Comparison of the radio data and model calculations of Jupiter's synchrotron radiation 1. The high energy electron distribution in Jupiter's inner magnetosphere

An electron distribution in Jupiter's magnetosphere as a function of energy, pitch angle and spatial coordinates is derived from a comparison of model calculations of the planet's synchrotron radiation with the radio data; the distribution is consistent with the information available from the Pioneer data. The model calculations are based upon the magnetic field configurations as derived by Acuna and Ness [1976a, b] (the O4 model) and Davis, Jones and Smith [quoted in Smith and Gulkis, 1979] (the P11 (3,2)A model) from the Pioneer data. The electrons are assumed to diffuse radially inwards with a rate D = 3 x 10-9 L3 s-1 (where L is McIlwain's value) and have a lifetime against local losses tau = 4 x 106 L/sup -0.6/ s, in agreement with the values derived by Goertz et al. [1979] from the Pioneer data. The number density of electrons with E> or =20 MeV at L = 3 is in agreement with the values measured by the spacecraft, but the energy distribution appears to be much flatter. Electrons are absorbed with survival probabilities of approx.0.5 diffusing inwardly past Amalthea's sweeping region (for 20-MeV electrons) and approx.0.35 past the ring, respectively. An energy dependent pitch angle scattering is found to occur at Amalthea's orbit, and there is no pitch angle scattering present near the ring