Overview of JT-60U results toward high integrated performance in reactor-relevant regime

Toward steady sustainment of high integrated performance, we have developed weak magnetic shear (high βp mode) and reversed magnetic shear plasmas. As a large-sized tokamak equipped with a variety of devices for heating, current drive and profile/shape control, JT-60U has high ability to approach the conditions required in reactors: low values of normalized Larmor radius and collisionality, high temperatures with Te > or approx. Ti, etc. This paper reviews recent JT-60U results with the emphasis on the projection to the reactor-relevant regime. Full non-inductive current drive has been achieved in a 1.8 MA high βp H-mode plasma with βN 2:4, HHy2=1.2 and high fusion triple product (3 x 1020 m-3keVs) owing to increased N-NB power. In a reversed shear plasma, HHy2=1.4 at ne/nGW 0.8 under the full non-inductive current drive has been achieved with injection of LHRF and N-NB. In box-type ITBs with reversed shear, barriers for ions and electrons were sustained in a regime with Te > or approx. Ti. The pedestal pressure was doubled with increased total poloidal beta in pellet-injected high triangularity plasmas with type I and II ELMs. Stable existence of current hole was demonstrated. (author)