Development of Nb3Sn conductors for fusion and high energy physics

In the recent years internal-tin Nb₃Sn conductors have been developed to a stage where the critical current densities obtainable are triple those exhibited by the bronze processed material. Outokumpu Advanced Superconductors has been producing a commercial quantity of Nb₃Sn wires mainly by using the internal-tin process. Nb₃Sn conductors, regardless of the method used in their fabrication, have to be made of different designs depending on their specific application. This paper describes design parameters of internal-tin Nb₃Sn conductors, which have been developed and made recently for use in fusion and high energy physics magnets, in particular. Their properties including the current carrying capacity and magnetization are given. The trade-offs between the critical current densities, AC losses, and how the design parameters affect these properties are also discussed.