On the iteration of coincidence summing correction for determination of gamma-ray intensities

In order to determine the γ-ray emission intensities of nuclei far from the β-stability line with HPGe detectors under large solid-angle geometry, coincidence summing corrections should be performed, even if full energy peak efficiencies of detectors are accurately measured with standard sources. Because the summing effects depend on decay schemes and emission intensities, the correction needs to be iterated several times starting from the initial values of intensities obtained directly from the measured peak counts of γ-rays. Considering 134Cs, 154Eu and 56Co as typical examples, we discuss the number of iterations of summing correction required for self-consistency with respect to the total efficiencies of the detectors. •Summing corrections are required for Iγ evaluation in close geometry measurement.•Self-consistent values of coincidence summing corrections are obtained by iteration.•The required number of iterations of coincidence summing correction was evaluated.•56Co, 134Cs and 154Eu were measured in specific solid angle geometries as examples.•At least 4 iterations needed to determine Iγ with uncertainties below 5%.