Comparison of the Radiation Shielding Properties of Wall Materials for the Manned Spacecraft for Future China Space Exploration Missions

The radiation environment in space poses significant challenges to human health, and it is a major concern in long duration, manned space missions. Outside Earth's protective magnetosphere, astronauts are exposed to higher levels of galactic cosmic rays (GCRs), whose physical characteristics are distinct from those of terrestrial sources of radiation, such as X-rays and gamma-rays. GCRs include high-energy heavy ions, many of which have ranges that exceed the depth of shielding and can be launched in realistic scenarios. Protecting the astronauts from these particles has been a key issue in manned space missions. Therefore, a need exists for reliable simulations of these harmful effects for risk assessment and shielding optimization in manned space missions. The aim of this work was to investigate shielding materials that can be used in deep space and planetary exploration. In this work, we used the Geant4 radiation transport code, originally developed by the International Geant4 Collaboration, and we compared the radiation shielding effectivenesses of polyethylene, aluminum, water, and carbon fiber targets hit by 1GeV/nucleon Fe-56 (considered as a representative of high-energy GCR). In addition, the total absorbed doses at the water phantom behind these targets were calculated using the Geant4 simulation code. The calculated results were analyzed, compared, and discussed. The results show that polyethylene is the best space radiation shielding material for a given areal density, followed by water, carbon fiber, and then aluminum.