Uncertainties in calculated correction factors for true coincidence-summing (TCS).

The aim of this work was to estimate the uncertainties in Monte Carlo calculated correction factors for true coincidence summing (TCS). In this work TCS-factors and their uncertainties were calculated for134 Cs and then the corrected activities compared to empirical data. The study was carried out using a close-end coaxial p-type detector (Ø80mm×54.5mm, 80% relative efficiency) and a cylindrical glass fiber sample (Ø60mm×14mm). It was shown that the uncertainty in the calculated correction factor for the primary gamma ray was below 0.5%, which means it will not contribute significantly to the combined uncertainty in an activity measurement for e.g. environmental monitoring.