Recent results and future plan on JT-60U

Recently, JT-60U has intensively addressed enhancement and long sustainment of steady state performance In the use of negative-ion based neutral beam injection (N-NBI) and electron cyclotron (EC) wave injection. The N-NBI increased the current drive efficiency up to 1.55 x 10(19) A/m(2)/W at 360 keV and enhanced the fusion triple product up to n(i)(0)tau(E)T(i)(0) similar to3.0x10(20) keVsm(-3) during a full current drive condition. Increasing the plasma triangularity extended the duration of a plasma with beta(N)similar to2.7 up to similar to60tau(E). The EC heating in combination with lower hybrid wave Injection produced a very high electron temperature of similar to26 keV for a reversed shear plasma. For reversed shear plasmas, the formation and sustainment of a central current hole was also discovered. High-field-side pellet Injection extended the confinement up to H(89p)similar to2 at n/n(G)similar to0.7. For the modification of JT-60, a fully superconducting tokamak, JT-60SC, is planned to further economical and environmental attractiveness in a tokamak DEMO reactor. The mission of JT-60SC is to realize high performance steady state operation and demonstrate the plasma applicability of low activation material for a plasma of break-even class relevant to the reactor plasma. Physics issues, design and machine description for JT-60SC with I-p=4 MA, B-t=3.8 T and R-p=2.8 m are outlined.