{'fraction_non_alphanumeric': 0.036286919831223625, 'fraction_numerical': 0.0270042194092827, 'mean_word_length': 4.542056074766355, '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}}
Multiply charged ions of Rb and Sr produced by 3d-shell photoionisation

Relative ion-yield spectra for Rbn+ (n=1-4) and Srn+ (n=1-4) produced by photoionisation have been determined using a combination of a time-of-flight mass spectrometry and monochromatised synchrotron radiation crossed with an atomic beam. The measurement was made in the energy region from the vicinity of the 3d ionisation threshold to the higher-energy tail of the 3d- in f shape resonance: 110 to 280 eV for Rb and 130 to 280 eV for Sr. The main products in this energy region are triply charged ions for both Rb and Sr. A strong 3d shape resonance peak is observed in the yield curves of Rb2+, Rb3+ and Sr3+. The yield curve of Rb4+ has its onset around the lowest photoelectron shake-off (4d-15s-1) state. Although the multiply charged ions are produced mainly by stepwise autoionisation from the 3d hole states, 3d ionisation with simultaneous ionisation of another electron (i.e. the photoelectron shake-off process) is found to have considerable probability. The photoelectron shake-off probability for Rb is estimated from the present data to be about 0.2 in the higher-energy region of this experiment.