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Acceleration of relativistic electrons via drift‐resonant interaction with toroidal‐mode Pc‐5 ULF oscillations
Author(s) -
Elkington Scot R.,
Hudson Mary K.,
Chan Anthony A.
Publication year - 1999
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl003659
Subject(s) - physics , electron , acceleration , electric field , field line , magnetic field , convection , toroid , van allen radiation belt , atomic physics , adiabatic process , computational physics , resonance (particle physics) , quantum electrodynamics , magnetosphere , plasma , mechanics , classical mechanics , quantum mechanics
There has been increasing evidence that Pc‐5 ULF oscillations play a fundamental role in the dynamics of outer zone electrons. In this work we examine the adiabatic response of electrons to toroidal‐mode Pc‐5 field line resonances using a simplified magnetic field model. We find that electrons can be adiabatically accelerated through a drift‐resonant interaction with the waves, and present expressions describing the resonance condition and half‐width for resonant interaction. The presence of magnetospheric convection electric fields is seen to increase the rate of resonant energization, and allow bulk acceleration of radiation belt electrons. Conditions leading to the greatest rate of acceleration in the proposed mechanism, a nonaxisymmetric magnetic field, superimposed toroidal oscillations, and strong convection electric fields, are likely to prevail during storms associated with high solar wind speeds.