Neutral beam injection experiments in the ISX-B tokamak

Technical Report · Tue Jan 01 04:00:00 EST 1980

OSTI ID:6309964

Murakami, M; Bates, S C; Bush, C E

Injection of up to 1 MW H/sup 0/ beam into D/sup +/ plasmas has produced root-mean-square beta up to 3.3%, volume-averaged beta up to 2.3%, and central beta up to 8% in the ISX-B tokamak. Although theoretical calculations indicate the observed equilibria should be unstable to ballooning instabilities, no catastrophic loss of confinement has been observed, and beta continues to increase with injection power. In these beam-dominated high-..beta.. discharges, the electron and ion energy confinement times are still similar to those obtained with ohmic heating. In the beam-dominated discharges the character of the MHD behavior changes, the particle confinement time decreases, and the inward impurity transport appears to be inhibited. These effects, however, may not be linked directly to beta. Understanding tokamak beta limits will require further test with increased injection power, low q operation, elongated plasmas, and more diagnostic capabilities, as planned for ISX-B, as well as more detailed studies of other effects of high power injection.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6309964
• Report Number(s): IAEA-CN-38/N-1; ON: DE81025621
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700104* -- Fusion Energy-- Plasma Research-- Plasma Kinetics-Experimental-- (-1987)
BEAM INJECTION
BETA RATIO
CHARGED PARTICLES
CONFINEMENT
DEUTERIUM IONS
IMPURITIES
IONS
ISX TOKAMAK
NEUTRAL ATOM BEAM INJECTION
PLASMA CONFINEMENT
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS