Energy dependence of the ionic charge state distribution during the November 1997 solar energetic particle event

Ionic charge state distributions for a variety of species, such as C, O, Ne , Mg, Si and Fe were obtained with the Solar Energetic Particle Ionic Charg e Analyzer (SEPICA) on ACE for the strongest of a series of energetic parti cle events after the November 4 and 7, 1997, flares. The capabilities of SE PICA allow a much more detailed analysis of the charge distributions than p revious instrumentation. Over the energy range from approximate to 0.2 to 1 MeV/Nuc a trend is observed that shows charge states increasing with energ y, in particular for Mg, Si and Fe. In addition, for Fe a mixed charge stat e distribution with a distinct peak at lower charge states (10 - 14) is obs erved simultaneously with a tail reaching to charge states up to approximat e to 20. This may be an indication of a mixture of different energetic part icle populations.