Variable energy positron beam studies of defects in heavy ion implanted palladium

The paper reports experimental studies of Palladium (Pd) exposed to 107 MeV Kr17 + ion irradiation. Heavy ion implantation of samples with fluences of 1012, 1013, 5 × 1013 and 1014 was performed at IC-100 cyclotron at Flerov Laboratory of Nuclear Reactions at Joint Institute for Nuclear Research (JINR) in Dubna, Russia. Radiation damages were investigated with variable energy positron beam (VEP). Doppler broadening spectroscopy (DB) was applied and the line shape S parameter of annihilation line was extracted. The analysis of S parameter profiles gives information about the presence of open volume defects in irradiated samples. The positron diffusion length extracted from the profile decreases with the dose increasing from 112 nm for a non-irradiated sample to 26 nm for the biggest fluence. It points out the increase of defect concentration with the increase of the fluence.