Critical currents and pinning mechanism of superconducting Nb3Sn multifilamentary tape

Results of transmission electron microscopy examination as well as critical current J(c) measurements at 4.2K under fields of up to nearly Hc(2) for superconducting Nb3Sn multifilamentary tape optimized with a new method of multiple heat treatment and processing cycles are presented. The pinning mechanism of the optimized samples is discussed with respect to these results, demonstrating the theoretical basis for the optimization process.