摘要
塑料闪烁微球(Plastic Scintillation microspheres,PSm)是一种新型闪烁材料,在放射性核素测量领域显示出良好的应用前景。本研究利用Hidex 300SL液闪计数器,研究了不同测量条件对PSm的本底计数率和计数效率的影响及其规律。结果表明:PSm与水混合后产生弱化学发光和光致发光干扰信号,可通过避光措施消除。随着PSm用量的增加,背景计数率呈正相关增加;随着PSm高度的增加,计数效率呈正相关提高。此外,液闪瓶材质对PSm测量的影响较小,其中,使用20 mL的塑料液闪瓶的最小检测活度(Minimum Detection Activity,MDA)最低。对比活度为574.5~3825.6 Bq·L^(−1)的^(14)C溶液进行测量,测量值与期望值一致性良好。研究结果表明:尽管PSm的本底计数率和计数效率受到多种因素影响,但在固定测量条件下,PSm测量具有良好的准确性。
[Background]Plastic scintillation microspheres(PSm)are a novel luminescent material with significant potential in the measurement and continuous monitoring of radionuclide activity.[Purpose]This study aims to optimize the application of PSm in radionuclide activity analysis by exploring the impact of different measurement conditions on the background count rate and counting efficiency of PSm.[Methods]Firstly,PSm samples were prepared by suspension polymerization method,with spherical particles mainly distributed between 95~200μm in size,and a Hidex 300SL liquid scintillation counter was employed to measure the chemiluminescence and photoluminescence of PSm.Then,the effect of PSm dosage and the type of liquid scintillation vial on the background count rate of PSm were investigated,and the counting efficiency of PSm under different conditions was determined using^(14)C as a reference radionuclide.Finally,a 20 mL plastic liquid scintillation vial with the lowest detection limit was selected for the activity analysis of^(14)C solution.[Results]Mesaurement results show that weak interference signals from chemiluminescence and photoluminescence are observed when PSm is mixed with water.This interference can be mitigated by keeping the samples in a light-protected environment.The background count rate is positively correlated with the volume of PSm,with larger volumes resulting in higher background counts.The counting efficiency is positively correlated with the height of PSm,with higher heights corresponding to higher counting efficiency.Differences between plastic and glass liquid scintillation vials of comparable specifications are minimal.The minimum detectable activity(MDA)of the 20 mL vial is lower.Analysis of^(14)C solutions in the range of 574.5 Bq·L^(−1)to 3825.6 Bq·L^(−1)shows good agreement between measured and expected values.[Conclusions]The study demonstrates that the background count rate and counting efficiency of PSm are influenced by various factors such as sample volume.Under fixed conditions,PSm measurements exhibit good accuracy.PSm shows promising potential in radionuclide analysis.
作者
张辉
王亚东
马彦
马莉娜
ZHANG Hui;WANG Yadong;MA Yan;MA Lina(China Institute for Radiation Protection,Taiyuan 030006,China;Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection,Taiyuan 030006,China)
出处
《核技术》
北大核心
2025年第5期150-156,共7页
Nuclear Techniques
关键词
塑料闪烁微球
液体闪烁计数器
背景计数率
计数效率
Plastic scintillation microspheres
Liquid scintillation counter
Background count rate
Counting efficiency
