Electron thermal effects on the Farley--Buneman fluid dispersion relation

Journal Article · Sat Apr 01 04:00:00 EST 1995 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871383· OSTI ID:172030

Kissack, R S; St-Maurice, J; Moorcroft, D R ^[1]

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1. Department of Physics, The University of Western Ontario, London, Ontario, N6A 3K7 (Canada)

The traditional linear fluid dispersion relation of Farley--Buneman waves has been generalized by including, for the electron gas, the effects of collisional energy exchange, as well as thermal force and thermoelectric effects associated with heat flow. The formalism used is that of Schunk [Rev. Geophys. Space Phys. {bold 15}, 429 (1977)] for Grad`s 8-moment approximation, to which inelastic energy exchange has been added phenomenologically. The resulting dispersion relation recovers both the traditional isothermal and adiabatic limits, as well as the dispersion relation of Pecseli {ital et} {ital al}. [J. Geophys. Res. {bold 94}, 5337 (1989)] as a special case. Owing to the fact that the electron--neutral interaction is far from being of the Maxwell molecule type, it is found that, contrary to suggestions in the literature, adiabaticity does not hold at the larger wavelengths of the instability. In the small wave-number limit, the linear instability threshold speed of the waves takes the form [({gamma}{sub {ital e}T}{sub {ital e}0}+{ital T}{sub {ital i}0})/{ital m}{sub {ital i}}]{sup 1/2}, with the effective {gamma}{sub {ital e}} being a sensitive function of aspect angle. Its value can be as small as 0.28 or as large as 3.4 depending on conditions. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

• OSTI ID: 172030
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 4 Vol. 2; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ADIABATIC PROCESSES
COLLISIONAL PLASMA
DISPERSION RELATIONS
E REGION
ELECTRON GAS
IONOSPHERE
PLASMA DRIFT
PLASMA MICROINSTABILITIES