Accession Number:

AD0608871

Title:

FRACTIONAL CELL LETHALITY APPROACH TO SPACE RADIATION HAZARDS,

Descriptive Note:

Corporate Author:

BOEING CO SEATTLE WASH

Personal Author(s):

Report Date:

1964-10-01

Pagination or Media Count:

17.0

Abstract:

A method of radiation hazard evaluation has been introduced in which the fractional number of inactivated cells of an organ is calculated. This fractional cell lethality FCL depends only on the particle energy spectrum and the probability of cell inactivation. Recent data on inactivation cross sections of human kidney cells have been used to calculate the contribution of protons, alpha particles, and M-group particles to the FCL of the kidney. The results indicate that the proton and alpha particle contributions would have been the same order of magnitude for the 12 November 1960 giant solar flare and their relative contribution does not vary much with shielding thickness. For a seated astronaut, the FCL values are on the order of 5 percent under reasonable shielding at points 4 and 6 cm inside the body at the waist. When data on inactivation cross sections become available on more critical organs, containing cells not replaced by the body, this approach may yield a realistic evaluation of the hazard from high-LET radiation on extended space missions. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE