A fluid description for Landau damping of dispersive MHD waves
The dynamics of long oblique MHD waves in a collisionless plasma permeated by a uniform magnetic field is addressed using a Landau-fluid model that includes Hall effect and electron-pressure gradient in a generalized Ohm's law and retains ion finite Larmor radius (FLR) corrections to the gyrot...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2004-01-01
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| Series: | Nonlinear Processes in Geophysics |
| Online Access: | http://www.nonlin-processes-geophys.net/11/245/2004/npg-11-245-2004.pdf |
| _version_ | 1819264526125629440 |
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| author | T. Passot P. L. Sulem |
| author_facet | T. Passot P. L. Sulem |
| author_sort | T. Passot |
| collection | DOAJ |
| description | The dynamics of long oblique MHD waves in a collisionless plasma permeated by a uniform magnetic field is addressed using a Landau-fluid model that includes Hall effect and electron-pressure gradient in a generalized Ohm's law and retains ion finite Larmor radius (FLR) corrections to the gyrotropic pressure (Phys. Plasmas 10, 3906, 2003). This one-fluid model, built to reproduce the weakly nonlinear dynamics of long dispersive Alfvén waves propagating along an ambient field, is shown to correctly capture the Landau damping of oblique magnetosonic waves predicted by a kinetic theory based on the Vlasov-Maxwell system. For oblique and kinetic Alfvén waves (for which second order FLR corrections are to be retained), the linear character of waves with small but finite amplitudes is established, and the dispersion relation reproduced in the regime of adiabatic protons and isothermal electrons, associated with the condition <i>m<sub>e</sub>/m<sub>p</sub> << β << T<sub>e</sub>/T<sub>p</sub></i>, where β is the squared ratio of the ion-acoustic to the Alfvén speeds. It is shown that in more general regimes, the heat fluxes are, to leading order, not gyrotropic and dependent on the Hall effect to leading order. |
| first_indexed | 2024-12-23T20:30:53Z |
| format | Article |
| id | doaj.art-f2ae3caf562d4db9a9838a8a17626dcb |
| institution | Directory Open Access Journal |
| issn | 1023-5809 1607-7946 |
| language | English |
| last_indexed | 2024-12-23T20:30:53Z |
| publishDate | 2004-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Nonlinear Processes in Geophysics |
| spelling | doaj.art-f2ae3caf562d4db9a9838a8a17626dcb2022-12-21T17:32:15ZengCopernicus PublicationsNonlinear Processes in Geophysics1023-58091607-79462004-01-01112245258A fluid description for Landau damping of dispersive MHD wavesT. PassotP. L. SulemThe dynamics of long oblique MHD waves in a collisionless plasma permeated by a uniform magnetic field is addressed using a Landau-fluid model that includes Hall effect and electron-pressure gradient in a generalized Ohm's law and retains ion finite Larmor radius (FLR) corrections to the gyrotropic pressure (Phys. Plasmas 10, 3906, 2003). This one-fluid model, built to reproduce the weakly nonlinear dynamics of long dispersive Alfvén waves propagating along an ambient field, is shown to correctly capture the Landau damping of oblique magnetosonic waves predicted by a kinetic theory based on the Vlasov-Maxwell system. For oblique and kinetic Alfvén waves (for which second order FLR corrections are to be retained), the linear character of waves with small but finite amplitudes is established, and the dispersion relation reproduced in the regime of adiabatic protons and isothermal electrons, associated with the condition <i>m<sub>e</sub>/m<sub>p</sub> << β << T<sub>e</sub>/T<sub>p</sub></i>, where β is the squared ratio of the ion-acoustic to the Alfvén speeds. It is shown that in more general regimes, the heat fluxes are, to leading order, not gyrotropic and dependent on the Hall effect to leading order.http://www.nonlin-processes-geophys.net/11/245/2004/npg-11-245-2004.pdf |
| spellingShingle | T. Passot P. L. Sulem A fluid description for Landau damping of dispersive MHD waves Nonlinear Processes in Geophysics |
| title | A fluid description for Landau damping of dispersive MHD waves |
| title_full | A fluid description for Landau damping of dispersive MHD waves |
| title_fullStr | A fluid description for Landau damping of dispersive MHD waves |
| title_full_unstemmed | A fluid description for Landau damping of dispersive MHD waves |
| title_short | A fluid description for Landau damping of dispersive MHD waves |
| title_sort | fluid description for landau damping of dispersive mhd waves |
| url | http://www.nonlin-processes-geophys.net/11/245/2004/npg-11-245-2004.pdf |
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