基于PGNAA技术的掩埋爆炸物检测装置设计及分析研究  

Design and Analysis of Buried Explosive Detection Device Based on PGNAA Technology

作　　者：李佳桐 罗恩康 汤亚军 李珍 贾文宝[4] 陈炼 蔡平坤 孙爱赟 黑大千 LI Jia-tong;LUO En-kang;TANG Ya-jun;LI Zhen;JIA Wen-bao;CHEN Lian;CAI Ping-kun;SUN Ai-yun;HEI Da-qian(MOE Frontiers Science Center for Rare Isotopes,Lanzhou University,Lanzhou 730000,China;School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China;Zhongnan Lanxin(Nanjing)Radiation Technology Research Institute Co.,Ltd,Nanjing 211300,China;Institute of Nuclear Analytical Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China)

机构地区：[1]兰州大学稀有同位素前沿科学中心,甘肃兰州730000 [2]兰州大学核科学与技术学院,甘肃兰州730000 [3]中南兰信(南京)辐射技术研究院有限公司,江苏南京211300 [4]南京航空航天大学,核分析技术研究所,江苏南京211106

出　　处：《分析测试学报》2024年第10期1598-1607,共10页Journal of Instrumental Analysis

基　　金：国家自然科学基金资助项目(12205131);国家重点研发计划青年科学家项目(2021YFC2900700)。

摘　　要：针对土壤中掩埋地雷的位置探测,开发了一种基于瞬发伽马射线中子活化分析技术(PGNAA)的多探测器地雷检测装置及检测方法。首先通过蒙特卡洛模拟,以D-T中子发生器以及BGO探测器作为核心部件进行装置设计,分别对探测器与中子发生器的相对位置、中子屏蔽层进行优化,并对仪器周围剂量进行模拟分析。在源与探测器的距离为21 cm,中子屏蔽层选择16 cm厚的含硼聚乙烯,D-T中子发生器中子产额为1×10^(8) n/s条件下,装置周围设置2 m安全范围即可满足辐射剂量安全要求。基于优化模型进行装置平台搭建,蒙特卡洛MCNP模拟计算及实验测试结果表明,计算的地雷位置坐标与预设位置坐标之间的相对偏差处于可接受范围内,说明采用多探测器地雷检测装置以及多探测器检测方法进行地雷位置检测具有可行性。同时,针对复杂的土壤环境,基于蒙特卡洛MCNP模拟计算考察了土壤含水率、土壤本底元素、地雷质量等环境因素对于装置检测地雷位置的影响。模拟结果表明,土壤含水率在正常范围内变化时,对地雷检测系统检测精度的影响较小,但会对装置的可探测范围产生一定的影响。当土壤含水率由0%增加至35%时,“有效中子”通量降低13.8%左右,最终导致装置可探测范围降低至45 cm区间内。当土壤中的氮元素含量为1%~5%时,土壤中本底元素对地雷检测装置的测量精度及装置的可检测范围影响较小。装置的最小可检出样品质量约为1100.8 g,随着样品质量的增大,其可检测范围随之增大,对于质量为3317.5 g的地雷样品,装置的可检测范围达73 cm。最后,基于上述多探测器地雷检测装置及检测方法,对单探测器地雷检测系统及检测方法进行了初步探究,结果显示利用单探测器响应可实现地雷位置的有效检出。Aiming at the problem of public safety,in the research,a multi-detector landmine detec⁃tion device with detection method based on prompt gamma-ray neutron activation analysis(PGNAA)technology was developed for measuring the location detection of buried mines in soil.Firstly,based on the Monte Carlo simulation,the device was designed and optimized with D-T neutron generator and BGO detector as the core modules.The relative positions of detector and D-T neutron generator,as well as the neutron shielding layer were optimized,respectively,and the dose around the device was simulated and analyzed.According to the MCNP simulated results,the distance between the source and the detector is chosen as 21 cm.The borated polyethylene is chosen as the material of the neutron shielding layer,with the thickness is as 16 cm.When the neutron yield of the D-T neutron generator is 1×10^(8) n/s,a safety range of 2 m is set around the device to meet the radiation dose safety requirements.Based on the optimization model,the experimental platform was built,and the Monte Carlo MCNP simulation and experiment was made for analysis.Both of the simulated and experimen⁃tal results showed that the relative deviations between the calculated landmine coordinates and the pre-set coordinates were almost within the acceptable range,which proved the feasibility of the multidetector landmine detection device and the multi-detector method for measuring the position of land⁃mine.In addition,facing the complex soil environment,the impact of environmental factors,such as soil moisture content,background elements in the soil and landmine quality,were explored based on Monte Carlo MCNP simulated calculation.The simulated results showed that when the soil mois⁃ture content changed within the normal range,it had little impact on the detection accuracy of the mine detection system,however,it made an influence on the detection range of the device.When the soil moisture content increased from 0%to 35%,the“effective neutron”flux decreased by about

关 键 词：爆炸物检测 瞬发伽马射线中子活化分析(PGNAA)技术 多探测器检测装置设计 蒙特卡洛MCNP模拟 单探测器响应 

分 类 号：O571.53[理学—粒子物理与原子核物理] TQ560.7[理学—物理]