Title :
Development of Nb/sub 3/Sn superconductors for a 1 GHz NMR magnet. Dependence of high-field characteristics on tin content in bronze matrix
Author :
Miyazaki, T. ; Murakami, Y. ; Hase, T. ; Shimada, M. ; Itoh, K. ; Kiyoshi, T. ; Takeuchi, T. ; Inoue, K. ; Wada, H.
Author_Institution :
Kobe Steel Ltd., Japan
fDate :
6/1/1999 12:00:00 AM
Abstract :
To realize a 1 GHz NMR magnet, superconducting properties such as critical current density (J/sub c/) and n-value are fundamental for conductors. J/sub c/ improvements of 15% to 27% have been observed in the conductor with Cu-15wt.%Sn-0.3wt.%Ti matrix compared with J/sub c/ in a conductor with Cu-13.wt%Sn-0.3wt.%Ti matrix. In contrast to J/sub c/, differences in n-values between conductors have not appeared. In this study, systematic analysis for dependence of J/sub c/ and n-value in the high field region on Sn content over 13wt.% in bronze was examined based on the microstructures, i.e. the amount of reacted layer, grain size of Nb/sub 3/Sn, and upper critical field (H/sub c2/) supported with stoichiometric analyses.
Keywords :
NMR spectrometers; composite superconductors; critical current density (superconductivity); grain size; niobium alloys; stoichiometry; superconducting magnets; tin alloys; type II superconductors; 1 GHz; Cu-Sn-Ti matrix; NMR magnet; Nb/sub 3/Sn; Nb/sub 3/Sn superconductors; bronze matrix; critical current density; grain size; high-field characteristics; microstructures; n-value; stoichiometric analyses; superconducting properties; tin content; upper critical field; Conductors; Grain size; Magnetic field measurement; Magnetic fields; Magnetic flux; Niobium; Nuclear magnetic resonance; Superconducting magnets; Superconductivity; Tin;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
