Superconducting behaviour of Nb-Ti-12.3 wt.% Ta and Nb-Ti-20.4 wt.% Ta multifilamentary superconducting wires

Multifilamentary wires based on ternary Nb- Ti- Ta alloys with 55 and 4620 filaments have been fabricated by several processing routes. Ternary alloys with 12.4 and 20.4 wt. % Ta were used having Tc 8.99 and 8.70 K. Critical currents of the wires have been measured at 5–13.5 T and at 4.2 and 2.2 K. Critical current densities of the wires with 60–40 µm filaments and 7–3.5 µm filaments, which were prepared under the identical conditions, were compared for both the compositions.