高空核爆炸瞬发辐射电离效应的数值模拟

采用蒙特卡罗方法模拟了高空核爆炸瞬发辐射中子、γ射线、X射线电离大气的过程,给出了几种爆炸场景下瞬发辐射产生的附加电离电子密度空间分布.针对大气密度随高度非均匀连续变化的特性,采用质量距离抽样方法取代常用的步长抽样方法,无需根据大气密度随高度的变化进行分层处理,提高了计算效率.结果表明:对于不同的爆高,瞬发辐射电离分布存在显著的差异;随着爆高的增加,瞬发辐射附加电离区范围增大,但电子密度的峰值减小. 关键词： 高空核爆炸 瞬发辐射 大气电离 蒙特卡罗方法

Numerical simulation of the ionization effects of prompt radiation from high-altitude nuclear explosions

In this paper, the Monte Carlo method is used to simulate atmospheric ionization effects of the prompt radiation from high altitude nuclear explosion (HANE). Simulation gives the instantaneous spatial distributions of the electron density in atmosphere. The atmosphere is a kind of non-uniform media, whose density drops rapidly with the increase of height. Therefore, a method, which samples the mass distance to replace the step length of the particle, is used to considerably increase the computing speed. The simulation results show that there is an obvious difference between additional ionization regions of different height of nuclear explosion. As the explosion-height increases, influence range of the prompt nuclear radiation will be wider, but the electron density will be lower.