Unstable dissipative drift modes in a sheared magnetic field

Journal Article · Wed Oct 01 00:00:00 EDT 1980 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.862876· OSTI ID:7183254

Chang, C L; Drake, J F; Gladd, N T; Liu, C S

Collisional, electrostatic drift waves are shown, within the context of a slab geometry with magnetic shear, to be destabilized by a positive electron temperature gradient eta/sub e/=dlnT/sub e//dlnn. The temperature gradient produces a well which localizes the drift eigenmode near the mode rational surfaces and for reasonable magnetic shear, e.g., L/sub n//L/sub s/=0.05, these dissipative drift waves are linearly unstable when the temperature gradient exceeds a threshold of ..nu../sub e/approx. =3. The crucial feature of this analysis is the inclusion of an energy dependent collision model (Lorentz model). Generally, the mode is most unstable for ..nu../sub c//..omega../sub asterisk/approx. =20 and is stable for ..nu../sub c//..omega../sub asterisk/ /sup greater-thangreater-than//sub less-thanless-than/20. We believe this is the first drift mode, driven solely by diamagnetic currents, which is absolutely unstable within the context of a slab model with magnetic shear. Other collisionless and collisional drift modes are found to be stable when the full electron dynamics are included. Finite ..beta.. effects are found to have a strong stabilizing influence on this instability.

• Research Organization: Department of Physics and Astronomy, University of Maryland, College Park, Maryland 20742
• OSTI ID: 7183254
• Journal Information: Phys. Fluids; (United States), Vol. 23:10
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DRIFT INSTABILITY
PLASMA WAVES
TEMPERATURE GRADIENTS
BOLTZMANN-VLASOV EQUATION
COLLISIONAL PLASMA
DISPERSION RELATIONS
DISSIPATION FACTOR
DISTRIBUTION FUNCTIONS
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
ELECTRONS
LANDAU DAMPING
MAGNETIC FIELDS
NORMAL-MODE ANALYSIS
NUMERICAL SOLUTION
PLASMA DIAMAGNETISM
PLASMA INSTABILITY
SHEAR
CURRENTS
DAMPING
DIAMAGNETISM
DIFFERENTIAL EQUATIONS
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
FUNCTIONS
INSTABILITY
LEPTONS
MAGNETISM
PLASMA
PLASMA MICROINSTABILITIES
700107* - Fusion Energy- Plasma Research- Instabilities
700108 - Fusion Energy- Plasma Research- Wave Phenomena