Stability of relativistic electron trapping by strong whistler or electromagnetic ion cyclotron waves

TitleStability of relativistic electron trapping by strong whistler or electromagnetic ion cyclotron waves
Publication TypeJournal Article
Year of Publication2015
AuthorsArtemyev, AV, Mourenas, D, Agapitov, OV, Vainchtein, DL, Mozer, FS, Krasnoselskikh, V
JournalPhysics of Plasmas
Volume22
Issue8
Pagination082901
Date Published08/2015
ISSN1070-664X
KeywordsCyclotron resonances; magnetic fields; Particle fluctuations; Plasma electromagnetic waves; Whistler waves
AbstractIn the present paper, we investigate the trapping of relativistic electrons by intense whistler-mode waves or electromagnetic ion cyclotron waves in the Earth's radiation belts. We consider the non-resonant impact of additional, lower amplitude magnetic field fluctuations on the stability of electron trapping. We show that such additional non-resonant fluctuations can break the adiabatic invariant corresponding to trapped electron oscillations in the effective wave potential. This destruction results in a diffusive escape of electrons from the trapped regime of motion and thus can lead to a significant reduction of the efficiency of electron acceleration. We demonstrate that when energetic electrons are trapped by intense parallel or very oblique whistler-mode waves, non-resonant magnetic field fluctuations in the whistler-mode frequency range with moderate amplitudes around 3−15 pT (much less intense than the primary waves) can totally disrupt the trapped motion. However, the trapping of relativistic electrons by electromagnetic ion cyclotron waves is noticeably more stable. We also discuss how the proposed approach can be used to estimate the effects of wave amplitude modulations on the motion of trapped particles.
URLhttp://scitation.aip.org/content/aip/journal/pop/22/8/10.1063/1.4927774
DOI10.1063/1.4927774
Short TitlePhys. Plasmas


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