Inter-Strand Resistance in the Termination of ITER Conductors

In large, cabled superconductors, a non-negligible level of current unbalance among the strands is unavoidable in dc operation due to non-homogeneous contact resistance distribution at the electrical connections. When the overloaded strands saturate their current carrying capability and start to develop current sharing voltage at the high field section, the excess current must be transferred to less loaded strands. The inter-strand current re-distribution takes likely place at the electrical connections, where the inter-strand resistance is lower. Two samples of electrical termination, made of large cable-in-conduit conductors, were formerly prepared and tested for contact resistance distribution at CRPP. One of these samples is now re-arranged to measure the inter-strand resistance in different combination. A discussion of the results allows ruling out speculations about the impact of current re-distribution effects on the voltage-current and voltage-temperature characteristics in short length conductor test.