Quantifying the Effects of Field Line Curvature Scattering on Radiation Belt Particle Dynamics

Abstract:

Magnetic curvature scattering (μ-scattering) can happen when particle’s gyro-radius is comparable to the magnetic field line curvature radius. It was known to play an important role in energetic plasma sheet particle dynamics. Here we investigate the importance of field line curvature scattering on radiation belt particle dynamics. First, we use test particle simulations to test different theoretical magnetic moment diffusion coefficients (D_μμ) of electrons and protons induced by μ-scattering in a magnetic field model. Then, we calculate the diffusion coefficients due to curvature scattering under different geomagnetic activity conditions using T89 magnetic field model. Spatial distribution of D_μμ from our calculations suggest that local field line stretch might be important in scattering energetic particle during geomagnetic active times.