Simulation study for cosmic ray muons to detect fissile nuclear materials

Cosmic ray muons with the mean energy 3-4 GeV shower the Earth at the rate of 1 cm-2·min-1 at sea level. They are highly penetrating, which can penetrate the protective layer of the common use. A muon passing through a material is deflected many small angle scatters off of the nuclei of the material. The size of the scattering angle is related to the atomic number of the material. Based upon the difference of the scattering angle of muon passing through object, the radiation imaging could be obtained. In this paper, we conclude that it is feasible to use the technique of Muon Tomography to identify the low, medium and high Z three types of material of the muon cumulate flux for a minute. (authors)