Mathematical method to calculate full-energy peak efficiency of detectors based on transfer technique

The full-energy peak efficiency of high-purity germanium well-type detector is extremely important to calculate the absolute activities of natural and artificial radionuclides for samples with low radioactivity. In this work, the efficiency transfer method in an integral form is proposed to calculate the full-energy peak efficiency and to correct the coincidence summing effect for a high-purity germanium well-type detector. This technique is based on the calculation of the ratio of the effective solid angles subtended by the well-type detector with cylindrical sources measured inside detector cavity and an axial point source measured out the detector cavity including the attenuation of the photon by the absorber system. This technique can be easily applied in establishing the efficiency calibration curves of well-type detectors. The calculated values of the efficiency are in good agreement with the experimental calibration data obtained with a mixed gamma-ray standard source containing Co-60 and Y-88.