Variations of the flux and the energy spectrum of neutrons born in the galactic cosmic ray proton interactions with the matter of Earth's satellites and orbital stations

This paper presents the energy spectra of secondary neutrons obtained from Monte Carlo simulations of the interactions of protons of galactic cosmic rays with the material of a spacecraft, and also the variation of the fluxes of these particles as a function of latitude. The variations of the secondary neutron flux with changing geometry and orientation of the craft, and detector position were evaluated as well. The simulations were conducted over a wide range of masses of spacecraft, from 300 kg (Earth Probe Total Ozone Mapping Spectrometer) to 420,000 kg (International Space Station in its full configuration), with calculations for the ISS also being carried out for its first development stage (mass of approx. 20,400 kg) and its configuration with a mass of approx. 81,000 kg. The calculations were carried out for circular orbits at altitudes of 500 km and for the energy intervals 0.001–10 MeV and 10–10,000 MeV, for both maximum and minimum solar activity. The results obtained agree reasonably well with results from previous calculations and do not contradict experimental data.