Perpendicular ion acceleration by localized high frequency electric fields in magnetized plasmas
1996; American Institute of Physics; Volume: 3; Issue: 9 Linguagem: Inglês
10.1063/1.871608
ISSN1527-2419
Autores Tópico(s)Geomagnetism and Paleomagnetism Studies
ResumoA basic process capable of explaining observations of fast perpendicular ions in a wide range of plasma environments is described. Spatial symmetry breaking perpendicular to the confining magnetic field is shown to cause irreversible energy gain for ions gyrating through an electric field having a nonuniform amplitude. The efficiency depends on the ratio of the ion Larmor radius to the scale length of the amplitude gradient, and on the scaled frequency ν≡ω/Ωi. A Landau resonance is not required, and there is no lower threshold on the electric field, because the mechanism is active in the linear regime. Theory, numerics, and particle-in-cell simulations are used to illustrate the interaction for electrostatic fields in the lower-hybrid range of frequencies, but the process does not depend on a particular type of mode.
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