Positron Interaction with Solid Surfaces

Current knowledge of positron-surface interactions is summarized with applications to surface science. The review interlinks four areas of positron physics which have developed almost independently, but which are possibly equally relevant to the study of surfaces: (1) the trapping at surfaces or the escape as positronium of positrons implanted in small solids, (2) the interaction of positrons with crystal defects and voids in solids, (3) the emergence of positrons from positron beam moderators, and (4) the formation of positronium in ground and excited states by positrons backscattered from solid surfaces. The positron method offers a potentially very sensitive technique for the systematic study of surfaces.