The role of electrostatic plasma oscillations in electron scattering in the Earth's outer magnetosphere

Abstract

The scattering of electrons in a spatially homogeneous magnetic field-free stable plasma by ion and electron plasma waves excited by suprathermal particles is considered using a test-particle approach. A previously derived theory is modified and extended to the case of ion-waves propagating in a current bearing plasma. The results are applied to electrons in the earth's magnetosphere and in the transition zone between the magnetosphere and the interplanetary medium, where the geomagnetic field is weak in the sense that Ω2 « ω2pe (Ω = eB/mc; ω2pe = 4πne2/m). It is found that interaction with electron plasma oscillations is competitive with whistlers in scattering suprathermal electrons, and that ion waves are the dominant mechanism for the diffusion of subthermal electrons across the magnetopause and the shock wave.