基于4H-SiC探测器多球谱仪的聚变中子能谱测量研究  

Research on fusion neutron energy spectrum measurement using a Bonner sphere spectrometer based on a 4H-SiC detector

作　　者：张明强 钟国强 黄娟 常加峰 杜勤 陈传凯 陆洋 陈乐 ZHANG Mingqiang;ZHONG Guoqiang;HUANG Juan;CHANG Jiafeng;DU Qin;CHEN Chuankai;LU Yang;CHEN Le(Institute of Plasma Physics,Hefei Institute of Physical Sciences,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230026,China;Energy Research Institute of Hefei Comprehensive National Science Center,Hefei 230051,China;Anhui Radiation Environment Supervision Station,Hefei 230071,China;Anhui Hefei Ecological Environment Monitoring Center,Hefei 230601,China)

机构地区：[1]中国科学院合肥物质科学研究院等离子体物理研究所,合肥230031 [2]中国科学技术大学,合肥230026 [3]合肥综合性国家科学中心能源研究院,合肥230051 [4]安徽省辐射环境监督站,合肥230071 [5]安徽省合肥生态环境监测中心,合肥230601

出　　处：《核技术》2024年第9期77-84,共8页Nuclear Techniques

基　　金：国家重点研发计划(No.2019Yfe03020004);国家自然科学基金(No.11975276);安徽省生态环境科研项目(No.2023hb0017);合肥综合性国家科学中心能源研究院(安徽省能源实验室)项目(No.GXXT-2022-001);中国聚变堆主机关键系统综合研究设施项目(No.2018-000052-73-01-001228)资助。

摘　　要：Bonner多球谱仪作为主要用于测量中子能谱和剂量的仪器,对于聚变装置的辐射监测与防护具有重要意义。为了研究超导托卡马克(Experimental Advanced Superconducting Tokamak,EAST)在中性束注入(Neutral Beam Injector,NBI)加热实验条件下的中子能谱和剂量当量,研制了一套由涂有6LiF的4H-SiC半导体探测器和8个慢化球组成的Bonner中子多球谱仪,在相应放电实验中进行了实验测量。通过与EAST上中子注量监测结果进行源强归一化处理,并结合模拟计算获得的每个慢化球中子响应函数,利用最大熵程序解算出大厅内部中子能谱分布。进一步通过中子注量-剂量转化系数获得中子剂量当量,并与蒙特卡罗方法模拟计算的主机大厅内相应位置的中子能谱和剂量当量进行比较,归一化聚变中子源项下测量位置的中子注量与模拟值的比值为0.98;归一化聚变中子源项下测量位置的周围剂量当量与模拟值的比值为1.05。对比结果验证了该多球谱仪在EAST装置上初步应用的可靠性。[Background]Measurements of neutron energy spectra and doses during discharges of fusion devices are crucial for radiation monitoring and protection,and Bonner sphere spectrometers are generally used to measure neutron energy spectra and doses.[Purpose]This study aims to investigate the neutron energy spectrum and dose equivalent of an Experimental Advanced Superconducting Tokamak(EAST)under experimental neutral beam injection(NBI)heating conditions.[Methods]First,a Bonner neutron sphere spectrometer consisting of a 6Li-coated 4H-SiC semiconductor detector and eight moderated spheres was developed,and measurements in NBI heating and discharge experiments were conducted.Subsequently,the experimental results were normalized with the neutron flux monitoring results of the fission ionization chamber(ZZ3)on the EAST device and combined with the neutron response functions obtained from the Monte Carlo simulation for each moderated sphere.Then,the maximum entropy program was used to calculate the neutron energy spectrum distribution of the experimental positions inside the hall.Finally,the neutron dose equivalent at this location was obtained using the fluence dose conversion coefficient and compared with the neutron energy spectrum and dose equivalent at the corresponding location in the main hall,simulated using an existing EAST Monte Carlo model.[Results]Comparison results show that the overall agreement between the simulated and experimental energy spectrum distributions of the measurement position is good,and the neutron flux at the measurement position under the normalized fusion neutron source is 1.38×10^(-7) cm^(-2),with a ratio of 0.98 to the simulated value.The surrounding dose equivalent is about 2.27×10^(-11)μSv,with a ratio of 1.05 to the simulated value,which shows consistency.[Conclusions]The results of this study demonstrate that the multisphere spectrometer is reliable for measuring neutron spectra and dose equivalents in the EAST hall and providing data for radiation protection in fusion devices.It

关 键 词：Bonner多球谱仪 4H-SiC探测器 中子能谱 EAST 

分 类 号：TL816.3[核科学技术—核技术及应用]