Copper matrix filamentary niobium-tin superconductors

Recent designs of filamentary niobium-tin superconducting composites are described and critical density and mechanical property performance data is given. Methods of improving the efficiency of the reaction are described and an aging process which degrades critical current density has been identified. The performance of a solenoid magnet constructed with a copper matrix composite is described. Conductor fabrication procedures are reported which have been developed to a sufficient degree to permit niobium-tin magnets to be wound and then reacted as a routine operation to give winding densities of 700 A mm-2 10 T, 280 A mm-2 14 T and in situ critical strains to the onset of flux instability in the range 0.2 to 0.5%. (author)