CRITICAL CURRENT DENSITIES AND MAGNETIC HYSTERESIS LOSSES IN SUBMICRON FILAMENT BRONZE-PROCESSED Nb3Sn WIRES

Submicron filament bronze-processed multifilamentary Nb3Sn wires with Cu-5at%Sn-X (X; Mn, Ni, Si, Ge, B, P, Zn, Al) ternary alloy matrix and Nb-lat%Ta alloy cores were fabricated. The cross-sectional structure of wires was the central-Cu-stabilizer type to facilitate, by external Sn diffusion, improvements in critical current density and hysteresis losses. The Nb- 1Ta core decreased the hysteresis loss in spite of increase of the critical current densities. By the addition of Zn, Al, the critical current densities and the hysteresis losses were improved. Although hysteresis losses were not decreased by Sn plating, the critical current densities were apparently improved at relatively low temperature heat treatment.