Optimization of the High Field Critical Current Density in MF Nb3Sn for Magnet Use

摘要

We here report new high field critical current measurements on 1 M Nb3Sn conductors together with some bend test data on a conductor to be used for a 15 teal’s magnet system. The results show that zero stress Jc values of 280 A/mM2 (measured over the bronze + Nb cross section) AT 15 teams are obtained. These high values have now been obtained for 3 different composites from 3 different sources, suggesting that it should now be possible to specify high Jc from filamentary Nb3Sn with some confidence. We have also made measurements of JC under tensile stress in the field range 13-16 teals obtaining values of over 500 A/mm at 15 tell, approximately twice as large as those obtained in zero stress measurements. We also report on some room temperature bend test measure ments for which no degradation in Jc was observed until strains of at least 0.5% were reached.