{'fraction_non_alphanumeric': 0.02304147465437788, 'fraction_numerical': 0.004608294930875576, 'mean_word_length': 4.821428571428571, '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}}
Multipulse effects in the damage to the LCLS reflective optics

The planned Linac Coherent Light Source (LCLS) will operate at a rate of 120 x-ray pulses per second. Therefore, when considering effects leading to the damage to its optics, one has to be concerned not only with a possible damage within one pulse, but also with effects accumulating during many pulses. Two of such effects: a thermal fatigue, and the intensity-dependent radiation damage, have been identified and analyzed in this paper. Constraints on the admissible fluence per pulse have been derived and ways for decreasing the impact of the multi-pulse effects have been suggested.