Magnetic flux penetration and AC loss in a composite superconducting wire with ferromagnetic parts

摘要

The current distribution and the AC loss in a composite superconducting tapecontaining a layer from magnetic material is calculated and compared withexperiments, showing a very good agreement. The situations of an alternatinguniform applied field or a transport current are studied. The newly developednumerical model is an approximation to the critical state model, adapted forthe applicability to commercial finite elements codes that solve the vectorpotential. Substantial feature of this procedure is that it can be carried outin the case when the critical current density in superconductor depends on themagnetic field and the magnetic layer material is non- linear. Additionally,the hysteresis loss in the magnetic material is estimated, based on itsmeasured magnetization loops. Measurements on Bi-2223 multifilamentary tapescovered on edges by nickel confirmed our predictions, showing a substantial acloss reduction in both the investigated regimes.