STABILITY AND AC LOSS OF SUPERCONDUCTING CABLES - ANALYSIS OF CURRENTIMBALANCE AND INTER-STRAND COUPLING LOSSES

The current imbalance and the inter-strand coupling losses are studied for the 3x3-twisted superconducting cables exposed to the temporally- changing external magnetic field or carrying the temporally-changing t ransport current, The current distribution is calculated based on elec trical circuit models. When the cable length is not the common multipl e of the twist pitches of the first-stage and second-stage cablings, t he current imbalance among strands appears in the cables made with ins ulated strands. When the insulation of strand is removed, the transver se current flows across the contact resistance between strands. This r esults in a local current imbalance among strands and an additional in ter-strand coupling loss.