Design, manufacturing, and testing of a Nb(3)Sn coil employing Ti alloy as structural material

Describes the design, manufacturing, and testing results of a Nb(3)Sn superconducting coil in which TiAlV alloys were used instead of stainless steel to reduce the magnetization contribution caused by the heat treatment for the A-15 Nb(3)Sn phase formation that affects the magnetic field homogeneity. Prior to the coil manufacturing several structural materials were studied and evaluated in terms of their mechanical and magnetic properties in as-worked, welded, and heat-treated conditions. The manufacturing process employed the wind-and-react technique followed by vacuum-pressure impregnation (VPI) at 1 MPa atm. The critical steps of the manufacturing process, besides the heat treatment and impregnation, are the wire splicing and joint manufacturing in which copper posts supported by Si(3)N(4) ceramic were used. The coil was tested with and without a background NbTi coil and the results have shown performance exceeding the design quench current confirming the successful coil construction.