Charged particle diffusion and acceleration in Saturn's radiation belts

In the present paper, an attempt is made to determine, from the observed intensity profiles for protons and electrons in the region of L smaller than 4, whether population of Saturn's innermost trapped radiation zones from an external source is possible. It is found that if diffusion proceeds in an episodic rather than a steady-state manner (long periods of quiescence interrupted by brief periods of rapid diffusion), the basic features of the observed phase space density profiles are qualitatively reproduced for both the trapped protons and electrons.