Defect Range and Evolution in Swift Xe-Ion Irradiated Pure Silver Studied by Positron Annihilation Technique

Variable energy positron beam and positron lifetime spectroscopy were used to study pure silver samples exposed to irradiation with swift Xe26+ ions of energy 167 MeV with different dose: of 10(13), 5 x 10(13) and 10(14) ions/cm(2). The positron lifetime spectroscopy revealed the presence of dislocations or vacancies associated with dislocations. They are distributed at the depth of about 6 mu m, and this correlates with the ion implantation range, i.e. 9 mu m. However, some defects are observed also to a depth of about 1 8 mu m. At the depth less than 1 mu m from the entrance surface strong dependence of positron diffusion length on the dose is observed. It indicates the presence of interstitial atoms and/or dislocation loops as a result of Xe26+ ions implantation.