作　　者： ; ; ; ;

机构地区： 清华大学工程物理系

出　　处： 《高能物理与核物理》 2004年第11期1238-1243,共6页

摘　　要： X光机正朝高能强流方向发展 .这些装置中普遍采用mm厚度的重金属厚靶 ,其辐射特性和各种参数间的规律受到关注 .本文采用基于蒙特卡罗法的EGS4程序比较全面的研究了高能X光机中所关心的靶厚度的选择、轫致辐射场的角分布和X射线能谱的规律 .同时还专门就X光强度和束流发射度、打靶焦斑尺寸三者的依赖关系进行分析 ,结论表明针对现有的X光机参数 ,不用担心因追求小焦斑而带来X光照射量的损失。文中还分析了强束流条件下单粒子蒙特卡罗模拟程序的适用性 .文中结论和已有实验结果吻合 ,对实际工作具有意义 . Variety of X-ray facilities are widely used in many fields. One of its developing trend is to gain harder and more intense X-rays which are yielded by electron beam with energy above 10MeV and current above kA impacting on thick-target. Dependence of bremsstrahlung characteristics on beam parameters and target thickness are much concerned. The paper studies the selection of the thickness of the target, the bremsstrahlung photons intensity distribution along emergence angle as well as the bremsstrahlung energy spectra. Also, the dependence of X-ray intensity on beam emittance and size of beam-target interaction spot is given. The result reveals at the usual emittance, the decreasing rate of the X-ray intensity with decreasing spot sige is much slowe than that claimed by other references. The consistency between the simulation with experimental results shows that the EGS4 codes can be effectively used in High Energy X-ray facility study.

关 键 词： 轫致辐射 高能 单粒子 角分布 束流 射线能谱 蒙特卡罗模拟 光照射量 焦斑尺寸 发射度

领　　域： [理学] [理学] [核科学技术]