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| Titel |
Exact theory for localized envelope modulated electrostatic wavepackets in space and dusty plasmas |
| VerfasserIn |
I. Kourakis, P. K. Shukla |
| 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 ; 12, no. 3 ; Nr. 12, no. 3 (2005-03-18), S.407-423 |
| Datensatznummer |
250010596
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| Publikation (Nr.) |
 copernicus.org/npg-12-407-2005.pdf |
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| Zusammenfassung |
| Abundant evidence for the occurrence of modulated envelope plasma
wave packets is provided by recent satellite missions. These
excitations are characterized by a slowly varying localized
envelope structure, embedding the fast carrier wave, which appears
to be the result of strong modulation of the wave amplitude. This
modulation may be due to parametric interactions between different
modes or, simply, to the nonlinear (self-)interaction of the
carrier wave.
A generic exact theory is presented in this study, for the
nonlinear self-modulation of known electrostatic plasma modes, by
employing a collisionless fluid model. Both cold
(zero-temperature) and warm fluid descriptions are discussed and
the results are compared. The (moderately) nonlinear oscillation
regime is investigated by applying a multiple scale technique. The
calculation leads to a Nonlinear Schrödinger-type Equation
(NLSE), which describes the evolution of the slowly varying wave
amplitude in time and space. The NLSE admits localized envelope
(solitary wave) solutions of bright-(pulses) or dark- (holes,
voids) type, whose characteristics (maximum amplitude, width)
depend on intrinsic plasma parameters. Effects like amplitude
perturbation obliqueness (with respect to the propagation
direction), finite temperature and defect (dust) concentration are
explicitly considered. Relevance with similar highly localized
modulated wave structures observed during recent satellite
missions is discussed. |
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