222Rn-220Rn分辨探测器参加国际比对结果分析

目的 提高²²²Rn与²²⁰Rn的累积测量水平，保证测量结果的准确性与可靠性。方法 采用中国疾病预防控制中心辐射防护与核安全医学所的氡课题组（以下简称本实验室）改进的LD-P型²²²Rn-²²⁰Rn分辨探测器参加日本放射线医学综合研究所（NIRS）组织的²²²Rn-²²⁰Rn累积探测器国际比对。将²²²Rn-²²⁰Rn分辨探测器寄往日本，在NIRS的²²²Rn室和²²⁰Rn室进行不同条件下的比对，暴露结束后再寄回本实验室进行蚀刻与分析，测量结果告知NIRS。最后NIRS将²²²Rn与²²⁰Rn暴露参考值回馈本实验室。结果 在高²²²Rn和低²²²Rn条件下，测量值与NIRS提供的参考值的相对百分偏差（RPD）分别为-12.0%、-11.8%；变异系数（COV）分别为3.0%、6.2%。在高²²⁰Rn和低²²⁰Rn条件下，测量值与NIRS提供的参考值的相对百分偏差（RPD）分别为-0.8%、-8.0%；变异系数（COV）分别为6.7%、4.5%。结论 本次比对LD-P型探测器²²²Rn与²²⁰Rn的测量结果均为NIRS规定的Ι级结果（PRD<10%），比对结果较好。

Analysis of intercomparison results for radon-thoron discriminative detector

Objective To increase the cumulative measurement level of ²²²Rn and ²²⁰Rn and ensure the accuracy and reliability of the measurement result.Methods By using improved ²²²Rn-²²⁰Rn discriminative detectors (LD-P detectors), the radon research group of National Institute for Radiological Protection Chinese Center for Disease Control and Prevention participated with the intercomparison organized by National Institute of Radiological Science (NIRS), Japan. Specifically, with the ²²²Rn-²²⁰Rn discriminative detectors being sent to Japan, the comparison was completed under different conditions in the ²²²Rn chamber and ²²⁰Rn chamber in NIRS. After exposure, the detectors were sent back to our laboratory for etching and analysis, and then measurement result were informed to NIRS. Finally, NIRS returned the exposure reference values of ²²²Rn and ²²⁰Rn to our laboratory.Results Under the conditions of high and low levels of ²²²Rn, the relative percentage differences (RPD) between the measured values and the reference value provided by the NIRS were -12.0% and -11.8%, respectively, while coefficients of variation (COV) were 3.0% and 6.2%, respectively. Under the conditions of high level and low levels of ²²⁰Rn, the relative percentage differences (RPD) between the measured value and the reference value provided by the NIRS were -0.8% and -8.0%, respectively; coefficients of variation (COV) were 6.7% and 4.5%, respectively.Conclusions This intercomparison result were categorized by NIRS (PRD<10%), with the satisfactory result of LD-P detectors available.