A practical in situ wire: a composite wire with many in situ processed Nb₃Sn cores of an internal diffusion type

As a superconducting in situ wire for practical use, we propose a new type of composite wire with fine cores consisting of in situ processed wires of an internal diffusion type. These Nb₃Sn wires have merit in a simple fabrication process and a high stability compared with ordinary multifilamentary Nb₃Sn wires. Expected properties of the new type of Nb₃Sn wires were estimated based on a series of experimental results for a single in situ Nb₃Sn wire used as a fine core. A quantitative reliability of the new design estimation was examined by comparing the theoretical values with observed data on the electromagnetic properties of a test wire.