Study of a method to correct for accidental coincidences in TDCR measurements

A recently proposed method from Dutsov et al. (2020) for correcting random coincidences in TDCR measurements was thoroughly examined. To achieve this, an extensive experimental study was conducted using various liquid scintillation (LS) samples. The study involved several radionuclides (³H, ³²Si/³²P, ⁵⁵Fe, ⁸⁹Sr, ¹⁵¹Sm, ²³⁸Pu, and ²⁴¹Am) as well as background samples. Different LS cocktails and activity levels were also considered. Data acquisition was performed using a fast digitizer, and the resulting list-mode data were analyzed by systematically varying the coincidence resolving time over a range from 10 ns to 1500 ns. All data were evaluated both with and without correction for random coincidences. In all cases, the measurement results exhibited significantly better consistency when the correction for random coincidences was applied. This also holds for background measurements. The improvement was particularly evident at longer coincidence resolving times. Moreover, it is demonstrated that the correction is essential for accurately evaluating uncertainties.