NEW SPECTRAL AND ABUNDANCE FEATURES OF INTERPLANETARY HEAVY-IONS IN COROTATING INTERACTION REGIONS

We have surveyed the composition and energy spectra of heavy ions acce lerated in 17 corotating interaction regions (CIRs) during solar minim um conditions between 1992 December and 1995 July. Using new high-sens itivity instruments on WIND and SAMPEX, we are able to cover the energ y range from approximately 20 keV nucleon(-1) to greater than 10 MeV n ucleon(-1), making it possible to distinguish differing forms of parti cle spectra. Previous measurements down to about 0.5 MeV nucleon(-1) f ound exponential energy spectra; however, at the even lower energies s tudied here, we find that the spectral forms become power laws in kine tic energy per nucleon. At 150 keV nucleon(-1) we find that the C:O an d Ne:O ratios depend on solar wind speed. These variations suggest tha t in addition to the solar wind, other sources of heavy ions contribut e to the CIR composition.