PURPOSE: To increase a critical current density remarkably by burying a wire material made of non-superconducting material along the longitudinal direction of a superconducting element wire, and inserting it to a metal billet, and performing diameter reducing processing, and performing wire drawing processing to form a primary element wire, and inserting multiple element wires into a metal billet, and thereafter, performing diameter reducing processing, and performing aging heat processing in the way of wire drawing processing to obtain the final wire material.
CONSTITUTION: Through holes are provided in NbTi alloy 10, and Nb rods 12 to be artificial pinning centers are inserted to all of the through holes, and furthermore, they are inserted to a copper billet 14. Thereafter, diameter reducing processing is performed, and furthermore, wire drawing processing is performed to obtain an element wire having a hexagonal cross section, of which distance between parallel opposite sides is 2mm. Copper of the outer housing covering this element wire is melted for elimination to obtain a primary element wire 16 having a hexagonal cross section, of which distance between parallel opposite sides is 1.78mm. After inserting this primary element wire 16 into a copper nickel billet 18, diameter reducing processing is performed, and furthermore, wire drawing processing is performed to obtain a secondary element wire 20 having a hexagonal cross section, of which distance between parallel opposite sides is 2mm. After inserting this secondary element wire 20 into a copper billet 22, diameter reducing processing is performed, and aging heat processing is performed and while wire drawing processing is performed to obtain the final wire material 24 having a circular cross section.
TANAKA YASUZO
MATSUMOTO KANAME
