The simulation of radiation effects to astronauts due to solar energetic particles in deep space

The exposure to interplanetary radiation poses a serious health risk to astronauts, especially for long-term missions. Protecting the astronauts from these particles has been the key issue to the manned space mission. High-energy space particles can penetrate the protective layer of a spacecraft, and probably cause deleterious effects to the astronauts. To estimate the size of these effects, a credible simulation of radioprotection is required. Using the Geant4 software toolkit, we have modeled the interaction processes and predicted the total energy deposit in a phantom (astronaut) as well as the similar information associated with secondary effects, due to Solar Energetic Particles (SEPs) at ∼1 AU caused by the large SEPs events in October 1989 and August 1972. In addition, we compared the characteristics of the energy deposit due to SEPs and Galactic Cosmic Rays (GCRs) and explained the differences between them by physical mechanism analysis.

► The fluxes of the two most abundant SEPs primaries have been adopted.
► A simplified spacecraft model has been used.
► The energy deposits in an astronaut are estimated using Geant4.