Midhead and gastrointestinal doses in tactical nuclear environments

The calculations were performed for a standing and a prone man at four different orientations to the burst and at two different ranges. The detailed nature of the calculations allowed the determination of the transmitted neutrons, the transmitted gamma-rays and the gamma-rays produced by neutron interactions in the human body. The corresponding transmission factors do not vary too much with orientation or range, but are very different for the head and the intestine. For instance only 13% of the free field neutron dose reach the GI tract, but 43% reach the midhead position. Most of the dose at the GI tract consists of gamma-rays even at high n/γ free field dose ratios. The calculations permit an easy computation of any critical organ dose, if neutron and gamma doses were recorded by a dosimeter. (orig./DG)