Development of a Nb3Sn multifilamentary wire for accelerator magnet applications

CEA/Saclay and Alstom/MSA have carried out a program to develop a Nb3Sn mul tifilamentary wire for accelerator magnet applications relying on the inter nal-tin process. The main wire specifications are: an overall diameter of 0 .825 mm, a critical current larger than 405 A at 4.2 K and 7 T, hysteresis losses lower than 450 mJ/cm(3) for a +/- 3 T trapezoidal cycle, and a coppe r-to-non-copper ratio greater than 1. The last phase of the optimization pr ogram was based on four different strands and we present here the results o f the characterization tests, including residual resistivity ratio, critica l current and AC loss measurements. (C) 2001 Elsevier Science B.V. All righ ts reserved.