NSLS-II Seminar

X-ray imaging techniques play important roles in modern science for which can provide high-resolution, element-sensitive structure information with long penetration length, in a non-destructive manner. X-ray coherent diffraction imaging technique (XCDI), taking advantage of coherence illumination delivered from 3rd generation synchrotron sources, has been growing rapidly in the recent years. XCDI is a lensless imaging technique and has potential to achieve atomic resolution, therefore it attracts more and more attentions from many different communities, from biology to material science. However, there are some difficulties in XCDI in both experimental and data-processing stages, for examples, avoiding parasitic scattering in the collected data and solving structure from the incomplete data. In the first part of this presentation, the developments made at APS that aim to solve these problems will be presented and discussed. Grating-based x-ray interferometer (XGI) is another recently developed imaging technique that allows the specimens' phase map to be retrieved from the interferogram in a straightforward way. Typically, the spatial resolution of XGI is limited by the grating period that is at best 1 micron level to-date. To improve the achievable spatial resolution with XGI, we can combine XGI with a transmission x-ray microscope (TXM). In the second half of this talk, the discussion on the optimal combination conditions of a XGI and a TXM based on coherence theory will be presented. The theoretical results of this work can be used to guide a successful combination setup in practice.