Bent Bragg–Laue monochromator for high-energy X-rays

Journal Article · Wed Jul 26 00:00:00 EDT 2017 · Journal of Applied Crystallography (Online)

DOI:https://doi.org/10.1107/S1600576717009098· OSTI ID:1393472

Shi, Xianbo ^[1]; Xu, Wenqian ^[1]; Yakovenko, Andrey ^[1]; Halder, Gregory ^[1]; Liu, Zunping ^[2]; Kurtz, Charles ^[1]; Ribaud, Lynn ^[1]; Beyer, Kevin ^[1]; Chapman, Karena ^[1]; Chupas, Peter ^[3]

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1. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS), X-ray Science Division
2. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS), APS Engineering Support Division
3. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS), X-ray Science Division, Photon Science Directorate

A bent Bragg–Laue monochromator (BLM) is proposed for high-energy X-ray (~25–60 keV) beamlines. The BLM has the unique feature of bi-directional focusing. A sagittally bent Laue crystal can focus the large horizontal fan of a bending magnet or wiggler source. A meridionally bent Bragg crystal focuses the beam vertically and corrects for the anticlastic bending effects of the Laue crystal. This monochromator geometry relies on the crystal orientations being optimized. We show that the focusing condition and Rowland condition can be simultaneously satisfied at a given energy. A detailed ray tracings indicate that a BLM can provide similar energy resolution and higher flux density compared to a sagittally bent double-Laue monochromator configuration. A prototype BLM with a symmetric Bragg crystal and an asymmetric Laue crystal was tested. Matching of the bend radii of the two crystals in the meridional direction was demonstrated. Generally, the horizontal acceptance of the sagittally bent Laue crystal is limited by the large curvature. This horizontal BLM acceptance could be increased by translating the Laue crystal along its sagittal bending axis.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1393472
• Journal Information: Journal of Applied Crystallography (Online), Journal Name: Journal of Applied Crystallography (Online) Journal Issue: 4 Vol. 50; ISSN 1600-5767; ISSN JACGAR
• Publisher: International Union of Crystallography
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
Bragg-Laue
highenergy X-ray monochromator
meridionally-bent Bragg crystal
ray tracing
sagittally-bent Laue crystal