Timescales for radiation belt electron acceleration and loss due to resonant waveparticle interactions: 1. Theory
Author  
Keywords  
Abstract 
Radiation belt electrons can interact with various modes of plasma wave in their drift orbits about the Earth, including whistlermode chorus outside the plasmasphere, and both whistlermode hiss and electromagnetic ion cyclotron waves inside the plasmasphere. Electrons undergo gyroresonant diffusion in their interactions with these waves. To determine the timescales for electron momentum diffusion and pitch angle diffusion, we develop bounceaveraged quasilinear resonant diffusion coefficients for fieldaligned electromagnetic waves in a hydrogen or multiion (H+, He+, O+) plasma. We assume that the Earth\textquoterights magnetic field is dipolar and that the wave frequency spectrum is Gaussian. Evaluation of the diffusion coefficients requires the solution of a sixthorder polynomial equation for the resonant wave frequencies in the case of a multiion (H+, He+, O+) plasma, compared to the solution of a fourthorder polynomial equation for a hydrogen plasma. In some cases, diffusion coefficients for fieldaligned waves can provide a valuable approximation for diffusion rates for oblique waves calculated using higherorder resonances. Bounceaveraged diffusion coefficients for fieldaligned waves can be evaluated generally in minimal CPU time and can therefore be profitably incorporated into comprehensive kinetic radiation belt codes.

Year of Publication 
2007

Journal 
Journal of Geophysical Research

Volume 
112

Date Published 
04/2007

ISSN Number 
01480227

URL 
http://onlinelibrary.wiley.com/doi/10.1029/2006JA011801/abstract

DOI 
10.1029/2006JA011801
