α粒子测量中的参数计算方法研究  

Calculation methods of parameters inαparticle measurement

作　　者：周雪梅[1] 罗焜 赖伟[1] 廖峰 都炳杰 刘卫[1] ZHOU Xuemei;LUO Kun;LAI Wei;LIAO Feng;DU Bingjie;LIU Wei(Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;Nanhua University,Hengyang 421001,China)

机构地区：[1]中国科学院上海应用物理研究所,上海201800 [2]南华大学,衡阳421001

出　　处：《核技术》2024年第11期66-72,共7页Nuclear Techniques

基　　金：甘肃省科技重大专项(No.23ZDGH001)资助。

摘　　要：放射性测量广泛应用于核技术的各个领域,测量不确定度、置信区间、探测限值等是放射性测量的重要参数,其计算结果直接影响相关决策。本研究采用偏导数方法和蒙特卡罗方法研究α粒子活度浓度测量中的重要参数。首先,对测量结果不确定度来源进行分析,再利用偏导数和蒙特卡罗方法计算α粒子活度浓度不确定度、置信区间、判定阈和探测限等。结果表明:当输入量不确定度高于10%时,两种计算方法所得置信区间与不确定度结果相对偏差大于15%;输入量相对不确定度较小时,探测限约判定阈的两倍。偏导数方法应用较广,但未考虑输入量的概率分布形式,不适用于复杂和特殊输入量的模型,此时可借助蒙特卡罗方法得到更加可靠的计算结果,这两种方法可以互补应用。[Background]Radioactivity measurement is widely used in various fields of nuclear technology application.The measurement uncertainty,confidence interval and detection limit are important parameters in radioactive measurement.Different calculation methods may get different results,and the calculation results directly affect some important and relevant decisions.[Purpose]This study aims at the calculation method of parameters inαparticle radioactivity measurement that is used properly.[Methods]Both the partial derivative method and Monte Carlo method were applied to determinate the important parameters ofαparticle radioactivity measurement in this study.Firstly,based on the measurement ofαactivity concentration in gas using Passivated Implanted Planar Silicon(PIPS)detector,the sources of uncertainty for the measurement results were analyzed in details.Then,measurement uncertainty,confidence limits,decision threshold and detection limit ofαparticle activity concentration under different input modes were derived and calculated by partial derivative and Monte Carlo methods,singly and jointly.Finally,calculation results were compared analyzed.[Results]The results show that when the input uncertainty is higher than 10%,the relative deviation between confidence interval and uncertainty results obtained by the two calculation methods is greater than 15%.When the relative uncertainty of the input is small,the detection limit is about 2 times of the decision threshold.[Conclusions]The partial derivative method is widely used without consideration of the probability distribution of the input,hence not suitable for complex and special input models.Under this circumstances,Monte Carlo method can be used to obtain more reliable calculation results.The two approaches can be applied jointly in complementary ways.

关 键 词：活度浓度 不确定度 判定阈 探测限 蒙特卡罗 

分 类 号：TL84[核科学技术—核技术及应用]