面向行星表面元素测量的小型化伽马谱仪原理样机设计  

Design of a Miniaturized Gamma-ray Spectrometer Prototype for Elemental Measurement of Planetary Surface

作　　者：黄磊 王轶超 封常青 王宇[1,2] 王婷 刘树彬[1,2,3] HUANG Lei;WANG Yichao;FENG Changqing;WANG Yu;WANG Ting;LIU Shubin(State Key Laboratory of Particle Detection and Electronics,University of Science and Technology of China,Hefei 230026,China;Department of Modern Physics,University of Science and Technology of China,Hefei 230026,China;Deep Space Exploration Lab,Hefei 230022,China)

机构地区：[1]中国科学技术大学核探测与核电子学国家重点实验室,合肥230026 [2]中国科学技术大学近代物理系,合肥230026 [3]深空探测实验室,合肥230022

出　　处：《核电子学与探测技术》2024年第1期6-17,共12页Nuclear Electronics & Detection Technology

基　　金：国家自然科学基金项目(资助编号11922510)。

摘　　要：对行星表面物质受宇宙射线激发或天然衰变而产生的伽马射线进行探测,是一种测量行星表面主要元素成分及其空间分布的可靠技术手段,已被多个行星探测任务采用。提出了将CZT探测器与SiPM读出闪烁晶体相结合的行星元素伽马谱仪方案,该方案兼具低能段的高能量分辨率和高能段的高探测效率,同时可以减小来自非探测方向伽马背景的影响,且具有较小的体积、重量和功耗。为进行初步的技术路线验证,设计了一个将CZT阵列(单个灵敏尺寸1 cm×1 cm×0.5 cm)与BGO探测器(晶体的主体尺寸8.4 cm×8.4 cm×4 cm)相结合的小型化伽马谱仪原理样机,并开展了物理模拟。完成了前端探测器模块、数据处理模块和FPGA控制逻辑的设计实现,以及原理样机的组装。使用放射源、上海光源激光伽马光束线和中子激发伽马对谱仪进行了测试,CZT探测器对^(137)Cs@662 keV伽马射线的能量分辨率(FWHM)为2.1%,可以较好地分辨低能伽马射线,BGO晶体能够较好地探测和分辨高能伽马射线。该方案为未来小型化行星伽马谱仪的工程设计提供了参考。The detection of gamma rays generated by cosmic-ray excitation or natural decay of planetary surface materials is a reliable technical method to measure the main elemental composition and spatial distribution on planetary surfaces,and has been adopted by multiple planetary exploration missions.This article proposes a planetary element gamma spectrometer scheme that combines CZT detectors with SiPM readout scintillation crystal.This scheme has the advantages of high energy resolution in the low energy range and high detection efficiency in the high energy range,while reducing the influence of gamma background that not from the detection directions,and has smaller size,weight,and power consumption.To conduct preliminary technical route verification,this paper designs a miniaturized gamma spectrometer prototype that combines a CZT array(single sensitive size 1 cm×1 cm×0.5 cm)with a BGO detector(main body size of crystal 8.4 cm×8.4 cm×4 cm),and conducts physical simulation.Subsequently,this article completes the design and implementation of the detector module,data processing module,and FPGA control logic,as well as the assembly of the prototype.The spectrometer was tested using radiation sources,Shanghai laser electron gamma source beamline,and neutron excited gamma rays.The energy resolution(FWHM)of CZT detectors for^(137)Cs@662 keV gamma rays is 2.1%,which can effectively distinguish low-energy gamma rays,while BGO crystal can effectively detect and distinguish high-energy gamma rays.This article provides a reference scheme for the engineering design of future miniaturized planetary gamma spectrometers.

关 键 词：伽马谱仪 行星元素测量 CZT探测器 读出电子学 

分 类 号：TL82[核科学技术—核技术及应用]