基于上层大气数值模型的X射线传输特性  

X-ray Transmission Characteristics Based on Numerical Model of Upper Atmosphere

作　　者：吕致辉 韦飞 张轩谊 彭松武 冯鹏远 LÜZhihui;WEI Fei;ZHANG Xuanyi;PENG Songwu;FENG Pengyuan(National Space Science Center,Chinese Academy of Sciences,Beijing 100190;University of Chinese Academy of Sciences,Beijing 100049;Beijing Key Laboratory of Space Environment Exploration,Beijing 100190)

机构地区：[1]中国科学院国家空间科学中心,北京100190 [2]中国科学院大学,北京100049 [3]天基空间环境探测北京市重点实验室,北京100190

出　　处：《空间科学学报》2023年第4期640-646,共7页Chinese Journal of Space Science

基　　金：国家重点研发计划项目资助(2021 YFA0718600)。

摘　　要：核爆炸的大部分能量是以X射线形式释放的,研究X射线辐射特性对于天基核爆事件监测,当量反演都具有一定参考价值。根据核爆炸X射线能谱特性,构建了黑体辐射模型;根据NRLMSIS大气模型成分数据和高度密度数据,构建大气分层数值模型,并结合NIST数据库,构建分层大气质量吸收系数模型,提高了大气模型与大气质量吸收系数模型准确度。使用数值模拟程序对X射线在大气中的传输特性进行研究,模拟在临近空间高度核爆炸产生的X射线经过大气吸收后的能谱特性以及不同海拔高度点位的能注量。结果表明,在检测点高度恒定的情况下,斜径角变小会增大X射线传输路径,X射线经过的大气吸收路径越长,能谱峰值越往高能处偏移。在相同高度下,爆炸点的正上方处能注量最大,其他位置随着斜径角减小能注量呈指数级衰减。Most of the energy of a nuclear explosion is released in the form of X-ray.It is important to understand the characteristics of the X-ray radiation for the monitoring of space-based nuclear explosion events and the calculation of explosion yield.In this paper,the blackbody radiation model is constructed based on the X-ray energy spectrum characteristics of nuclear explosion,and a stratified atmospheric numerical model is constructed based on the NRLMSIS atmospheric model composition data and height density data.The stratified atmospheric mass absorption coefficient model is combined with the NIST database to improve the accuracy of the atmospheric model and the atmospheric mass absorption coefficient model.The transmission characteristics of X-ray in the atmosphere are studied using the code,and the energy spectral characteristics of X-ray generated by nuclear explosions at near-space altitude were simulated,after atmospheric absorption and assuming the energy injection at different altitude points.The results show that the height of the detection point is constant,the smaller the slant angle the larger the ray transmission path,i.e.,the longer the atmospheric absorption path that the ray passes through,and thus the more the peak of the energy spectrum will shift to the higher energy.At the same height,the energy fluence is the largest directly above the explosion point,and the energy fluence at other positions decays exponentially as the angle decreases.

关 键 词：大气数值模型 X射线 大气吸收 能谱 能注量 

分 类 号：P351[天文地球—空间物理学] O434.1[天文地球—地球物理学]