Development of high current density, large superconducting coil for fusion machines: the DPC-TJ Program

A 40 A mm −2 , 24 kA, high rigidity, large forced-cooled, (NbTi) 3 Sn superconducting coil referred to as the DPC-TJ was developed during collaboration between the Japan Atomic Energy Research Institute and Toshiba Corporation. The purpose of the DPC-TJ Program is to demonstrate the realizability of a high average current density with a large coil wound by a large Nb 3 Sn superconductor which meets the requirements of the conductor for the next thermonuclear fusion machine. The DPC-TJ was fabricated as the first coil of the preformed-armour type, which was developed in this programme as a fabrication method that enables us to achieve high rigidity and high current density simultaneously without difficulty. Testing of the DPC-TJ coil was performed successfully and the DPC-TJ Program was completed having accomplished its objectives.