铼的中子辐射俘获反应截面测量  

Measurement of Neutron Radiation Capture Reaction Cross Section for Rhenium

作　　者：王晓宇 贺国珠[1] 张奇玮[1] 罗淏天 徐阔之 李倩 解立坤 栾广源 阮锡超[1] 邹翀 陈玄博 吴鸿毅 樊瑞睿[4,5] 蒋伟 曹平 余滔[2] WANG Xiaoyu;HE Guozhu;ZHANG Qiwei;LUO Haotian;XU Kuozhi;LI Qian;XIE Likun;LUAN Guangyuan;RUAN Xichao;ZOU Chong;CHEN Xuanbo;WU Hongyi;FAN Ruirui;JIANG Wei;CAO Ping;YU Tao(Key Laboratory of Nuclear Data,China Institute of Atomic Energy,Beijing 102413,China;Department of Modern Physics,University of Science and Technology of China,State Key Laboratory of Particle Detection and Electronics,Hefei 230026,China;China Shipbuilding Trading Co.,Ltd.,Beijing 100048,China;Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;Spallation Neutron Source Science Center,Dongguan 523803,China;School of Nuclear Science and Technology,University of Science and Technology of China,State Key Laboratory of Particle Detection and Electronics,Hefei 230026,China)

机构地区：[1]中国原子能科学研究院核数据重点实验室,北京102413 [2]中国科学技术大学近代物理系,核探测与核电子学国家重点实验室,安徽合肥230026 [3]中国船舶工业贸易有限公司,北京100048 [4]中国科学院高能物理研究所,北京100049 [5]散裂中子源科学中心,广东东莞523803 [6]中国科学技术大学核科学技术学院,核探测与核电子学国家重点实验室,安徽合肥230026

出　　处：《原子能科学技术》2024年第11期2262-2268,共7页Atomic Energy Science and Technology

基　　金：国家自然科学基金(11675268,11975317,12275363,11975318);核数据重点实验室基金(JCKY2022201C158);稳定支持基础科研计划(BJ010261223282)。

摘　　要：铼及铼钼合金是空间堆建造中的重要结构材料,其高精度的中子辐射俘获反应截面等数据在空间堆设计中具有重要意义。利用γ射线全吸收型BaF2探测装置(GTAF)和瞬发γ射线在线测量方法,在中国散裂中子源(CSNS)的反角白光中子束线(Back-n)上,在线测量了铼的两个同位素样品^(185)Re和^(187)Re的中子辐射俘获反应截面。初步得到了^(185)Re和^(187)Re在0.5 eV~10 keV能区中子辐射俘获反应的激发函数,并将^(185)Re(n,γ)^(186)Re和^(187)Re(n,γ)188Re的激发函数实验数据与ENDF/B-Ⅷ.0数据库中的评价曲线进行比对分析,实验数据与评价曲线在可分辨共振峰处基本一致,进一步印证了评价曲线,也为在CSNS白光中子源开展更高精度的中子辐射俘获反应截面测量提供支持,为空间堆物理研究提供数据基础。Re and Re-Mo alloys are important structural materials in the space reactor study due to the characteristics of the small thermostriction,high melting point and so on.The exact neutron radiation capture reaction cross sections of the rhenium isotopes are of great significance in the space reactor design.However,in the space reactor simulation by Monte Carlo method,it was found that the keff values of the space reactor will have a great difference when different database was referenced.So,the existing database cannot meet the requirements of the space reactor research and high-precision experimental data are needed.In this work,the neutron radiation capture reaction cross sections of ^(185)Re and ^(187)Re,two natural isotopes of rhenium,were measured at the back-streaming white neutron source(Back-n)of the China Spallation Neutron Source(CSNS),by using the gamma total absorption facility(GTAF)and prompt gamma ray measurement method.The experiment was carried out at the second experiment station of the Back-n neutron source,and the data were measured by the digital waveshape acquiring technique based on flash analog-to-digital converter(FADC)cards.The neutron energy was determined by the time-of-flight method,and the proton pulse T0 signal was used as the start signal.To suppress the accidental coincident backgrounds,the parameter that the detector multiplicity greater than or equal to 2 was applied,means that within the preset time window the signal amplitude of two or more channels exceeded the threshold.In the off-line data processing the interference ofα-particles which caused by the radium impurity in the BaF2 crystal were reduced by particle discrimination based on digital waveshape identification.The total energy spectrum of theγray cascades,radiated by the decay of the excited compound nucleus that produced in(n,γ)reactions,was reestablished by summarizing pulse’s energies of all the bombarded detectors.By the total energy spectrum analyzing,the counts of(n,γ)reaction events occurred in the sample wer

关 键 词：铼 瞬发γ射线测量方法 (n γ)反应 

分 类 号：TL11[核科学技术—核能科学] O571.55[理学—粒子物理与原子核物理]