Analytic calculation of the parallel mean free path of heliospheric cosmic rays

II. Dynamical magnetic slab turbulence and random sweeping slab turbulence with finite wave power at small wavenumbers

Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universität Bochum, 44780 Bochum, Germany

Corresponding author: A. Teufel, andreasm4@yahoo.com

Received: 16 August 2002
Accepted: 7 October 2002

Abstract

The parallel mean free path of cosmic ray particles in partially turbulent electromagnetic fields is calculated for two particular turbulence models: slab-like dynamical and random sweeping turbulence. Using the general results for the pitch-angle Fokker-Planck coefficient from Teufel & Schlickeiser (2002) the rigidity dependence and the absolute value of the mean free path for these specific turbulence models are calculated for a turbulence power spectrum with finite wave amplitude at very small wavenumbers. We demonstrate that this modification affects especially the mean free path at very large rigidities. We also derive approximations for the mean free path for realistic Kolmogorov-type turbulence power spectra which include the steepening at high wavenumbers due to turbulence dispersion and/or dissipation.