Accession Number : AD0263476

Title :   PRINCIPLES FOR THE CALCULATION OF RADIATION DOSE RATES IN SPACE VEHICLES

Corporate Author : LITTLE (ARTHUR D) INC CAMBRIDGE MASS

Personal Author(s) : EVANS,ROBLEY D.

Report Date : JUL 1961

Pagination or Media Count : 1

Abstract : The analysis takes into account the angular distribution of the incident protons and electrons and the angular distribution of the electron bremsstrahlung. The distribution with depth in the propellant is determined for the dose rate due to protons, for the dose rate due to electron bremsstrahlung, and for the deposition of stopped protons. Whereas the dose rates for monoenergetic protons or electrons are maximum at the surface of the propellant, the deposition of protons has its minimum at the surface and increases linearly with depth up to the range of the protons. For the case of protons, the maximum surface dose rate depends primarily on the total number of protons striking the surface, and only slightly on their energy, so long as their energy is sufficient for them to clearly penetrate the surface medium. Illustrative calculations are carried out for the Freden and White spectrum of protons and for the Walt et al. spectrum of electrons incident on thin-walled stainless steel vehicles carrying liquid H2 or liquid O2. The numerical results for O2 would be closely similar to those for biological materials. (Author)

Descriptors :   *DOSE RATE, *RADIATION EFFECTS, *SPACECRAFT, BREMSSTRAHLUNG, DIFFUSION, ELECTRONS, HYDROGEN, LIQUEFIED GASES, LIQUID ROCKET PROPELLANTS, OXYGEN, PROTONS, DAMAGE, RADIATION EFFECTS, STAINLESS STEEL

Distribution Statement : APPROVED FOR PUBLIC RELEASE