Pitch-Angle Diffusion of Radiation Belt Electrons and Precipitating Particle Fluxes: Dependence on VLF Wavefield Parameters

The dependence of the pitch-angle diffusion efficiency of energetic electrons in the Earth’s magnetosphere on the distribution of the whistler wave field along the geomagnetic flux tube is quantitatively studied for parameters corresponding to the location of the Sura and HAARP HF heating facilities. The expansion of the precipitation energy range with the increase of the region of geomagnetic latitudes occupied by the waves is shown. Using the calculated pitch-angle diffusion coefficient for a given spectrum of waves and their distribution along the flux tube, the ratio of the fluxes of precipitating and trapped particles at low altitude is determined. It is shown that at typical wave intensities corresponding to chorus VLF waves and plasmaspheric hiss, the fluxes of precipitating and trapped electrons can be comparable to each other. At the same time, for the wave amplitudes observed as a result of the action of heating facilities, the flux of precipitating electrons is negligible.