Analysis of irradiated materials by intense slow positron beams

Slow positron beams (variable-energy positron beams) are powerful analytical tools to investigate vacancy-type defects in materials with depth-dependent defect profiles and/or surface layers. In particular, it is very important for ion-irradiated materials in which defect distribution is localized from surfaces to projected ranges. In this paper, fundamental aspects and facilities of positron annihilation spectroscopy using slow positron beams are reviewed as well as analysis examples of irradiated materials such as ion-irradiated semiconductors.