Bronze route conductors for 1 GHz NMR superconducting magnet

Bronze route Nb3Sn conductors applied to 1 GHz nuclear magnetic resonance spectrometer have been manufactured. Cu-15 wt %Sn-0.3 wt %Ti (15 %Sn-bronze) Nb3Sn conductors employed in inner coils have shown overall J(c) over 100 A/mm(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(c) of 15%-bronze conductors is enhanced to match that of the tube-processed Nb3Sn conductors in the middle magnetic field region of 12-16 T.