Application of Na-22 positron source to the investigation of ion-implanted iron samples

Abstract

In the field of positron annihilation spectroscopy, the investigation of a thin near-surface region, modified with ion implantation, has been usually performed by slow positron beams. Experiments carried out to simulate radiation effects in Fe-based alloys, were reported widely in the past [1,2]. Radioisotope positron sources, such as 22Na, provide only a little information from the near-surface area, probing the bulk region particularly. With more and more accessible high-energy particle accelerators in research institutes, modified layers can reach up to several tens of micrometres into the bulk, enabling to use conventional 22Na positron source for their investigation. This paper addresses some practical issues of the application of unmoderated radioisotope sources for the investigation of radiation effects in solids, simulated by ion implantation.In the field of positron annihilation spectroscopy, the investigation of a thin near-surface region, modified with ion implantation, has been usually performed by slow positron beams. Experiments carried out to simulate radiation effects in Fe-based alloys, were reported widely in the past [1,2]. Radioisotope positron sources, such as 22Na, provide only a little information from the near-surface area, probing the bulk region particularly. With more and more accessible high-energy particle accelerators in research institutes, modified layers can reach up to several tens of micrometres into the bulk, enabling to use conventional 22Na positron source for their investigation. This paper addresses some practical issues of the application of unmoderated radioisotope sources for the investigation of radiation effects in solids, simulated by ion implantation.