Experiment of Current Imbalance Correction Using Iron Core

Superconducting conductors which are composed of many superconducting strands have a problem of current imbalance. This may cause the conductors to quench at a current level below its design value. This paper proposes the iron core methods to fix the current imbalance problem. The iron core method is the one in which two insulated strands are passed through an iron core with electric currents circulating in opposite directions. We investigated the current imbalance by using Ag sheathed Bi-2223 high temparature superconducting wire. We observed that the current imbalance was corrected by using ferrite iron core in liquid nitrogen. Finally, we discuss the size of iron core needed to solve the current imbalance problem.