Development of a 13 T-640 MJ Superconducting Pulsed Coil for Fusion Machines

Abstract

As research and development of central solenoids for fusion reactors, a 13 T, 640 MJ superconducting pulsed coil has been constructed. The coil has a 1.6m inner diameter, a 3.6m outer diameter and a 1.7m height, which is composed of a inner module and an outer one. The coil has been fabricated with layer winding method in order to realize compact machine. A forced cooled Nb₃Sn cable-in-conduit conductor with a rectangular incoloy conduit with a circular hole has been used for the coil windings. The coil is designed to be charged up to 46 kA corresponding to 13 T with a ramp rate of 0.4 T/s and discharged to 0 kA with a time constant of 10.8 s, which corresponds to the maximum ramp rate of 1.2 T/s. The ac loss in the coil is expected to be about 10 kW during operation with a ramp rate of 0.4 T/s.