Abstract
HTS wires have been improved to the extent that they have practical properties, and various HTS coils have been designed and fabricated. One of the features of an HTS coil is high thermal stability against thermal disturbances. The minimum quench energy (MQE) of an HTS coil is several orders higher than that of an LTS coil. However, thermal runaway, which shows almost the same phenomenon as quenching observed in an LTS coil, is observed in a conduction-cooled HTS coil when the HTS coil is operated under a high load factor. Thermal runaway causes degradation of an HTS coil, so it is important to quantitatively evaluate the thermal runaway currents of a conduction-cooled HTS coil. This paper shows the thermal runaway evaluation test results for a conduction-cooled HTS coil wound with an Ag-sheathed Bi2223 wire.
