Development of a New 4πβ–4πγ Detection System for Absolute Measurement of Radionuclide Activity

A new system for the implementation of the 4πβ (plastic scintillator)–4πγ coincidence counting technique was developed and tested by measuring the activity of a ⁶⁰Co solution. This system captures energy and time stamps in the form of binary list mode data to implement an offline-analysis method (OAM) through Python scripts. This technique enables us to easily refine and modify the analysis parameters without having to constantly gather new data. The OAM allows us to address various challenges such as dead time and accidental coincidences. It also incorporates corrections for background and decay. To determine the activity of a source, the β efficiency was varied using computerized discrimination methods and extrapolated to an efficiency of 100%. The results of our study demonstrated excellent agreement with the reference value. This study contributes valuable insights into radionuclide measurement techniques, offering a robust system for precise absolute radioactivity measurements.