Bronze route conductors for 1 GHz NMR superconducting magnet

Abstract

Bronze route Nb/sub 3/Sn conductors applied to 1 GHz nuclear magnetic resonance spectrometer have been manufactured. Cu-1Swt%Sn-0.3wt%Ti (15% Sn-bronze) Nb/sub 3/Sn conductors employed in inner coils have shown overall J/sub c/ over 100 A/mm/sup 2/ in 21 T at 1.8 K. Other conductors with a Ta-core as a reinforcement employed in outer coils have presented a 0.2% proof strength of 300 MPa at 4.2 K. It is also reported that J/sub c/ of 15%-bronze conductors is enhanced to match that of the tube-processed Nb/sub 3/Sn conductors in the middle magnetic field region of 12-16 T.