Simulation study of cold neutron radiography

Cold neutron radiography lies in that neutrons react with 6Li nucleus in the scintillator to produce charged alpha particles, which interact with fluorescent material and yield photons; hence the photons distribution is recorded by detector. The paper introduces briefly the character of cold neutron radiography, gives the macroscopic total section with different neutron energy, and simulates neutron images of different energy by MCNP, which indicates the contrast difference below and above Bragg cutoff, processes the neutron images by difference imaging, which shows the advantages of cold neutron radiography. (authors)