Mode conversion at the higher ion cyclotron harmonics

Conference · Sat Jul 01 04:00:00 EDT 1989 · AIP Conference Proceedings (American Institute of Physics); (USA)

OSTI ID:6508731

Chiu, S C; Chan, V S; Harvey, R W ^[1]; Porkolab, M ^[2]

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1. General Atomics, San Diego, CA (USA)
2. Massachusetts Institute of Technology, Cambridge, MA (USA)

It has been demonstrated that mode conversion of fast waves to ion Bernstein waves can be calculated from a reduced second order differential equation for the wave fields rather than the 4th order equations used in earlier studies near the ion-ion hybrid resonance and the second harmonic resonance. Here the underlying justification of the method is discussed. It is shown that the method works for high harmonic resonances and an analytical formula for the tunneling coefficient is derived. The result is a generalization of a previous result obtained by Ngan and Swanson and is applicable when {kappa}{sub {perpendicular}}{rho}{sub {ital i}} is large. Recently, there is interest in using fast waves for current drive at high ion cyclotron harmonics frequencies in tokamaks. Generally, the fast wave will encounter ion cyclotron harmonics within the plasma cross-section. For efficient current drive, the minimization of the mode conversion processes sets restrictions to the choice of frequencies and magnetic fields. This is discussed using the derived formula.

• DOE Contract Number: AC03-89ER53277
• OSTI ID: 6508731
• Report Number(s): CONF-8905120--
• Conference Information: Journal Name: AIP Conference Proceedings (American Institute of Physics); (USA) Journal Volume: 190:1
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
BERNSTEIN MODE
CLOSED PLASMA DEVICES
CONTROL
CYCLOTRON RESONANCE
HARMONICS
HEATING
HIGH-FREQUENCY HEATING
ICR HEATING
ION CYCLOTRON-RESONANCE
MODE CONTROL
OSCILLATION MODES
OSCILLATIONS
PLASMA HEATING
RESONANCE
THERMONUCLEAR DEVICES
TOKAMAK DEVICES