Measurement of accidental coincidences in β–γ coincidence counting using non-equal dead times

Abstract It is shown that the multi-channel time-scaling (MCTS) method is particularly suitable for the direct measurement of accidental coincidences even if the dead times of the two counting channels are of different length. We prepared five samples, with activities from 900 to 2100 s −1 . The dead time of the gamma channel was 12 μs for all measurements, but for the beta channel it varied from 12 to 20 μs. The true coincidence rates determined by the MCTS method are compared with those obtained by using conventional technique.