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| Titel |
Compressive high-frequency waves riding on an Alfvén-cyclotron wave in a multi-fluid plasma |
| VerfasserIn |
Daniel Verscharen, Eckart Marsch |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250045741
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| Zusammenfassung |
| We study weakly-compressive high-frequency plasma waves which are superposed on a
large-amplitude Alfvén wave in a multi-fluid plasma consisting of protons, electrons, and
alpha particles. For these waves, the plasma environment is inhomogeneous due to the
presence of the low-frequency Alfvén wave with large amplitude, a situation that may
apply to space plasmas such as the solar corona and solar wind. The dispersion
relation of the plasma waves is determined from a linear stability analysis using a new
eigenvalue method that is employed to solve the set of differential wave equations
which describe the propagation of plasma waves along the direction of the constant
component of the Alfvén wave magnetic field. This approach allows one to consider also
weak compressive effects. In the presence of the background Alfvén wave, the
dispersion branches obtained differ significantly from the situation of a uniform
plasma. Due to compressibility, acoustic waves are excited and couplings between
various modes occur, and even an instability of the compressive mode. In a kinetic
treatment, these plasma waves would be natural candidates for Landau-resonant
wave-particle interactions, and may thus via their damping lead to particle heating. |
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