Investigation of the Relationship Between Unbalanced Current Distribution and Twist Pitches in Cable-in-Conduit Conductors

Unbalanced current distribution in cable-in-conduit conductors (CICCs) is a phenomenon that shows the dependence of stability performance on the ramp rate (ramp-rate limitation) in fusion magnets. In this study, we investigated the effect of the twist pitches of the cable stages in a CICC on the current distribution among its strands. We calculated the self-inductance of each strand and the mutual inductance between strands based on a geometrical model that analytically computes the strand's trajectory. Then, we created an equivalent circuit model and calculated the current distribution in the CICC. The current distribution was analyzed for CICCs with different twist pitch configurations. The result shows that combining the cabling stage twist pitches affects the current distribution.