Charged Particle Diffusion in Isotropic Random Magnetic Fields

• Published in: The Astrophysical journal Vol. 837; no. 2; pp. 140 - 149
• Main Authors: Subedi, P., Sonsrettee, W., Blasi, P., Ruffolo, D., Matthaeus, W. H., Montgomery, D., Chuychai, P., Dmitruk, P., Wan, M., Parashar, T. N., Chhiber, R.
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 10.03.2017; IOP Publishing
• Subjects: astroparticle physics; ASTROPHYSICS; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CHARGED PARTICLES; COMPARATIVE EVALUATIONS; Computer simulation; COMPUTERIZED SIMULATION; COSMIC RADIATION; cosmic rays; DIFFUSION; Diffusion coefficient; LARMOR RADIUS; MAGNETIC FIELDS; MEAN-FIELD THEORY; Particle diffusion; Particle energy; RANDOMNESS; SCATTERING; THREE-DIMENSIONAL CALCULATIONS; TURBULENCE
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/aa603a

The investigation of the diffusive transport of charged particles in a turbulent magnetic field remains a subject of considerable interest. Research has most frequently concentrated on determining the diffusion coefficient in the presence of a mean magnetic field. Here we consider the diffusion of charged particles in fully three-dimensional isotropic turbulent magnetic fields with no mean field, which may be pertinent to many astrophysical situations. We identify different ranges of particle energy depending upon the ratio of Larmor radius to the characteristic outer length scale of turbulence. Two different theoretical models are proposed to calculate the diffusion coefficient, each applicable to a distinct range of particle energies. The theoretical results are compared to those from computer simulations, showing good agreement.