Title:
Instability of a current-carrying finite-beta collisional plasma
Authors:
E.Y.
Choueiri (EPPDyL,
Princeton University)
Document type:
Published in Physical Review, E, 64(6):Article No. 066413, 2001.
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Abstract:
The micro-instability of a cross-field current
carrying plasma in which the
electrons collisions are important on the time scale of the
oscillations and can be modeled with a BGK operator is studied using
linearized kinetic theory under conditions of finite electron beta.
The finiteness of beta allows for coupling between
electrostatic and electromagnetic modes and necessitates dealing with
the entire dispersion tensor. New fundamental features of
the resulting instability are identified and contrasted with those
found in previous studies of the lower hybrid current-driven
instability in which either collisions or finite-beta effects were
neglected. In the electrostatic limit collisions
are found to revert from a stabilizing to a destabilizing role as the
propagation angle with respect to the
magnetic field is increased. As beta increases collisions play a more
important role in destabilization,
alter the character and extent of electromagnetic coupling, shift
the instability to more
perpendicular modes, and lead to a recapturing of some of the
fluid-like properties the modes have in the
electrostatic limit in contrast with their highly kinetic character
in the collisionless limit.
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