Effect of Ge Addition on Microstructure and Critical Current Density of Internal Tin Processed Nb_3Sn Strands

摘要

In order to investigate effect of Ge addition to the Cu matrix on the microstructure and the critical current density, three kinds of the internal tin processed Nb_3Sn strands with pure Cu, Cu-0.4wt%Ge and Cu-0.8wt%Ge alloys were prepared. Nb_3Sn formation was observed to be suppressed by Ge addition. J_c in high magnetic fields, n value and the B_(c2) was confirmed to be improved by the Ge addition compared to the none additive one.