At-wavelength characterization of X-ray wavefronts in Bragg diffraction from crystals

The advent of next-generation synchrotron radiation sources and X-ray free-electron lasers calls for high-quality Bragg-diffraction crystal optics to preserve the X-ray beam coherence and wavefront. This requirement brings new challenges in characterizing crystals in Bragg diffraction in terms of Bragg-plane height errors and wavefront phase distortions. Here, a quantitative methodology to characterize crystal optics using a state-of-the-art at-wavelength wavefront sensing technique and statistical analysis is proposed. The method was tested at the 1-BM-B optics testing beamline at the Advanced Photon Source for measuring silicon and diamond crystals in a self-referencing single-crystal mode and an absolute double-crystal mode. The phase error sensitivity of the technique is demonstrated to be at the λ /100 level required by most applications, such as the characterization of diamond crystals for cavity-based X-ray free-electron lasers.

Source: Journal of Synchrotron Radiation - October 10, 2023 Category: Physics Authors: Shi, X. Qiao, Z. Pradhan, P. Liu, P. Assoufid, L. Kim, K.-J. Shvyd'ko, Y. Tags: wavefront sensing crystal diffraction coded mask phase error at-wavelength metrology research papers Source Type: research