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Title: A Vlasov moment description of cyclotron wave{endash}particle interactions

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.871733· OSTI ID:279769
;  [1]
  1. Laboratory for Extraterrestrial Physics, National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

A quasifluid formalism designed to capture some effects of cyclotron interactions is presented. Starting from the contractions of exact moments of the Vlasov equation, a closure for cyclotron interactions is achieved by using kinetic information directly. This nonperturbative approach does not require {ital a} {ital priori} assumptions about zeroth-order particle velocity distributions. The nonlinear coupling between field-aligned particle thermal velocities and transverse cyclotron wave and thermal motions are described by off-diagonal elements of the pressure tensor. These elements are related to the growth and damping of cyclotron wave energy. A functional form for an effective wave{endash}particle momentum transport coefficient is derived from the requirement of consistency between the energy and momentum moment equations, but its specific magnitude and sign, determined by threshold temperature anisotropy levels, must be input from kinetic theory. This effective transport coefficient has a nondefinite sign, reminiscent of the gyroviscous coefficients of classical transport, and is consistent with the time reversibility of the Vlasov equation. A coupled set of cyclotron equations of state for the evolution of the parallel and perpendicular pressures are derived. This formalism provides a connection between known kinetic solutions of cyclotron interactions and fluid plasma equations. {copyright} {ital 1996 American Institute of Physics.}

OSTI ID:
279769
Journal Information:
Physics of Plasmas, Vol. 3, Issue 4; Other Information: PBD: Apr 1996
Country of Publication:
United States
Language:
English