Field line wandering and perpendicular scattering of charged particles in Alfvénic slab turbulence

Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universität Bochum, 44780 Bochum, Germany e-mail: andreasm4@yahoo.com

Received: 7 June 2007
Accepted: 24 August 2007

Abstract

We describe analytically the magnetic field line random walk in Alfvénic slab turbulence. This result can easily be combined with a compound transport model to describe analytically the perpendicular scattering of charged cosmic rays. We demonstrate that the well known subdiffusive solution for magnetostatic turbulence is only valid for shorter time scales. For longer times, perpendicular diffusion of charged test-particles is recovered due to wave propagation effects. For low energy cosmic rays, this new result could be important for understanding heliospheric observations.