{'fraction_non_alphanumeric': 0.021158129175946547, 'fraction_numerical': 0.01002227171492205, 'mean_word_length': 4.953642384105961, '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}}
High-power extreme-ultraviolet source based on gas jets

We report on the development of a high-power laser plasma extreme UV (EUV) source for EUV. The source is based on the plasma emission of a recycled jet beam of large Xe clusters and produces no particular debris. The source will be driven by a pulsed laser delivering 1500 W of focused average power to the cluster jet target. To develop condensers and to optimize source performance, a low-power laboratory cluster jet prototype has been used to study the spectroscopy, angular distributions, and EUV source images of the cluster jet plasma emission. In addition, methods to improve the reflectance lifetimes of nearby plasma-facing condenser mirrors have been developed. The resulting source yields EUV conversion efficiencies up to 3.8 percent and mirror lifetimes of approximately 109 plasma pulses, with further improvement anticipated.