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| Titel |
Analysis and simulation of BGK electron holes |
| VerfasserIn |
L. Muschietti, I. Roth, R. E. Ergun, C. W. Carlson |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1023-5809
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| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics ; 6, no. 3/4 ; Nr. 6, no. 3/4, S.211-219 |
| Datensatznummer |
250003226
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| Publikation (Nr.) |
 copernicus.org/npg-6-211-1999.pdf |
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| Zusammenfassung |
| Recent observations from satellites crossing
regions of magnetic-field-aligned electron streams reveal solitary potential
structures that move at speeds much greater than the ion acoustic/thermal
velocity. The structures appear as positive potential pulses rapidly drifting
along the magnetic field, and are electrostatic in their rest frame. We
interpret them as BGK electron holes supported by a drifting population of
trapped electrons. Using Laplace transforms, we analyse the behavior of one
phase-space electron hole. The resulting potential shapes and electron
distribution functions are self-consistent and compatible with the field and
particle data associated with the observed pulses. In particular, the spatial
width increases with increasing amplitude. The stability of the analytic
solution is tested by means of a two-dimensional particle-in-cell simulation
code with open boundaries. We consider a strongly magnetized parameter regime in
which the bounce frequency of the trapped electrons is much less than their
gyrofrequency. Our investigation includes the influence of the ions, which in
the frame of the hole appear as an incident beam, and impinge on the BGK
potential with considerable energy. The nonlinear structure is remarkably
resilient |
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