Journal article
Parametric interaction and spatial collapse of beam-driven Langmuir waves in the solar wind
Journal of geophysical research. Space physics, Vol.86(A10), pp.8833-8841
09/30/1981
DOI: 10.1029/JA086iA10p08833
Abstract
This paper presents observations of the parametric decay and spatial collapse of Langmuir waves driven by an electron beam streaming into the solar wind from the Jupiter bow shock. High-resolution frequency-time spectrograms from Voyager-1 and -2 show that long-wavelength Langmuir waves upstream of the bow shock are effectively converted into short-wavelength Langmuir waves that are no longer in resonance with the beam. This conversion is shown to be the result of a nonlinear interaction involving the beam-driven pump, a sideband emission, and a low-level of ion-acoustic turbulence that always appears to be present in the solar wind. The onset of the interaction occurs at about the time that the amplitude of the pump wave saturates, which indicates that parametric processes are probably playing an important role in stabilizing the electron beam. Detailed examination of the electric field wave forms shows that the beam-driven Langmuir wave emission breaks up into a complex sideband structure with both positive and negative Doppler shifts. Positive frequency shifts correspond to waves propagating away from the Sun, and negative frequency shifts correspond to waves propagating toward the Sun. In some cases, the sideband emissions consist of isolated wave packets with very short durations, sometimes lasting only a few msec. These short-duration bursts, which are usually very intense, are thought to consist of envelope solitons that have collapsed down to spatial scales of only a few Debye lengths.
Details
- Title: Subtitle
- Parametric interaction and spatial collapse of beam-driven Langmuir waves in the solar wind
- Creators
- D A Gurnett - University of Iowa, Physics and AstronomyWilliam S Kurth - University of Iowa, Physics and Astronomy
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.86(A10), pp.8833-8841
- DOI
- 10.1029/JA086iA10p08833
- ISSN
- 0148-0227
- Comment
- This article also appears in: Voyager Missions to Jupiter
- Language
- English
- Date published
- 09/30/1981
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984454340102771
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