NEW DEVELOPMENTS ON CALCULATING AND MEASURING AC LOSSES IN COMPOSITE SUPERCONDUCTORS

A method for the complete numerical solution of the Maxwell equation in a multifilamentary wire carrying and a transport current and subject to applied fields of any direction compared with the axis of the wire, both current and applied fields of arbitrary time dependence has been developed. First results show unexpected differences from analytical models which were used in the past and are reviewed in this paper. From both approaches current degradation effects can be estimated and loss contributions resulting from combined action of applied field and current can be calculated.