Modeling of Laboratory Animals Exposure Conditions behind Local Concrete Shielding Bombarded by 650-MeV Protons

Abstract

Purpose: To estimate the radiation fields formed after the passage of high-energy protons through the concrete protection for subsequent radiobiological experiments on animals on this model. Material and methods: The results of the calculation of the secondary characteristics of a field of mixed radiation behind the local concrete with thickness 20, 40, and 80 cm, bombarded by a proton beam of 650 MeV at the JINR Phasotron and experimental estimation of the values of the absorbed dose phantoms of mice irradiated for protection during radiobiological experiments. The calculation was performed by the Monte Carlo method according to the MCNPX program for secondary protons, neutrons, π-mesons, and gamma rays. To verify the adequacy of calculations was performed the comparison of calculated and measured in the experiment spatial distribution of activation threshold detectors for aluminum protection, as well as a comparison of the calculated values of absorbed dose for radiation protection with the results of absorbed dose measurements with a diamond detector. Results: The calculations made it possible to obtain the characteristics of the fields of mixed secondary radiation behind local concrete shields of different thickness irradiated with protons with an energy of 650 MeV and to estimate the values of absorbed doses in the irradiation sites of mice in the radiobiological experiment. The reliability of the calculations was confirmed by experimental verification of the activation of aluminum threshold detectors behind a 20 cm thick protection, as well as direct measurements using a diamond detector. Conclusion: The calculated assessment of radiation fields formed after protons pass through the concrete protection and its comparison with the results of radiation dose measurements for the subsequent radiobiological experiment on animals on this model in the interests of designing protective structures on the Moon and other space bodies, as well as biological defenses on charged-particles accelerators.