Low-Temperature Recovery in Irradiated Copper

This paper considers the suggestion in the literature that $I_D$ recovery in copper is due to a superposition of unresolved close-pair processes, instead of being due to the correlated recovery of the freely migrating interstitial as Corbett, Smith, and Walker had argued. It is shown that the initial portion of the $I_D$ recovery in 1.4-MeV electron damage is proportional to the square root of the recovery time, precisely as required by correlated recovery. The $\surd t$ dependence is exploited to show that the initial $I_D$ recovery exhibits an activation energy of ≈0.12 eV, as does the rest of $I_D$ and $I_E$ recovery. Thus all $I_D$ and $I_E$ recovery are described by the motion of one type of defect and there is no need to invoke unresolved close-pair processes. It is suggested that the fine structure observed in $I_D$ recovery in deuteron-irradiation experiments may be due to the influence of the correlation between Frenkel pairs upon the kinetics of the recovery.