Characteristics and control system of 0.5 MJ superconducting pulsed magnet

The research on superconducting pulse magnets has been actively carried out since 1970s in Japan. The purpose was to perform the basic research for developing the pulse coils for plasma heating in magnetic containment type nuclear fusion reactors as superconducting magnets. When the magnetic field of a fusion reactor is changed in pulsing state at the rate over 10 T/s by the pulsing current in coils, current is induced in plasma, and the plasma is heated by its ohmic loss. On the other hand, by rapidly charging and discharging the energy stored in pulse magnets, the stabilization of power system can be effectively carried out. The Superconduction Engineering Experiment Center, Osaka University, has developed a 0.5 MJ pulse magnet, and experimental study has been performed on the characteristics of the magnet and its control system. In this paper, the current control performance as high rate as 6.1 T/s obtained by direct digital control method, and the completion of the sequence control system for the main circuit, which does not hinder the magnet and power source at the time of charging, discharging and quenching, are reported. (Kako, I.)