ABSTRACT
Space radiation has long been acknowledged as a major showstopper for long-term space missions, especially interplanetary, exploratory-class missions. Space radiation is generally divided into three components: trapped radiation, solar particle events, and galactic cosmic radiation. Cosmic radiation effects could be studied directly in space. Several radiobiological studies have been carried out during spaceflights. Protons are by far the most abundant component in the space radiation environment. In addition, secondary neutrons are produced in space and they can contribute an important fraction of the equivalent dose in shielded areas. Virtually all electrostatic accelerators and cyclotrons can produce protons at energies below 30 MeV.
