High-speed flows of H(+) and He(2+) ions at the magnetosphere

Observations of high-speed flows of H(+) and He(2+) ions obtained by the hot plasma composition experiment on AMPTE/CCE provide direct support for the single-particle approach to acceleration in current layers. These high-speed flows are attributed to single-fluid momentum balance across a magnetopause with a normal magnetic field and a tangential electric field. The flow speeds of the two ion species are found to be approximately equal.