{'fraction_non_alphanumeric': 0.007345225603357817, 'fraction_numerical': 0.002098635886673662, 'mean_word_length': 5.235294117647059, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Effects of heat load on the performance of a grating monochromator on an undulator beamline: simulation

A new simulation method has been developed for evaluating the performance of a monochromator whose grating is exposed to intense undulator radiation. Analytic expressions for the thermally deformed surface figure and distorted groove pattern of the grating are determined first by a finite element method and then they are incorporated into a ray tracing procedure. The method is applied to a simple beamline optics consisting of a U3.9 undulator of the Advanced Light Source and a water-cooled metal grating to see whether this objective monochromator can stand for heat load without degrading its designed performance. The results show that the simulation method is capable of evaluating the performance of a thermally distorted grating and that the heat load would not cause any significant degradation in the spectral resolution and throughput.