Speaker
Description
Purpose: This study aims to evaluate the effectiveness of various shielding configurations in attenuating proton radiation and secondary particles, using Monte Carlo simulations. The focus is on comparing single-layer concrete shields with multilayer combinations involving concrete, iron (Fe), and polyethylene (PE).
Methods: Monte Carlo simulations were performed using the PHITS code to model proton radiation transport through different shielding materials and configurations. Proton energies from 50 to 250 MeV were simulated, with varying shield thicknesses, material densities, and source-to-shield distances. Both single-layer (concrete) and multilayer shields (e.g., concrete + Fe, concrete + PE) were analyzed. Output metrics included proton fluence, secondary particle production (photons, neutrons), and flux at the detector.
Results: Multilayer shielding configurations significantly outperformed single-layer concrete in attenuating both primary and secondary particles. Specifically, a shield composed of 10 cm concrete (ρ = 2.3 g/cm³) followed by 10 cm iron resulted in near-complete elimination of proton, photon, and neutron flux at the detector for all simulated energies. Proton flux decreased consistently with increased material density and multilayer configurations, especially those including heavy elements like iron.
Conclusion: Multilayer shields incorporating dense materials such as iron provide superior protection against proton radiation and associated secondary particles. These findings support the use of optimized multilayer shielding structures—particularly concrete combined with iron—for improved radiation safety in proton therapy and related facilities.
