Nb₃Sn 線材の超伝導特性に対するひずみ効果のメカニズム

抄録

Nb ₃ Sn superconducting wires are very important for superconducting magnets generating high fields of more than 10 T. From the viewpoint of practical use, one of the serious problems for Nb ₃Sn wires is enumerated that their superconducting properties are sensitively deteriorated due to the applied strain, when a large electromagnetic force is added to the high field superconducting magnet. Recent experimental results suggest that the three-dimensional strain state has to be evaluated to understand the strain dependence of superconducting properties for Nb ₃ Sn wires. In this article, the strain effects for Nb ₃ Sn wiresin high magnetic fields are introduced. The physical background and a three-dimensional strain model for the strain effect on Nb ₃ Sn wires are explained in order to understand the strain dependence of superconducting properties for Nb ₃Sn.