Positron and electron solid interactions

Abstract

Variable-energy positron beams have been attracting considerable attention in recent years as novel probes of surface, thin-film, and interfacial properties in solid systems. The Positron Beam Laboratory at the University of Western Ontario supports research into three separate programs. The first involves the study of re-emitted positrons from thin-films grown on single-crystal substrates under ultra-high vacuum conditions. The second area of research is the non-destructive depth profiling of defects in semiconductor materials. This area promises to dominate positron solid-state research in the near future, as it is rapidly evolving into a very sensitive quantitative probe of structural point defects. The third area of research is the fundamental study of positron and electron scattering and energy loss processes in various solids. This program is especially important in gaining a full theoretical understanding of the positron-solid interaction, which is essential for the application of positron-beam techniques to any area of research. In this manuscript, we briefly introduce and review all of these areas, with a special emphasis on the fundamental collision results.