Coincidence-summing correction for efficiencies of a large-size HpGe detector at close geometries related to a search for a 17-keV neutrino

摘要

The peak efficiency of gamma rays for a large-size HpGe-detector(294cm~3) was determined with high precision in the energy range of 66-401 keV by using the ~(75)Se source. The influence of the coincidence-summing effect on the efficiency was systematically investigated for the source-to-detector distances between 0 and 200 mm. The correction method of the effect based on the decay scheme was developed by considering the summing up to triple coincidence. As a result, it was found that the corrected efficiencies can be reliable even for very short source-to-detector distances.