Plasma conductivity in the comet Halley ionosphere
The conductivity tensor for a 3-species plasma is shown to become diagonal in the frame of reference moving with electrons. In this frame anisotropy of the conductivity (associated with the magnetic field) disappears. If electrons are moving with ions (so that the electric current is small), and the...
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| Veröffentlicht in: | Advances in space research 1997, Vol.20 (2), p.287-289 |
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| Hauptverfasser: | , |
| Format: | Artikel |
| Sprache: | eng |
| Online-Zugang: | Volltext |
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| Zusammenfassung: | The conductivity tensor for a 3-species plasma is shown to become diagonal in the frame of reference moving with electrons. In this frame anisotropy of the conductivity (associated with the magnetic field) disappears. If electrons are moving with ions (so that the electric current is small), and the effective collision time, τ, is greater than the electron gyration time (
ωτ ≳ 1), then the magnetic Reynolds number Re
m ⪢ 1, and an approximation of ideal MHD holds. According to the Giotto data, this is the case for comet Halley. |
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| ISSN: | 0273-1177 1879-1948 |
| DOI: | 10.1016/S0273-1177(97)00549-8 |