Tokamak and spherical tokamak research in Japan

Takase, Yuichi*; Kikuchi, Mitsuru; Maekawa, Takashi*; Matsukawa, Makoto; Nagata, Masayoshi*; Nishio, Satoshi; Ono, Yasushi*; Sato, Konosuke*; Tobita, Kenji

Japanese tokamak and spherical tokamak (ST) research programs are described. Tokamak research will focus on steady state high( = 3.5-5.5) research on JT-60SA (formerly NCT) in support of ITER and DEMO. JT-60SA will also serve as the Satellite Tokamak under the JA-EU Broader Approach framework. ST research has been reorganized as the All-Japan ST Research Program, aiming for creative and innovative research focused on ultra-high and ultra-long pulse regimes. Results of plasma start-up, RF heating, and plasma merging reconnection experiments are summarized. Prospects of contribution of low aspect ratio tokamaks to fusion energy development, are presented.