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Rapid acceleration of electrons in the magnetosphere by fast-mode MHD waves

Danny Summers·Chunyu Ma
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Abstract

During major megnetic storms, enhanced flux of relativistic electrons in the inner magnetosphere have been observed to correleated with ULF waves. The enhancements can take place over a period of several hours. In order to account for such a rapid generation of relativistic electrons, we examine the mechanism of transit-time acceleration of electrons by low-frequency fast-mode MHD waves, here the assumed form of ULF waves. Calcaulations of the acceleration timescales in the model show that fast-mode waves in the Pc4 to Pc5 frequency range, with typically observed wave amplitudes 10--20 nT, can accelerate the seed electrons to energies of order MeV in a period of a few hours.

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Danny Summers, Chunyu Ma. 2000-03-29. Rapid acceleration of electrons in the magnetosphere by fast-mode MHD waves. https://doi.org/10.1029/1999ja000408

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