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Title: Beta dependence of electron heating in decaying whistler turbulence: Particle-in-cell simulations

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.3676155· OSTI ID:22043573
 [1];  [2]
  1. National Institute of Information and Communications Technology 4-2-1, Nukui-Kitamachi, Koganei, Tokyo 184-8795 (Japan)
  2. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

Two-dimensional particle-in-cell simulations have been carried out to study electron beta dependence of decaying whistler turbulence and electron heating in a homogeneous, collisionless magnetized plasma. Initially, applied whistler fluctuations at relatively long wavelengths cascade their energy into shorter wavelengths. This cascade leads to whistler turbulence with anisotropic wavenumber spectra which are broader in directions perpendicular to the background magnetic field than in the parallel direction. Comparing the development of whistler turbulence at different electron beta values, it is found that both the wavenumber spectrum anisotropy and electron heating anisotropy decrease with increasing electron beta. This indicates that higher electron beta reduces the perpendicular energy cascade of whistler turbulence. Fluctuation energy dissipation by electron Landau damping responsible for the electron parallel heating becomes weaker at higher electron beta, which leads to more isotropic heating. It suggests that electron kinetic processes are important in determining the properties of whistler turbulence. This kinetic property is applied to discuss the generation of suprathermal strahl electron distributions in the solar wind.

OSTI ID:
22043573
Journal Information:
Physics of Plasmas, Vol. 19, Issue 1; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
Country of Publication:
United States
Language:
English