Electrical resistivity and length variations of iron and nickel during low temperature electron irradiations

Abstract

Low concentrations of Frenkel pairs are produced in polycrystalline iron and nickel targets during irradiations with 1.9 to 2.5 MeV electrons at 5 or 20 K. During irradiation (and subsequent thermal annealing for the nickel target) we simultaneously measure on the targets the changes of electrical resistivity, and of length with two different linear systems: a capacitive and an inductive device.

The measured ratios of relative length to electrical resistivity increases are (Δl/l)/Δρ]_Fc = and (Δl/l)/Δρ]_Nj = 1020 ±120(Ωcm)^?1. Values of Frenkel pair formation volumes of ν _Fc = 1.35 ± 0.25 and ν _Ni = 2.06 ± 0.30 atomic volumes are proposed.