Development of a forced-cooled superconducting coil for fusion applications

Abstract

The test coil was wound from a NbTi cable-inconduit type conductor with 54 strands and the total conductor length was 36 I&. It was cooled with supercritical helium forcedly. The critical current of the test coil was 3.5 kA at 7 tesla. The test coil was in--stalled in a back-up coil which generated the magnetic field up to 7 tesla. This paper describes the experimental results about the propagation velocity of normal zone and the pressure rise when the forced-cooled superconducting coil quenched. We also analyzed the stability margin of the coil using computer simulation.