A numerical approach to calculate the full-energy peak efficiency of HPGe well-type detectors using the effective solid angle ratio

Abstract

In the field of gamma-ray spectroscopy with HPGe detectors, applied to measurements of activity when the sample to be measured is small and has low radioactivity, the well-type HPGe detectors are widely used. To determine the sample activity, the full-energy peak efficiency is needed. In this work, the efficiency transfer method (ET) in an integral form is proposed to calculate the full-energy peak efficiency and to correct the coincidence summing effect for the HPGe well-type detector. This approach is based on the calculation of the effective solid angles ratio for a well-type detector with a cylindrical source inside and an axial point source outside the detector cavity, taking into account the attenuation of the gamma-rays. The calculated values of the full-energy peak efficiency are found to be in a good agreement with the measured experimental data obtained by using a mixed radionuclide gamma-ray source containing 60Co and 88Y.