Measurement of Strands Location and Inter-Strand Contact Resistance in a CIC Conductor

Abstract

The cable-in-conduit (CIC) conductor is the most popular one for high-field magnets installed in fusion devices. The conductor is made of hundreds of superconducting thin strands in multi stage twisted sub-cables. In spite of the current imbalance among strands resulting in degradation of conductor Ic, precise analysis of current distribution of each strand has not been done yet. In this study, we measured the strand locations and inter-strand resistance distributions which affect the current imbalance for the full-size conductor. We have investigated the resistances theoretically by using tribological analysis. It indicated that the resistance did not depend upon nominal length of distributed contact and showed the values varied by two orders of magnitude.