{'fraction_non_alphanumeric': 0.028233151183970857, 'fraction_numerical': 0.010018214936247723, 'mean_word_length': 5.3526011560693645, '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}}
IONOSPHERIC ION ACCELERATION BY MULTIPLE ELECTROSTATIC WAVES

Observations by Topaz 3 show ionospheric O+ and H+ ions, with ambient energies of around 0.3 eV, to be transversely (to the geomagnetic field) energized, to around 10 eV, within lower hybrid structures composed of broadband large-amplitude (100–200 mV/m) electrostatic waves. In this paper we show that the energization of O+ ions can be explained by a new nonlinear coherent interaction mechanism involving multiple electrostatic waves propagating across the magnetic field. Low-energy ions, whose velocities are well below the phase velocities of the waves, are shown to gain energy monotonically increasing in time when averaged over a cyclotron orbit. We examine the properties of this coherent energization mechanism numerically and by an analytical, multiple timescale, analysis. We find, in accordance with observations, that the tail of the O+ distribution is most likely to be energized. The analysis provides the spatial extent, along the geomagnetic field, of the lower hybrid structures needed for the observed energization.