HR: 0800h
AN: SM51A-1265 [Abstracts]
TI: Local and Bounce-Averaged Wave-Particle Resonances in Quasilinear Theory
AU: Brizard, A
EM: abrizard@smcvt.edu
AF: Saint Michael's College, Department of Physics, Colchester, VT 05439
United States
AU: * Chan, A
EM: aac@rice.edu
AF: Rice University, Department of Physics and Astronomy, Houston, TX 77005
United States
AB:
In recent work, a general formulation of bounce-averaged quasilinear
transport has yielded a 3×3 diffusion tensor that describes the cyclotron-,
bounce- and drift-resonant interactions of relativistic magnetically-trapped
particles with electromagnetic waves of general polarization [Brizard
and Chan, Phys. Plasmas 11, 4220 (2004)]. In the appropriate limits, the
3-3 element of the diffusion tensor has been shown to reduce to the classic
radial diffusion coefficient of Falthammar [JGR 70, 2503 (1965)].
However, along with some similarities to earlier energy and pitch-angle
diffusion coefficients due to cyclotron resonances, including the pioneering
work by Kennel, Lyons and Thorne, there are some interesting differences. For
example, in contrast to the well-known local resonance condition ω -
k∥ v∥ - ℓ ωc = 0 (where ω is the wave
frequency, k∥ is the parallel component of the wave vector,
v∥ is the parallel component of the particle velocity, ℓ is
an integer, and ωc is the cyclotron frequency) which appears in the
early work, the resonance condition in the recent work is ω -
ℓ <ωc> - n ωb - m <ωd> =
0 (where n is an integer, ωb is the bounce frequency, m is the
azimuthal mode number, ωd is the drift frequency, and angle brackets
denote bounce averaging). We note in particular that the bounce-averaged
cyclotron frequency appears in the latter resonance condition, rather than
the local cyclotron frequency. In this presentation, we show how the effects
of local resonances are contained in our general formulation and we
investigate the connection between the local and bounce-averaged
wave-particle cyclotron resonances.
DE: 2720 Energetic particles: trapped
DE: 2752 MHD waves and instabilities (2149, 6050, 7836)
DE: 2772 Plasma waves and instabilities (2471)
DE: 2774 Radiation belts
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005