The origin of high-energy 3He-rich solar particle events

Observed isotope abundances in the energy range >15 MeV nucleon(-1) by the ERNE instrument on board Solar and Heliospheric Observatory show a group of high-energy He-3-rich solar particle events that apparently has not been identified in earlier observations. Those events are observed to start well after the. are, when the associated coronal mass ejection (CME) already extends to similar to0.3 AU from the Sun. We present the first model of interplanetary reacceleration of He-3 that explains main properties of the new group of solar particle events. Our numerical simulations suggest that appearance of He-3 in the unusually high-energy range can be caused by a reacceleration of similar to1 MeV solar ions in oblique shocks or compressions driven by not very fast CMEs associated with those events.