Simulation study on the protection from high energy charged particle radiation

Accompanying the increase of the utilization of cosmic space and the increase of the medical treatment facilities using high energy charged particles (particularly heavier than protons), the establishment of the technology for evaluating the radiation exposure dose of human bodies has become important. In this research, as to the galactic radiation which may become one of the causes of the exposure of crews at the time of space flight, investigation was carried out, and the method of evaluating the exposure dose by simulating accurately the behavior of radiation when it entered human bodies was examined. Besides, investigation was carried out on the codes required for those calculations, and the present problems and the matters required for resolving them are summarized. As for high energy charged particles among cosmic radiations, because of their strong penetrating power and strong interaction (ionization, excitation and nuclear reaction) with substances, the effect on the evaluation of exposure dose is large. The effect of radiation on living bodies, the way of thinking on exposure evaluation, the method of evaluating effective dose for high energy radiation, and the calculation code used for evaluating equivalent dose and its limit are explained. (K.I.)