Design and trial manufacturing of JT-60SA vacuum vessel

Masaki, Kei; Shibama, Yusuke; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira

JT-60 is planned to be upgraded to JT-60SA superconducting tokamak machine. This project is the JA-EU satellite tokamak program under both Broader Approach program and Japanese domestic program. The JT-60SA tokamak is composed of the following main components; vacuum vessel (VV), thermal shield, superconducting coils (toroidal field coil, equilibrium field coil, center solenoid), cryostat, heating facilities. The VV has a D-shape poloidal cross section and a double wall structure to ensure high rigidity and high toroidal one-turn resistance simultaneously. The material of the VV is 316L stainless steel with low cobalt content of 0.05wt%. Before start of the VV manufacturing, fundamental welding R&D was performed to study the manufacturing procedures. The manufacturing procedures were successfully established with a trial manufacturing of 20 upper half of the VV. Based on the results, the actual VV manufacturing has started in November 2009.