Contact resistance distribution at the termination of cable-in-conduit conductors

For large cable-in-conduit conductors, a current unbalance among the strands may be the reason for reduced performance in both DC and pulsed operation. The resistance distribution of the strands at the conductor termination has been investigated as the key parameter controlling the current distribution in operation. A Nb₃Sn cable-in-conduit conductor consisting of 144 Cr plated strands has been used to prepare two terminations, one of them filled with low resistivity solder. The resistance distribution results for the two layouts are compared with the expected distribution from the count of the strand contacts, carried out on several conductor sections. Conclusions are drawn on the role of interstrand resistance and the degree of current unbalance that can be expected in the conductor next to the joint