Thermal quench study in HTSC pancake coil

Abstract In spite of rather high general stability of high temperature superconducting(HTSC) Bi-based magnets, catastrophic thermal quench (TQ) may appear in them under certain circumstances. It happens because of non-linearity of voltage–current characteristics in HTSC superconductors. Starting with small samples in our previous works, we continue to study the TQ with large samples. We prepared a highly instrumented HTSC pancake coil. It is wound using the Bi-2223-based tape. We attached many potential taps to the tape and installed in the winding 10 cryogenic thermocouples (TC) and two heaters. Quench development in the coil was measured under different temperatures, different magnetic fields and different cooling conditions. In this paper, the experimental details and the results obtained are presented. The results are discussed from the point of view of scaling theory for quenching in HTSC devices.