Electron heating by mode-converted ion-Bernstein waves in ICRF heating of tokamak plasmas

Conference · Tue Sep 01 04:00:00 EDT 1987 · AIP Conf. Proc.; (United States)

OSTI ID:6930769

Ram, A K; Bers, A

In a tokamak plasma, ion-Bernstein waves (IBW) can be excited by mode-conversion of the externally launched fast wave for ICRF heating. This conversion process is known to be efficient for low k/sub parallel/'s which carry substantial power from a single loop antenna. A detailed numerical analysis of the propagation of the IBW shows that the initial small k/sub parallel/ are significantly enhanced along the rays due to toroidal effects. The upshift can occur for short radial distances of propagation and is large enough so that the IBW can Landau damp onto the electrons. This could help explain the observed strong electron heating by ICRF waves in tokamak plasmas. The numerical ray trajectory analysis is done in toroidal geometry for a hot Maxwellian plasma with gradients in temperature, density, toroidal and poloidal magnetic fields included in a WKB sense. A simple analytical model is derived which explains the upshift in k/sub parallel/ and gives results very close to the numerically obtained values. Approximate analytical conditions for appreciable electron Landau damping of the IBW are also given.

• Research Organization: Plasma Fusion Center, M.I.T., Cambridge, MA 02139
• OSTI ID: 6930769
• Report Number(s): CONF-870570-
• Conference Information: Journal Name: AIP Conf. Proc.; (United States) Journal Volume: 159:1
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101 -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
ANALYTICAL SOLUTION
ANNULAR SPACE
ANTENNAS
BERNSTEIN MODE
BOLTZMANN STATISTICS
CHARGED PARTICLES
CLOSED PLASMA DEVICES
CONFIGURATION
CONVERSION
DAMPING
DATA
EFFICIENCY
ELECTRICAL EQUIPMENT
ELECTRON TEMPERATURE
ENERGY CONVERSION
ENERGY-LEVEL TRANSITIONS
EQUIPMENT
EXCITATION
HEATING
HIGH-FREQUENCY HEATING
HOT PLASMA
ICR HEATING
INFORMATION
IONS
LANDAU DAMPING
MATHEMATICS
NUMERICAL ANALYSIS
NUMERICAL DATA
OSCILLATION MODES
PLASMA
PLASMA HEATING
PLASMA SIMULATION
SIMULATION
SPACE
TEMPERATURE GRADIENTS
THEORETICAL DATA
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TOROIDAL CONFIGURATION
TRAJECTORIES
WKB APPROXIMATION