Inductive Excitation Tests of REBCO-Assembled Conductor Coil in Liquid Hydrogen by Using Alternating-Current Primary Coil

This paper presents an AC inductive energization method for evaluating high-temperature superconducting (HTS) assembled conductors cooled by liquid hydrogen. A short-circuited secondary coil composed of REBCO wires was fabricated and tested under liquid-nitrogen and liquid-hydrogen environments. In liquid-nitrogen cooling, phase shifts and waveform distortions in the Rogowski-coil voltage were observed when the secondary current approached the conductor's critical current (IC), demonstrating that voltage signals can serve as reliable indicators ofICUnder liquid-hydrogen cooling, secondary currents up to 4985 A were achieved before the power supply shut down because of overvoltage protection. These results establish AC inductive energization as a safe, non-destructive diagnostic method for HTS conductors and highlight the potential of liquid hydrogen for next-generation large-scale superconducting devices