Interpretation of time-dependent current and resistance of HTS closed loop with superconducting joint considering flux creep

Abstract

Abstract A low circuit resistance is required for a superconducting magnet operated in persistent mode using superconducting joints. We performed current decay measurements on a high-temperature superconducting (HTS) closed loop with a superconducting joint to evaluate the time dependence of the current and resistance. The results have been quantitatively explained by considering current sharing and flux creep. After the elapse of 105 s, current sharing was suppressed and a circuit resistance of less than 10−13 Ω was observed. The main finding is that joint resistance of an HTS closed loop is inversely proportional to time, contributing to low circuit resistance.