production process of superconducting wires which starts with composite sheets that are stacked and rolled together to form a cylinder with a spiral cross-section Note 1 to entry: A composite is first made of a bronze (Cu-Sn alloy) sheet and a mesh-like plate of Nb, wound together concentrically, and then area-reducing processes such as wire drawing are done to produce a thin wire, followed by heat-treatment to form Nb3Sn intermetallic compounds at the interface between Nb and the matrix. Note 2 to entry: The jelly roll process is named the modified jelly roll (MJR) process when a mesh component is used instead of a sheet or plate. Note 3 to entry: A similar process is used for Nb3Al superconducting wires. |