Simulation of bent Laue crystals for a high-energy X-ray monochromator with heat load consideration

Abstract

The performance of a double-crystal Laue-case monochromator has been evaluated for the Engineering Material beamline at the High Energy Photon Source. Expanding on the xrt framework, the crystal simulation incorporates the Penning–Polder and multilamellar models to determine the crystal diffraction profiles and utilizes two approaches, analytical expression and discrete point, for crystal depiction. The simulation accounts for the heat load by treating it as both face distortion and bulk distortion. Three scenarios are discussed: an ideally bent crystal without heat load, a bent crystal with thermally induced face distortion and a bent crystal with thermally induced bulk distortion. The mutual consistency in tracing confirms the validity of the crystal simulation. Two thermal distortion assessment tools are available: one for the rapid evaluation of the impact of significant distortions, and the other for the refined reflection of interior lattice plane distortions, which constitutes a key innovation of the simulation. The tracing outcomes offer valuable guidance for decision making and risk mitigation in the optical design process.