Well-type HPGe-detector absolute-peak-efficiency calibration and true-coincidence correction

A personal-computer-based program SWELL has been developed for well-type HPGe detector effective-solid-angle calculation. This program is very useful in constructing the absolute-peak efficiency (εp) versus γ-ray energy (Eγ) curves for different sample geometries based on a pre-determined εp under a reference counting geometry. The validity of using this program for εp(Eγ) conversion was successfully demonstrated for photons in the energy range ∼20 keV–1.5 MeV; the overall uncertainty can be controlled to be within 3%. In addition, a semi-empirical method has been developed to estimate the true-coincidence correction (COI) factor for well-type HPGe detector. Results based on 60Co, 139Ce, 133Ba and 59Fe sources indicated that the estimated COI factors are in good agreement with the experimentally validated COI values.