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| Titel |
Double power-law spectra of energetic electrons in the Earth magnetotail |
| VerfasserIn |
A. V. Artemyev, M. Hoshino, V. N. Lutsenko, A. A. Petrukovich, S. Imada, L. M. Zelenyi |
| 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. 1 ; Nr. 31, no. 1 (2013-01-18), S.91-106 |
| Datensatznummer |
250017740
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| Publikation (Nr.) |
 copernicus.org/angeo-31-91-2013.pdf |
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| Zusammenfassung |
| In this paper, we consider electron acceleration in the vicinity of
X-line and corresponding formation of energy spectra. We develop an
analytical model including the effect of the electron trapping by
electrostatic fields and surfing acceleration. Speiser, Fermi and
betatron mechanisms of acceleration are also taken into account. Analytical
estimates are verified by the numerical integration of electron
trajectories. The surfing mechanism and adiabatic heating are responsible for
the formation of the double power-law spectrum in agreement with the previous
studies. The energy of the spectrum knee is about ~150 keV for typical
conditions of the Earth magnetotail. We compare theoretical results with the
spacecraft observations of electron double power-law spectra in the
magnetotail and demonstrate that the theory is able to describe typical
energy of the spectra knee. We also estimate the role of relativistic effects
and magnetic field fluctuations on the electron acceleration: the
acceleration is more stable for relativistic electrons, while fluctuations of
the magnetic field cannot significantly decrease the gained energy for
typical magnetospheric conditions. |
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