Manufacturing design and development of the current feeders and coil terminal boxes for JT-60SA

Feeders and coil terminal boxes (CTBs) of the superconducting magnets for JT-60SA have been designed. A small tool which can connect soldering joint with vertical direction in the cryostat has been developed. The joint resistance of the sample showed 1.7 nΩ at 2 T, 4.2 K, 20 kA which is within the requirement of <5 nΩ. A prototype feeder in CTB with crank shape was manufactured. The maximum dimensional error was 3 mm being within the requirement of ±10 mm. Feeder insulation samples showed a shear strength >60 MPa which is much higher than the requirement of 10 MPa as derived from analysis. Since all the manufacturing processes concerned have been proof-tested, the production of feeders and CTBs has been released.