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| Titel |
Coupling between reconnection and Kelvin-Helmholtz instabilities in collisionless plasmas |
| VerfasserIn |
D. Grasso, D. Borgogno, F. Pegoraro, E. Tassi |
| 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 (2009-04-03), S.241-249 |
| Datensatznummer |
250013135
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| Publikation (Nr.) |
 copernicus.org/npg-16-241-2009.pdf |
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| Zusammenfassung |
| In a collisionless plasma, when reconnection instability takes place, strong
shear flows may develop. Under appropriate conditions these shear flows become
unstable to the Kelvin-Helmholtz instability. Here, we investigate the coupling
between these instabilities in the framework of a
four-field model. Firstly, we recover the known results in the low β
limit, β being the ratio between the plasma and the magnetic pressure.
We concentrate our attention
on the dynamical evolution of the current density and
vorticity sheets which evolve coupled together
according to a laminar or a turbulent
regime.
A three-dimensional extension in this limit is also discussed.
Secondly, we consider finite values of the β parameter, allowing for
compression of the magnetic and velocity fields along the
ignorable direction. We find that the current density and vorticity sheets
now evolve separately. The Kelvin-Helmholtz instability involves only the
vorticity field, which ends up in a turbulent regime, while the current
density maintains a laminar structure. |
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