A Sagittally Bent Crystal for the Short Pulse X-ray Beamline at the Advanced Photon Source

17th Pan-American Synchrotron Radiation Instrumentation Conference

Strons, Philip^1 ; Khounsary, Ali^1 ; Antimonov, Mikhail^1 ; Dufresne, Eric M.^1 ; Reininger, Ruben^1

Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439, United States^1

关键词: Advanced photon source;    Double crystal monochromators;    Focused beams;    Mechanical interactions;    Minimal effects;    Pico-second pulse;    Sample position;    Second crystal;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/493/1/012023/pdf
DOI  :  10.1088/1742-6596/493/1/012023

来源: IOP

【 摘 要 】

The Short Pulse X-ray Imaging and Microscopy (SPXIM) Beamline at the Advanced Photon Source (APS) is being designed to provide a short-pulse focused beam at the sample some 60 m from the source. The second crystal in the horizontally diffracting double-crystal monochromator system is sagittally bent to focus the full vertical fan of the beam, preserving the flux of a typical undulator beamline at the APS, while providing a time-angle correlated beam on the sample with a few-picosecond pulse duration. An energy scan using this system requires changing the bent radius of the second crystal. Undesirable distortions in the sagittally bent second crystal are due to anticlastic deformations. In this paper, the analysis and design of the bent crystal is presented including an examination of the mechanical interaction between the crystal and the two pairs of rollers used to bend it. Ray tracings including the anticlastic deformations obtained from an optimized finite element model show a minimal effect on the spot size at the sample position.