The Effects of Galactic Cosmic Rays on the Central Nervous System: From Negative to Unexpectedly Positive Effects That Astronauts May Encounter.

Galactic cosmic rays (GCR) pose a serious threat to astronauts' health during deep space missions. The possible functional alterations of the central nervous system (CNS) under GCR exposure can be critical for mission success. Despite the obvious negative effects of ionizing radiation, a number of neutral or even positive effects of GCR irradiation on CNS functions were revealed in ground-based experiments with rodents and primates.

Radiation environment created with GCRs inside a spacecraft.

We use the GEANT4 Monte Carlo code to calculate the radiation dose equivalent due to Galactic Cosmic Rays (GCRs) during an out-of-magnetosphere space flight. We provide a detailed analysis of the radiation dose composition, distinguishing between the contribution of primary GCR particles and different species of secondary particles. We show that for realistic shielding thicknesses, the radiation dose equivalent is mostly due to GCR protons and alpha particles.

Ray-tracing simulation of the radiation dose distribution on the surface of the spherical phantom of the MATROSHKA-R experiment onboard the ISS.

Space radiation is one of the main concerns for human space flights. The prediction of the radiation dose for the actual spacecraft geometry is very important for the planning of long-duration missions. We present a numerical method for the fast calculation of the radiation dose rate during a space flight.