Quench evolution of YBCO ring based on weak link model

The quench process of a YBCO high temperature superconducting ring was studied in relation with the electromagnetic and thermal effect. The characteristics of the resistance in the high-Tc superconducting ring after it quenches to resistive state was numerically evaluated with the heat conduction equation. An experimental model consists of a primary coil and a secondary high-Tc superconducting ring, which are magnetically coupled through the magnetic core. The quench process is initiated by a fast increase of an induced ac current exceeding a critical value in the weak link. The characteristics of the quench process in a bulk ring are well explained by numerical analysis. This analysis could be used for designing real devices such as a high temperature superconducting switch and a current limiter.