Noninductive Current Drive and Steady-State Operation in JT-60U

Journal Article · Sun Sep 15 04:00:00 EDT 2002 · Fusion Science and Technology

OSTI ID:20845852

Ushigusa, K; Ide, S; Oikawa, T; Suzuki, T; Kamada, Y; Fujita, T; Ikeda, Y; Naito, O; Matsuoka, M; Kondoh, T; Isayama, A; Seki, M; Imai, T; Sakamoto, K; Umeda, N; Hamamatsu, K; Fujii, T; Uehara, K; Yamamoto, T; Miura, Y ; Kikuchi, M; Kuriyama, M; Ninomiya, H ^[1]

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1. Japan Atomic Energy Research Institute (Japan)

Studies on noninductive current drive (CD) and development of an integrated steady-state high performance operation in JT-60 are reviewed. Experiments on lower hybrid current drive (LHCD) in JT-60 have shown a large noninductive current up to 3.6 MA, high current drive efficiency of 3.5 x 10{sup 19} m{sup -2}A/W, and a flexible current profile control. Basic studies on LH waves, such as an effect of accessibility condition, fast electron behaviors, and so on, in JT-60 have contributed to understanding LHCD physics. Significant progress in neutral beam current drive (NBCD) has been made in JT-60 by testing the performance of negative ion-based (N) neutral beam injection (NBI) (N-NBI). The CD efficiency of {approx}1.5 x 10{sup 19} m{sup -2}A/W and negative ion-based neutral beam (N-NB) driven current of {approx}1 MA have been demonstrated in N-NBCD. Strongly localized noninductive driven current by electron cyclotron current drive (ECCD) was identified with a fundamental O-mode scheme from a low field side injection. ECCD in JT-60 has shown CD efficiency of 0.5 x 10{sup 19} m{sup -2}A/W and EC-driven current of 0.2 MA. Modification of local current profile was demonstrated and was used for suppression of neoclassical tearing mode. Based on these developments, two integrated steady-state operation scenarios were developed in JT-60, which are reversed magnetic shear (R/S) plasmas and high {beta}p ELMy H-mode. In these operation regimes, discharges have been sustained near the steady-state current profile under full noninductive current drive (High {beta}p; HH{sub y2} {approx} 1.4 and {beta}{sub N} {approx} 2.5 with N-NB, R/S; HH{sub y2} {approx} 2.2 and {beta}{sub N} {approx} 2 with f{sub BS} {approx} 80%). High performance plasmas with a high n{sub Do}{tau}{sub E}T{sub io} and at high normalized density were also produced under fully noninductive condition in high {beta}p ELMy H-mode and R/S mode.

• OSTI ID: 20845852
• Journal Information: Fusion Science and Technology, Journal Name: Fusion Science and Technology Journal Issue: 2,3 Vol. 42; ISSN 1536-1055
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANIONS
BEAM CURRENTS
ECR CURRENT DRIVE
EDGE LOCALIZED MODES
EFFICIENCY
ELECTRONS
H-MODE PLASMA CONFINEMENT
JT-60 TOKAMAK
JT-60U TOKAMAK
LOWER HYBRID CURRENT DRIVE
MAGNETIC FIELD CONFIGURATIONS
NEOCLASSICAL TRANSPORT THEORY
NEUTRAL ATOM BEAM INJECTION
PERFORMANCE
PLASMA
PLASMA DENSITY
REVERSED SHEAR
STEADY-STATE CONDITIONS
TEARING INSTABILITY