Physics
Abstract
Traditional liquid scintillation measurement instruments face challenges in field measurements of radon in water: their bulky size and reliance on a stable power supply hinder the on-site analysis of large numbers of water samples. To address this, the study aims to develop a portable liquid scintillation system for radon concentration measurement in water, enabling rapid on-site detection.
In the system design, a 3×4 array of silicon photomultipliers (SiPMs) is used to replace the traditional photomultiplier tubes (PMTs) typically employed in such detection systems. This approach aims to reduce the overall size while maintaining high detection efficiency.
After developing the power supply, signal summing, and amplification circuits, the signals from the SiPM array are integrated and transmitted to a digital multichannel analyzer (DMA) for signal counting and statistical analysis. Finally, radon concentration is calculated using a calibrated conversion factor.
The entire system is powered by a 5 \si{\volt} portable power supply, enabling measurements in field environments without a fixed power source. The results from the radon decay method testing indicate that the instrument exhibits good linearity.
Through comprehensive evaluation and verification, the instrument's minimum detection limit at a 95\% confidence interval is determined to be 0.2188 \si{Bq/L}. This study offers an innovative solution for measuring radon in field water samples.
This study provides an innovative technical solution for on-site radon detection in diverse water samples (e.g., groundwater, rivers, and lakes), addressing the practical needs of field-based water radioactivity monitoring.