Demountable Coaxial Clamped Joint for ITER Central Solenoid Module Final Test Program

The ITER Central Solenoid Modules (CSM) are being fabricated at General Atomics (GA) at their Magnet Technologies Center in Poway, CA. Each of the seven modules will undergo final testing at the GA facility to demonstrate their performance at 48.5 kA, 11 T, and at 4.5 K. In order to perform tests on multiple modules, a demountable coaxial joint using indium wires was developed to connect the modules to the feeders. Two full scale joints were fabricated to establish the assembly technique and preliminarily tested (up to 3 kA) on the CSM qualification coil (Cu conductor). The same joint components were then tested using a superconducting jumper (NbTi) and their resistance measured (2.3 and 4.9 nΩ, at 4.5 K, 40 kA). In parallel to measuring the voltage across the joints, a calorimetric evaluation was also performed and it confirmed the low resistance measurements of both joints. Testing of the same coaxial clamped joints on a heat treated Nb 3 Sn jumper took place in February 2019 and the results are reported in this paper. With these acceptable results, the same joint components and assembly techniques will be utilized to connect the 14 joints on the seven CSM (Nb3Sn) for full current testing.