Chemical sensitivity in positron annihilation with just one single Ge detector

Abstract

AbstractWe present a novel method for analyzing the data from momentum distribution measurements employing positron annihilation, using just one single Ge‐detector, but employing a mathematically sufficiently well suited model for background subtraction. For a variety of high purity metals the resulting momentum distributions have exactly the same shapes up to 35 × 10–3 m0c as those obtained with coincidence Doppler broadening of the annihilation radiation using a two‐detector system. This data analysis applies to any positron source without high energy gammas or a slow positron beam system with just a single Ge‐detector and enables the possibility of analysing the chemical surrounding at the positron trapping site without any additional hardware. In particular, in combination with a slow positron microbeam, it allows a spatially resolved measurement of the electron's momentum distribution. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)