A New Model for Estimating Space Proton Dose to Body Organs

It has been presumed that geometrically faithful man models are required to accurately account for the effect of body self-shielding on space radiation dose to radiation-sensitive organs other than the skin and lens of the eye. It is demonstrated that a simple equivalent sphere model reproduces the results of comprehensive dose analyses that employ a detailed man model, with an accuracy sufficient for dose assessments. A correlation has been established analytically that holds for the full range of observed solar proton spectra and for a range of vehicle shielding worths from 0 to 10 g/cm² of aluminum. Equivalent sphere model parameters are presented for the blood forming organs, the gastro-intestinal tract, and the testes.