Open AccessAnomalous and classical diffusion of cosmic rays due to nonlinear two‐dimensional structures and random magnetic fields
Author(s) -
Verkhoglyadova O. P.,
le Roux J. A.
Publication year - 2005
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2004ja010871
Subject(s) - gyroradius , physics , cosmic ray , magnetic field , anomalous diffusion , diffusion , heliosphere , vortex , turbulence , computational physics , field (mathematics) , turbulent diffusion , quantum electrodynamics , classical mechanics , solar wind , mechanics , astrophysics , quantum mechanics , knowledge management , innovation diffusion , mathematics , pure mathematics , computer science
Magnetic field turbulence in the heliosphere is modeled by two‐dimensional coherent vortex structures and random‐phase linear wave fields added to a background magnetic field. Energetic particle trapping and acceleration by interaction with the turbulent fields are studied numerically. The corresponding radial and field‐aligned diffusion coefficients are estimated. Different diffusion regimes (subdiffusion, superdiffusion, classical diffusion) are controlled by the following parameters: the ratio between amplitudes of the random component and the regular vortex field, ε 1 , and the ratio between the average particle gyroradius and the magnetic field correlation length, ε 2 . The anomalous diffusion regime occurs when the correlation length of magnetic field disturbances is about the same or larger than the particle gyroradius (ε 2 ≤ 1). Applications of our results to cosmic ray transport are discussed.