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| Titel |
Electron acceleration at Jupiter: input from cyclotron-resonant interaction with whistler-mode chorus waves |
| VerfasserIn |
E. E. Woodfield, R. B. Horne, S. A. Glauert, J. D. Menietti, Y. Y. Shprits |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 31, no. 10 ; Nr. 31, no. 10 (2013-10-02), S.1619-1630 |
| Datensatznummer |
250086114
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| Publikation (Nr.) |
 copernicus.org/angeo-31-1619-2013.pdf |
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| Zusammenfassung |
| Jupiter has the most intense radiation belts of all the outer planets.
It is not yet known how electrons can be accelerated to energies of
10 MeV or more. It has been suggested that cyclotron-resonant wave-particle
interactions by chorus waves could accelerate electrons to
a few MeV near the orbit of Io. Here we use the chorus wave intensities observed
by the Galileo spacecraft to calculate the changes in electron flux
as a result of pitch angle and energy diffusion. We show that, when
the bandwidth of the waves and its variation with L are taken into
account, pitch angle and energy diffusion due to chorus waves is a factor of 8 larger
at L-shells greater than 10 than previously shown. We have used the
latitudinal wave intensity profile from Galileo data to model the
time evolution of the electron flux using the British Antarctic Survey
Radiation Belt (BAS) model. This profile confines intense chorus waves near
the magnetic equator with a peak intensity at ∼5° latitude.
Electron fluxes in the BAS model increase by an order of magnitude
for energies around 3 MeV. Extending our results to L = 14 shows
that cyclotron-resonant interactions with chorus waves are equally
important for electron acceleration beyond L = 10. These results suggest
that there is significant electron acceleration by cyclotron-resonant
interactions at Jupiter contributing to the creation of Jupiter's
radiation belts and also increasing the range of L-shells over which
this mechanism should be considered. |
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