Characterisation of a Broad Energy Germanium (BEGe) detector. Simulation and experimental results

Abstract

Characterisation of High Purity Germanium (HPGe) detectors in order to predict the response of the detector to different gamma ray interactions is one of the current goals in the Nuclear physics community. This purpose includes a theoretical study of the detector from the simulation point of view and an experimental stage to validate the goodness of the considerations performed. In this work, the detector under study is a Broad Energy Germanium detector. The simulation has been performed with the Multi Geometry Simulation (MGS) program, that provides the predicted electric field and the charge pulse shapes expected at the contacts for a given detector geometry. The experimental setup included two type of scans with different collimated sources across its front and bottom faces, storing the data with a fully digital acquisition system. Subsequent data analysis and the use of Pulse Shape Analysis (PSA) techniques has allowed the knowledge of internal characteristics of the detector such as the contact limits or orientation of crystallographic axes; as well as the comparison between experimental and simulated pulse shapes.