Phase space densities are calculated from measurements of energetic electrons and protons made during the Voyager 2 encounters with Uranus and Neptune, and they are expressed in terms of the adiabatic invariants &mgr;, K, and &PHgr;. Low-energy charged particle data are binned by adiabatic invariants using an offset, tilted dipole model of the planetary magnetic field. By this method, no interpolation is necessary in pitch angle or energy, and therefore a much larger fraction of the available data is analyzed here than has been done previously. On the basis of this new binned data set, several outstanding issues of the Uranian and Neptunian magnetospheres are addressed, for example, satellite interaction effects and the variation of spectral properties. Assuming a power law spectrum, the spectral index &ggr; is calculated for data within narrow second-adiabatic-invariant bins. We find the spectral index generally increases with increasing L shell, with local peaks at L shells corresponding to maximum absorption locations of planetary satellites. We also find data indicate that &ggr; varies strongly with K. ¿ American Geophysical Union 1996