Bragg Coherent Diffraction Imaging at the Advanced Photon Source 34-ID Beamline

Ross Harder
Argonne National Laboratory

The 34-ID-C beamline at the APS is dedicated to Bragg Coherent Diffraction Imaging (BCDI). In recent years we have become good at measuring and analyzing coherent diffraction patterns from small (sub micrometer) crystals. Given the coherent flux of the current APS, we focus primarily on metals, battery materials and condensed matter systems that provide significant diffraction signal in low order Bragg peaks. Additionally, we are extremely effective in the regime of “low strain”, meaning crystals that don’t have too many defects, or are not extremely heterogeneous. Such structures are “easy” to image at high resolution (10s of nanometers).
This talk will introduce the basics of the BCDI measurements done at 34-ID-C of the APS and discuss our current state of the art phase retrieval algorithms. It will also introduce the limitations of the current method, show a lot of data that we currently can’t use and hopefully inspire some discussion regarding the advances required for experiments on more diverse samples. Additionally, in light of the coming upgrade of the APS to a fourth generation high coherence source, new data rate challenges will present themselves. The anticipated size and/or number of data sets could strain our ability to conduct effective investigations of materials.

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