Temperature dependences of superconducting critical current density and upper critical field for V2(Hf, Zr) multifilamentary wire

The temperature dependences of the critical current density, Jc, and the upper critical field, uoHc2, have been studied for newly developed V2(Hf,Zr) multifilamentary wires. At 4.2 K, a μoHc2of 22 T and an over-all Jcof A/cm²at 17 T are obtained for these wires. At 1.8 K, overall Jcin 15 T of these wires are twice as large as that of the bronze-processed Nb3Sn multifilamentary wire. The enhanced Jcat reduced temperatures may be attributed to the rapid increase in μoHc2by using the temperature scaling law of the pinning force density, μoHc2measured in pulsed fields is about 28 T at 2.0 K. According to the temperature scaling law, the overall Jcfor 1.8 K and at 20 T is estimated to be A/cm². Thus, the present V2(Hf,Zr) multifilamentary wires are very promising for use of generating high magnetic fields in the superfluid liquid helium environment.