Relativistic Electron Scattering by Electromagnetic Ion Cyclotron Fluctuations: Test Particle Simulations

Relativistic electron scattering by electromagnetic ion cyclotron (EMIC) fluctuations is studied using a test particle simulation code. The EMIC fluctuation input comes from a one dimensional, self-consistent hybrid simulation model and is due to the growth of the ion cyclotron instability driven by the ion temperature anisotropy, T$_{i\bot } \quad >$ T$_{i\parallel }$, in a magnetized, homogeneous, collisionless plasma with a single ion species. The test particle code follows the motion of relativistic test electron particles in the input EMIC fluctuations. The time evolution of the mean-square pitch angle change is calculated and used to estimate the pitch angle diffusion coefficient. Finally the results are compared with quasi-linear diffusion theory. The present study has applications to relativistic electron dynamics in the terrestrial magnetosphere.