Channeling Measurements of Damage in Ion Bombarded Iron

Abstract

<p> This project is concerned with medium energy heavy ion (60 KEV 75As, 40Ar, 120 KEV 150As2) implantation into single crystal iron at room temperature and 35°K. Resulting crystal properties are measured using the technique of high energy light ion (1.0 MEV 4He) channeling and backscattering. The phenomenon of oxygen recoil implantation by the bombarding ion is found to be an important effect to avoid if radiation damage is to be measured. In cases where oxygen recoil implantation has been eliminated, radiation damage was evident from an increase in the minimum channeling yield. The existence of damage beyond the expected damage range at room temperature is attributed to diffusion of defects. Some annealing of damage is observed in samples which have been damaged at 35°K and warmed to room temperature. At doses of about 10^16 atoms/cm^2, 80(±10)% of the implanted As is found to be at lattice sites.</p> <p> The merits and limitations of this technique as a simulation of 14 MEV neutron radiation damage are also discussed.</p>