Radio-frequency wave excitation and damping on a high. beta. plasma column

Thesis/Dissertation · Sun Jan 01 00:00:00 EST 1984

OSTI ID:5989176

Meuth, H

Azimuthally symmetric (m = 0) radio-frequency (RF) waves for zero and for finite axial wave number k/sub z/ are investigated on the High BETA Q Machine, a two-meter, 20 cm-diameter, low-compression linear theta pinch (T greater than or equal to 200 eV, n approx. = 10/sup 15/cm/sup -3/) fast rising (0.4 ..mu..s) compression field. The (k/sub z/ = 0) modes occur spontaneously following the implosion phase of the discharge. A novel 100-MW 1 to 1.3 MHz, short wavelength current drive excites the plasma column in the vicinity of the lowest fast magnetoacoustic mode at various filling pressures. This current drive is designed as an integral part of the compression coil, which is segmented with a 20-cm axial wavelength (k/sub z/ = 0.314 cm/sup -1/). The electron density oscillations along major and minor chords at various positions are measured by interferometry perpendicular to the pinch axis. The oscillatory radial magnetic field component between pinch wall and hot plasma edge is measured by probes. Phases, amplitudes and radial mode structure are studied for the free (k = 0) modes and the externally driven (k does not equal 0) modes for various filling pressures of deuterium. The energy deposition from the externally driven RF wave leads to a radial expansion of the plasma column, as observed by axial interferometry and by excluded flux measurements.

• Research Organization: Washington Univ., Seattle (USA)
• OSTI ID: 5989176
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
HIGH-BETA PLASMA
WAVE PROPAGATION
LINEAR THETA PINCH DEVICES
PLASMA WAVES
DAMPING
EXCITATION
ELECTRON DENSITY
MAGNETOACOUSTIC WAVES
RADIOWAVE RADIATION
ELECTROMAGNETIC RADIATION
ENERGY-LEVEL TRANSITIONS
HYDROMAGNETIC WAVES
LINEAR PINCH DEVICES
OPEN PLASMA DEVICES
PINCH DEVICES
PLASMA
RADIATIONS
THERMONUCLEAR DEVICES
700108* - Fusion Energy- Plasma Research- Wave Phenomena
700101 - Fusion Energy- Plasma Research- Confinement
Heating
& Production