Radiation Dosages From Electrons and Bremsstrahlung in the Van Allen Belts

Radiation dose rates have been calculated for six electron spectra. The decrease in dose rate with shielding was determined -- and in each case the electron does becomes insignificant with 2 to 6 gm/cm2 of aluminum. Electron bremsstrahlung doe rates versus absorber thickness were also calculated. Detailed dosage calculations for an Apollo-type spacecraft were made and mission dosages for four lunar trajectories are given, to show the effects of trajectory selection. These are compared with the dosages from protons and secondary neutrons in the Van Allen Belt. Doses as a function of orbital altitude, of inclination and of absorber thickness are also presented for the latest version of the inner belt.