RECENT RESULTS AND FUTURE-PROSPECTS ON THE JT-60U TOKAMAK

Recent results on JT-60U experimental activities are presented. High fusion performance of n(p)(0)tau(E)T(i)(0)= 1.1x10(21) m(-3) s keV, Q(DT) = 0.6, S-n=5.1x10(16) s(-1), T-i(0) = 37 keV and H-factor = 3.6 has been achieved in the regime named ''high-beta(p) H-mode.'' A fractional bootstrap current has reached similar to 0.5 in a series of high fusion performance plasmas of I-p less than or equal to 2.5 MA and B-t=4.4 T. Attaining broadened pressure profile and peaked current profile, on the other hand, beta limit has substantially extended to beta(N)=4.2 and beta(p)=4.7 in a low current and field regime of I-p=0.4 similar to 0.9 MA and B-t=1 similar to 1.5 T. This operation regime has enabled quasi-steady state ELMy H-mode discharges to be sustained with the high performance of beta(N)=2.5 similar to 3, beta(p)=2.5 similar to 3.1 and H-factor = 1.8 similar to 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-p= 0.5 MA and B-t=1.5 T. LHCD has demonstrated the noninductive current drive up to 3.6 MA and the current drive efficiency of 3.5x10(19) m(-2) A/W, while 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.