Fabrication and properties of multifilament Nb3Sn conductors

Multifilament conductors have been fabricated in several configurations employing various combinations of Cu, Sn, Cu-Sn bronze and Nb. These conductors are in the 8-100 mil size range and contain 400-13,000 filaments. Filament sizes range from 8-100 microns in diameter. Heat treatment studies and their effect upon superconducting properties have been performed for temperatures in the range 600-800°C. Sample evaluation has included measurements of Tc, resistivity and Jcup to 150kG. Mechanical tests to assess allowable bending diameters and metallurgical studies to determine the distribution of constituent elements subsequent to heat treatment have been made. These results will be discussed and compared in the context of optimizing the properties of these conductors for high field magnet applications.