Strong cosmic-ray scattering in an anisotropic random magnetic field

We calculate the kinetic coefficients and the transport mean free paths of high-energy particles parallel to the regular magnetic field in the approximation of a large-scale anisotropic random magnetic field by using a nonlinear collision integral, i.e., by taking into account the processes of strong random scattering. We consider the diffusion of solar and Galactic cosmic rays by two-dimensional turbulence. Strong random scattering by two-dimensional turbulence is shown to reduce the parallel transport mean free path severalfold. The momentum dependence of the parallel mean free path does not change, Lambda(parallel to) proportional to P2-nu. In the case of strong random scattering by turbulence formed by several modes, the parallel transport mean free path is A(parallel to) proportional to p. We show that two-dimensional turbulence can make a major contribution to the parallel transport mean free paths of cosmic rays in the heliosphere and the interstellar medium. (c) 2005 Pleiades Publishing, Inc.