DEVELOPMENT OF THE ADVANCED DISK TYPE COIL FOR THE TOROIDAL FIELD COIL

The excellent technique used to the coil(advanced disk type coil), which has a rigid winding and a reliable insulation with no Ic degradation, was developed for the toroidal field coils of the ITER. Because the Nb 3 Sn cable–in– conduit type conductor is supported directly by the stainless steel disk, a strain in the Nb 3 Sn strand is held to low levels during operation. A 30–kA Nb 3 Sn cable–in–conductor was manufactured using the advanced technique in which the cable was drawn into a seamless tube. A 2.5 m–diameter, double–pancake coil was completed in order to verify the fabricating technique. The 3–turn test coil, wound with the 30–kA conductor, was also fabricated and tested. The obtained results demonstrated that the advanced disk type coil is suitable for the toroidal field coil of the ITER.