Monte Carlo analysis of germanium detector performance in slow positron beam experiments

Positron annihilation Doppler broadening spectroscopy is one of the most popular positron annihilation vacancy characterization techniques in experimental materials research. The measurements are often carried out with a slow positron beam setup, which enables depth profiling of the samples. The key measurement devices of Doppler broadening spectroscopy setups are high-purity germanium detectors. Since Doppler broadening spectroscopy is one of the standard techniques in defect characterization, there is a demand to evaluate different kinds of factors that might have an effect on the results. Here we report the results of Monte Carlo simulations of detector response in different geometries and compare the data to experiments.