Backgroud: Chinese Spallation Neutron Source under construction consists of a proton accelerator which can speed up protons to 1.6 GeV. High-energy proton beams are used for radiography due to their high penetrability. Purpose: In order to understand how protons interact with materials when transmitting an object

the transport process of 1.6-GeV protons in different materials is simulated by Geant4. Methods: Energy loss

multiple coulomb scattering

inelastic and elastic collisions with nucleus are simulated independently by setting the physics process in Geant4. Beryllium

copper and tungsten are chosen as low-Z

middle-Z and high-Z material respectively. With respect to the effect of thickness

Tungsten of 5 g?cm?2

10 g?cm?2 and 15 g?cm?2 is chosen as the material. Results: Number

energy and direction of motion are changed after protons penetrate an object. Changes are related to the composition and thickness of materials. Conclusion: The simulation results imply that transmission

energy-loss and distribution of scattering angle can reflect the thickness (in g?cm?2) and material composition of an object.Cited