Enrichment of heavy nuclei in 3He-rich flares

Five 3He-rich solar-flare particle events were observed in 1973--1974 with 3He/4He ranging from 0.2 to approx.8 at 2.9--12.7 MeV per nucleon. In all five events the (Zgreater than or equal to6)/1H ratio at approx.3 MeV per nucleon was enriched by approx.10 to approx.100 times and the (Zgreater than or equal to6)/4He ratio was enriched by approx.3 to approx.30 times, when compared with average solar-particle abundances measured over this 2-year period. It is suggested that the simultaneous enhancement of Zgreater than or equal to6 and 3He nuclei and the absence of 2H and 3H may be partly due to a preferential acceleration process which depends on the Z2/A of the nuclei