Installation of the W-shaped divertor in JT-60U

In JT-60U, the modification from the open divertor to the W-shaped divertor with pumps was conducted from February to May in 1997. To install a new divertor in the vessel, pre-inspection of the vacuum vessel, test of installation procedure with mock-ups of the divertor components being designed were carried out, and information obtained from these procedures was taken into the installation procedure as well as the design. The actual installation works such as determination of datum lines, adjustment of new divertor components and the preparations concerning with working environment are described. The status of initial operations is also shown.