TEMPERATURE AND MAGNETIC-FIELD DEPENDENCE OF SUPERCONDUCTING CRITICAL CURRENT DENSITIES OF MULTIFILAMENTARY NB3SN AND NBTI COMPOSITE WIRES

Commercial NbTi and Nb3Sn multifilamentary superconducting wire is becoming increasing important for use in research and commercial magnet systems. In both materials the temperature dependence of J plays a major role in the determination or magnet system operating parameters and design stability margins. We report here critical current density measurements as a function of temperature from 4.2 to 19 K and of applied magnetic field upto to 8 T for multi-filamentary Nb3Sn wire and for 2 alloys of NbTi superconducting wire. From this data [∂Jc(Ha)/∂T] and [ ∂HC2/∂T] T=TC can be obtained and stability criteria and other superconducting parameters of the wires may be extracted. © 1979 IEEE