Performance of a 'react and wind' 12 T KfK-NET-TF subsize conductor under static and cyclic axial strain

A forced flow Nb/sub 3/Sn subsize conductor for the 12-T Next European Torus (NET) toroidal field coils fabricated by the react-and-wind process was developed. It consists of a flat core housing the Nb/sub 3/Sn cable soldered between two stabilizing copper units which are surrounded by a stainless steel jacket. The jacket was tightly drawn onto the already reacted cable. Critical current, I/sub c/, vs. both magnetic field, B, and axial strain, in /sub a/, measurements show that this delicate procedure has not adversely affected the I/sub c/ vs. (B, in /sub a/) characteristic. At B=12 T the I/sub c/ vs. in /sub a/ curve exhibits a maximum of I/sub c/=5.25 kA at a prestrain of in /sub a/=0.36% which degrades to I/sub c/=3.93 kA at in /sub a/=0. This behavior is not influenced by 10/sup 3/ strain cycles between 0.1 and 0.36% strain. The results have demonstrated both the mechanical integrity and the predicted properties of react-and-wind conductors.