Effect of drift-resonance broadening on radial diffusion in the magnetosphere

The purpose of this work is to address a conceptual problem inherent in the theory of magnetospheric radial diffusion. In the usual formulation (e.g., Falthammar, 1968), one considers the radiation belts to be immersed in randomly fluctuating electrostatic and electromagnetic fields (superimposed on the earth's time-averaged B field). The fluctuations are considered adiabatic on the gyration and bounce time scales, but describable by smooth spectra that are nonvanishing at the particle drift frequency (Omega sub 3)/2 pi. The radial-diffusion coefficient (D sub LL) is then proportional to the spectral density at omega = (Omega sub 3).