Nb3Sn composite with distributed internal Sn

This paper describes the results of one of many Nb3Sn multifilamentary composites we are currently investigating. The wire is fabricated with so called "internal Sn methods". The Sn is distributed between the filaments rather than the center of wire in order to shorten the Sn diffusion distance and utilize the space in the wire effectively. A 6 micron thick uniform fine grain Nb3Sn layer has been produced with a diffusion heat treatment temperature of 680°C. A critical current density of 2290 A/mm²(10 T, 4.2 K, 10^-14ΩM) was attained.