Electrical and Mechanical Properties of Strands in Superconducting Triplets

Contact resistance on strands is an important parameter for characterizing stability of cable-in-conduit conductors. We prepared triplets made of three strands with four different twist pitches (25, 50, 65 mm and untwisted). The electrical and mechanical properties of the strands were measured, after cycling 10 times with a peak force of 667 N/m. The contact area between the strands could be precisely estimated, and then the surface resistance was evaluated. As a result, the contact resistance and the surface resistance between the strands depended on the twist pitches of the wires. The results become fundamental data to simulate an electric circuit model consisting of more than one sub-cable, and also to estimate the inter-coupling losses in the cables