Examining the Abundance of Rare Elements in Solar Energetic Particle Events

Abstract

Using data accumulated with the Solar Isotope Spectrometer on ACE during 27 large solar energetic pa1ticle (SEP) events the effects of charge-to-mass (Q/M) fractionation on rare elements arc examined. In an attempt to correct for these fractionation effects and obtain preliminary estimates of the coronal abundances of K, Ti, Cr, Mn, Co, Ni, Cu, and Zn, the SEP events are classified according to their Fe/Si ratio. The data from all events within an Fe/Si category are summed and the rare element abundances extracted over an energy interval of 20 to 65 MeV/nucleon. We estimated the apparent Q/M fractionation, corrected for it, and obtained initial results which are encouraging.