{'fraction_non_alphanumeric': 0.027142857142857142, 'fraction_numerical': 0.012857142857142857, 'mean_word_length': 4.563492063492063, '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-Order Above-Threshold Ionization in a Laser Field: Influence of the Ionization Potential on the High-Energy Cutoff

High-energy above-threshold ionization by a strong linearly polarized laser field is analyzed using the strong-field approximation and the quantum-orbit formalism. An analytical formula for the cutoff is derived. The maximal electron kinetic energy is 10.007 U P + 0.538 I P. The first term with the ponderomotive energy U P is equivalent to the known classical cutoff law, while the second term is a new result and depends on the ion- ization potential I P. The validity of this formula is confirmed by comparison with the numerical results for the high-energy electron spectra.