Characteristic of the radiation field in low earth orbit and in deep space

The radiation exposure in space by cosmic radiation can he reduced through careful mission planning and constructive measures as example the provision of a radiation shelter, but it cannot he completely avoided. The reason for that tire the extreme high energies of particles in this field and the herewith connected high penetration depth in matter. For missions outside the magnetosphere ionizing radiation is recognized as the key factor through its impact on crew health and performance. In absence of sporadic solar particle events the radiation exposure in Low Earth orbit (LEO) inside Spacecraft is determined by the galactic cosmic radiation (protons and heavier ions) and by the protons inside the South Atlantic Anomaly (SAA), an area where the radiation belt conies closer to the earth surface (hie to a displacement of the magnetic dipole axes from the Earth's center. lit addition there is tit? albedo source of neutrons produced as interaction products of the primary galactic particles with the atoms of the earth atmosphere. Outside the spacecraft the dose is dominated by the electrons of the horns of the radiation belt located at about 60 latitude in Polar Regions. The radiation field bus spatial and temporal variations in dependence of the Earth magnetic field and the solar cycle. The complexity, of the radiation field inside a spacecraft is further increased through the interaction of the high energy components with the spacecraft shielding material and with the body of the astronauts. In interplanetary missions the radiation belt will he crossed in a couple of minutes and therefore its contribution to their radiation exposure is quite small, but suhsequently, the protection by the Earth magnetic field is lost, leaving only shielding measures as exposure reduction means. Tire report intends to describe the radiation field in space, the interaction of the particles with the magnetic field and shielding material and give some numbers on the radiation exposure in low earth orbits and in interplanetary, missions.