高能X射线辐射成像的定量模拟与密度重建(英文)  

Quantitative Simulation and Density Reconstruction in High-energy X-ray Radiography

作　　者：许海波[1] 胡渊[2] 魏素花[1] 

机构地区：[1]北京应用物理与计算数学研究所,北京100094 [2]中国工程物理研究院研究生部,北京100088

出　　处：《计算物理》2011年第6期906-914,共9页Chinese Journal of Computational Physics

基　　金：Supported by National Natural Science Foundation of China(Grant No.10971244);Science and Technology Developing Foundation of China Academy of Engineering Physics(Grant No.2009B0202020)

摘　　要：利用蒙特卡罗方法得到的数值图像研究高能X射线辐射成像的密度重建,提出多能X射线源、多材料客体辐射成像的密度重建方法.这种方法不仅能够对包括光源能谱、角分布和尺寸在内的密度重建,而且具有显含质量吸收系数的优点.利用约束共轭梯度算法和变分正则化技术进行法国试验客体的密度重建.结果表明,该方法能够有效地进行高能X射线辐射成像的密度重建,成像光子的能谱效应对于精确的密度重建十分重要.Numerical radiograph using Monte Carlo method is used to study fidelity of density reconstruction in high-energy X-ray radiography.A density reconstruction method for a polyenergetic X-ray source and an object composed of different materials is proposed.The method includes energy spectrum,angular spectrum and spot size of photon source.And it indudes mass absorption coefficients explicitly in density reconstruction as well.A constrained conjugate gradient algorithm and variation regularization are applied to determine material edges and density reconstruction of a French test object.It shows that the method is valid for density reconstruction and energy spectrum of imaging photons is important in obtaining accurate material densities in high-energy X-ray radiography.

关 键 词：高能X射线辐射成像 蒙特卡罗程序 法国试验客体 密度重建 

分 类 号：O443[理学—电磁学]