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Title: Ion thermal and dispersion effects in Farley-Buneman instabilities

Farley-Buneman modes are an example of the collisional instability, which is thought to be the dominant mechanism for the irregularities in low ionosphere region. Despite high collisionality due to electron-neutral and ion-neutral collisions, the kinetic effects associated with finite temperature are important for determination of the mode frequencies and growth rate. This is especially important for ion component that is largely unmagnetized due to low ion cyclotron frequency. The ion thermal effects are strongly pronounced for shorter wavelengths and are crucial for the growth rate cut-off at high wavenumbers. We develop an extended fluid model for ion dynamics to incorporate the effects of ion thermal motion. The model is based on the extended MHD model that includes the evolution equations for higher order moments such as ion viscosity and ion heat flux. We also develop the generalized Chapman-Enskog closure model that provides exact linear closures based on the linearized kinetic equation. The results of these models are compared and tested against the linear kinetic model. The dispersion of Farley-Buneman modes and growth rate behavior are investigated in the short wavelength region.
Authors:
;  [1] ;  [2] ;  [3] ;  [2] ;  [4]
  1. Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada)
  2. Department of Physics, University of Texas at Austin, Austin, Texas 78712 (United States)
  3. (Egypt)
  4. (United States)
Publication Date:
OSTI Identifier:
22490033
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CYCLOTRON FREQUENCY; DISPERSIONS; ELECTRON-ATOM COLLISIONS; HEAT FLUX; ION-ATOM COLLISIONS; KINETIC EQUATIONS; MAGNETOHYDRODYNAMICS; OSCILLATION MODES; PLASMA INSTABILITY; TEMPERATURE DEPENDENCE; VISCOSITY; WAVELENGTHS