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| Titel |
Alfvén wave filamentation and dispersive phase mixing in a high-density channel: Landau fluid and hybrid simulations |
| VerfasserIn |
D. Borgogno, P. Hellinger, T. Passot, P. L. Sulem, P. M. Trávníček |
| 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 ; 16, no. 2 ; Nr. 16, no. 2 (2009-04-08), S.275-285 |
| Datensatznummer |
250013138
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| Publikation (Nr.) |
 copernicus.org/npg-16-275-2009.pdf |
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| Zusammenfassung |
| The propagation of dispersive Alfvén waves in a low-beta collisionless plasma
with a high-density channel aligned with the ambient
magnetic field, is studied in three space dimensions. A fluid model retaining
linear Landau damping and finite Larmor radius corrections is used,
together with a hybrid
particle-in-cell simulation aimed to validate the predictions
of this Landau-fluid model.
It is shown that when the density enhancement is moderate
(depending on the pump wavelength and the plasma parameters),
the wave energy concentrates into a filament whose transverse size is prescribed
by the dimension of the channel. In contrast, in the case of a stronger
density perturbation, the early formation of a magnetic
filament is followed by the onset of thin helical ribbons and the development of
strong gradients. This "dispersive phase mixing" provides a
mechanism permitting
dissipation processes (not included in the present model) to act and
heat the plasma. |
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