The development of elemental technologies is required for the practical use of React-and-Wind (R&W)-processed Nb3Sn coil applications. The critical currents (Ic) of a Nb3Sn strand under several common strains are able to be estimated using both characteristics of the Ic-magnetic field-temperature-axial strain (Ic-B-T-ε) property and considerations of the bending strain effects. However, designing the Ic of a large-scale Nb3Sn conductor becomes much more difficult because the Nb3Sn wires are under extremely complicated strains. Recently, Nb-rod-method Cu-Nb reinforced Nb3Sn wires were successfully developed using the bronze process. The performance of the Cu-Nb/Nb3Sn Rutherford cables was improved by utilizing the pre-bending process. It is expected that pre-bent Cu-Nb/Nb3Sn wires will be very useful for R&W-processed Nb3Sn coil. This paper describes the progress and prospects for developing elemental technologies used in R&W Nb3Sn wires.
