^(6)LiF单晶金刚石中子探测器制备及性能研究  

Fabrication and Performance of Single-crystal Diamond Neutron Detector with^(6)LiF Thermal Neutron Converter

作　　者：王利斌 张逸韵[3] 李海俊 马志海 席善学 刘辉兰[1] 宋玉收[1] 周春芝 WANG Libin;ZHANG Yiyun;LI Haijun;MA Zhihai;XI Shanxue;LIU Huilan;SONG Yushou;ZHOU Chunzhi(College of Nuclear Science and Technology,Harbin Engineering University,Harbin 150001,China;State Key Laboratory of NBC Protection for Civilian,Beijing 102205,China;Research and Development Center for Wide Bandgap Semicondectors,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China)

机构地区：[1]哈尔滨工程大学核科学与技术学院,黑龙江哈尔滨150001 [2]国民核生化灾害防护国家重点实验室,北京102205 [3]中国科学院半导体研究所宽禁带半导体研发中心,北京100083

出　　处：《原子能科学技术》2025年第1期176-182,共7页Atomic Energy Science and Technology

基　　金：国家重点研发计划(2022YFB3608600,2022YFB3604604);国家自然科学基金(12227810,62134006)。

摘　　要：中子监测领域亟需耐辐照、响应快、能量分辨率高的中子探测器。金刚石材料具有禁带宽度大、抗辐照能力强、载流子迁移率高等优点,适合进行中子测量。本文设计并制备了基于^(6)LiF热中子转换材料的单晶金刚石中子探测器,通过探测^(6)Li(n,α)~3H反应产生的次级带电粒子提高单晶金刚石探测器的热中子灵敏度。为提高金刚石探测器对热中子的探测效率,针对^(252)Cf中子源基于单晶金刚石探测器进行了蒙特卡罗计算确定测量热中子所需聚乙烯慢化体厚度为5^(6)cm,在此基础上制备了1μm厚的^(6)LiF热中子转换层的单晶金刚石中子探测器,并测量了该探测器对^(252)Cf中子源及D-T中子发生器14 MeV中子源的响应谱。研究结果表明,所研制的探测器与不含^(6)LiF转换层的探测器相比,对慢化后的^(252)Cf热中子计数率最大可提高3.2%,响应谱氚特征峰能量分辨率为7.7%,优于奥地利Cividec B6-C金刚石探测器。制备的金刚石探测器对D-T中子发生器14 MeV单能中子响应谱能量分辨率为1.95%。该研究成果有望应用于现有^(252)Cf中子源标定及14 MeV中子响应谱测量,同时为金刚石中子探测器制备和中子束流监测提供理论和数据支撑。.Neutron detectors with excellent resolution,responsiveness,and radiation tolerance are desperately needed in the field of neutron monitoring.Diamond material has several advantages such as a wide bandgap,strong radiation tolerance,and high carrier mobility,making it suitable for neutron measurement applications.In this work,a single-crystal diamond neutron detector equipping with^(6)LiF thermal neutron converter was designed and fabricated to improve thermal neutron efficiency by detecting secondary charged particles produced by the^(6)Li(n,α)~3H reaction.To improve the thermal neutron detection efficiency of diamond detector,Monte Carlo simulations were conducted based on polyethylene moderator,^(6)LiF thermal neutron converter and a single-crystal diamond detector for the^(252)Cf neutron source.Optimal thicknesses for both the moderator and the thermal neutron converter were determined through these calculations.The required thickness of polyethylene moderator for detecting thermal neutrons was determined to be 5 to 6 cm.Subsequently,a single-crystalline diamond neutron detector with a 1μm-thick layer of^(6)LiF was fabricated based on these results.The singlecrystal diamond neutron detector structure was designed as a metal-semiconductor-metal structure.In the central 3.5 mm×3.5 mm area of both the upper and lower surfaces of the single-crystal diamond material,Ti/Au electrodes were deposited by electron beam evaporation with thicknesses of 30/400 nm respectively.The material was fixed onto a PCB board and corresponding shell design was made.By magnetron sputtering for 24 h,a 1μm-thickness^(6)LiF conversion layer was deposited onto standard copper nut.The coated nut was then combined with the detector to fabricate a thermal neutron detector The energy spectral response of the detector to both the^(252)Cf neutron source and the D-T neutron source at 14 MeV was measured.The research results indicate that the fabricated detector,compared to the detector without the^(6)LiF converter,can achieve a maximum increa

关 键 词：金刚石探测器 中子探测 响应能谱 半导体探测器 

分 类 号：TL99[核科学技术—核技术及应用]