The Characterization of Nb3Sn Superconductors for Use in Magnets of 19 T and Greater
Increased resolution of NMR spectrometry will require the use of very high field Nb3Sn superconducting magnets. Here we report the results of our investigation into mechanical and temperature effects on internal-Sn superconductors similar to those proposed for use in a 900 MHz, 21 T NMR magnet system. Thermal precompression was found to be about 0.225%, and the irreversible strain was about 0.8%. Fatigue degradation was not observed at cyclic intrinsic strains below 0.575%. Additions of reinforcing steel in cable conductors was found to reduce the critical current by as much as 50% compared to similar, unreinforced cables. Reduction of the testing temperature to 2.3 K did not increase the critical current in steel-reinforced cables to a level significantly above that of unreinforced samples.
KeywordsNuclear Magnetic Resonance Critical Current Applied Strain Steel Reinforcement Lawrence Livermore National Laboratory
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- 4.J.R. Miller and L.T. Summers, “The Effects of Various Conductor Components on Nb3Sn Filament Prestrain in Cable-in-Conduit Conductors”, Adv. Cryo. Eng., V. 34, 553, 1988.Google Scholar