Stored Energy, Volume, and Resistivity Change in Neutron Irradiated Aluminium

Abstract

Abstract Pure aluminium samples are irradiated at 4 °K in the core of the Munich Research Reactor. Measurements are then made of the release of the stored energy (Δ Q and the changes in the length (Δ l ) and electrical resistivity (Δ∂) during annealing between 4 and 300 °K. For the first annealing stage, observed between 4 and 55 °K, these measurements yield \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{{\Delta Q}}{{\Delta \varrho}} = 38.3 \pm 1.3Ws/g\mu \Omega {\rm cm,}\frac{{\Delta l/l}}{{\Delta \varrho}} = 0.12 \pm 0.005\frac{\%}{{\mu \Omega {\rm cm}}}$ \end{document} . The corresponding ratios for the two other observed stages have similar values. The experimental results suggest the following values for specific properties of defects in aluminium ( E F , E i , E v being the energies of a Frenkel defect, an interstitial, and a vacancy, respectively; V F is the volume change per Frenkel defect; ∂ F , ∂ i , ∂ v are the resistivity changes per unit concentration of Frenkel defects, interstitials, and vacancies, respectively): E F = 3.4 eV; E v = 0.8 eV; E i = 2.6 eV; V F = 1.2 atomvol.; ∂ F = 340 μΩcm; ∂ v = 220 μΩcm; ∂ i = 120 μΩcm.