Stability of Composite Superconductors Under AC Conditions

Abstract

The conditions of thermal equilibrium for a composite conductor subjected to the passage of a direct current while immersed in liquid helium has recently been thoroughly investigated[1]. In this study, regions of stable and unstable equilibrium states were found and the concept of the maximum equilibrium current I* was introduced. It was also noted that there was a displacement of current to the substrate when I > I * resulting in an uncontrolled increase in temperature and an overheating of the conductor.