Efficiency calibration and self-attenuation correction in radioxenon measurement using β-γ coincidence method

• Published in: Journal of environmental radioactivity 2023-01, Vol.256, p.107054-107054, Article 107054
• Main Authors: Li, Qi, Wang, ShiLian, Fan, Yuanqing, Zhao, Yungang, Jia, Huaimao, Zhang, Xinjun, Zhang, Ruiqin
• Format: Article
• Language: English
• Subjects: CTBT; Detection efficiency calibration; Radioxenon isotopes; Self-attenuation effects; β-γ coincidence
• ISSN: 0265-931X; 1879-1700
• DOI: 10.1016/j.jenvrad.2022.107054

Measurement of the four radioxenon isotopes, namely 131mXe, 133mXe, 133Xe, and 135Xe, play a key role in underground nuclear test monitoring for ensuring compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). To improve detection sensitivity, a β-γ coincidence technique is commonly used. Due to the presence of the gas matrix, such as stable xenon, nitrogen, helium, the self-attenuation effects should be taken into account when measuring different types of sample. In order to improve the accuracy of the measurement, the detection efficiencies of X-rays and γ-rays were derived by using a simulation gas calibration source with low density of sponge matrix. The detection efficiencies of β-particles and conversion electrons (CEs) were calibrated by measuring radioxenon sample. The self-attenuation correction factors of X-rays and γ-rays were determined by Geant4 simulation method. The self-attenuation correction factors of β-particles and CEs were provided by measuring the radioxenon samples with different volumes of xenon, nitrogen and helium. •The self-attenuation effects were significant for β-particles in radioxenon measurement using β-γ coincidence equipment.•The detection of γ-rays was calibrated by using a simulation gas calibration source with the self-attenuation correction.•The detection efficiencies and self-attenuation factors of β-particles were determined experimentally.