Lower hybrid heating and current drive, and ion cyclotron heating experiments on the Alcator C and the Versator II tokamaks

Conference · Wed Aug 01 04:00:00 EDT 1984

OSTI ID:6145419

Porkolab, M; Blackwell, B; Bonoli, P; Griffin, D; Knowlton, S; Lloyd, B; Moody, J; Schuss, J J; Takase, Y; Texter, S

Lower hybrid electron Landau heting experiments have been carried out on the Alcator C tokamak at densities 0.8 x 10/sup 14/ less than or equal to anti n(cm/sup -3/) less than or equal to 1.7 x 10/sup 14/, and at B = 7 T - 11 T. Using SiC coated graphite limiters, upon injection of 850 kW of power at a density of anti n/sub e/ approx. = 1.3 x 10/sup 14/cm/sup -3/ in deuterium typical temperature increases of ..delta..Ti approx. = 0.7 keV, ..delta..T/sub e/ approx. = 1.0 keV were observed. Current drive and ramping experiments have also been carried out at densities 10/sup 13/ less than or equal to anti n/sub e/(cm/sup -3/) less than or equal to 10/sup 14/. The maximum current drive efficiency, defined as eta = anti n(10/sup 14/ cm/sup -3/)I(MA)R(m)/P(MW), was eta approx. = 0.12 at B = 10 T and eta approx. = 0.08 at B = 8 T. Current ramping experiments have resulted in ramping rates of ..delta..I/..delta..t approx. = 400 kA/sec with P/sub rf/ approx. = 860 kW at a density of anti n/sub e/ approx. = 3.0 x 10/sup 13/ cm/sup -3/. Initial results from the Alcator C 180 MHz ICRF heating program are reported. Significant heating results were obtained in the hydrogen minority regime: upon injection of 400 kW of rf power the ion temperature rose by as much as 600 eV at a density of anti n/sub e/ less than or equal to 1.9 x 10/sup 14/ cm/sup -3/. In Versator II, during lower hybrid current drive experiments the global particle confinement increased by approximately a factor of two above the ohmic discharge value when the Parail-Pogutse electron tail instability was stabilized.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA). Plasma Fusion Center
• DOE Contract Number: AC02-78ET51013
• OSTI ID: 6145419
• Report Number(s): DOE/ET/51013-131; PFC/CP-84-14; CONF-840910-20; ON: DE85004918
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
ALCATOR DEVICE
CLOSED PLASMA DEVICES
CURRENT-DRIVE HEATING
ELECTRIC HEATING
HEATING
HIGH-FREQUENCY HEATING
ICR HEATING
ION TEMPERATURE
JOULE HEATING
LOWER HYBRID HEATING
PLASMA DENSITY
PLASMA HEATING
RESISTANCE HEATING
THERMONUCLEAR DEVICES
TOKAMAK DEVICES