Bounce resonance scattering and proton precipitation

Abstract

Pitch angle scattering of energetic protons due to bounce resonance with fluctuating geomagnetic field is studied both at low and high latitudes. It is found that like electron diffusion, proton diffusion is also quite weak at low latitudes (<i>L= </i>1.1,1.5), but the maximum contribution of bounce resonance scattering is ≈ 0.1% only in both cases. It is also seen that bounce resonance favours precipitation of protons of higher pitch angles (i.e. those mirroring near or at the equator), and low energy protons will easily be bounce-scattered at all shells in comparison to high energy ones. Further diffusion is found to increase with increase in <i>L</i>-value and decrease in proton energy.