The performance of first CORC cable solenoid insert for development of CFETR high-field magnet

Abstract

A ReBCO coated conductor maintains high current-carrying capability under a high magnetic field and superior mechanical performance. As a promising candidate material for high-field high-temperature superconductor magnets, it has been designed for application in the China Fusion Engineering Test Reactor CS coil, with a maximum magnetic field requirement higher than 17 T. In practical application of the ReBCO tapes, the characteristic Ic response with respect to electromagnetic (EM) and thermal stress is important for safe operation of the magnet. In this paper, a nine-turn solenoid magnet was wound from 4 m of CORC cable and tested at 4.2 K in a background magnetic field of up to 19 T. The aim is to check the stability of the current-carrying properties of the ReBCO cable under combined thermal and EM loads. The solenoid coil results in a combined peak magnetic field on the conductor of 19.4 T at a critical current of 888 A. Furthermore, no performance degradation was observed after 20 cycles of operation at 800 A (90% Ic) under a background field of 19 T and 10 cycles of warm-up–cool-down between 77 K and room temperature. This demonstrates the stable performance of ReBCO conductors for high-field magnet application with EM and thermal cycles.