BISMUTH SUPERCONDUCTING WIRES AND THEIR APPLICATIONS

The combination of a bismuth high T(c) phase (T(c) = 110 K) and powder-in-tube processing technology enables the fabrication of superconducting wires with high critical current density, mass producibility and flexibility. The maximum critical current density in liquid nitrogen reached 53 700 A cm-2 in zero magnetic field, 42 300 A cm-2 at 0.1 T and 12 000 A cm-2 at 1.T. J(c) and J(c) -B enhancements were obtained with finely dispersed non-superconducting phases and clean grain boundaries. Various prototypes were made to clarify their feasibility, such as 114 m long wires (J(c) not-equal-to 10 000 A CM-2 at 77.3 K), large current conductors (I(c) = 2300 A at 77.3 K), a 0.21 T coil at 77.3 K, a 20.35 T coil at 20.3 K and a 23.37 T coil at 4.2 K.