Qualification of joints for the inner module of the ITER CS model coil

The US-ITER home team has constructed a prototype, low-loss, low-resistance lap joint sample using materials, fabrication techniques, machine tooling and quality assurance procedures identical to those for the layer-to-layer joints in the inner module of the ITER Central Solenoid Model Coil. The joint sample was tested at the MIT Pulse Test Facility to 50 kA current, in both parallel and transverse time-varying fields at ramp rates from 0.05 to and background induction to 4T, to qualify performance to ITER-relevant operating conditions. The joint shows DC below 2.5 nOhm and pulsed, transverse field losses for a 1.5 ramp at 0.4 T/s below 90 J; both values are well within target limits for the ITER-CS joints.