Fluid, kinetic, and electromagnetic effects on rippling instabilities in tokamaks

Thesis/Dissertation · Wed Jan 01 00:00:00 EST 1986

OSTI ID:7163589

Benchikh-Lehocine, M E

Tokamak plasmas are unstable against small perturbations that convect resistivity across the confining magnetic field, B vector. The rippling instability is due to the presence of a current along B vector, and a resistivity gradient across B vector. In this thesis the impact on the rippling instability of electron and ion diamagnetic drifts, electron parallel heat conductivity, and electron viscosity is considered. Electromagnetic effects are accounted for, albiet approximately, by means of a vector potential, A vector in parallel with B vector. The linear, normal mode stability calculations are carried out for a plasma slab in a sheared magnetic field. It is found that when the electron temperature, T/sub e/, is low, the rippling mode is unstable and becomes more so as T/sub e/ decreases. For T/sub e/ large, the mode is stable and tends toward marginal stability. This latter trend is overridden by viscosity. Stabilization is due to heat conduction, and stability is enhanced by ion FLR effects. The general conclusion is that the rippling mode is essentially electrostatic, and poses no threat to confinement save at the edge of tokamaks where T/sub e/ is fairly low.

• Research Organization: Wisconsin Univ., Madison (USA)
• OSTI ID: 7163589
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
PLASMA INSTABILITY
ELECTRON DRIFT
ION DRIFT
TOKAMAK DEVICES
ELECTROMAGNETIC FIELDS
ELECTRON TEMPERATURE
THERMAL CONDUCTIVITY
VISCOSITY
CLOSED PLASMA DEVICES
INSTABILITY
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES
THERMONUCLEAR DEVICES
700107* - Fusion Energy- Plasma Research- Instabilities