Cause Analysis and Correction Method of the Center Layer Artifact in Cosmic-ray Muon Radiography

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.