Derivation of I/sub c/ degradation rate for Nb/sub 3/Sn coils through the react & wind technique

To estimate critical current, I/sub c/, degradation when bending and tensile strains are applied to Nb/sub 3/Sn wires through the react & wind (RW from the center of the wire toward the inside. The strain range of the Nb/sub 3/Sn filaments is from 0.40% to -0.06% when the wire is wound into a coil. The strain of the filaments increases 0.14% when the coil is cooled to 4.2 K. The additional Hoop's strain of 0.033% is applied to the wire for passing current to the coil. The I/sub c/ degradation rate based on the I/sub c/-strain characteristics of the wire was estimated to be 8.5%. We also succeeded in generating a maximum field of 9.2 T for a commercial scale coil manufactured by the R&W process.