Recent experimental results for steadystate high performance plasma on JT-60U are described, emphasizing plasmacontrol, especially active control of profiles.In reversed shear (RS) plasma, a DT equivalent fusion gain of 0.5was sustained for 0.8 s (∼ the energy confinement time) bycontrolling plasma β with a newly developed stored energyfeedback control technique.An internal transport barrier (ITB) with an RSconfiguration was successfully maintained by means of LHCD in full current drive quasi-steady state for 4.7 s.The viability of a steady state RS configuration sustained by a largebootstrap current fraction has been demonstrated in ELMy H mode edge RSplasmas for the first time.In high-βp ELMy H mode plasmas, an integrated core plasmaperformance with H factor of 2.56, βN = 2.4, and bootstrap currentfraction and non-inductively driven current fraction close to the ITERrequirements was achieved at Ip = 1.5 MA in a near fullcurrent drive state by negative ion based NB (N-NB) injection.A rudimentary simulation of a reactor operation with simultaneous feedback control of both the core and divertor plasmas has beendemonstrated in ELMy H mode plasma.Aiming at active control of the pressure gradient at the ITB in RSplasmas, a feedback control system of the electron temperaturegradient has been developed and optimization of the dischargescenario using this system has recently started.
Overview of JT-60U results towards the establishment of advanced tokamak operation