Understanding the Space Radiation Environment
L. S. Pinsky 1*
1 Physics Department, University of Houston
The radiation environment in space is dramatically different than anything normally encountered near the Earth’s surface. While there are many sources, they are all dominated by energetic particles, which can be neutrons or relativistic heavy ions from protons through the very heaviest nuclei. In trying to assess the risk to astronauts and to equipment from exposure to this radiation, a considerable amount of Nuclear Physics needs to be understood. At a minimum, the incident energetic particles will traverse the tissue in the body and besides the normal electromagnetic ionization processes there will be a significant number of nuclear interactions. In addition, the incident fluence will also necessarily have to penetrate the material in the spacecraft and/or a space suit as well. Not only will the fragmenting incident nuclei create a complex dosimetric issue, but when the interactions occur within the tissue in the body, the so-called target fragments will in many cases be even more problematic. To the physics uncertainties one must also add the uncertainties in the radiobiology in order to provide estimates of the risks to astronauts on present and potential future long-duration missions. The talk will summarize the current situation and briefly outline future planned efforts to confront them.
Space Radiation Sources (from J. Barth, NASA/GSFC)