核爆炸地面感生放射性辐射环境的蒙特卡罗模拟  

Monte Carlo Simulation of Ground Environment of Induced Radioactivity Radiation Produced by Neutrons of Nuclear Explosion

作　　者：商鹏 黄流兴[1] 牛胜利[1] 左应红[1] 朱金辉[1] SHANG Peng;HUANG Liuxing;NIU Shengli;ZUO Yinghong;ZHU Jinhui(Northwest Institute of Nuclear Technology,Xi’an 710024,China)

机构地区：[1]西北核技术研究所,西安710024

出　　处：《现代应用物理》2022年第1期20-25,74,共7页Modern Applied Physics

基　　金：国家重点研发计划资助项目(2020YFA0709800)。

摘　　要：为模拟核爆炸中子在爆区地面产生的感生放射性辐射环境,基于蒙特卡罗方法提出了一种两步计算方法,实现了中子输运核素活化光子辐射剂量探测的多过程一体化精细模拟。利用蒙特卡罗方法模拟计算给出了中子活化土壤放射性核素数密度随深度的变化关系,分析了γ辐射分层体源模型的土壤层厚度及半径对地面感生放射性的影响。计算结果表明,当γ辐射体源模型土壤层厚度为60 cm,半径为40 m时,能获得符合相对偏差要求的模拟计算结果,且具有较高的计算效率。利用两步计算方法计算给出了爆心高度为200 m,典型氢弹爆炸时,地面上方1 m高度处感生放射性γ衰变中剂量率及放射性核素剂量贡献比随时间的变化关系。To simulate the induced radioactivity radiation environment in the ground of explosion area produced by neutrons of nuclear explosion,a two-step calculation method based on Monte Carlo method is proposed.The first step is to build a layered statistical model of neutron transport andγradiator source model.In the second step,the model parameter conversion technology is used to combine the two model parameters and carry out simulation calculation.The multi process integrated fine simulation of“neutron transport nuclide activation photon radiation dose detection”is realized.The variation of radionuclide density in neutron activated soil with depth is given by Monte Carlo simulation.The influences of soil layer thickness and radius ofγlayered-radiator source model on the ground induced radioactivity is analyzed.The calculation results show that when the soil layer thickness ofγradiator source model is 60 cm and the radius is 40 m,the relative devaition meets the requirements of the simulation results.The variations of dose rate and radionuclide dose contribution ratio with time inγinduced radioactivity decay at the height of 1 m above the ground are calculated by two-step calculation method when the explosion height of a typical hydrogen bomb is 200 m.

关 键 词：感生放射性 蒙特卡罗 放射性核素 中子活化 

分 类 号：O571[理学—粒子物理与原子核物理] TL91[理学—物理]