Conceptual design of superconducting magnet system for JT-60SA

Yoshida, Kiyoshi; Kizu, Kaname; Tsuchiya, Katsuhiko; Tamai, Hiroshi ; Matsukawa, Makoto; Kikuchi, Mitsuru; della Corte, A.*; Muzzi, L.*; Turt, S.*; Di Zenobio, A.*; Pizzuto, A.*; Portafaix, C.*; Nicollet, S.*; Lacroix, B.*; Decool, P.*; Duchateau, J. L.*; Zani, L.*

The upgrade of JT-60U magnet system to superconducting coils (JT-60SA) has been decided by both parties of Japan and EU in the framework of the Broader Approach agreement. The magnet system for JT-60SA consists of 18 toroidal field (TF) coils, a central solenoid (CS) with four modules, seven equilibrium field (EF) coils. TF case encloses the winding pack and is the main structural component. CS consists of four winding pack modules with its pre-load structure. Seven EF coils are attached to the TF coil cases through supports which include flexible plates. Since CS modules are operated at high magnetic field, NbSn superconductor is used. While NbTi superconductor is used in TF coils and EF coils. The magnet system has large heat load from nuclear heating by DD fusion and large AC loss from control actions. This paper descries the technical requirements, the operational interface and the conceptual design of the superconducting magnet system for JT-60SA.