Plasmoid-associated energetic ion bursts in the distant geomagnetic tail

The results of a detailed study of plasmoid-associated energetic ion enhancements observed by the EPAS instrument on ISEE 3 in the distant geomagnetic tail are summarized and are illustrated by a representative example. The overall structure of the events is discussed in terms of the neutral line model of substorms and it is shown that the observations are quite consistent with expectations. The relationship between the thermal plasma bulk speed and speeds deduced from energetic ion anisotropies, plasmoid lengths deduced therefrom, the dependence of energetic ion fluxes on the thermal plasma temperature, and the motion and orientation of the energetic particle boundary layer surrounding the plasma sheet as deduced from the ion data are also discussed.