UPSTREAM AND MAGNETOSHEATH ENERGETIC IONS WITH ENERGIES TO APPROXIMATE-TO-2 MEV

We present the first observations of approximate to 2 MeV ion bursts d etected in the upstream region and file magnetosheath by the three-dim ensional (3D) plasma and energetic particles instrument on the WIND sp acecraft. This instrument measures the full 3D distribution of particl es from a few eV to several MeV, and allows characterization of the up stream ions in both pitch angle and energy. The new feature observed i s the presence of bursts of ions at energies extending up to approxima te to 2 MeV, both upstream and in the magnetosheath. The observation o f MeV ions has strong implications for the ion source and acceleration mechanisms.