A conductor, with uncoupled 2.5 μm. diameter filaments, designed for the outer cable of SSC dipole magnets

A conductor, with a stabilizer to superconductor ratio of 1.8/1 and containing 22,900, 2.5 μm. diameter, filaments at a wire diameter of 0.65 mm., has been produced. The fabrication procedures used to make this material from a full production size billet, 305 mm. in diameter, are described. Metallographic, electrical and magnetization data are presented and these illustrate that the filaments are completely uncoupled at the size used in the outer SSC cable. This work indicates the feasibility of the commercial manufacture of such a 2.5 μm. diameter filamentry material. Preliminary tests show relatively low J/sub c/'s and n values. It is likely that materials with smaller spacings than those used in this work, will be required before the J/sub c/'s specified for the SSC can be obtained reproducibly