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Title: Generation of Alfven waves by a plasma inhomogeneity moving in the Earth's magnetosphere

Abstract

The generation of an Alfven wave by an azimuthally drifting cloud of high-energy particles injected in the Earth's magnetosphere is studied analytically. In contrast to the previous studies where the generation mechanisms associated with the resonant wave-particle interaction were considered, a nonresonant mechanism is investigated in which the wave is excited by the alternating current produced by drifting particles. It is shown that, at a point with a given azimuthal coordinate, a poloidally polarized wave, in which the magnetic field lines oscillate predominantly in the radial direction, is excited immediately after the passage of the particle cloud through this point. As the cloud moves away from that point, the wave polarization becomes toroidal (the magnetic field lines oscillate predominantly in the azimuthal direction). The azimuthal wavenumber m is defined as the ratio of the wave eigenfrequency to the angular velocity of the cloud (the drift velocity of the particles). It is shown that the amplitudes of the waves so generated are close to those obtained under realistic assumptions about the density and energy of the particles.

Authors:
;  [1]
  1. Russian Academy of Sciences, Institute of Solar-Terrestrial Physics, Siberian Division (Russian Federation)
Publication Date:
OSTI Identifier:
21100176
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plasma Physics Reports; Journal Volume: 33; Journal Issue: 5; Other Information: DOI: 10.1134/S1063780X07050042; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Ltd; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALFVEN WAVES; ALTERNATING CURRENT; AMPLITUDES; ANGULAR VELOCITY; CLOUDS; COORDINATES; DENSITY; EARTH MAGNETOSPHERE; EIGENFREQUENCY; MAGNETIC FIELDS; PARTICLES; PLASMA; POLARIZATION

Citation Formats

Mager, P. N., and Klimushkin, D. Yu. Generation of Alfven waves by a plasma inhomogeneity moving in the Earth's magnetosphere. United States: N. p., 2007. Web. doi:10.1134/S1063780X07050042.
Mager, P. N., & Klimushkin, D. Yu. Generation of Alfven waves by a plasma inhomogeneity moving in the Earth's magnetosphere. United States. doi:10.1134/S1063780X07050042.
Mager, P. N., and Klimushkin, D. Yu. Tue . "Generation of Alfven waves by a plasma inhomogeneity moving in the Earth's magnetosphere". United States. doi:10.1134/S1063780X07050042.
@article{osti_21100176,
title = {Generation of Alfven waves by a plasma inhomogeneity moving in the Earth's magnetosphere},
author = {Mager, P. N. and Klimushkin, D. Yu.},
abstractNote = {The generation of an Alfven wave by an azimuthally drifting cloud of high-energy particles injected in the Earth's magnetosphere is studied analytically. In contrast to the previous studies where the generation mechanisms associated with the resonant wave-particle interaction were considered, a nonresonant mechanism is investigated in which the wave is excited by the alternating current produced by drifting particles. It is shown that, at a point with a given azimuthal coordinate, a poloidally polarized wave, in which the magnetic field lines oscillate predominantly in the radial direction, is excited immediately after the passage of the particle cloud through this point. As the cloud moves away from that point, the wave polarization becomes toroidal (the magnetic field lines oscillate predominantly in the azimuthal direction). The azimuthal wavenumber m is defined as the ratio of the wave eigenfrequency to the angular velocity of the cloud (the drift velocity of the particles). It is shown that the amplitudes of the waves so generated are close to those obtained under realistic assumptions about the density and energy of the particles.},
doi = {10.1134/S1063780X07050042},
journal = {Plasma Physics Reports},
number = 5,
volume = 33,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}