Nuclear fusion device

Object: To obtain a current converter coil cut-off circuit having high performance by determining the high precision time interval between opening of a circuit breaker and a closure of a closure switch. Structure: A plasma circuit and a current converter coil are magnetically coupled to each other. The coil is connected in parallel with a commutation circuit (resistor), and the commutation is effected by a switch means. This switch means has a multi-electrode circuit breaker, with some of the electrodes provided for causing a current through the current converter coil and the other electrodes provided as switch for delivering a command for causing current to a capacitor. With this capacitor current command switch, the time precision of the current conduction command is increased. (Kamimura, M.)