Switching reaction of Nb3Sn persistent current switch with a high current capacity

We designed a persistent current switch (PCS) consisting of Nb3Sn supercond ucting wire for superconducting magneto-hydrodynamic propulsion ship. Nb3Sn has T-c higher than NbTi, which is commonly used for the conventional PCS, and thus Nb3Sn is expected to show a higher stability against disturbance. We performed numerical simulations for the heat transfer in a 3-kA-class N b3Sn PCS by using a finite element method. We then constructed a 3 kA-6 Ome ga Nb3Sn PCS and measured its switching performance. The results obtained i n 3-kA PCS are utilized for the simulation of 10-kA-class switching perform ance including numerical simulations for the heat transfer. The results of switching performance will be presented based on the computer simulation fo r temperature distribution during the heating and cooling cycles. We also p resent the estimated time for the transition from the superconducting to no rmal state (off-state) and vice versa (on-state). (C) 2001 Elsevier Science B.V. All rights reserved.