The influence of radiation induced atomic disorder on the superconducting properties of nb 3sn

Abstract

After high dose neutron or ion irradiation of Nb 3Sn several authors have observed a marked depression of T c , H c2 and J c . By a model calculation within the framework of the linear chain model it is shown that these effects might be explained by the decrease of the electronic density of states at the Fermi level, E F, due to radiation induced atomic disorder. The influence of atomic disorder on E F, T c, and on the intrinsic superconducting material parameters λ, ξ, κ, h c , H c2 is calculated numerically and the results are compared with experiments. The depression of the critical current density for doses φ > 2 × 10 18 n/cm 2 , in spite of a softening of the elastic properties of the flux line lattice after irradiation, is shown to be due to a drastic decrease of the elementary pinning forces.