Suppression of void nucleation by injected interstitials during heavy ion bombardment

In a heavy ion irradiation the injected ions come to rest at the end of range as interstitials without a vacancy partner. These extra interstitials perturb the delicate balance of vacancy and interstitial flux to voids. It is shown that the void nucleation rate is drastically reduced by the injected interstitials whenever recombination is an important process. As a result, void nucleation is suppressed in ion-bombardment experiments below a characteristic threshold temperature in the region of the ion deposition. This leads to a void free zone near the end of range in low temperature ion-bombardment experiments. The results obtained are in qualitative agreement with earlier experimental observations.