Cosmic ray propagation in a fractal galactic medium

Simple cosmic ray diffusion in magnetic fields is often discussed in terms of a characteristic scattering mean free path or equivalent diffusion coefficient. This assumes very simple properties of the structure of astrophysical magnetic fields. A better approximation is to assume that the magnetic s...

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Bibliographic Details
Main Authors: Hamid Kermani, Jalileldin Fatemi
Format: Article
Language:English
Published: Academy of Science of South Africa 2011-01-01
Series:South African Journal of Science
Subjects:
Online Access:http://192.168.0.121/index.php/sajs/article/view/9888
Description
Summary:Simple cosmic ray diffusion in magnetic fields is often discussed in terms of a characteristic scattering mean free path or equivalent diffusion coefficient. This assumes very simple properties of the structure of astrophysical magnetic fields. A better approximation is to assume that the magnetic structure has fractal properties and there is then the possibility of including very short and very long interaction lengths when modelling the propagation. Results of modelling such propagation in a fractal medium are discussed. Values of the propagation parameter (α) less than 2 were obtained and confirm the plausibility of the hypothesis that supernova are the origin of galactic cosmic rays in the energy range below the knee in the spectrum.
ISSN:1996-7489