用于宇宙射线μ子成像的MLS-EM重建算法加速研究

Research on Accelerating MLS-EM Reconstruction Algorithm for Cosmic Ray Muon Radiography

宇宙射线μ子检测技术具有穿透力强、对高Z材料敏感等特点,特别适合检测特殊核材料,是监控核材料走私的有效方式。图像重建问题是实现该技术的一个关键难点,MLS-EM算法是目前成像质量较好的算法,但其过长的运算时间制约了该算法在实际μ子检测系统中的应用。根据μ子检测系统的特点,本文提出了一种加速方法,在使用POCA重建图像作为迭代初值基础上进一步采用OS方法进行EM加速。模拟实验结果表明该方法能够有效地对MLS-EM重建算法进行加速,这对于宇宙射线μ子成像技术早日投入实际应用具有积极的意义。

Cosmic ray muon radiography which has a good penetrability and sensitivity to high-Z materials is an effective way for detecting shielded nuclear materials.Reconstruction algorithm is the key point of this technique.Now,MLS-EM reconstruction algorithm is a better one than other existing radiographic methods.However,its reconstruction time is too long to let it be used into a real detective system.Because of that,based on the characteristics of the muon radiography system,this paper proposed a good method to accelerate MLS-EM.It used the POCA algorithm as the initial value of the EM,and then accelerated the algorithm using the function of the OS.Finially,the simulation experiments demonstrated that this method could effectively accelerate MLS-EM.Therefore,it played a significant role to do a further step to let the technique of cosmic muon radiography into our real life.