Radiation environment created with GCRs inside a spacecraft

Abstract

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. The Blood-Forming Organs (BFO) dose equivalent is the same in the shielding spheres with the radius of 50 and 100 cm, although the dose composition differs. We show that indirectly scattered secondary particles make up to 60% to the net radiation dose. Up to 90% of the secondary neutron dose equivalent is associated with indirectly scattered particles.