The dynamics of energetic electrons in the Earth's outer radiation belt during 1968 as observed by the Lawrence Livermore National Laboratory's Spectrometer on Ogo 5

An account is given of measurements of electrons made by the LLNL magnetic electron spectrometer (60–3000 keV in seven differential energy channels) on the Ogo 5 satellite in the earth's outer-belt regions during 1968 and early 1969. The data were analyzed to identify those features dominated by pitch angle and radial diffusion; in doing so all aspects of phase space covered by the data were studied, including pitch angle distributions and spectral features, as well as decay rates. The pitch angle distributions are reported elsewhere. The spectra observed in the weeks after a storm at L ∼3–4.5 show the evolution of a peak at ∼1.5 MeV and pronounced minima at ∼0.5 MeV. The observed pitch angle diffusion lifetimes are identified as being the shortest decays observed and are found to be highly energy and L dependent with minimum lifetimes of ∼1–2 days occurring at L ∼3–4.5. Two contiguous periods of decay, following the intense storm injection on October 31 and November 1, were analyzed in terms of radial diffusion. Significant differences were found between the derived values of DLL for the two periods; also significant energy dependence shows in the results. Although the values of DLL vary by about a factor of 10, representative values are 0.3 day−1 at L=6, 0.06 at L=4, 0.015 at L=3, and 0.001 at L=2.5. Despite the wide variation of many prior results in the literature, there is a family of results in approximate agreement with the present results. By noting the variations in DLL, as a function of the invariant quantities, we are able to order a fair body of previous results with our new results.