A New DCC Software for 4πβ(LS) – γ Coincidence Counting

Abstract

Coincidence counting (CC) is a widely applied method for radionuclide activity measurement. The 4πβ( LS) -γ coincidence counting is a type of CC that is applied to determine the activity of radionuclides that undergo β-γ decay. A liquid scintillation (LS) counter has the advantages of no self-absorption and simple sample preparation. Hence, this study focuses on the 4πβ( LS) -γ method to measure the activity of LS sources with a standard triple-to-double coincidence ratio (TDCR) system for LS measurements in the β channel and a NaI(Tl) scintillation detector in the γ channel. In this study, high-accuracy digital coincidence counting (DCC) software was developed to determine the activity of radionuclides using this 4πβ( LS) -γ coincidence counting method. The software is characterized by the application of the living time method during true event discrimination and the TDCR technology to estimate the effect of system noise and after-pulses in the β channel. The developed software was validated by comparing the results obtained using the software with standardized <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sup> Co activity measurement at the National Institute of Metrology (NIM) applying previously validated methods. The results showed that the activity measured by the developed DCC software had a tolerable error. It has good potential activity measurement, and it is expected to be applied to calibrate radionuclides with more complex decay diagrams in the future.