Reaction treatment, critical current, transition temperature and bend properties of a niobium-bronze process multifilamentary superconductor

Critical current, T
c
, and bend properties were measured on samples of a 0.010" (.025 cm) diameter bronze and niobium multifilament conductor which were reacted at 650-800°C. The conductor consisted of 4453 niobium filaments in a 13 wt% bronze matrix. The critical currents exhibit a peak as a function of reaction time at each temperature. The highest I
c
of 98 amperes, corresponding to an overall current density of 1.8×10
⁵
Amp/cm
²
at 7 T and 4.2 K was achieved for a reaction at 650C for 7000 minutes. Inductive T
c
measurements and critical current as a function of bend diameter are reported.