COSMIC-RAY PITCH-ANGLE SCATTERING IN IMBALANCED MHD TURBULENCE SIMULATIONS

Journal Article · Sun Sep 20 04:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/811/1/8· OSTI ID:22525427

Weidl, Martin S. ^[1]; Jenko, Frank ^[2]; Teaca, Bogdan ^[3]; Schlickeiser, Reinhard ^[4]

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1. Max-Planck-Institut für Plasmaphysik, D-85748 Garching (Germany)
2. Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)
3. Applied Mathematics Research Centre, Coventry University, Coventry CV1 5FB (United Kingdom)
4. Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany)

Pitch-angle scattering rates for cosmic-ray particles in MHD simulations with imbalanced turbulence are calculated for fully evolving electromagnetic turbulence. We compare with theoretical predictions derived from the quasilinear theory of cosmic-ray diffusion for an idealized slab spectrum and demonstrate how cross helicity affects the shape of the pitch-angle diffusion coefficient. Additional simulations in evolving magnetic fields or static field configurations provide evidence that the scattering anisotropy in imbalanced turbulence is not primarily due to coherence with propagating Alfvén waves, but an effect of the spatial structure of electric fields in cross-helical MHD turbulence.

• OSTI ID: 22525427
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 811; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ALFVEN WAVES
ANISOTROPY
COMPARATIVE EVALUATIONS
COSMIC RADIATION
DIFFUSION
ELECTRIC FIELDS
HELICITY
INCLINATION
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
QUASILINEAR PROBLEMS
SCATTERING
TURBULENCE
WAVE PROPAGATION