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

Abstract

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 drivenmore » RF wave leads to a radial expansion of the plasma column, as observed by axial interferometry and by excluded flux measurements.« less

Authors:
Publication Date:
Research Org.:
Washington Univ., Seattle (USA)
OSTI Identifier:
5989176
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English
Subject:
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

Citation Formats

Meuth, H. Radio-frequency wave excitation and damping on a high. beta. plasma column. United States: N. p., 1984. Web.
Meuth, H. Radio-frequency wave excitation and damping on a high. beta. plasma column. United States.
Meuth, H. Sun . "Radio-frequency wave excitation and damping on a high. beta. plasma column". United States.
@article{osti_5989176,
title = {Radio-frequency wave excitation and damping on a high. beta. plasma column},
author = {Meuth, H},
abstractNote = {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.},
doi = {},
url = {https://www.osti.gov/biblio/5989176}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1984},
month = {1}
}

Thesis/Dissertation:
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