Quality control measures of thermoluminescent dosimetry system used in environmental radiation monitoring

Abstract

Objective To discuss the quality control measures of the thermoluminescent dosimetry system and to verify its propriety of when used in environmental radiation monitoring. Methods The quality control measures included the stability test, the dispersibility screening and the uncertainty evaluation of measurement results of the TLD reader and TLD detector, in addition, the environmental radiation accumulated dose monitoring results obtained by the high pressure ionization chamber were compared with those by the thermoluminescent dosimetry system. Results The variation range of TLD reader’s light source coefficient is within 0.070~0.073 during the preheating and measuring process, which meets the requirements of stability; The χ 2 value of the TLD detector is 2.088, which obeys the normal distribution; The thermoluminescent dosimetry system’s nonlinear response, coefficient of variation and energy response meet the measurement requirements; There is a deviation of −6.58% the largest between the cumulative dose obtained by TLD and the high pressure ionization chamber. Conclusion The quality control measures discussed in this paper can be used as a reference for similar thermoluminescent dosimetry system. Our system has passed all the tests and can meet the environmental radiation cumulative dose monitoring requirements. 摘要： 目的 探讨热释光测量系统的质量控制方法, 验证热释光测量系统能否准确有效的用于环境辐射水平监测。 方法 采取的环境辐射监测用热释光测量系统质量控制方法包括热释光测量系统的稳定性检验、热释光探测器的分 散性筛选、测量结果不确定度评定, 并与高气压电离室测量方法进行对比。 结果 读出器预热及测读过程中光源系数 变化范围在 0.070~0.073, 稳定性符合使用要求; 热释光探测器的 χ 2 值为 2.088, 服从正态分布;热释光测量系统满足 非线性响应、变异系数和能量响应的计量要求; 热释光累积剂量测量结果与高气压电离室相比偏差最大 −6.58%。 结论 本实验室采取的质控措施可作为同类热释光测量系统的质控措施的参考;本实验室的热释光测量系统通过了 各项检验, 满足环境辐射累积剂量监测的使用要求。