Tests and Analyses on Quench Behavior of Conduction-Cooled No-Insulation Racetrack Coils

This is the authors' abstract. We don't add key points for this paper.

This paper reports quench tests and accompanying analyses of no-insulation (NI) REBCO (Rare-Earth Barium Copper Oxide) double pancake racetrack coil under conduction cooling conditions. The tested racetrack coil with 450× 2 turns were tested at 55K under feedback temperature control. The current was ramped up to its critical value and then held until a quench occurred, while the terminal voltage, center magnetic field, and temperatures were monitored. The current was manually ramped down to zero once the sudden change in the magnetic field was observed. To ensure reproducibility of the results, the coil underwent quench testing multiple times. Circuit-based simulations comparing the coil parameters before and after quench events revealed no change in inductance, resistance, or critical current, confirming that the winding survived without electrical or mechanical degradation. An energybalance assessment suggests that some fraction of the stored magnetic energy is absorbed by nearby copper and aluminium structures, naturally limiting both voltage spikes and temperature rises. Finally, an inversecalculation method was applied to estimate peak coil temperatures that were not directly captured by the external sensors.