Characterization of multifilamentary Nb3Sn superconducting wires for use in the 45-T hybrid magnet

摘要

The National High Magnetic Field Laboratory (NHMFL), in collaboration with the Francis Bitter National Magnet Laboratory, is constructing a 45-T hybrid magnet system. Here we report the results of studies to characterize candidate Nb3Sn superconductor for use in the superconducting outsert coils. We have determined the effects of strain and magnetic field on the critical current, measured ac losses, and measured residual resistivity ratios (RRR). Critical currents in excess of 1000 A mm-2 non-Cu have been measured in sample wires at 12 T and 4.2 K combined with a hysteresis loss of less than 500 mJ cm-3 We also present predicted 1.8 K performance, based on empirical models, and present a methodology for calculating sample holder prestrain.