water. Aluminum natively forms a tough, impervious oxide (Al2O3) layer on its surface upon natural exposure to air. This impedes the redox reaction until it is removed. Acidic (< pH 4) and basic (> pH 9) conditions will dissolve the oxide layer and accelerate aluminum corrosion as well. Several groups have investigated the kinetics of the Cu/Al displacement reaction with and without added chloride, termed a copper cementation reaction. , , I have determined that the kinetics model developed for a rotating aluminum disk in reaction with a copper(II) solution works well for the much simpler reaction of household aluminum foil with copper(II) solution. In addition, my research has revealed that bromide also accelerates the corrosion of aluminum. The ‘halide acceleration effect’ was found to be quite significant, speeding up the reaction by about 100x and shortening the induction period. What the halide ion does to actually speed up the reaction is still unclear. I plan to continue my investigations to determine the dependence of the acceleration effect on the relative concentration of chloride as well as investigate the relative effect of fluoride on aluminum corrosion.

  544. NSLS-II Seminar

    "Beam Dynamics Aspects of Crab Cavities in the Large Hadron Collider"

    Presented by Dr. Yipeng Sun

    Thursday, September 24, 2009, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Sam Krinsky

    Modern colliders bring into collision a large number of bunches to achieve a high luminosity. The long-range beam-beam effects arising from parasitic encounters at such colliders are mitigated by introducing a crossing angle. Under these conditions, crab cavities (CC) can be used to restore effective head-on collisions and thereby to increase the geometric luminosity. Such crab cavities have been proposed for both linear and circular colliders. The crab cavities are RF cavities operated in a transverse dipole mode, which imparts on the beam particles a transverse kick that varies with the longitudinal position along the bunch. The use of crab cavities in the Large Hadron Collider (LHC) may not only raise the luminosity, but it could also complicate the beam dynamics, e.g. crab cavities might not only cancel synchro-betatron resonances excited by the crossing angle but they could also excite new ones, they could reduce the dynamic aperture for off-momentum particles, they could influence the aperture and orbit, also degrade the collimation cleaning efficiency, and so on. In this paper, we explore the principal feasibility of LHC crab cavities from beam-dynamics point of view. The implications of the crab cavities for the LHC optics, analytical and numerical luminosity studies, dynamic aperture, aperture and beta-beating, emittance growth, beam-beam tune shift, long-range collisions, and synchro-betatron resonances, crab dispersion and collimation efficiency will be discussed.

  545. Brookhaven Accelerator Forum (BAF)

    "Accelerator Physics Challenges for the NSLS -II Storage Ring"

    Presented by Sam Krinsky, NSLS-II

    Wednesday, September 23, 2009, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: Satoshi Ozaki

    Abstract The NSLS-II is an ultra-bright synchrotron light source based upon a 3-GeV storage ring with a 30-cell (15 super-period) double-bend-achromat lattice with damping wigglers used to lower the emittance below 1 nm. In this talk, we discuss the accelerator physics challenges for the design including: optimization of dynamic aperture; estimation of Touschek lifetime; achievement of required orbit stability; and analysis of ring impedance and collective effects.

  546. NSLS-II Seminar

    "A Control Systems Perspective to Nanopositioning"

    Presented by Srinivasa Salapaka and Chi Bum Lee, University of Illinois, Urbana-Champaign

    Tuesday, September 22, 2009, 9:30 am
    NSLS-II Large Conference Room, Bldg. 703

    Hosted by: Evgueni Nazaretski

    If you would like to meet with these speakers after this presentation, please contact the host, prior to this presentation to coordinate a time slot. This talk will focus on control systems theoretic analysis and synthesis of new modes of operations that significantly expand the range of performance specifications of nanopositioning systems. We will present a systems theory framework to study fundamental limitations on the performance of these devices. In particular, we will characterize the inherent fundamental trade-offs between resolution, tracking-bandwidth, and reliability specifications on positioning capability of these devices. In addition to determining fundamental limitations, this framework leads to a better understanding of existing technology and in overcoming some technological hurdles that were previously thought to be fundamentally limiting. The analysis is done in robust optimal-control setting with various architectural constraints that arise typically in nanopositioning systems imposed on both one- and two- degrees of freedom control-design frameworks. We show design strategies for improving some common existing nanopositioning systems, making nanopositioning systems insensitive to modeling uncertainties, and feedback designs that achieve simultaneously high bandwidth, resolution and robustness to modeling uncertainties. The outcomes of this research will be corroborated with experimental results on a nanopositioning system of an atomic force microscope. Experimental results that demonstrate significant improvements in bandwidth, resolution and robustness over common existing designs will be presented.

  547. National Synchrotron Light Source Lunch Time Seminar

    "Elemental Trends in Ocean Chemistry, Revealed by Synchrotron Microprobe of Echinoderms"

    Presented by Aaron Frodsham, Stony Brook University

    Friday, September 18, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  548. National Synchrotron Light Source Lunch Time Seminar

    "Probing the Influence of Polyvinyl Pyrrolidone (PVP) on Platinum Electrocatalysts Using in Situ X-ray Absorption Spectroscopy"

    Presented by Badri Shyam, George Washington University

    Friday, September 18, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  549. National Synchrotron Light Source Seminar

    "Some Aspects of the Low Energy Excitations in High-Tc Cuprates via ARPES"

    Presented by Wei-Sheng Lee, Stanford University

    Monday, September 14, 2009, 11 am
    Seminar Room, Bldg. 725

    Hosted by: Yong Cai / Chi-Chang Kao

    Angle-resolved photoemission spectroscopy has revealed several energy scales in the low energy excitations of high-Tc cuprates. In this presentation, I will discuss two important features in this hierarchy from my thesis work. Starting from the lowest energy, I will first discuss energy gap issues in high-Tc cuprates, specifically, our temperature dependence and doping dependence studies on the two-gap phenomena (superconducting gap vs. pseudogap). Moving to the higher energy scale, a “kink” in the dispersion near the nodal region is observed around 70 meV, and I will discuss materials dependence on this band renormalization effect based on our recent ARPES measurements on Tl-family cuprates. We have found a distinct evolution of this dispersion kink from nodal toward antinodal region between single-layer and multi-layer compounds, giving us a further hint about the origin of the renormalization effect. Finally, if time permits, I will briefly introduce our proposed time resolved x-ray scattering experiment using the x-ray free electron laser, the LCLS at SLAC.

  550. National Synchrotron Light Source Lunch Time Seminar

    "Novel Biaxial Smectic Phases"

    Presented by Chenhui Zhu, University of Colorado

    Friday, September 11, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  551. NSLS-II Seminar

    "Nanopositioning, Scanning Probe Microscopy and Metrology in Extreme Environments"

    Presented by Dr. Pierre-Francois Braun, Dipl. Ing. Florian Pon, Attocube Systems AG/Inc., German

    Friday, September 11, 2009, 11 am
    NSLS-II Large Conference Room, Bldg. 703

    Hosted by: Evgueni Nazaretski

    If you would like to meet with these speakers after this presentation, please contact the host @ prior to this presentation to coordinate a time slot. Attocube Systems, a German company located in Munich, manufactures and provides ultra high precision spatial positioning systems and complete probing tools which are particularly suitable for extreme environmental conditions such as cryogenic temperatures (10mK - 300 K), high magnetic fields (+31 T) and ultra high vacuum environments (5 x 10-11 mbar). We will present the technology incorporated in the range of nanopositioners, complete microscope systems and novel approaches regarding displacement sensors and AFM solutions in an SEM environment. The product lines of attocube systems are: nanoPOSITIONING, LTSYS, nanoSCOPY, nanoTOOLING, nanoSEMsolutions, and attoCONTROL.

  552. NSLS-II Seminar

    "Recent Mechanical Upgrades to the Louisiana State University Center for Advanced Microstructures and Devices (CAMD)"

    Presented by Kevin Morris

    Thursday, September 10, 2009, 10:15 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Andrew Broadbent

    Scientific programs at CAMD have developed over the last several years leading to increased demand for photon energies beyond the original design criterion of the synchrotron. This talk outlines two projects at CAMD that impact opposite ends of the available photon spectrum. Modifications to, and the ultimate replacement of, a 7T superconducting wavelength shifter for higher brightness hard X-ray photons and construction of a new dipole vacuum chamber to access the far infrared region.

  553. NSLS-II Seminar

    "Insight into heterogeneous geomaterials through XANES Imaging Spectroscopy."

    Presented by Vincent De Andrade, ESRF, X-ray microscopy beamline ID21, 38043 Grenoble

    Wednesday, September 9, 2009, 9 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Juergen Thieme

    Because of their complex genesis, materials are commonly polycrystalline heterogeneous systems, with both chemical and structural heterogeneities at various scale-level. As most of the micro- and nano- analytical techniques relying on scanning instruments with a pencil-beam, XANES (X-ray Absorption Near Edge Structure) technique offers high spatial resolution but suffers from long acquisition times imposing practical limits on the field of view. Now, region of interest in samples are generally several orders of magnitude larger than the beam size. Along this presentation, an overview will be given onto the on-going technical developments of the ESRF ID21-beamline Scanning Microscope, relating to detection (multi-elements detector, in-house developed WDX spectrometer) and optics (Fresnel zone plate, KB mirrors). Then, we will focus on an original setup developed and optimized to perform spectroscopic imaging on geomaterials, with relatively short acquisition time (≈1 h) and large field of view (0.5-2 mm2) while keeping a sub-micron resolution. The setup consists in coupling full-field absorption radiographies with a large parallel beam of hard X-rays, XANES and PIC (Polarization Imaging Contrast) techniques. The potential of this combined approach will be demonstrated on metamorphic rocks. This non-invasive method enables 2D quantitative Fe3+/Fetotal estimates revealing subtle redox variations inside mineralogical phases. Moreover, besides providing crystalline orientations at the pixel scale, the PIC and XANES combination allowed to correct XANES estimates from polarization effects, which is a tricky but important task in polycrystalline materials. Finally, the last application concerns an experimental study of a bentonite analog (clayey material) considered for nuclear wastes and CO2 storage. Mapping of the proportions of finely mixed phases at the µm3 scale were extracted from hyperspectral data acquired on a reference bentonite. The spatial repartition o

  554. National Synchrotron Light Source Lunch Time Seminar

    "Element- and Site-Specific Electronic Structure of Planar Organics: Soft X-ray Emission and Absorption Spectroscopy of Hexadecafluoro Phthalocyanine"

    Presented by Louis Piper, Boston University

    Friday, September 4, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  555. National Synchrotron Light Source Lunch Time Seminar

    "Micro-spectroscopy at the U5UA beamline: graphene on transition metals"

    Presented by Jurek Sadowski, CFN, BNL

    Friday, September 4, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  556. NSLS-II Seminar

    "Exploring Quantum Phase Transitions in Strongly Correlated Materials Using Optical Spectroscopy"

    Presented by Harini Barath, University of Illinois at Urbana-Champaign

    Monday, August 31, 2009, 11 am
    NSLS-II Bldg. 703, Room 20

    One of the primary areas of interest in contemporary condensed matter physics is the study of strongly correlated materials, which are materials in which there is a strong coupling between charge, spin, lattice and orbital degrees of freedom. Because of the interplay between various competing orders, these systems have highly complex phase diagrams and exhibit interesting phenomena such as colossal magnetoresistance (CMR), high temperature superconductivity and charge/orbital ordering (COO). In this talk, I will present the results of our temperature- and magnetic- eld-dependent inelas- tic light scattering studies of two such correlated materials: (i) In TbMnO3, a magnetoelectric multiferroic, we map out the temperature and eld phase diagram, and find evidence for field-induced quantum uctuations of commensurate domains near the field-tuned incommensurate-commensurate phase transition. (ii) In the charge-density-wave (CDW) system, TiSe2, we study the collapse of the CDW state as a function of Cu-intercalation and examine the novel emergent phases that result from the competition between CDW and superconducting orders in this complex system.

  557. National Synchrotron Light Source Lunch Time Seminar

    "Bacteriophage T7 DNA polymerase and its processivity factor, E. coli thioredoxin: a structure-function study"

    Presented by Barak Akabayov, Harvard University

    Friday, August 28, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  558. National Synchrotron Light Source Lunch Time Seminar

    "Ethanol and ethylene glycol (EG) TPD on Pt/transition metal oxide nanoparticles: a metal-support interaction study"

    Presented by Zhong He, New Jersey Institute of Technology

    Friday, August 28, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Christie Nelson

  559. NSLS Town Meeting

    Thursday, August 27, 2009, 1 pm
    NSLS Seminar Room

    Hosted by: NSLS Users' Executive Committee

  560. National Synchrotron Light Source Seminar

    "Applications of X-ray characterization for advanced materials in the electronics industry"

    Presented by Assunta Vigliante, Bruker-AXS

    Monday, August 24, 2009, 2:30 pm
    Seminar Room, Bldg. 725

    Hosted by: K. Evans-Lutterodt

  561. National Synchrotron Light Source Lunch Time Seminar

    "Zinc, it's more important that you think: its role in brain and behavior"

    Presented by Dr. Jane Flinn, George Mason University

    Friday, August 21, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

  562. National Synchrotron Light Source Lunch Time Seminar

    "Looking at the magnetoelectric coupling in multiferroic materials from their lattice dynamics perspective"

    Presented by Ricardo Lobo, School of Physics and Chemistry of Paris, CNRS

    Friday, August 21, 2009, 12 pm
    Seminar Room, Bldg. 725

  563. NSLS-II Seminar

    "X-ray Fluorescence Holography in Theory and Experiment"

    Presented by Jainming Bai, University of Tennessee

    Thursday, August 20, 2009, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Eric Dooryhee

    X-ray fluorescence holography is a new structure determination method developed in the last two decades. It can provide 3D atomic image around a fluorescence atom in a crystal structure and thus being considered as a promising tool for determination of local structures of doped atoms, buried clusters and impurities in a bulk crystal, as well as solving structures of nano-crystals, quasi-crystals or other structures lacking of long range translational order. The current state of the atomic resolution x-ray holography will be discussed with emphases on the near field effects and the recent XFH/MEXF measurements conducted at NSLS will be reported.

  564. NSLS-II Seminar

    "X-ray Microscopy of Crystalline Alkanes and Semi-crystalline Polyethylene Thin Films"

    Presented by Dr. Ying Zou, Department of Physics, University of Milwaukee-Wisconsin

    Monday, August 17, 2009, 3 pm
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Juergen Thieme

    Abstract: Scanning transmission x-ray microscopy (STXM) has been used to establish a correlation of Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra of crystalline n-tetracontane (C40H82) with its structural anisotropy in orthorhombic (001) plane. Two subcomponent peaks of the spectral doublet near 287.5eV reverse their intensity ratio when the orientation of polarization vector of incident light swaps from along a axis to b axis [1]. Such an intra-plane linear dichroism complements prior known linear dichroism along c axis [2]; together they can be used to determine three dimensional orientations for linear alkane chains or ordered C-C backbone chains in semi-crystalline polyethylene (PE). This new information allows us to understand details of the growth orientation of polyethylene (PE) in ultrathin films. In linear low density PE (LLDPE) films, STXM shows large dichroic signals between various sample features for photon energies of ~287.4 eV and ~294 eV, irrespective of film thickness. This suggests that in these thin films, the average C-C bonds are in the plane of the thin film with predominantly edge-on lamellae orientation. In very thin films, the averaged NEXAFS spectrum switches from a slight dominance of b-axis signal to one of slight a-axis signal dominance. This suggests that the interfacial constraints alter the average orientations of crystallites. Linear medium density PE (LMDPE) thin films showed a transition from edge-on to flat-on lamellae (C-C backbone parallel to the surface normal) in films thinner than 30 nm [3]. References: 1. Y. Zou, T. Araki, G. Appel, A.L.D. Kilcoyne, H. Ade, Chem. Phys. Lett. 430, 287 (2006) 2. J.X. Fu, S.G. Urquhart, J. Phys. Chem. A, 109, 11724 (2005); T. Ohta, K. Seki, R. Yokoyama, I. Morisada, and K. Edamatsu, Physica Scripta 41, 150 (1990) 3. Y. Wang, M. Rafailovich, J. Sokolov, D. Gersappe, T. Araki, Y. Zou, A.D.L. Kilcoyne, H. Ade, G. Marom, A. Lustiger, Phys. Rev. Lett. 96, 028303 (2006)

  565. National Synchrotron Light Source Lunch Time Seminar

    "Smart Matrix Theory: is collagen a brilliant string or a dumb rope?"

    Presented by Jeff Ruberti, Northeastern University, Boston

    Friday, August 14, 2009, 12 pm
    Seminar Room, Bldg. 725

    Hosted by: Elaine DiMasi

    Nature places structural material in the path of high loads where it persists. Indeed, multicelled plants and animals must resist dissipation at multiple scales to survive. However, it is not yet clear precisely how highly-organized, load-bearing structures are produced in biological systems. Traditionally, control of fibrillar organization has been attributed to cells, which are thought to directly place components in the extracellular matrix. However, we have developed a working hypothesis which suggests that nature has evolved a set of structural molecules whose interaction profoundly simplifies the production of anisotropic materials (suitable for load-bearing). Among these, collagen, defined most simply as Gly-X-Y, is the structural molecule of choice and most abundant protein in vertebrates, comprising 25% of total body protein. Collagen arose approximately 700 MYA and appears to have played a major role both in metazoan radiation and evolutionary success. Fibrillar collagens can be found in arteries, bone, ligament, tendon, skin, cornea, anulus fibrosus and cartilage. It seems that wherever there are difficult mechanical design criteria, collagen is employed. Our laboratory has been compiling evidence which suggests that fibrillar collagen (and other associated ECM moieties) comprise the basis of a smart, adaptable structural system. We are currently developing a “smart matrix theory” which posits that the development and growth of collagenous matrix proceeds by three mechanisms: 1) spontaneous formation of highly-organized tissue rudiments from concentrated solutions (~50-400 mg/ml) of collagen monomers, 2) strain-driven load-adaptation of the rudiments and 3) strain-driven growth of the rudiments through preferential polymerization.

  566. NSLS-II Seminar

    "Longitudinal Beam dynamics in PEP-X with a Passive Third Harmonic Cavity"

    Presented by Lanfa Wang

    Friday, August 14, 2009, 10 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Samuel Krinsky

    A proposed high-brightness synchrotron light source (PEP-X) is under design at SLAC. The 4.5-GeV PEP-X storage ring has four theoretical minimum emittance (TME) cells to achieve the very low emittance and two double-bend achromat (DBA) cells to provide spaces for IDs. Damping wigglers will be installed in zero-dispersion straights to reduce the emittance below 0.1 nm. The Touschek lifetime is short due to the small beam’s emittance. High Harmonic Cavity (HHC) can be used to lengthen the bunch in order to improve the Touschek lifetime. Transient beam loading in the main cavities and harminic cavities with a uneven beam filling pattern can cause significant variation of the bunch synchrotron phase and bunch length along the bunch train. We studied the impact of HHC on beam dynamics of a bunch train with a gap. The beam loading effect is anaylized based on the linear theory. We also simulated the phase shift, bunch lengthening and beam instability for various options of the cavities.

  567. NSLS-II Seminar

    "Design, Construction and Hard Won Lessons at the Australian Synchrotron"

    Presented by Bradley Mountford, Australian Synchrotron, Australia

    Thursday, August 13, 2009, 11 am
    NSLS-II Seminar Room, Bldg. 817

    Hosted by: Andrew Broadbent

    The Australian Synchrotron is a 3rd Generation light source which has been receiving users since 2007. The topics of this presentation will range from the design and construction of the machine with attention to the storage ring vacuum system and frontends, and then move on to a detailed look at the design and construction of the SAXS/WAXS Endstation. A summary will be made of design projects currently under way which include a Multi Crystal Analyzer for use on the Powder Diffra