Thermal quench study in HTSC pancake coil

In spite of rather high general stability of high temperature superconducti ng (HTSC) Bi-based magnets, catastrophic thermal quench (TQ) may appear in them under certain circumstances, It happens because of non-linearity of vo ltage-current characteristics in HTSC superconductors. Starting with small samples in our previous works, we continue to study the TQ with large sampl es, 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 ins talled in the winding 10 cryogenic thermocouples (TC) and two heaters. Quen ch development in the coil was measured under different temperatures, diffe rent magnetic fields and different cooling conditions. In this paper, the e xperimental details and the results obtained are presented, The results are discussed from the point of view of scaling theory for quenching in HTSC d evices. (C) 2000 Elsevier Science Ltd. All rights reserved.