Accounting for Overcounting Induced by ²²²Rn Contamination in ¹⁴C Measurements Performed with Liquid Scintillation Counting

Abstract

This research paper introduces a methodology for estimating overcounting resulting from uranium series radionuclides, with a specific focus on 222Rn contamination. The method is demonstrated using the Quantulus 1220TM spectrometer. Exponential fitting is employed for the calculations, utilizing a custom algorithm developed in MATLAB® R2022b. The proposed method allows for the determination of the sample count rate correction, F14C and radiocarbon age without the need for additional chemical treatment or specialized electronics during liquid scintillation counting (LSC) measurements with the Quantulus 1220TM spectrometer. However, the method does have certain limitations. It requires a significant number of cycles and extended measurement time per cycle, but it can be applied to samples with significant 222Rn contamination that require rapid 14C analysis.