Mode conversion and absorption of lower-hybrid waves in inhomogeneous magnetic fields

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5215252

Cho, S

The combination of the two types of mode conversion when the lower-hybrid turning point is in the vicinity of a cyclotron harmonic requires a sixth-order equation with a quadratic coefficient, for which the usual technique utilizing the Laplace transform has no advantage since the transformed equation is second order and the general solution is not available. Some numerical methods are applied without success. Another type of six-order equation, which has only linear coefficients and represents the three-wave problem marginally, is solved analytically without including the absorption term. Applying the results of this analysis, it is shown that the direct-mode coupling to the ion-Bernstein wave from the incident lower-hybrid wave takes place effectively only when the lower-hybrid turning point is very close to the harmonic resonance such that the distance between their respective turning points is similar in magnitude to the common wave length of the coupling. Finally, the damping and the absorption of the wave are compared for the unmagnetized dispersion relation, the full magnetized dispersion relation, and the mode-conversion analysis as the wave propagates in a magnetically confined plasma with slab geometry.

• Research Organization: Auburn Univ., AL (USA)
• OSTI ID: 5215252
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
ABSORPTION
BERNSTEIN MODE
CYCLOTRON HARMONICS
DAMPING
HARMONICS
HEATING
HIGH-FREQUENCY HEATING
INHOMOGENEOUS PLASMA
LOWER HYBRID HEATING
OSCILLATION MODES
OSCILLATIONS
PLASMA
PLASMA HEATING
PLASMA WAVES