Solar wind
Saturn has relatively weak radiation belts, because energetic particles are absorbed by the moons and particulate material orbiting the planet. The densest (main) radiation belt lies between the inner edge of the Enceladus gas torus at 3.5 Rs and the outer edge of the A Ring at 2.3 Rs. It contains protons and relativistic electrons with energies from hundreds of kiloelectronvolts (keV) to as high as tens of megaelectronvolts (MeV) and possibly other ions. Beyond 3.5 Rs the energetic particles are absorbed by the neutral gas and their numbers drop, although less energetic particles with energies in the range of hundreds keV appear again beyond 6 Rs—these are the same particles that contribute to the ring current. The electrons in the main belt probably originate in the outer magnetosphere or Solar wind, from which they are transported by the diffusion and then adiabatically heated. However, the energetic protons consist of two populations of particles. The first population with energies of less than about 10 MeV has the same origin as electrons, while the second one with the maximum flux near 20 MeV results from the interaction of cosmic rays with solid material present in the Saturnian system (so called cosmic ray albedo neutron decay process—CRAND). The main radiation belt of Saturn is strongly influenced by interplanetary solar wind disturbances.