定量中子数字成像散射校正的蒙特卡罗模拟  

Monte-Carlo simulation of scattering correction for quantitative neutron imaging system

作　　者：魏彪[1] 马晓昕[1] 金炜[2] 冯鹏[1] 米德伶[1] 

机构地区：[1]重庆大学光电技术及系统教育部重点实验室,重庆400044 [2]宁波大学信息科学与工程学院,浙江宁波315211

出　　处：《强激光与粒子束》2008年第9期1545-1550,共6页High Power Laser and Particle Beams

基　　金：国防科技基础研究基金资助课题;重庆市自然科学基金资助课题(CSTC2007BB3174)

摘　　要：中子数字成像过程中,散射中子可降低像质致使提取样品的定量信息变得困难。针对该情况,分析了中子微光成像系统图像散射降质的原理,采用点扩展函数的叠加来表征散射中子引起图像降质的过程,借助于蒙特卡罗方法(MC)对点扩展函数进行模拟和建模,将点扩展函数描述为样品厚度以及样品到探测器距离为参量的解析函数,研究了点扩展函数的计算方法。研究结果表明,借助于MC方法构建系统的点扩展函数之解析函数,并利用该函数对中子图像进行散射校正,是一种行之有效的定量中子数字成像散射校正方法。Neutron digital imaging is a low light level imaging technique. It is difficult to extract the quantitative information of samples due to the image degradation caused by scattering neutrons in the imaging process. In this situation, the principle of socalled scattering degradation of the low light level neutron imaging system is analyzed, and the degradation process in this system is characterized by point spread function（PSF） superposition. Using Monte Carlo method, the PSF is simulated and modeled as an analytical function of two parameters, the thickness of sample and the distance from sample to detector, and then the calculation method of PSF is presented. The result shows that constructing the PSF of this system and applying it to scattering correction for neutron images is an effective scattering correction method for quantitative neutron radiography, which has the theoretically guiding significance for reducing the adverse effect on imaging quality induced by scattering neutrons.

关 键 词：定量中子数字成像 微光成像系统 散射校正 点扩展函数 蒙特卡罗方法 

分 类 号：O799[理学—晶体学]