Conductivity tensor for anisotropic plasma in gyrokinetic theory
Authors: P. Porazik and J. R. Johnson
Abstract: It has been argued that the oblique firehose and
mirror instabilities are important candidates for regulation of
temperature anisotropy in the solar wind. To quantify the role of
anisotropy driven instabilities, global kinetic simulations of the
solar wind would be extremely useful. However, due to long time
scales involved, such simulations are prohibitively expensive.
Gyrokinetic theory and simulations have proven to be valuable tools
for the study of low frequency phenomena in nonuniform plasmas,
however there are discrepancies between the anisotropy driven
instabilities appearing in the gyrokinetic theory and those of a
fully kinetic one. We present a derivation of the conductivity
tensor based on the arbitrary frequency gyrokinetics, and show that
relaxing the condition that ω/Ω ≪ 1, where ω is the wave frequency,
and the Ω is the cyclotron frequency, eliminates these
discrepencies, while preserving the advantages of the gyrokinetic
theory for global kinetic simulations.
Submitted to: Physics of Plasmas
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Download PPPL-53681.4 MB (19 pp)
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