{'fraction_non_alphanumeric': 0.01834862385321101, 'fraction_numerical': 0.005504587155963303, 'mean_word_length': 4.870967741935484, '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}}
Focusing of 28.5 GeV electron and positron beams in meter-long plasmas

Plasmas can focus both electron and positron beams. However, while the incoming Gaussian transverse profile of an electron beam is preserved upon focusing, the focusing of a positron beam by a long, high-density plasma results in a tightly focused core with the formation of a charge halo. The plasma acts on the positron beam as focusing element with transverse and longitudinal aberrations. The analysis of the focused positron beam transverse profiles is presented here.