Recent results and future prospects on the JT-60U tokamak
- 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-; ISSN 0748-1896; TRN: 95:002923-0019
- Journal Information:
- Fusion Technology, Vol. 26, Issue 3; Conference: 11. topical meeting on the technology of fusion energy, New Orleans, LA (United States), 19-24 Jun 1994; Other Information: PBD: Nov 1994
- Country of Publication:
- United States
- Language:
- English
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