Japan has the procurement responsibility for 9 of ITER’s 19 superconducting toroidal field winding packs and all 19 of the toroidal field coil cases. In a major production milestone the first winding pack has been completed. At QST—the National Institutes for Quantum and Radiological Science and Technology which oversee the procurement of all the ITER components allocated to Japan—teams have been hard at work on the fabrication of the toroidal field coils.
ITER’s powerful D-shaped coils consist of a winding pack enclosed in a thick stainless steel case. The multistep fabrication process of the inner core starts with the winding of seven double pancake modules according to rigorous manufacturing specifications. Next, helium inlets and joints are created and each double pancake module undergoes heat treatment.
After heat treatment, radial plates are transferred carefully between conductor layers without causing strain greater than 0.1 percent. The conductors are then extracted from the radial plate grooves and wrapped in insulating tape before being gently reinserted. At this stage of the process, the double pancake modules are sealed with cover plates by welding.
The milestone was achieved at the Futami plant of Mitsubishi Heavy Industries Ltd/Mitsubishi Electric Co.