An automatic efficiency calibration method with high precision for HPGe detectors

The method used by gamma spectrum analysis software often has a single formula to calibrate efficiency, which is imposed at some reference point sometimes located far from the efficiency curve. The method presented in this article uses four different formulas (can also use more than four) and by using a computer algorithm the efficiency can be automatically calibrated by choosing the closest formula to each point of the data efficiency. This method suggests dividing the energies into three categories: low, medium and high energies. Subsequently, the average of the errors is calculated for each suggested formula, which allows choosing the most accurate formula for each energy range. Finally, a comprehensive efficiency curve is obtained by merging the three selected formulas. In addition, free and open source software named AEC (Automatic Efficiency Calibration) has been created to implement this method. This software offers users an additional tool to existing gamma spectrum analysis software in addition to specifying the efficiency calibration. The AEC is available on GitHub (https://github.com/LAHCEN-EL-AMRI/AEC-v1) and a detailed PDF guide is also included in the software to simplify its use (https://github.com/LAHCEN-EL-AMRI/AEC-v1/blob/main/Doc/guide.pdf).