基于遗传算法的快中子靶站束流引出优化设计  

Optimization Design of Fast Neutron Target Station Beam Extraction Based on Genetic Algorithm

作　　者：覃子倩 谭新建[2,3] 张小东 潘清泉[1] 刘霄 QIN Ziqian;TAN Xinjian;ZHANG Xiaodong;PAN Qingquan;LIU Xiao(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Northwestern Institute of Nuclear Technology,Xi’an 710024,China;National Key Laboratory of Environmental Simulation and Effect of Intense Pulse Radiation,Xi’an 710024,China)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240 [2]西北核技术研究所,陕西西安710024 [3]强脉冲辐射环境模拟与效应全国重点实验室,陕西西安710024

出　　处：《原子能科学技术》2025年第3期700-707,共8页Atomic Energy Science and Technology

基　　金：国家自然科学基金(12305190,12075192)。

摘　　要：为获得高能量分辨率的中子束流,本文对高重频中子源靶站进行了引出结构设计。以未碰撞中子数目、占比以及周围中子数目为目标函数,以靶与准直器的距离、准直器的内径和材料厚度以及真空管道的内径为参数变量,通过遗传算法与蒙特卡罗模拟耦合的方式对中子引出管道的结构组成进行了优化。结果表明,相较于初始方案,优化方案的周围总中子通量降低了3.6%,使用的准直器材料总厚度减小了约30%,真空管道的内径减小了7.17 cm,并提升了测量区域内0.8%的未碰撞中子占比。优化后整体结构的周围剂量率低于1μSv/h,满足剂量防护的要求,在距离靶5 m处管道中心直径50 mm范围内的中子通量相对均匀分布。An accelerator neutron source target station for energy calibration using the time-of-flight(TOF)method was designed in this paper.Considering the special requirements of high-repetition-rate proton pulses from the accelerator and the off-target facility(OTF)method for calibration,it is necessary to reduce the impact of scattering on the trajectory of neutrons generated by the target to obtain the highest possible proportion of uncollided neutrons.At the same time,to achieve a lightweight and compact structure for the target station,constraints were also placed on the dose rate around the measurement point,mainly referring to the neutron flux values outside the diameter range of 5 m toϕ50 mm from the compound target during the optimization process.During calibration,the intensity of neutrons will also affect the overall efficiency,so the value of the uncollided neutron flux is also an important design indicator.The distance between the target and the collimator,the material thickness and structure of the collimator,and the inner diameter of the vacuum pipeline are variable parameters that affect the aforementioned indicators.Therefore,the aforementioned parameters are used as variables,and the three important indicators are taken as the objective function.The structural composition of the neutron extraction pipeline was optimized through theoretical simulation,coupled with a genetic algorithm and Monte Carlo code.In the optimization design,the genetic algorithm was used to initialize and adjust the optimization parameters,generate Monte Carlo input files,and call the Monte Carlo code for calculation.The total number of iterations is 20000(200×100),with each calculation taking approximately 1 minute.The Monte Carlo code can simulate physical processes such as neutron,photon,proton,and coupled neutron-photon transport,and record physical quantities such as uncollided neutron flux,total neutron flux,and neutron flux around the measurement point.The software simulation uses the ENDF/B-Ⅶdatabase for cross-sections

关 键 词：靶站设计 遗传算法 蒙特卡罗模拟 屏蔽准直器 飞行时间法 

分 类 号：TL99[核科学技术—核技术及应用]