Simulation of a HPGe Detector with GEANT4

Abstract

Gamma spectroscopy is an analytic technique that identifies isotopes through gamma rays. Currently, gamma spectroscopy is widely used in several science fields, for instance, the study of the hydrodynamics of soils and other applications. Considering the development of computers, it has been developed Monte-Carlo simulation packages, in order to estimate the response of gamma spectroscopy detectors. This work aims to develop a GEANT4 application to estimate the full energy peak efficiency for a HPGe detector and determine the deviation with experimental data. It was carried out measurements of the next radioactive sources, Am-241, Eu-152, Cs-137, and Co-60. These measurements were made at different distances, they were at 0, 5, 10, 20, and 25 cm from the detector’s cover layer. Meanwhile, the simulation was carried out through user action classes to extract energy deposited in the sensitive detector. It was determined full energy peak efficiency of experimental data, through these results, it was estimated a detection factor that measures the deviation between experimental and simulated data. A reason for the deviation was that the simulation did not include the electronic chain of acquisition. Finally, it was suggested that future works should develop a more accurate simulation for multi-emitters isotopes.