Experimental study of the post-implosion phase of a theta pinch

Journal Article · Sat Jan 01 04:00:00 EST 1977 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.861694· OSTI ID:7327681

Commisso, R J; Griem, H R

Using 90degree Thomson scattering and magnetic probes, the time and space resolved electron temperature and density and magnetic field profiles were obtained for a small, 15 kJ theta pinch. At times after the implosion phase, tapproximately-greater-than0.45--0.5 ..mu..sec, the plasma is characterized by a high ..beta.., 0.5approximately-less-than..beta..approximately-less-than1.0, T/sub e//T/sub i/<1, and v/sub E//sub theta/approximately-less-than v/sub i/ (where v/sub E//sub theta/ is the E x B drift speed and v/sub i/ is the ion thermal speed). The current sheath width, ..delta..L/sub s/, and plasma resistivity in the sheath eta/sub eff/, were obtained from the measured temperature, density, and field profiles at these late times. The results show that ..delta..L/sub s/approximately-less-than 3c/..omega../sub p//sub i/very-much-greater-thanc/..omega../sub p//sub e/, eta/sub eff/approx. =100 eta/sub perpendicular/, and the effective collision frequency, ..nu..'/sub eff/, ..omega../sub 1//sub h/approximately-less-than..nu..'/sub eff/very-much-less-than..omega../sub p//sub i/, where eta/sub perpendicular/ is the classical, Spitzer--Haerm resistivity, and ..omega../sub 1//sub h/ is the lower hybrid frequency. These results indicate that plasma turbulence is an important factor when considering heating and transport, even in the low drift velocity regime. Theoretical estimates based on the lower-hybrid-drift instability are in reasonably good agreement with the measured resistivity and ion heating rate. (AIP)

• Research Organization: Department of Physics and Astronomy, University of Maryland, College Park, Maryland 20742
• OSTI ID: 7327681
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 20:1; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
&amp; Production
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON DENSITY
ELECTRON TEMPERATURE
HEATING
IMPLOSIONS
LASER-RADIATION HEATING
LINEAR PINCH DEVICES
LINEAR THETA PINCH DEVICES
MAGNETIC FIELD CONFIGURATIONS
OPEN PLASMA DEVICES
PHYSICAL PROPERTIES
PINCH DEVICES
PLASMA
PLASMA HEATING
THERMONUCLEAR DEVICES
TURBULENCE