Performance of quartz- and sapphire-based double-crystal high-resolution (~10 meV) RIXS monochromators under varying power loads

Journal Article · Thu May 31 00:00:00 EDT 2018 · Journal of Synchrotron Radiation (Online)

DOI:https://doi.org/10.1107/S1600577518005945· OSTI ID:1473620

Gog, Thomas ^[1]; Casa, Diego M. ^[1]; Knopp, Jonathan ^[1]; Kim, Jungho ^[1]; Upton, Mary H. ^[1]; Krakora, Richard ^[1]; Jaski, Alan ^[1]; Said, Ayman ^[1]; Yavaş, Hasan ^[2]; Gretarsson, Hlynur ^[3]; Huang, Xian Rong ^[1]

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1. Argonne National Lab. (ANL), Lemont, IL (United States)
2. Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
3. Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

In the context of a novel, high-resolution resonant inelastic X-ray scattering spectrometer, a flat-crystal-based quartz analyzer system has recently been demonstrated to provide an unprecedented intrinsic-energy resolution of 3.9 meV at the IrL₃ absorption edge (11.215 keV) [Kimet al.(2018)Sci. Rep.8, 1958]. However, the overall instrument resolution was limited to 9.7 meV because of an 8.9 meV incident band pass, generated by the available high-resolution four-bounce Si(844) monochromator. In order to better match the potent resolving power of the novel analyzer with the energy band pass of the incident beam, a quartz(309)-based double-bounce, high-resolution monochromator was designed and implemented, expected to yield an overall instrument resolution of 6.0 meV. The choice of lower-symmetry quartz is very attractive because of its wealth of suitable near-backscattering reflections. However, it was found that during room-temperature operation typical levels of incident power, barely affecting the Si monochromator, caused substantial thermal distortions in the first crystal of the quartz monochromator, rendering it practically unusable. Finite-element analyses and heat-flow analyses corroborate this finding. As a high-flux, lower resolution (15.8 meV) alternative, a two-bounce sapphire(078) version was also tested and found to be less affected than quartz, but notably more than silicon.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1473620
• Journal Information: Journal of Synchrotron Radiation (Online), Vol. 25, Issue 4; ISSN 1600-5775
• Publisher: International Union of Crystallography
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
non-traditional crystal materials
RIXS
high-resolution monochromators
resonant inelastic X-ray scattering
x-ray optics