Testing of EFFTRAN and Angle software in comparison to GEANT 4 simulations in gamma spectrometry of cylindrical and noncylindrical sample geometries

Abstract Being able to accurately determine the efficiency of detection, in respect of having precise measurements of radioactivity, represents one of the main objectives of every gamma spectrometry laboratory. In standard gamma spectrometry practice, activities of low-energy emitters can prove to be difficult for measurement. Gamma spectrometry is often used as an initial monitoring tool to determine basic parameters of the unknown sample found in the field, especially when it is suspected that this material can be a part of illicit trafficking involving radioactive materials. The main concern in most cases is uranium, as one of its isotopes (235U) can be used in the production of a nuclear bomb. Gamma spectrometry is the most applicable, non-destructive technique used in a nuclear forensic investigation for uranium isotopic composition analysis. The main idea of this paper was to test the advantages and disadvantages of semi-empirical methods by using two software (EFFTRAN and Angle) and simulation method in GEANT 4 applied on samples containing uranium and thorium isotopes. Special attention was devoted to non-cylindrical sample geometries. The general purpose of the presented study was to investigate the possibilities of routine gamma spectrometry laboratory to be able to respond to a nuclear security event. Based on the obtained results, general recommendations for the use of semi-empirical and simulation methods are given.