Measurement of the absolute efficiency of a semiconductor detector using an isotropic spherical source

The calibration of hyper pure germanium semiconductor detectors is required to calculate the activity of radioactive sources. To find out the activity, the detector full-energy peak efficiency is required. The full-energy peak efficiency of HPGe semiconductor detector for an isotropic radiating spherical source is obtained experimentally. We compared the measured efficiency values with theoretical calculations. Furthermore, the variation of the window materials of the detector on the full-energy peak efficiency have been studied. By comparison, the theoretical and experimental full-energy peak efficiency values are in good agreement. The difference percentage between the measured efficiency values and the calculated ones is less than 4%