Unusual heliospheric energetic ion abundances due to resonant wave-particle processes

The resonant wave-particle effects which enhance spectacularly the abundanc e of the He-3 isotope and heavy elements in impulsive solar flares are anal yeed. Primordial nucleosynthesis and galactic evolution confines the corona l ratio of the He isotopes, He-3/He-4, to several times 10(-4); this ration is enhanced during impulsive pulsive flares by up to four orders of magnit ude due to interaction with electromagnetic ion cyclotron (emic) waves. The heavy elements, which are produced during galactic evolution and which are not fully ionized at coronal temperatures, are also accelerated by emic wa ves through higher gyroharmonic resonances. The oblique emic waves, which p ropagate undamped over large distances, are observed on auroral field lines in conjunction with dynamically evolving electron fluxes, and, analogously , are postulated on coronal field lines in conjunction with the X-ray emitt ing electrons. Quasilinear simulations show that the dynamically evolving e lectron velocity distribution consisting of a core, halo and beam can enhan ce the low-frequency modes, while quenching the high-frequency Langmuir wav es and preserving some positive slope. This positive slope may drive the lo w-frequency electromagnetic waves. The acceleration of He-3 by the emic wav es and the enrichment of specific elements and charge states, at different coronal conditions, is described. (C) 1998 Elsevier Science Ltd. All rights reserved.