ABSTRACT
Objective To discuss the distribution characteristics of the Bragg peak in proton therapy using the SRIM code. Methods Based on the SRIM code, the transport processes of a high-energy proton beam injecting into different materials (H2O, C2H6O、C8H8、Al and Fe)with incident energies of 50 MeV～250 MeV have been simulated and analyzed. And the relationship between the incident energies, different materials and thickness, and the depth of the Bragg peak was also discussed when the protons injected into different materials and compared with the simulation results of professional Monte Carlo code, such as Fluka 2011 and MCNPX. Results The simulation results indicate that the depths of the Bragg peak increase gradually and the peaks broaden with the increase of incident proton energies for different materials; The ratio of the depth of the Bragg peak in different materials to that in water under the same incident energy changes little and is approximately a constant which doesn’t depend on the proton incident energy. A good consistency was found between the results and those obtained using Fluka and MCNPX programs. Conclusion The simulation accuracy of the SRIM on the proton beam transport is acceptable, and is suitable for the beginning learners.