Design and Test of Current Leads With Parallel HTS Tapes for MRI Applications

Abstract

The design, analysis and experimental test of a High Temperature Superconductor (HTS) current lead with parallel HTS tapes for MRI applications are presented. Two HTS tapes are electrically shunted in parallel in each current lead to increase its current-carrying capability. Analytical and finite element analysis has been conducted to investigate the current distribution of parallel HTS tapes under the impact of various design parameters, including the geometry, symmetricity and resistance of copper terminals, and the resistance of the interface between copper terminals and the HTS tapes. The analysis concludes that the electric resistance from the copper terminal to each of the parallel HTS tapes needs to be relatively close in order to balance the current sharing between two tapes. Making the copper terminal electrical resistance dominantly greater than the interface resistance would result in a robust current leads design. The FEA simulation meets well with prototype HTS leads test result.