Development Progress and Future Prospects of Cu-Nb Reinforced Nb₃Sn Wires

This is the authors' abstract. We don't add key points for this paper.

The Cu-Nb/Nb3Sn wires have much higher superconducting properties under large mechanical stresses compared to conventional Cu/Nb3Sn wires. In the developments of the Cu-Nb/Nb3Sn Rutherford cables for 25 T cryogen-free superconducting magnet with Tohoku University, we succeeded in improving both superconducting performance and mechanical properties by pre-bending treatment using the React-and-Wind（R&W）method. Subsequently, we have made many prototypes of Cu-Nb/Nb3Sn wires that satisfy the properties required for various Nb3Sn coil applications. As a result, we established technologies related to Cu-Nb/Nb3Sn wires such as higher strength, higher critical current density, rectangular shape, enamel coating, thinner wires for small radius bending, and stranded cables. We also confirmed the effectiveness of Cu-Nb/Nb3Sn wires not only in the R&W method but also in the W&R method. This paper describes the development progress and future prospects of Cu-Nb/Nb3Sn wires.