Numerical analysis of AC transport current loss measurements using a pick-up loop

We suggested a pick-up loop method for measuring AC transport current loss in high temperature superconducting (HTS) tapes, which avoids a direct electrical connection with the HTS tape. This method requires a correction factor, which is related to the ratio of the linkage magnetic flux determined by the distribution of the transport current in the HTS tape and pick-up loop. We reported previously that the correction factor for an HTS tape obtained experimentally corresponded with the numerical analysis result. In this study, we numerically analyzed the correction factor for rectangular and spiral pick-up loops. The correction factor for an ideal pick-up loop does not depend on the amplitude of the transport current and is not affected by the position of the HTS tape, even if slightly altered. Our numerical analysis suggests the ideal shape for a pick-up loop to measure AC transport current loss without an electrical connection.