高能X光照相中密度重建的共轭梯度算法

计算物理 ›› 2006, Vol. 23 ›› Issue (2): 144-150.

高能X光照相中密度重建的共轭梯度算法

许海波, 魏素花

北京应用物理与计算数学研究所, 北京 100088

收稿日期:2004-11-18 修回日期:2005-04-07 出版日期:2006-03-25 发布日期:2006-03-25
作者简介:许海波(1966-),男,河南灵宝,副研,博士,从事粒子输运与闪光照相方面的研究.
基金资助:
中国工程物理研究院科学技术基金(20040654);国家自然科学基金委员会与中国工程物理研究院联合基金(10576013)资助项目

A Conjugate Gradient Algorithm for Density Reconstruction in High-energy X-ray Radiography

XU Hai-bo, WEI Su-hua

Institute of Applied Physics and Computational Mathematics, Beijing 100088, China

Received:2004-11-18 Revised:2005-04-07 Online:2006-03-25 Published:2006-03-25

摘要/Abstract

摘要： 通过对高能X光照相过程的物理分析,得到了辐射照相的点扩展函数,给出了估价函数的表达式.并以典型的法国试验客体模型为例,将共轭梯度算法应用到高能X光照相的密度重建中,得到了较满意的结果.这种方法从模拟辐射照相过程出发,将辐射照相的模拟结果与实际测量结果做比较并找出最大可能解.可在一定程度上克服其它密度重建算法通过反卷积过程消除模糊效应所引起的不确定性.

关键词: X光照相, 点扩展函数, 估价函数, 共轭梯度算法, 密度重建

Abstract: A point spread function and a cost function are obtained with a physical analysis of the high-energy x-ray radiography. Taking the French Test Object model as an example, the conjugate gradient algorithm is applied to the density reconstruction in high-energy x-ray radiography, and the result is satisfactory. The algorithm starts at a simulation in radiography and searches for a maximum likelihood by comparing the simulated radiographs with the measured radiographs. To some extent, the algorithm overcomes the uncertainty in eliminating the blurting effects through a deconvolution process in reconstruction methods.

Key words: x-ray radiography, point spread function, cost function, conjugate gradient algorithm, density reconstruction

中图分类号:

O443

许海波, 魏素花. 高能X光照相中密度重建的共轭梯度算法[J]. 计算物理, 2006, 23(2): 144-150.

XU Hai-bo, WEI Su-hua. A Conjugate Gradient Algorithm for Density Reconstruction in High-energy X-ray Radiography[J]. CHINESE JOURNAL OF COMPUTATIONAL PHYSICS, 2006, 23(2): 144-150.

[1]	许海波, 胡渊, 魏素花. 高能X射线辐射成像的定量模拟与密度重建[J]. 计算物理, 2011, 28(6): 906-914.
[2]	彭现科, 许海波. 粒状磷光增感屏点扩展函数的蒙特卡罗研究[J]. 计算物理, 2010, 27(6): 816-822.