Measurements of heavy elements in 3He-rich SEP events

Using the Solar Isotope Spectrometer (SIS) on the Advanced Composition Explorer (ACE), we have studied the properties of a selection of small 3He-rich solar energetic particle (SEP) events with heavy ion enhancements in the energy range ∼11-22 MeV/nucleon. These events contain significantly increased 3He/4He ratios over the solar wind value of 0.0004 in the energy range ∼4.5-5.5 MeV/nucleon. In order to characterize the events, the following features have been investigated. First, the heavy element content has been measured and compared to that found in past studies of impulsive SEP events. Next, the simultaneous 38-53 keV electron flux, measured with the Electron, Proton, and Alpha Monitor (EPAM) on ACE, has been examined for possible activity near the 3He-rich event onset times. Finally a list of measured solar X-ray flares, with corresponding H-alpha flares where possible, has been scrutinized for potential correlations with these events. The results show an apparent correlation between event onset and increased electron flux, and a possible association with X-ray flares