The ultrahigh energy resolution IXS spectrometer being developed at the National Synchrotron Light Source II (NSLSII) employs an innovative optical design. Its analyzer system utilizes an L-shaped laterally graded multilayer mirror in tandem with a multi-crystal arrangement. The multi-crystal arrangement explores the angular dispersion effect in extremely asymmetric Bragg reflections to achieve sub-meV energy resolution at an energy about 9.1 keV. Its angular acceptance (~ 0.1 mrad) is about two orders of magnitude lower than the spherically-bent backscattering analyzers conventionally used in other IXS spectrometers. The L-shaped laterally graded multiplayer mirror was designed to increase the angular acceptance of this new multi-crystal optics to a comparable level. It performs angular collimation of the incoming beam from about 15 mrad down to 0.1 mrad in both vertical and horizontal directions. Here we present simulations of the mirror performance and study the positioning and stability requirements in conjunction with the multicrystal energy analyzer.

Date Published: 5 September 2014
PDF: 6 pages
Proc. SPIE 9209, Advances in Computational Methods for X-Ray Optics III, 92090Y (5 September 2014); doi: 10.1117/12.2061844

Published in SPIE Proceedings Vol. 9209:
Advances in Computational Methods for X-Ray Optics III
Manuel Sanchez del Rio; Oleg Chubar, Editor(s)