Theoretical model of the nonlinear resonant interaction of whistler-mode waves and field-aligned electrons

The nonlinear resonant interaction of intense whistler-mode waves and energetic electrons in the Earth's radiation belts is traditionally described by theoretical models based on consideration slow–fast systems. Such reduce electron dynamics around resonance to single pendulum equation that provides solutions for scattering (phase bunching) phase trapping. Applicability this approach limited not-too-small pitch-angles (i.e., sufficiently large magnetic moments), whereas model predictions contradict test particle results small pitch-angle electrons. This study focused such field-aligned (small pitch-angle) resonances. We show can be Hamiltonian system with separatrix crossing. For first cyclotron resonance, increase all electrons, contrast decrease predicted scattered derive threshold value moment transition a new regime interaction. proposed magnitude changes resonance. supplements existing contributes theory waves.