Beta and confinement experiments on Doublet III with high-power neutral beam heating

Journal Article · Tue Jan 01 04:00:00 EST 1985 · Sov. J. Plasma Phys. (Engl. Transl.); (United States)

OSTI ID:5557989

DeBoo, J C; Armentrout, C J; Baur, J F; Blau, F P; Bramson, G; Burrell, K H; Chase, R P; Ejima, S; Fairbanks, E S; Groebner, R

Beta and energy confinement experiments with up to 7.5 MW of neutral beam heating power injected into both limited and diverted equilibria are discussed. We have studied beta limits at both the low q (high ..beta../sub T/, low ..beta../sub p/) and high q (low ..beta../sub T/, high ..beta../sub p/) ends of the ideal MHD n = infinity ballooning limit curve. Discharges which disruptively terminate have not clearly exceeded predicted ballooning limits but have been within 20% of marginal stability for ideal ballooning modes. Energy confinement time studies show that tau/sub E/ scales linearly with plasma current and deteriorates with beam power, although there are indications that tau/sub E/ may be approaching a new asymptotic value at high power levels. We find that diverted equilibria afford up to a factor of 2 greater confinement times at high power levels. Transport analysis indicates that electron conduction is the major heat loss mechanism and that the electron conductivity is generally 2--3 times lower in divertor discharges compared to limiter discharges with comparable parameters. We observe a strong correlation between improved confinement and the separation between the limiter and separatrix flux surface.

• Research Organization: GA Technologies Inc., San Diego, California 92138
• DOE Contract Number: AC03-84ER51044
• OSTI ID: 5557989
• Journal Information: Sov. J. Plasma Phys. (Engl. Transl.); (United States), Journal Name: Sov. J. Plasma Phys. (Engl. Transl.); (United States) Vol. 11:1; ISSN SJPPD
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
BALLOONING INSTABILITY
BEAM INJECTION HEATING
CONFINEMENT TIME
DIVERTORS
DOUBLET REACTORS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY LOSSES
HEAT LOSSES
HEATING
INSTABILITY
LOSSES
PHYSICAL PROPERTIES
PLASMA HEATING
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
POWER
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS