JT-60SA vacuum vessel manufacturing and assembly

The JT-60SA vacuum vessel (VV) has a D-shaped poloidal cross section and a toroidal configuration with 10° segmented facets. A double wall structure is adopted to ensure high rigidity at operational load and high toroidal one-turn resistance. The material is 316L stainless steel with low cobalt content (<0.05%). The design temperatures of the VV at plasma operation and baking are 50 °C and 200 °C, respectively. In the double wall, boric-acid water is circulated at plasma operation to reduce the nuclear heating of the superconducting magnets. For baking, nitrogen gas is circulated in the double wall after draining of the boric-acid water.The manufacturing of the VV started in November 2009 after a fundamental welding R&D and a trial manufacturing of 20° upper half mock-up. The manufacturing of the first VV 40° sector was completed in May 2011. A basic concept and required jigs of the VV assembly were studied.This paper describes the design and manufacturing of the vacuum vessel. A plan of VV assembly in torus hall is also presented.

► The design of the JT-60SA vacuum vessel body was completed with the demonstration of manufacturing procedure by the mock-up fabrication of the 20° upper half of VV.
► The actual VV manufacturing has started since November 2009.
► The first product of the VV 40° sector was completed in May 2011.
► A basic VV assembly scenario and procedure were studied to complete the 360° VV including positioning method and joint welding.