High-energy charged particles in the innermost jovian magnetosphere

The energetic particles investigation carried by the Galileo probe measured the energy and angular distributions of the high-energy particles from near the orbit of lo to probe entry into the jovian atmosphere. Jupiter's inner radiation region had extremely large fluxes of energetic electrons and protons; intensities peaked at similar to 2.2R(J) (where R(J) is the radius of Jupiter). Absorption of the measured particles was found near the outer edge of the bright dust ring. The instrument measured intense fluxes of high-energy helium ions (similar to 62 megaelectron volts per nucleon) that peaked at similar to 1.5R(J) inside the bright dust ring. The abundances of all particle species decreased sharply at similar to 1.35R(J); this decrease defines the innermost edge of the equatorial jovian radiation.