The development of low-loss Nb3Sn for AC power transmission: A review

A superconducting cable incorporating Nb3Sn is briefly described and requirements for the superconductor discussed. State of the art metallurgical procedures for reducing ac losses and increasing critical currents of Nb3Sn are reviewed. The loss behavior is then related to presently available theoretical models and shown to depend largely on surface currents which are attributed to the surface barrier. Effects of temperature, trapped magnetic flux, cladding, and cable configuration are discussed.