Dosimetry in Space: The shielding effectiveness for the radioprotection of astronauts against 1 GeV protons

The study of materials suitable for radiation protection of astronauts in space missions is always a topic of fundamental importance. The main aim of any radiation protection program in space is to minimize the crew’s exposure to ionizing radiation. This work concerns the effectiveness of shielding materials against radiation in space conditions, in particular for the Galactic Cosmic Radiation. The study was conducted by developing a simulation tool based on the Geant4 framework. The physics case reported here deals with the interaction of a 1 GeV proton beam (protons represent about 87% of the GCR flux with the energy spectrum peak around 1 GeV) with a target added with boric acid or gadolinium (Gd) to deplete neutron escaping. Charge, mass and energy distributions of secondary particles generated by the interaction are computed on the basis of different interaction models. It is found that the particles escaping the shielding material and reaching an ionization chamber located in the opposite side of the shield are still mainly protons and neutrons. The added boric acid acts as an effective neutron mitigating material. However, the average dose does not change effectively because of the additional production of alpha particles from the reaction 10B(n, α).