Electron acceleration by Alfven waves in the magnetosphere

Journal Article · Wed Apr 01 04:00:00 EST 1992 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JA03101· OSTI ID:5595079

Hui, C H; Seyler, C E ^[1]

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1. Cornell Univ., Ithaca, NY (United States)

The self-consistent electron kinetics of Alfven waves on the electron inertial scale is studied using a two-dimensional hybrid-kinetic description. The ions follow a fluid description for Alfven waves at frequencies below the ion cyclotron frequency. The parallel electron dynamics are treated kinetically using particle-in-cell techniques. In this model the electron plasma mode is eliminated and only the physics of the Alfven waves is retained. At sufficiently large amplitudes, it is found that oblique Alfven waves break due to finite electron inertia in a cold plasma. The consequence of wave breaking is the formation of an electron beam which can be unstable to the beam-plasma instability. The electrons supporting the parallel current thermalize into a non-Maxwellian distribution with an energetic tail up to several keV, assuming a reasonable magnetospheric Alfven speed. In hot plasma simulations, electron trapping is the principal mechanism of electron acceleration. It is proposed that wave breaking or electron trapping of oblique Alfven waves at 1 R{sub E} can result in electron acceleration and may explain some observed auroral phenomena.

• OSTI ID: 5595079
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 97:A4; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
ALFVEN WAVES
BEAM-PLASMA SYSTEMS
BEAMS
COLD PLASMA
CYCLOTRON FREQUENCY
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRON BEAMS
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
HYDROMAGNETIC WAVES
KINETICS
LEPTON BEAMS
LEPTONS
PARTICLE BEAMS
PLASMA
TRAPPED ELECTRONS