Cosmic ray kinetics in a strong large-scale magnetic field: a transverse diffusion

A consistent theory of cosmic ray propagation in a strong large-scale random magnetic field (MF) is developed. If both the gyrofrequency of the particle around the lines of force of the large-scale MF and the characteristic frequency of random MF changes substantially exceed the collision frequency of particles in small-scale MF inhomogeneities, large-scale MF fluctuations are claimed to result in transverse diffusion with respect to the mean MF direction. If the collision frequency is substantially higher than all the other characteristic frequencies (i.e., if the diffusion mode is considered basic), the fluctuations of the large-scale MF do not lead to the generation of additional transverse particle diffusion. Transport equations are derived for both cases and kinetic coefficients are determined for frozen-in magnetoturbulence. (author). 34 refs