Wave acceleration of electrons in the Van Allen radiation belts

TitleWave acceleration of electrons in the Van Allen radiation belts
Publication TypeJournal Article
Year of Publication2005
AuthorsHorne, RB, Thorne, RM, Shprits, YY, Meredith, NP, Glauert, SA, Smith, AJ, Kanekal, SG, Baker, DN, Engebretson, MJ, Posch, JL, Spasojevic, M, Inan, US, Pickett, JS, Decreau, PME
JournalNature
Volume437
Pagination227 - 230
Date Published09/2005
ISSN0028-0836
KeywordsLocal Acceleration due to Wave-Particle Interaction
AbstractThe Van Allen radiation belts1 are two regions encircling the Earth in which energetic charged particles are trapped inside the Earth's magnetic field. Their properties vary according to solar activity2, 3 and they represent a hazard to satellites and humans in space4, 5. An important challenge has been to explain how the charged particles within these belts are accelerated to very high energies of several million electron volts. Here we show, on the basis of the analysis of a rare event where the outer radiation belt was depleted and then re-formed closer to the Earth6, that the long established theory of acceleration by radial diffusion is inadequate; the electrons are accelerated more effectively by electromagnetic waves at frequencies of a few kilohertz. Wave acceleration can increase the electron flux by more than three orders of magnitude over the observed timescale of one to two days, more than sufficient to explain the new radiation belt. Wave acceleration could also be important for Jupiter, Saturn and other astrophysical objects with magnetic fields.
URLhttp://www.nature.com/nature/journal/v437/n7056/full/nature03939.html
DOI10.1038/nature03939


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