Coincidence summing of X- and γ-rays in γ-ray spectrometry

A new method for theoretical calculation of coincidence summing of X- and gamma rays for germanium spectrometers has been presented. The counting rate equations, derived by this method, enable to determinate peak efficiencies as well as the activity of the source. The root of the counting rate equations can be determined by commercial mathematical programs. The method was applied to the decay of 139Ce and the derived relationships were compared with the Korun's and Martinčić's results obtained by matrix formalism. The method was also applied to the decay of 57Co and the calculated results were confirmed by the experiment.