Radiation shielding of spacecraft's in manned interplanetary flights

Abstract

The high energy protons of the Solar Cosmic Rays (SCR) are by far the most dangerous for the health of the astronauts in manned flights outside the protection of the Earth magnetic field. However, since the astronauts are in any case protected by the walls of the spaceship, only protons with kinetic energy exceeding 20 MeV must be taken into consideration. They have a small dispersion around the direction of the solar wind, what makes easier the protection against their action because absorber's of adequate thickness can be located in the side of their arrival direction. The mass of the required absorber rapidly increases with the energy of the proton, and is already 1,400 kg/m 2 for stopping protons of 500 MeV. It is therefore necessary to have recourse to the use of magnetic superconducting lenses for defocussing the beam of the arriving protons and protect the astronauts behind them. It is presented and discussed a scheme of toroidal lens protecting a volume of 10 m 2 cross section at all energies of interest and weighing a few hundred kg. It is presented the program for developing a prototype of such a lens to be validated on board of the International Space Station and for sending an interplanetary probe for mapping the characteristics of the high energy SCR from Earth to Mars and correlating them with the solar activity phenomena.