Loss cone distributions of radiation belt electrons

Abstract

The electron population in and near the loss cone comprises trapped electrons, electrons that have diffused into the loss cone since their last bounce, and electrons that have interacted one or more times with the atmosphere. The distribution function of these electrons has been calculated by stepwise integrating the local pitch angle diffusion equation for wave-particle interactions along the magnetic field line. Above the atmosphere the diffusion mechanism is wave-particle interactions. At the atmosphere the scattering and energy loss collisions with atoms were included in the calculation. The results show that the pitch angle distributions of loss cone electrons depend strongly on the wave-particle diffusion coefficients and that measurements of electron fluxes can be used to derive values of these coefficients. Comparisons of the theoretical distributions with presently available data show the promise of the procedure but demonstrate the need for additional experimental data.