ACCELERATION OF SOLAR-FLARE HE-3 AT THE EARTHS BOW SHOCK

The STEP instrument on the WIND spacecraft observed several upstream e vents in coincidence with He-3 and Fe-rich solar energetic particle ev ents in late 1994. The distinctive ion composition of the impulsive so lar energetic particle population provides an opportunity to study mec hanisms that produce upstream events. We report energy spectra and mas s composition of both the upstream event ions and SEP ions as well as the first detection of He-3 ions in an upstream event. The detection o f He-3 unambiguously demonstrates that salar energetic particles can u ndergo further acceleration near the Earth.