Simulation of charge collection processes in semiconductor CdZnTe γ-ray detectors

We present a Monte Carlo algorithm for the simulation of charge collection behavior of semiconductor γ-ray detectors. The model takes into account the electrical properties of the detectors, transport properties of the material, trapping induced by impurities, experimental setup characteristics and γ-ray-matter interaction processes. We demonstrate how to include electrostatic repulsion as a correction to diffusion coefficient for Gaussian-shaped charge distribution. Comparison of simulated and measured data for different γ-ray sources for a CdZnTe single-sided charge-sharing strip detector are shown to demonstrate the efficiency of the model even for small electrode-pitch detector simulation.