{'fraction_non_alphanumeric': 0.037489812550937245, 'fraction_numerical': 0.05460472697636512, 'mean_word_length': 5.429319371727749, 'pattern_counts': {'":': 0, '<': 1, '<?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}}
The role of cascade processes in electron-impact excitation of the (3p54s2)2P3/2, 1/2 autoionizing levels in potassium

The cascade population of the (3p54s2)2P3/2, 1/2 lowest autoionizing levels in potassium has been studied to shed light on recent experimental observations of a noticeable enhancement in the cross sections around 22 eV incident electron energy. The ejected-electron excitation functions of both levels have been re-measured in the range of 20–28 eV, and calculations of the decay parameters for the 3p54s4p levels have been performed in single-configuration Hartree–Fock and configuration-interaction approaches. The analysis of these results, together with other available experimental and theoretical data on the 3p subshell excitation in potassium, revealed a relatively small contribution (<3%) of radiative transitions from the (3p5 4s4p1P)2P, 2D levels to the apparent (including cascade contributions) excitation cross sections of the (3p54s2)2P3/2, 1/2 levels. However, the decay of negative-ion resonances associated with the upper doublets in the 3p54s4p and 3p53d4s configurations may lead to a significant cascade population of the (3p54s2)2P3/2, 1/2 levels in the impact energy region 21–28 eV.