High beta results in ISX-B with intense neutral beam injection

Conference · Fri Jan 01 04:00:00 EST 1982

OSTI ID:5455666

Edmonds, P H; Bates, S C; Bell, J D

Experiments on the ISX-B device show a deterioration in confinement at high beam power. In particular the electron energy confinement time falls catastrophically with increasing beam power. The maximum volume averaged beta values achieved are <2.5%; this is much less than would be predicted by extrapolating the low power data. Elongation has not been observed to have any significant effect on the maximum attainable beta, perhaps due to the limited range of both internal and external elongation. The electron energy confinement time does not follow Alcator scaling at high injection powers. There are two likely candidates for the loss of confinement. The phenomena may be ..beta../sub p/ specific and caused by the gradual onset of resistive MHD pressure driven modes producing deteriorating confinement through fluctuations in the poloidal magnetic field. Alternatively the phenomena may be specific to the method of heating, neutral injection, being caused, for example, by plasma rotation, where the rotation speed approaches the ion thermal velocity. Experiments are in progress to investigate both of these possibilities.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5455666
• Report Number(s): CONF-820345-5; ON: DE82011966
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
&amp; Production
BEAM INJECTION
BETA RATIO
CONFINEMENT
HIGH-BETA PLASMA
INSTABILITY
ISX TOKAMAK
NEUTRAL ATOM BEAM INJECTION
PLASMA
PLASMA CONFINEMENT
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS