The health risks from exposure to the space radiation environment makes it important
to have reliable simulation models for the radiation doses inside spacecrafts. Simulations
of the heavy ion parts, especially iron, of the Galactic Cosmic Ray (GCR) radiation has
been carried out using the simulation software Geant4 with geometry models from the
DESIRE project. The total dose rate from iron ions is found to be 1.57
Gy=d and dose
equivalent is found to be 17
Sv=d. This means that iron contributes between 5% and
10% to the total dose equivalent from the GCR radiation, substantially higher than its
relative abundance of 0.03 percent.
67% of the dose rate from iron comes from particles with energies in the range 1 000 -
10 000 MeV/nucleon, and 26% comes from particles in the 10 000 - 50 000 MeV/nucleon
range. The great majority of the dose is deposited by iron ions, opposed to secondary
particles. This result was not expected. Calculated dose rates are found not to be
significantly dependent of the ISS altitude.
2013. , 22 p.