Study of 3D reconstruction algorithm used in cosmic-ray muon radiography

Cosmic-ray muon radiography is a novel method to detect high-Z materials in thick shield, and the reconstruction algorithm is the key point of this technique. In this paper, we have improved the traditional maximum likelihood algorithm, using EM method to get the estimation and OS technique to accelerate, and using the result from the Point of Closest Approach algorithm as the initial value. Having done the simulated numerical experiments in three dimensional space, we get some preliminary reconstruction results. This new method will be embedded into platform program and expanded into widely practical applications in muon tomography.