JT-60SA superconducting magnet system

Koide, Yoshihiko; Yoshida, Kiyoshi; Wanner, M.*; Barabaschi, P.*; Cucchiaro, A.*; Davis, S.*; Decool, P.*; Di Pietro, E.*; Disset, G.*; Genini, L.*; Hajnal, N.*; Heller, R.*; Honda, Atsushi; Ikeda, Yoshitaka; Kamada, Yutaka; Kashiwa, Yoshitoshi; Kizu, Kaname; Kamiya, Koji; Murakami, Haruyuki; Michel, F.*; Marechal, J. L.*; Phillips, G.*; Polli, G. M.*; Rossi, P.*; Shibanuma, Kiyoshi; Takahata, Kazuya*; Tomarchio, V.*; Tsuchiya, Katsuhiko; Usui, Katsutomi; Verrecchia, M.*; Zani, L.*; JT-60SA Team

The most distinctive feature of the superconducting magnet system for JT-60SA is the optimized coil structure in terms of the space utilization as well as the highly accurate coil manufacturing, thus meeting the requirements for the steady-state tokamak research: A conceptually new outer inter-coil structure separated from the casing is introduced to the toroidal field coils to realize their slender shape, allowing large-bore diagnostic ports for detailed plasma measurements. A method to minimize the manufacturing error of the equilibrium-field coils has been established, aiming at the precise plasma shape/position control. A compact butt-joint has been successfully developed for the Central Solenoid, which allows an optimized utilization of the limited space for the Central Solenoid to extend the duration of the plasma pulse.