Development of a Nb3Sn conductor containing Ga and Mg dopants

Future high energy physics accelerators and fusion machines will require superconducting magnets generating fields of 12 T and above. These magnets will most probably utilize Nb₃Sn superconductor, since Nb₃Sn-based conductors are a proven technology. The high-field performance of Nb₃Sn-based conductors can be improved through the use of dopants. Among the elements that have been investigated as potentially beneficial dopants for Nb₃Sn are Ga and Mg. Ga has been shown to increase both the critical temperature and upper critical field of Nb₃Sn, while Mg has been reported to provide grain refinement, which is essential for high critical current density. Supercon has recently investigated a method for improving high field critical current density in bronze-route Nb₃Sn through the simultaneous addition of Ga and Mg dopants. The results of the investigation, including critical current density and critical temperature data, are presented and the performance of the doped conductors is evaluated in comparison to an un-doped control