抄録
Diffusion coefficient of pitch angle scattering near 90° pitch angle is extensively studied for particle rigidity of 1GV-9GV by the method of JONES et al. (1973). Our calculations are based on a slab model with transverse (x, y) field fluctuations varying only along the direction (z) of the average magnetic field ‹B›. The root mean square of fluctuation field ‹ΔB2›1/2 is fixed to 0.3 times the average field ‹B› through this calculation. The fluctuations have a power spectrum proportional to k-γ at large wave numbers, where k is a wave number and γ is a power spectral exponent varying from 1.5 to 2.3.
A big hump in the calculated pitch-angle-scattering diffusion coefficient near 90° pitch angle and its dependence on particle rigidity and γ are discussed in terms of test particle motion trapped in magnetic bottles formed in random magnetic field realizations. It is concluded that the hump does not mean a real enhanced pitch angle diffusion through 90° pitch angle.
