Both small AC loss and robustness against quench are required for the AC applications of coated conductors. Plated copper or an alternative copper layer is required essentially in order to shunt the current in case of normal transition and to suppress the hot-spot temperature. Striating superconductor layer of a coated conductor into filaments is an approach to reduce AC loss, but it must be associated with twisting for the effective AC loss reduction in practically long conductors, not for short sample pieces. However, twisting tape-shape coated conductors is impossible practically. We are proposing the concept of SCSC cable (or double “SC” cable, standing for Spiral Copper-plated Striated Coated-conductor cable), in which we wind copper-plated striated coated conductors spirally around a round metal core. The spiral geometry of the striated coated conductors plays the equivalent role to a twisted geometry: its confines the loop of coupling current into the half pitch of the spiral and, then, reduces the coupling time constant. We fabricated short model samples of the SCSC cable and measured their magnetization losses in order to determine their coupling time constants. As the starting point to clarify the quench property of the SCSC cable, we experimentally studied the quench property of single straight samples of striated coated conductors and that of the spiral non-striated coated conductors such as CORC wires. Besides such experimental results, we will present a couple of designs of SCSC cable in order to show the potential of the concept.

This work was supported by JST-Mirai Program Grant Number JPMJMI19E1, Japan. Authors N.A. and Y.S. acknowledge students in their group for their cooperation to conduct experiments. They will report the details of experiments separately.