Influence of turbulence dissipation effects on the propagation of low-energy cosmic rays in the galaxy

Abstract

The propagation of cosmic rays in the Galaxy is controlled by spatial diffusion coefficients. Since parallel scattering is the strongest scattering effect, it is believed that the diffusion coefficient along the mean magnetic field controls the confinement of charged cosmic particles in the Galaxy. In this paper, we combine a turbulence spectrum with dissipation range with a nonlinear particle diffusion theory to compute transport parameters. We find a decreasing parallel diffusion coefficient for increasing particle energy for particles having rigidities lower than 3 GeV. Our approach provides an explanation of the observed boron-to-carbon ratio at these particle energies without the need to introduce stochastic acceleration. © 2010 The American Astronomical Society. All rights reserved.