Vacancy type defect formation in irradiated α-iron investigated by positron beam Doppler broadening technique

Vacancy type defects formations have been investigated in virgin and irradiated a-iron samples using slow positron beam Doppler broadening technique.
Mono-vacancies and vacancy clusters are observed in 1.5 MeV 4He ions irradiated Fe samples at varying fluences from 1×1013 to 1×1017 cm-2.
In the 1.2 MeV Yttrium ions implantation at low fluence 1×1014 cm-2 vacancy clusters with higher concentration and larger size are formed.
In this sample, vacancy defects are detected deeper than predicted by SRIM calculation due to channelling.