High-Performance Niobium-Tin-Tantalum Superconductors Formed by Mechanical Alloying and Near-Net Shape Tube Filling

60325 For future high field (15T+) dipole magnets, such as those used in high energy physics research, there is a need for higher performance superconductors like Nb-Sn-Ta, but at a cost close to the price of conventional NbTi wires. Recent powder metallurgy work in Japan has shown very high Jc results at high fields. This project will combine a Nb-Sn-Ta powder metallurgy approach (to achieve high current densities), with a continuous tube forming and filling process (to achieve a low manufacturing cost for the superconductor). Phase I demonstrated Nb-Sn-Ta mechanical alloyed powders with satisfactory Jc levels. The powder metallurgy wire was made in lengths of 50-100 meters. Also, issues with making multifilamentary wire were explored. Phase II will focus on increasing the Jc level and increasing the filament count for multifilamentary wires. Three variations of making long length (300-1000 meters) Nb-Sn-Ta superconducting wires will be investigated. Commercial Applications and Other Benefits as described by the awardee: The largest market will be for accelerator and fusion magnets. However, high high field magnets (above 5 tesla) can be used for MRI, NMR, high gradient magnetic separators, and SMES applications