Recent RF activities on JT-60U

Journal Article · Mon Sep 20 04:00:00 EDT 1999 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.59748· OSTI ID:21210466

Ikeda, Y; Fujita, T; Hamamatus, K; Ide, S; Imai, T; Isayama, A; Iwase, M; Kasugai, A; Kondoh, T; Kusama, Y; Moriyama, S; Naito, O; Nemoto, M; Oikawa, T; Sakamoto, K; Seki, M; Shinozaki, S; Simono, M; Takahashi, T; Terakado, M ^[1]

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1. Japan Atomic Energy Research Institute, Naka Fusion Research Establishment Mukoyama 801-1, Naka-machi, Naka-gun, Ibaraki-ken, 311-0193 (Japan)

Recently, the JT-60U has employed ECRF system in addition to LHCD and ICRF systems. Three types of RF experiments on JT-60U have been performed. A reversed magnetic shear (R/S) configuration with internal transport barrier (ITB) was successfully maintained for 4.7 s in a quasi-steady state by LHCD in addition to the bootstrap current, where all profiles of temperature and plasma current were almost stationary. On the normal operation without heating during plasma current ramp-up, high electron temperature (T{sub e0}{approx}10 keV) with a strongly peaked profile was produced by LHCD alone at the density of {approx}0.5x10{sup 19} m{sup -3}. This peaked temperature profile was featured by a reduction in core density. The central electron temperature and density slowly changed in several seconds. The performances of ICRF (2{omega}{sub CH}) on the R/S configuration were also studied. Degradation of confinement of energetic particles was observed probably due to the large banana orbit loss. An 110 GHz ECRF system has been operated on JT-60U. Its gyrotron has successfully generated power at the level of up to 830 kW for 300 ms and is under conditioning. On the initial operation, the power of 620 kW was injected into plasmas. The central electron temperature increased from 3 keV to 5.5 keV at n{sub e}{approx}0.6x10{sup 19} m{sup -3}. A controllability of local heating was also demonstrated by the poloidally steerable mirror.

• OSTI ID: 21210466
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 485; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BANANA REGIME
BOOTSTRAP CURRENT
CHARGED-PARTICLE TRANSPORT
ECR HEATING
ELECTRON TEMPERATURE
GHZ RANGE
ICR HEATING
JT-60U TOKAMAK
KEV RANGE
LOWER HYBRID CURRENT DRIVE
MAGNETIC FIELD CONFIGURATIONS
PLASMA
PLASMA DENSITY
REVERSED SHEAR
RF SYSTEMS
STEADY-STATE CONDITIONS
TEMPERATURE MEASUREMENT
THERMAL BARRIERS