Three-Dimensional Strain Model for Various Kinds of $\hbox{Nb}_{3}\hbox{Sn}$ Wires

The three-dimensional strain dependence of the superconducting property for an internal-tin Nb
₃
Sn wire was investigated, because three-dimensional strains are necessary to understand the strain effect of superconducting properties for Nb
₃
Sn wires. The three-dimensional strain dependence of
B
_c2
and residual strains were measured by the strain gauge method and neutron diffraction, experimentally. As a result, the three-dimensional strain model based on the experimental results for bronze route Nb
₃
Sn wires explained the strain dependence of superconducting properties for an internal-tin Nb
₃
Sn wire. We found that the strain effect of
B
_c2
for bronze route and internal-tin Nb
₃
Sn wires are expressed by three-dimensional strain model.