The full-energy peak efficiency of gamma-ray spectrometry by numerical calculation method

The full-energy peak efficiency allow radioactivity determination in gamma-ray spectrometry. In the determination of the full-energy efficiency, numerical calculation method has been widely used because of its accessibility, stability, and low computational cost. The current study presents a new direct numerical method that is based on the determining of the total efficiency and the escape efficiency. The method provides a detailed description of the generation and escape of secondary photons from the sensitive volume. It is applicable to any source-detector geometry and also considers the self-attenuation of the source matrix and the attenuation caused by absorber layers between the source and the sensitive volume. The results of comparing the new numerical method with experimental measurement for the point source test model demonstrate relative errors within -2.73 similar to 5.57 %, indicating the high reliability of this new method for sourceless efficiency calibration.