Speaker
Description
The bronze-processed Cu-Nb/Nb3Sn wires, composed of the Nb-rod-method Cu-Nb reinforcing stabilizer around the Nb3Sn filament bundle, have superior mechanical strength at both low temperature and room temperature after Nb3Sn creation heat-treatment. Therefore, in react-and-wind (R&W) process, the Cu-Nb/Nb3Sn wires are able to be handled easily with applying strains not to exceed the irreversible strains that the characteristics deteriorate due to cracks of mechanically brittle Nb3Sn filaments. Moreover, the non-Cu-Jc values of Cu-Nb/Nb3Sn wires have been remarkably enhanced by applying the high tin bronze and the appropriate pre-bending treatment. In this study, we discuss improved acceptable values of tensile stress and bending strain for the various Cu-Nb/Nb3Sn wires in the R&W process and the R&W magnet operations. Additionally, we propose some specific designs of Cu-Nb/Nb3Sn wires applicable to practical R&W coils, and describe their advantages against the conventional wires such as NbTi wires and wind-and-react (W&R) process Nb3Sn wires.
