中文摘要：

PoCA算法和MLSD算法是宇宙线μ子成像中常用的两种算法,其成像结果在中心面普遍存在分布均匀、灰度值较小的层状伪影。本文通过分析μ子成像的物理机制和重建算法原理,研究上述中心面伪影,指出其产生原因是成像空间中存在本底物质,并在此基础上提出一种校正方法,模拟实验表明该方法能在不影响μ子三维重建的前提下有效地消除中心面伪影。

英文摘要：

In cosmic-ray muon radiography, we often use PoCA or MLSD algorithms for reconstruction. There always exists a layer of artifacts with small and homogeneous gray scale value, located in the middle plane of the reconstruction result. In this paper, we analyze the artifacts through the physics mechanism and reconstruction algorithm of cosmic-ray muon radiography, and point out that this is mainly due to the influence from the background material in the imaging space. Based on the analysis, we propose a correction method with some simulation experiments to verify that our method is able to correct the artifact effectively without influencing the reconstruction in three dimensional cases.