Mode conversion at the higher ion cyclotron harmonics

Conference · Wed Mar 01 04:00:00 EST 1989

DOI:https://doi.org/10.1063/1.38540· OSTI ID:6266492

Chiu, S. C.; Chan, V. S.; Harvey, R. W.; Porkolab, M.

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 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 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. 14 refs., 1 fig.

• Research Organization: General Atomics, San Diego, CA (USA)
• DOE Contract Number: AC03-89ER53277
• OSTI ID: 6266492
• Report Number(s): GA-A-19608; CONF-8905120-1; ON: DE89010033
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700100* -- Fusion Energy-- Plasma Research
BERNSTEIN MODE
CALCULATION METHODS
CLOSED PLASMA DEVICES
DIFFERENTIAL EQUATIONS
EQUATIONS
HEATING
HIGH-FREQUENCY HEATING
ICR HEATING
ION PLASMA WAVES
ION WAVES
OSCILLATION MODES
PLASMA HEATING
PLASMA WAVES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES