Plasma end-loss studies on Scylla I-C

Technical Report · Sun Aug 01 00:00:00 EDT 1976

DOI:https://doi.org/10.2172/7258515· OSTI ID:7258515

McKenna, K F; York, T M

The end-loss process in the collision dominated Scylla I-C plasma has been investigated with a local pressure sensitive diagnostic, integrated density measurement and axially arrayed diamagnetic loop probes. The development of a plasma loss orifice, well within the theta-pinch coil, has been identified. The magnitude of the observed orifice is found to be in excellent agreement with that predicted from collisional MHD theories. The axially flowing plasma is well confined until it flows through the loss orifice. After passing through the orifice, rapid axial expansion is observed. An indication of the existence of inward traveling rarefaction waves has been observed from the plasma midplane temperature data; an abrupt decrease in the plasma temperature at t approximately equal to 6.5 ..mu..s corresponds to the predicted time of arrival of rarefaction waves at the coil midplane. The plasma loss rate derived from the pressure data indicates an initial period (t < 4 ..mu..s) of rapid particle loss followed by a period (t > 4 ..mu..s) of gradual decay in the loss rate. This initial period of high loss rate is predicted from the MHD flow theories when the measured, time dependent plasma parameters are substituted into the analytical models. The loss rate determined from the end-on interferograms does not respond to the detailed structure of the plasma loss process.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 7258515
• Report Number(s): LA-6412-MS; TRN: 76-023357
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
SCYLLA DEVICES
PLASMA CONFINEMENT
COLLISIONAL PLASMA
ENERGY LOSSES
MAGNETIC PROBES
MAGNETOHYDRODYNAMICS
PLASMA DENSITY
CONFINEMENT
FLUID MECHANICS
HYDRODYNAMICS
LINEAR PINCH DEVICES
LINEAR THETA PINCH DEVICES
MECHANICS
OPEN PLASMA DEVICES
PINCH DEVICES
PLASMA
PROBES
THERMONUCLEAR DEVICES
700101* - Fusion Energy- Plasma Research- Confinement
Heating
&amp; Production