Lower-hybrid wave absorption in the presence of simultaneous density and magnetic field gradients

Journal Article · Sat Sep 01 04:00:00 EDT 1979 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.862807· OSTI ID:5921074

Puri, S

It is shown that for the lower-hybrid wave (the slower of the two cold-plasma modes propagating at an angle to the static magnetic field), the WKB requirements are satisfied in almost the entire region from the antenna up to and including the ion-cyclotron-harmonic resonance. Expressions for the electric field and the energy density in the WKB approximation are derived. Both the collisionless and collisional damping become significant near the resonance, and the wave attenuation due to the two processes is estimated. From the differential equation for the electric field valid near the resonance, it is found that the wave energy would be completely assimilated even in the absence of a damping mechanism. The effect of impurities, although negligible near the plasma edge, becomes important following wave conversions and a significant fraction of the wave energy may end up heating the impurity ions in the plasma interior. The implications of using the ''local'' dielectric tensor approximation in the above context are examined. An alternative scheme for heating at the ion-cyclotron frequency using the lower-hybrid (quasi-shear) wave instead of the usual compressional wave is pointed out.

• Research Organization: Max--Planck--Institut fuer Plasmaphysik, D-8046 Garching, Federal Republic of Germany
• OSTI ID: 5921074
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 22:9; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
BOLTZMANN STATISTICS
CHARGED PARTICLES
COLLISIONAL HEATING
CYCLOTRON HARMONICS
DIFFERENTIAL EQUATIONS
DISPERSION RELATIONS
EQUATIONS
HARMONICS
HEATING
HIGH-FREQUENCY HEATING
HYBRID RESONANCE
IMPURITIES
IONS
MAGNETIC FIELDS
MAGNETIC-PUMPING HEATING
MAXWELL EQUATIONS
OSCILLATIONS
PERMITTIVITY
PLASMA HEATING
PLASMA WAVES
RESONANCE
TENSORS
WKB APPROXIMATION