Evaluation of Space Radiation Doses Received Within a Typical Spacecraft

An analysis of radiation levels that may be expected from the natural radiation environment is presented for (1) primary solar flare protons and protons contained in the inner Van Allen belt; (2) secondary radiation such as neutrons from (p,xn) nuclear reactions, gamma rays from (p,x gamma ) nuclear reactions, and protons from (p,xp') nuclear reactions; and (3) electrons and electron-produced bremsstrahlung. The proton, neutron, and bremsstrahlung energy spectra and radiation doses are evaluated within aluminum spherical shells of various thicknesses for models of the proton fluxes from the May 10, 1959 and February 23, 1956 solar flares and protons contained in the inner Van Allen belt, as well as for models of the electron fluxes contained in the inner and outer Van Allen belts. Finally, these radiation quantities are evaluated within a typical spacecraft, considering its detailed material and equipment layout. (auth)