Study of Quench Phenomena with Superconducting Model Coils

Abstract

A quench phenomenon is very important for superconducting power devices, such as SMES, superconducting generator, superconducting current limiter, and so on. Because the reliability of such devices depends on the stability against quench, in which superconducting state varies into normal state rapidly. We have produced two kinds of coils, and investigated experimentally the relation between stability and several parameters, for example, external magnetic field, electrical current, duration time of heating by a heater. A quench phenomenon has been simulated numerically with the same conditions as experiments, and the stability has been estimated quantitatively. As the result, it is found that the larger an external field or a coil current, the less stabilized for quench. Experimental results have been reproduced on our simulation. We improved our two-dimensional quench simulation code considering the delay time of heat transfer due to insulator and the thermal capacity of insulator and spacer. An expansion of quenched region has been recorded with high speed video camera, and the two-dimensional expansion of quenched region such as quench propagation between superconducting wires has been reviewed on our simulation.