21 Tesla powder metallurgy processed Nb3Sn(Ti) using (Nb-1.2 wt%Ti) powders

Powder metallurgy (P/M) processed Nb3Sn(Ti) wires were made with alloyed Nb(Nb-1.2wt%Ti) powders using a Cu-45wt% (Nb-1.2wt%Ti) composite. Nominal areal reductions of about 10⁴were used and Sn was introduced by means of a central Sn core. With a Sn-5wt%Cu core a critical current density Jc= 10⁴A/cm²at 4.2K was measured at 19.7 tesla. Further additions of Ti were made using Sn-xwt%Ti cores furnished by M. Suenaga of Brookhaven National Laboratory. Values of Jc(4.2K) = 10⁴A/cm²at 21.4 tesla were achieved. These values are larger than those obtained with Cu-45wt%Nb P/M processed wires. The effects of prestrain are compared with unalloyed Nb P/M processing. Higher values of Jcare obtained in strain-free wires and/or at temperatures below 4.2 K. Electron microprobe measurements of the Ti distribution throughout the single core wires are also presented.