Collisionless flow and end loss from a high-energy theta-pinch plasma

Journal Article · Tue Jul 01 04:00:00 EDT 1980 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.863128· OSTI ID:5233443

McKenna, K F; Bartsch, R R; Commisso, R J; Ekdahl, C; Quinn, W E; Siemon, R E

End-loss experiments on the high-energy (T/sub e/+T/sub i/=3.3 keV, n/sub e/=1.5 x 10/sup 16/ cm/sup -3/) 5 m Scylla IV-P theta pinch are reported. The evolution of the theta-pinch plasma parameters in the presence of axial losses and the behavior of the exhausting plasma near the ends of the device have been investigated. The measured decay of the theta-pinch plasma electron temperature agrees with code predictions based on classical axial thermal conduction losses. However, the axial ion heat flux is found to be unmeasurably small in the collisionless ion plasma. Energy-line-density measurements at the coil midplane also agree with code predictions and provide evidence of inward traveling rarefaction-like waves. At the theta-pinch ends, the exhausting plasma is comprised of a collimated plasma core which remains radially confined for tens of centimeters, strongly convects magnetic fields, and contains the bulk of the ejected plasma. This collimated core is surrounded by a plasma annulus that expands rapidly to the walls after leaving the theta-pinch coil. The radially confined exhaust plasma is successfully modeled as one-dimensional flow through a converging-diverging nozzle. The new results obtained in Scylla IV-P have led to a re-analysis of the particle end-loss data obtained in previous experiments. The subsequent comparison of experiments and theory shows that the normalized particle end-loss time is independent of both the plasma beta and collisionality regime.

• Research Organization: Los Alamos Scientific Laboratory, University of California, Los Alamos, New Mexico 87545
• OSTI ID: 5233443
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 23:7; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700102 -- Fusion Energy-- Plasma Research-- Diagnostics
700104* -- Fusion Energy-- Plasma Research-- Plasma Kinetics-Experimental-- (-1987)
ALFVEN WAVES
CAPACITORS
CHARGED PARTICLES
COLLISIONLESS PLASMA
COLLISIONS
COMPUTERIZED SIMULATION
ELECTRIC FIELDS
ELECTRICAL EQUIPMENT
ELECTRON COLLISIONS
ELECTRON TEMPERATURE
END EFFECTS
EQUIPMENT
FLUID MECHANICS
HIGH-BETA PLASMA
HYDRODYNAMICS
HYDROMAGNETIC WAVES
INSTABILITY
INTERFEROMETRY
IONS
LINEAR PINCH DEVICES
LINEAR THETA PINCH DEVICES
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MECHANICS
ONE-DIMENSIONAL CALCULATIONS
OPEN PLASMA DEVICES
PHOTOGRAPHY
PINCH DEVICES
PLASMA
PLASMA DRIFT
PLASMA INSTABILITY
PLASMA WAVES
SCYLLA DEVICES
SHOCK WAVES
SIMULATION
SPECTROSCOPY
THERMONUCLEAR DEVICES
TRANSIENTS