2015 Volume 50 Issue 4 Pages 180-185
Nb3Sn wires are widely used for high-field superconducting magnets. For the improvement of superconducting properties, several producing processes have been developed such as bronze-route process, internal diffusion process and powderin-tube process. Nb3Sn wires of high critical current density (Jc) can contribute to advanced applications: nuclear magnetic resonance (NMR) spectrometers are the most successful case. This paper reviews the manufacturing processes of Nb3Sn in each case, reviewing the Jc improvement methodology first. Then, the research on high Jc Nb3Sn wires at Kobe Steel, Ltd. and Japan Superconductor Technology, Inc. is described. We have achieved high Jc Nb3Sn wires by focusing development on the amount of Nb3Sn phase and grain size composition. We have also developed Nb3Sn wire for the International Thermonuclear Experimental Reactor (ITER) project. These wires are utilized for high field superconducting magnet applications.
