DEVELOPMENT OF A PROTECTION CIRCUIT FOR SUPERCONDUCTING COILS IN THE LARGE HELICAL DEVICE

A new protection circuit for the superconducting coils in the Large Helical Device has been developed. The circuit transfers a high dc current from a power supply to a dump resistor at a coil quench. It is composed of a conventional ac vacuum circuit breaker, disconnectors, power fuse(s), diodes and a dump resistor. Its features include excellent cost performance and reliability and handling of currents up to 32kA in DC.