Open AccessDamping of long‐wavelength kinetic Alfvén fluctuations: Linear theory
Author(s) -
Gary S. Peter,
Borovsky Joseph E.
Publication year - 2008
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2008ja013565
Subject(s) - landau damping , physics , isotropy , electron , proton , wavelength , dispersion relation , wavenumber , kinetic energy , quantum electrodynamics , magnetic field , plasma oscillation , plasma , atomic physics , computational physics , condensed matter physics , classical mechanics , quantum mechanics
The full electromagnetic linear dispersion equation for kinetic Alfvén fluctuations in a homogeneous, isotropic, collisionless, Maxwellian electron‐proton plasma is solved numerically in the long‐wavelength limit. At propagation sufficiently oblique to the background magnetic field B o , the wave number dependence of the damping rate of such modes is summarized by an analytic expression which scales as k ⊥ 2 k ∥ where the subscripts denote directions relative to B o . This damping progressively (although not monotonically) increases with increasing electron and proton β , corresponding to four distinct damping regimes: nonresonant, electron Landau, proton Landau, and proton transit‐time damping.