An in depth characterization of (NbTa)3Sn filamentary superconductor

Further to our programme of investigations of new, technical superconductive materials which are of interest to designers of practical devices, we present the results of a detailed study of the critical parameters of the ternary addition A.15 material (Nb7.Sw/oTa)3Sn manufactured by Vacuumschmelze GMBH, Hanau F.R.G. The basis of the results we report is a comprehensive Jc(B, T) characterization within the range, O<B<15.5T, 2K<T<Tc, with particular emphasis on the temperature in the region of Tc. From these data we extract the relevant information relating to the flux pinning behaviour of the material and discuss its implications. The techniques and apparatus used broadly follow those reported previously although some refinements and improvements we have developed will be described.