Ionic Charge States Inferred from Elemental and Isotopic Composition in ^3He-rich Solar Energetic Particle Events

Data from the ACE Solar Isotope Spectrometer have been used to study heavy ion elemental and isotopic abundances at energies above 10MeV/nuc in a number of ^3He-rich solar energetic particle events. The isotopic composition observations have revealed a fractionation pattern in which heavy isotopes are enhanced relative to lighter isotopes of the same element as a power law in the ratio of the masses. Adopting the assumption that this represents a special case of a general fractionation law in which different ion species are fractionated as a power law in Q/M , we infer ionic charge state values (Q) for a number of elements and compare them with direct measurements, when available. The relationship between these Q values and the observed elemental fractionation patterns are discussed.