Development of ${\rm Nb}_{3}{\rm Al}$ Wires With High Critical Current Density for Future Accelerator Magnets

Recent studies of RHQ-processed Nb3Al wires for future accelerator magnets are presented and discussed. Test wires were prepared with different fabrication parameters, such as the Nb matrix ratio, RHQ current, area reduction ratio of the wire after an RHQ treatment and the 2nd heat treatment condition. Measurements of the critical current density (Jc) and n-value have been performed during the past several years. Recently, we performed the critical temperature (Tc) measurement, and the relationship between Jc and Tc was investigated by an RHQ treatment, a 2nd heat treatment, the Nb matrix ratio, and the area reduction effect.