PERFORMANCE OF A REACT AND WIND 12 T KFK-NET-TF SUBSIZE CONDUCTOR UNDER STATIC AND CYCLIC AXIAL STRAIN

A forced flow Nb3Sn subsize conductor for the 12 T NET toroidal field coils fabricated by the "react and wind" process was developed by KfK. It consists of a flat core housing the Nb3Sn 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(c), versus both magnetic field, B, and axial strain, epsilon-a, measurements show that this delicate procedure has not negatively affected the I(c) vs (B, epsilon-a) characteristic. At B = 12 T the I(c) vs epsilon-a curve exhibit a maximum of I(c) = 5.25 kA at a prestrain of epsilon-a = 0.36% which degradates to I(c) = 3.93 kA at epsilon-a = 0. This behavior is not influenced by 10(3) strain cycles between 0.1 and 0.36% strain. The present results have demonstrated both the mechanical integrity and the predicted properties of "react and wind" conductors.