摘要
基于Marshall-Palmer指数分布和Gamma分布雨滴谱,建立了全空间分布的球形雨滴几何结构模型,采用蒙特卡罗程序,结合密度迭代自动权窗减方差技术,计算研究了降雨对核爆炸中子大气输运的影响,给出了中子产生的剂量场随降雨强度和输运质量距离的变化关系。计算结果表明,降雨气象情形下,由于空气中氢元素含量的增加,使空气对中子的吸收衰减增强,中子组织吸收剂量随降雨强度的增加而降低;对于Marshall-Palmer指数分布雨滴谱,特大暴雨情形下,在距离源2 km处,中子组织吸收剂量比标准大气情形下低15%;对于Gamma分布雨滴谱,相同情形下降低23%。进一步拟合给出了降雨情形与标准大气情形下中子组织吸收剂量的比值随质量距离和含水率变化关系的修正函数,可用于降雨气象条件下核爆炸瞬发中子剂量场的快速预估。
Based on Marshall-Palmer exponential distribution and Gamma distribution of raindrop spectra,a geometric structure model of spherical raindrops with full spatial distribution is established.Using Monte Carlo program and density iterative automatic weight window variance reduction technology,the influence of rainfall on neutron atmospheric transport in nuclear explosion is calculated and studied,and the variation relationship of neutron dose field with rainfall intensity and transport mass distance is given.The results show that in the case of rainfall meteorology,due to the increase of hydrogen content in the air,the absorption attenuation of neutrons in the air is enhanced,and the tissue absorbed dose of neutron decreases with the increase of rainfall intensity;For the raindrop spectrum of Marshall Palmer index distribution,in the case of extraordinary rainstorm,the tissue absorbed dose of neutron is 15%at 2 km away from the source lower than that in the case of standard atmosphere;For Gamma distribution raindrop spectrum,it is reduced by 23%in the same case.The correction function of the ratioδof tissue absorbed neutron under rainfall to tissue absorbed dose of neutron under standard atmosphere versus mass distance and moisture content is further fitted,which can be used for the rapid prediction of the instantaneous neutron dose field of nuclear explosion under rainfall meteorological conditions.
作者
伏琰军
商鹏
左应红
朱金辉
牛胜利
FU Yanjun;SHANG Peng;ZUO Yinghong;ZHU Jinhui;NIU Shengli(Northwest Institute of Nuclear Technology,Xi’an 710024,China)
出处
《现代应用物理》
2022年第2期47-52,58,共7页
Modern Applied Physics
基金
国家重点研发计划资助项目(2020YFA0709800)。
关键词
降雨
中子输运
中子组织吸收剂量
蒙特卡罗模拟
rainfall
neutron transport
tissue absorbed dose of neutron
Monte Carlo simulation
