DMCA
grating X-ray spectrometers (2010)
BibTeX
@MISC{Strocov10gratingx-ray,
author = {V. N. Strocov and A T. Schmitt and A U. Flechsig and A L. Patthey A and G. S. Chiuzbăian B},
title = {grating X-ray spectrometers},
year = {2010}
}
Share
 |
 |
 |
 |
||
OpenURL
Abstract
Operation of an X-ray spectrometer based on a spherical variable-line-spacing (VLS) grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and spectrometer geometry. The analysis is illustrated with optical design of a model spectrometer to deliver a resolving power above 20400 at a photon energy of 930 eV (Cu L-edge). With this energy taken as reference, the VLS coefficients are optimized to cancel the lineshape asymmetry (mostly from the coma aberrations) as well as minimize the symmetric aberration broadening at large grating illuminations, dramatically increasing the aberration-limited vertical acceptance of the spectrometer. For any energy away from the reference, corrections to the entrance arm and light incidence angle on the grating are evaluated to maintain the exactly symmetric lineshape. Furthermore, operational modes when these corrections are coordinated are evaluated to maintain either energy-independent focal curve inclination or maximal aberration-limited spectrometer acceptance. The results are supported by analytical evaluation of the coma term of the optical path function. This analysis thus gives a recipe for designing a high-resolution spherical VLS grating spectrometer operating with negligible aberrations at large acceptance and over an extended energy range.
Keyphrases
x-ray spectrometer energy-independent focal curve inclination entrance arm fast optimization large acceptance grating parameter analytical evaluation light incidence angle operational mode cu l-edge maximal aberration-limited spectrometer acceptance negligible aberration vls coefficient spectrometer geometry ray-tracing software optical path function high-resolution spherical vls optical design model spectrometer aberration-limited vertical acceptance coma term coma aberration extended energy range symmetric lineshape spherical variable-line-spacing symmetric aberration broadening photon energy lineshape asymmetry
