A critique of the unsaturable trap model of radiation damage in metals

The unsaturable trap model, which attributes the increase of the electrical resistivity of fcc metals during electron irradiation in the temperature regime of Stage-II recovery to the trapping of Stage-I_E interstitials at impurity atoms, is shown to be in serious disagreement with the experiments, contrary to opposite statements in the literature. As shown recently, the predictions of the unsaturable trap model are independent of the dimensionality of the diffusion of the Stage-I_E interstitials. Previous attempts to rule out a one-dimensional migration of the Stage-I_E interstitials (and hence the two-interstitial model) on the basis of the alleged agreement of the unsaturable trap model with Stage-II damage curves are thus meaningless. On the contrary, it is demonstrated that the two-interstitial model accounts for minute details of the measured Stage-II damage curves in a natural way.