On the cosmic ray cross-field diffusion for solar wind turbulence

Center for Solar Physics and Space Weather, Department of Physics, The Catholic University of America, Washington, DC 20064, USA Obserwatorium Astronomiczne, Uniwersytet Jagielloński, ul. Orla 171, 30-244 Kraków, Poland

Received: 8 February 2001
Accepted: 12 June 2001

Abstract

The cross-field diffusion coefficient of charged particles in the presence of pure isotropic Alfvén waves, pure isotropic magnetosonic waves and their mixture is considered using Monte Carlo particle simulations. We show that the cross-field diffusion coefficient strongly depends on the assumed spectrum and amplitude of MHD turbulence but much less on the type of waves considered. It is demonstrated that transport perpendicular to the average magnetic field is mostly determined by compound diffusion which combines the effects of scattering off magnetic irregularities with magnetic braiding. The ratio is independent of rigidity over the wide range considered.