Enhancement of jcat 10-12 T in Nb3Sn wires by artificial Ta inclusions distributed at a nanometre scale

A new type of multifilamentary Nb 3 Sn wires prepared by the bronze route but with composite cores is found to exhibit considerably enhanced j c values with respect to conventional Ta alloyed wires in the intermediate field range, i.e. >30% between 10 and 12 T. The enhancement of j c is obtained by artificially introduced continuous ribbon-like Ta inclusions of