太阳耀斑硬X射线能谱演变特征  

THE EVOLUTION OF HARD X-RAY ENERGY SPECTRUM IN SOLAR FLARES

作　　者：林华安[1] 

机构地区：[1]中国科学院空间科学与应用研究中心,北京100080

出　　处：《空间科学学报》1999年第4期295-300,共6页Chinese Journal of Space Science

摘　　要：太阳硬Ｘ射线是耀斑高能电子束流与太阳大气相互作用产生的韧致辐射，根据简单的太阳耀斑环物理模型，假定具有流量与能谱同步变化的高能电子束流从耀斑环顶部注入，计算了硬Ｘ射线辐射在不同的靶物质密度区的能谱演变特征．结果表明：硬Ｘ射线辐射在低大气密度靶区呈现软一硬一硬的能谱演变特征，在高密度靶区硬Ｘ射线能谱则具有软一硬一软的变化特征．高能电子束流持续时间影响谱型转变区域在耀斑环中的高度．The hard X-rays of solar flares are produced by Bremsstrahlung interaction ofhigh energy electron beam impinging on solar atmosphere. Based on a simple physical model of flare loop, and under the assumption that the high energy electronswith synchronous variation between the beam flux and spectrum index are injectedfrom the top of the loop, some calculated results about hard X-ray spectrum evolution with different atmosphere density are obtained in this paper. These resultsshow: in low density area, such as in the top of loop, the hard X-ray spectrum hassoft-hard--hard evolution property, in high density area, such as in the foot points ofloop, the spectrum possesses soft--hard--soft variation. The time duration of injectingelectrons will influence the height of region in the loop where the one type of hardX-ray spectrum evolution will transform into the other one.

关 键 词：耀斑 硬X射线 能谱演变 时变辐射方程 

分 类 号：P182.52[天文地球—天文学]