A High Current Density, Low Magnetization, Tubular Filamented Nb3Sn Superconductor

72068-A competitively priced, copper stabilized, Nb3Sn superconductor, with small continuous individual filaments and high current densities, is not currently available in production quantities from a manufacturer in the United States. Therefore, this project will develop and demonstrate a process for the production of tubular filamented Nb3Sn superconductors using an inexpensive, easily fabricated core material and proven wire fabrication methods. In Phase I, a series of prototype, tubular filamented superconducting wire designs, having small individual filaments and high tin content cores, were fabricated, heat treated, and analyzed. In addition, a manufacturing process was designed that would utilize equipment that is either presently available or is currently under development. Phase II will futher develope and optimize the tubular filament supersonducting wire and provide test lengths for critical current testing. Optimization will center on efficient use of the Nb tubing and other cost savings tecniques, in order to produce high critical currents. Commercial Applications and Other Benefits as described by awardee: Tubular filamented, copper stabilized superconductors should meet the future requirements of high critical current density, high critical field, low alternating current loss, very high field, very large magnets, as required by high energy physics applications. Because the billet assembly and fabrication process will be much the same as for conventional titanium niobium superconductors, the new superconductors could become commercially available on a large scale within several years. The cost of the end product should be considerable lower than for any currently existing Nb3Sn fabrication processes.