By Mona S. RowePrint
May 28, 2014
NxtGen presents a new set of acronyms to learn at the National Synchrotron Light Source II (NSLS-II). And that’s good!
First announced in May 2012, NxtGen is a set of eight beamlines at NSLS-II that are now being developed by reusing components from multiple beamlines at the existing NSLS, which is shutting down at the end of September 2014.
“NSLS-II is a new world-class synchrotron source. The NxtGen beamlines will use the bending magnet ports to significantly increase the science base in infrared, tender x-ray and medium x-ray scattering and absorption spectroscopy, diffraction, and imaging,” said Julian Adams, NxtGen project manager.
“The performance of the NxtGen beamlines will be significantly greater than the NSLS programs that they are continuing,” he added. “These beamlines will provide complementary capabilities to the NSLS-II insertion-device beamlines, add significant capacity, and serve to transition much of the existing NSLS user community and their scientific programs to the new facility.”
Here’s the list of NxtGen beamlines and the beamline group leaders.
CMS and QAS will be completed in 2015, and TES and XFM will follow in the first half of 2016.
Adams explained that NxtGen is a phased project, funded through the Photon Sciences operations budget. “To optimize the resources of the directorate, we developed a phased plan of beamline development,” he said. “This has the QAS and CMS beamlines being delivered first, TES and XFM in the second phase. IXD and MPP are in the third phase, and MID and FIS/Met in the last phase. The phases were determined by the size of the user base and the complexity of the beamline to deliver.”
NxtGen beamlines will be attached to bending-magnet, three-pole-wiggler, or infrared (IR) sources at NSLS-II. Bending magnets (dipoles) are used to steer electrons in the synchrotron storage ring. When the electrons bend, they give off a broad fan of photons at a tangent. At NSLS-II, the critical energy of this photon fan is 2.4 thousand electron volts (keV), which serves the IR, soft x-ray (longer wavelength) and tender x-ray (shorter wavelength) beamlines. To use the bending magnet ports in the medium-energy x-ray spectrum, a three-pole wiggler (type of insertion device) is added immediately upstream of the bending magnet. The critical energy of the wiggler is 6.8 keV, which facilitates science up to 30 keV with significant beam intensity and power density.
At present, NSLS is supporting 2,400 users, most of them from the Northeast. Operating since 1982, it’s been a tremendous resource for the science community that uses photons to do research. “NxtGen offers capabilities that are broadly appealing to this community,” said Adams. “We have a team working hard to get the NxtGen beamlines up and running at NSLS-II.”
CMS is an x-ray scattering beamline on a three-pole wiggler source that will be dedicated to studies of the bulk and interfacial structures of complex materials, including nanomaterials, soft matter, and biomolecular materials. The beamline will provide instrumentation for simultaneous small- and wide-angle x-ray scattering (SAXS, WAXS) measurements, as well as scattering in grazing incidence geometry (GISAXS, GIWAXS), in the x-ray energy range of 10 – 17 keV. These measurements will give access to complementary structural information at multiple length scales, ranging from Angstroms to submicrons. Another key feature of the CMS is the ability to focus the beam down to tens of microns, which will enable scattering-based microprobe measurements to characterize domain morphologies in heterogeneous materials. The sample area will be compatible to both in-vacuum and in-air measurements, to accommodate a wide variety of sample environments ranging from thin films under vacuum to bulk solutions, buried interfaces, and liquid surfaces. The beamline will also develop automated sample handling capabilities to enable high-throughput exploration of large sample parameter spaces.
QAS will enable in situ studies of chemical and physical transformations by both slow and quick x-ray absorption and scattering measurements. QAS covers the energy range of 4.7 – 31 keV. It will be located at port 7-BM at NSLS-II and use a three-pole wiggler source. It will provide for the investigation of fast kinetics of samples from the fields of catalysis, energy storage/conversion and other scientific disciplines. It will allow measurements using combined XAS and XRD techniques, as well as combining these techniques with those provided by end stations with IR and Raman spectroscopy capabilities, in different sample environments. It will offer users a wide variety of specialized cells and reactors. Beamline optics include a vertical collimating mirror, a quick-scanning capable monochromator and a toroidal focusing mirror for spot sizes less than 0.5mm2.
TES is a tender-energy (1-8 keV, covering the energy range between “hard” and “soft” x-rays) beamline for spatially resolved and in-situ XAS and imaging. It will be situated at a bend-magnet source and employ compound focusing to achieve high flux in spot sizes tunable from 1 mm to 1 micron. Two endstations are optimized for characterization of materials and processes in climate and energy sciences, as well as earth, space and biological sciences. Endstation 1 is a helium-atmosphere microbeam endstation for XRF imaging, microbeam EXAFS, and XAS imaging. Endstation 2 is a bulk and in-situ XAS endstation optimized for controlled sample environments and reactions, particularly in catalysis and electrochemistry research. An important aspect for both endstations is the capability to scan energy on the fly for fast XAS (~30-second XANES, ~1-minute EXAFS), and to measure high-quality EXAFS on heterogeneous, structured and dynamic systems.
XFM is a versatile hard x-ray (4-20 keV) microprobe beamline with capabilities for x-ray fluorescence imaging and tomography, x-ray absorption spectroscopy, and x-ray microdiffraction. It will be situated on a three-pole wiggler source and employ compound focusing to achieve a user-tunable spot size from 1 to 20 microns. XFM is optimized for spatially resolved characterization of elemental abundances and molecular speciation in “as-is” samples that are heterogeneous at the micrometer scale. It has a long-working distance to accommodate custom in-situ environmental cells and physically large samples. Sample environment is ambient atmosphere with accommodations for He atmosphere, cold-stage and cryo-stream sample cooling. If desired, a macro-focused beam (1 x 1 mm) can be produced at the sample position for bulk XAS measurements or full-field computed tomography.
2014-4929 | INT/EXT | Media & Communications Office
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