便携式LaBr_(3)(Ce)γ谱仪稳谱技术研究  

Study on spectrum stabilization technique for a portable LaBr_(3)(Ce)gamma spectrometer

作　　者：陈宸 吴桓 CHEN Chen;WU Huan(Technology Center,Chongqing Jian An Instrument Co.Ltd.,Chongqing 400060,China)

机构地区：[1]重庆建安仪器有限责任公司技术中心,重庆400060

出　　处：《核技术》2021年第4期43-50,共8页Nuclear Techniques

摘　　要：稳谱作为γ能谱分析领域的重要任务之一,其主要作用是抑制探测器因环境变化而形成的“谱线漂移”。实验探讨了一种基于LaBr_(3)(Ce)探测器的便携式γ谱仪稳谱技术。该技术利用LaBr_(3)(Ce)探测器自身本底谱中的36 keV与天然本底谱中40K的1460 keV特征峰作为稳谱使用的参考峰,采用自定义的能谱关联度公式对实测能谱与标准本底谱的关联性进行度量,提出一种将参考峰与能谱关联度结合进行稳谱的方法。实验结果表明:在-30~50℃温度范围内,该稳谱方法无需事先标定参考峰与温度的关系曲线,也可有效防止在有干扰核素存在的条件下发生错误稳谱的情形,并且在温变速率超过50℃∙h^(-1)的突变情况下确保参考峰的峰漂稳定在±1道以内。[Background]As one of the most important issues in the field of gamma spectrum analysis,the main function of spectrum stabilization is to suppress the"spectral line drift"caused by environmental changes.Portable LaBr_(3)(Ce)gamma spectrometer is mainly used to analyze and process the gamma spectra of radionuclides and obtain qualitative and quantitative information about radionuclides.It often works in the field complex environment where the spectrum drift is inevitable,hence must have the function of spectrum stabilization.[Purpose]This study aims to improve the performance of spectrum stabilization technique for a portable LaBr_(3)(Ce)gamma spectrometer.[Methods]The intrinsic characteristic peak of LaBr_(3)(Ce)detector and the peak of 40K in the natural background were made of as the reference peaks.Then,the concept of"spectrum similarity"was defined to calculate the similarity between the measured spectrum and the standard background spectrum.Finally,a new spectrum stabilization method using standard reference peak and"spectrum similarity"was proposed to measure and correct the deviation.Experiments were carried out verify the performance of this new method.[Results]Experimental results show that the technology can effectively stabilize spectrum in the temperature range of-30℃to 50℃without calibration of the relationship curve between the reference peak and the temperature,and the peak drift of the reference peak is stable within±1 channel even if the temperature changes more than 50℃∙h^(-1).[Conclusions]This technology effectively improves the application range of portable LaBr_(3)(Ce)spectrometers.

关 键 词：LaBr3(Ce) γ 谱仪 稳谱 

分 类 号：TL81[核科学技术—核技术及应用]