Recent results and future prospects on the JT-60U tokamak

Journal Article · Tue Nov 01 04:00:00 EST 1994 · Fusion Technology

OSTI ID:41434

Yoshida, H ^[1]

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1. Japan Atomic Energy Research Institute, Ibaraki (Japan)

Recent results on JT-60U experimental activities are presented. High fusion performance of n{sub D}(0){tau}{sub E}T{sub i}(0) = 1.1{times}10{sup 21}m{sup {minus}3} s keV, Q{sub DT} = 0.6, S{sub n} = 5.1{times}10{sup 16} s{sup {minus}1}, T{sub i}(0) = 37 keV and H-factor = 3.6 has been achieved in the regime named {open_quotes}high-{beta}{sub p} H-mode.{close_quotes} A fractional bootstrap current has reached {approximately} 0.5 in a series of high fusion performance plasmas of I{sub p} {le} 2.5 MA and B{sub t} = 4.4 T. Attaining broadened pressure profile and peaked current profile, on the other hand, beta limit has substantially extended to {beta}{sub N} = 4.2 and {beta}{sub p} = 4.7 in a low current and field regime of I{sub p} = 0.4{approximately}0.9 MA and B{sub t} = 1{approximately}1.5 T. This operation regime has enabled quasi-steady state ELMy H-mode discharges to be sustained with the high performance of {beta}{sub N} = 2.5{approximately}3, {beta}{sub p} = 2.5{approximately}3.1 and H-factor = 1.8{approximately}2.2 under non-inductive full current drive condition that the fraction of bootstrap current and beam driven current was 0.60 and 0.48, respectively, at I{sub p} = 0.5 MA and B{sub t} = 1.5 T. LHCD has demonstrated the non-inductive current drive up to 3.6 MA and the current drive efficiency of 3.5{times}10{sup 19} m{sup {minus}2} A/W, which non-inductive full current drive has been also achieved by NB and NB+LHCD. Active current profile control has been successfully investigated by LH wave and tangential NB. In ELMy H-mode discharges there have been observed the reduction of the heat load on divertor plates and the reduction of the helium density in core plasma. Future plans of JT-60 program are presented, which include 500 keV negative-ion based NBI system, new radiative pumped divertor, and JT-60 Super Upgrade.

• OSTI ID: 41434
• Report Number(s): CONF-940630--
• Journal Information: Fusion Technology, Journal Name: Fusion Technology Journal Issue: 3 Vol. 26; ISSN 0748-1896; ISSN FUSTE8
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
H-MODE PLASMA CONFINEMENT
JT-60U TOKAMAK
NON-INDUCTIVE CURRENT DRIVE
OPERATION
PLASMA DENSITY