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This paper develops a unified linear theory of cross field plasma instabilities, including the Farley–Buneman, electron thermal, and ion thermal instabilities, in spatially uniform collisional plasmas with partially unmagnetized multi-species ions. Collisional plasma instabilities in weakly ionized, highly dissipative, weakly magnetized plasmas play an important role in the lower Earth's ionosphere and may be of importance in other planetary ionospheres, stellar atmospheres, cometary tails, molecular clouds, accretion disks, etc. In the Earth's ionosphere, these collisional plasma instabilities cause intense electron heating. In the solar chromosphere, they can do the same—an effect originally suggested from spectroscopic observations and modeling. Based on a simplified 5-moment multi-fluid model, the theoretical analysis presented in this paper produces the linear dispersion relation for the combined Thermal Farley–Buneman Instability with an important long-wavelength limit analyzed in detail. This limit provides an easy interpretation of different instability drivers and wave dissipation. This analysis of instability, combined with simulations, will enable us to better understand plasma waves and turbulence in these commonly occurring collisional space plasmas.
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Simulations of ion–dust streaming instability in a highly collisional plasma
The excitation of low frequency dust acoustic (or dust density) waves in a dusty plasma can be driven by the flow of ions relative to dust. We consider the nonlinear development of the ion–dust streaming instability in a highly collisional plasma, where the ion and dust collision frequencies are a significant fraction of their corresponding plasma frequencies. This collisional parameter regime may be relevant to dusty plasma experiments under microgravity or ground-based conditions with high gas pressure. One-dimensional particle-in-cell simulations are presented, which take into account collisions of ions and dust with neutrals, and a background electric field that drives the ion flow. Ion flow speeds of the order of a few times thermal are considered. Waveforms of the dust density are found to have broad troughs and sharp crests in the nonlinear phase. The results are compared with the nonlinear development of the ion–dust streaming instability in a plasma with low collisionality.
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- Award ID(s):
- 1740203
- PAR ID:
- 10226367
- Date Published:
- Journal Name:
- Journal of Plasma Physics
- Volume:
- 86
- Issue:
- 6
- ISSN:
- 0022-3778
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1017/S002237782000135X
