Ponderomotive force effects on temperature-gradient-driven instabilities

Journal Article · Tue Dec 01 04:00:00 EST 1992 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860340· OSTI ID:7192810

Sundaram, A K; Hershkowitz, N ^[1]

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1. Department of Nuclear Engineering and Engineering Physics, University of Wisconsin, 1500 Johnson Drive, Madison, Wisconsin 53706 (United States)

The modification of temperature-gradient-driven instabilities due to the presence of nonuniform radio-frequency fields near the ion cyclotron frequency is investigated in the linear regime. Employing the fluid theory, it is shown that the induced field line compression caused by ion cyclotron range of frequencies (ICRF) fields makes the net parallel compressibility positive, and thus provides a stabilizing influence on the ion-temperature-gradient-driven mode for an appropriately tailored profile of radio-frequency (rf) pressure. Concomitantly, the radial ponderomotive force generates an additional contribution via coupling between the perturbed fluid motion and the equilibrium ponderomotive force and this effect plays the role of dissipation to enhance or decrease the growth of temperature-gradient-driven modes depending upon the sign of rf pressure gradients. For decreased growth of temperature-gradient-driven instabilities, the plasma density gradients and rf pressure gradients must have opposite signs while enhancement in growth arises when both gradients have the same sign. Finally, the kinetic effects associated with these modes are briefly discussed.

• DOE Contract Number: FG02-88ER53264
• OSTI ID: 7192810
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 4:12; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
CLOSED PLASMA DEVICES
COMPRESSIBILITY
CYCLOTRON RESONANCE
ELECTROMAGNETIC RADIATION
FLUID MECHANICS
HYDRODYNAMICS
INSTABILITY
INSTABILITY GROWTH RATES
ION CYCLOTRON-RESONANCE
MAGNETOHYDRODYNAMICS
MECHANICAL PROPERTIES
MECHANICS
PLASMA INSTABILITY
RADIATIONS
RADIOWAVE RADIATION
RESONANCE
TEMPERATURE GRADIENTS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES