Second Generation Superconducting Wires for Power Applications (Postprint)

We review conceptual and experimental explorations of magnetization losses in multifilament, multiply connected coated superconductors exposed to time-varying magnetic field. In these conductors the superconducting layer is divided into parallel stripes segregated by non-superconducting grooves. In order to facilitate the current sharing between the stripes and thus increase their reliability, a sparse network of superconducting interfilament bridges needs to be introduced. We find that the presence of the bridges does not substantially increase the magnetization losses, both hysteresis and coupling, as long as they are placed along the neutral lines that always exist in twisted conductors. These are lines along which the induced electric field vanishes. These results indicate that it is possible to find a reasonable compromise between the competing requirements of connectivity and loss reduction in an ac-tolerant version of the high temperature coated conductors designed for power applications.