Improved Internal-Tin Nb3Sn Conductors for ITER and Other Fusion Applications

78471S In the near future, there will be an urgent need for large quantities of Nb3Sn superconductor for the International Thermonuclear Experimental Reactor (ITER), an experimental fusion device, and the DOE has only a few domestically located companies that are capable of supplying this need. Two of these are subsidiaries of European companies that already have orders and commitments to the EU fusion program. There is a serious need for a U.S. company that is interested in, and capable of, helping to supply some of the requirements. In this project, small quantities of material meeting the U.S. specifications will be made in Phase and scaled-up in Phase II to full production-size billets. The ultimate goal is to demonstrate that a U.S. company can satisfy the DOE requirements for this superconductor material. In Phase I, two 88.9 mm (3.5") ¿ billets, both of a four-row drilled design, one with Nb filaments and the other with Nb7.5wt.%Ta filaments, will be made into two groups of 19 and 37-subelement restacks. Half will have tin cores and the other half Sn2wt.%Ti cores. These will be tested for current carrying capability and losses and the most economical, i.e., the one that meets the specifications with the largest margin, will be selected for scale-up in Phase II. Commercial Applications and Other Benefits as described by the awardee: In addition to being used in ITER and other fusion applications, the resultant material should have appliation to open area Magnetic Resonance Imaging (MRI) where the patient is more accessible to the surgeon. MRI is the largest commercial application of low temperature superconductors (LTS). Other applications include Nuclear Magnetic Resonance and High Energy Physics ¿ for the latter, the materials could find use in high magnetic field magnets for accelerator applications.