Fusion plasma performance and confinement studies on JT-60 and JT-60U

Kamada, Yutaka; Fujita, Takaaki; Ishida, Shinichi; Kikuchi, Mitsuru; Ide, Shunsuke; Takizuka, Tomonori; Shirai, Hiroshi; Koide, Yoshihiko; Fukuda, Takeshi; Hosogane, Nobuyuki; Tsuchiya, Katsuhiko; Hatae, Takaki; Takenaga, Hidenobu; Sato, Masayasu; Nakamura, Hiroo; Naito, Osamu; Asakura, Nobuyuki; Kubo, Hirotaka; Higashijima, Satoru; Miura, Yushi; Yoshino, Ryuji; Shimizu, Katsuhiro; Ozeki, Takahisa; Hirayama, Toshio; Mori, Masahiro; Sakamoto, Yoshiteru; Kawano, Yasunori; Isayama, Akihiko; Ushigusa, Kenkichi; Ikeda, Yoshitaka; Kimura, Haruyuki; Fujii, Tsuneyuki; Imai, Tsuyoshi; Nagami, Masayuki; Takeji, Satoru; Oikawa, Toshihiro; Suzuki, Takahiro; Nakano, Tomohide; Oyama, Naoyuki; Sakurai, Shinji; Konoshima, Shigeru; Sugie, Tatsuo; Tobita, Kenji; Kondoh, Takashi; Tamai, Hiroshi ; Neyatani, Yuzuru; Sakasai, Akira; Kusama, Yoshinori; Itami, Kiyoshi; Shimada, Michiya; Ninomiya, Hiromasa; Urano, Hajime*

With the main aim of providing physics basis for ITER and the steady-state tokamak reactors, JT-60/JT-60U has been developing and optimizing the operational concepts, and extending the discharge regimes toward sustainment of high integrated performance in the reactor relevant parameter regime. In addition to achievement of the equivalent break-even condition (QDTeq up to 1.25) and a high fusion triple product = 1.5E21 m-3skeV, JT-60U has demonstrated the integrated performance of high confinement, high beta-N, full non-inductive current drive with a large fraction of bootstrap current in the reversed magnetic shear and in the high-beta-p ELMy H mode plasmas characterized by both internal and edge transport barriers. The key factors in optimizing these plasmas are profile and shape controls. As represented by discovery of various Internal Transport Barriers, JT-60/JT-60U has been emphasizing freedom and restriction of profiles in various confinement modes. JT-60U has demonstrated applicability of these high confinement modes to ITER and also clarified remaining issues.