Composition of the hot magnetospheric plasma as observed with the PROGNOZ-7 satellite

The PROGNOZ 7 ion composition data in the 0.2 to 17 keV/q energy range are discussed. Plasma mantle, dayside boundary layer, auroral particles at 2 to 5 R sub e altitude, and ring current are considered. In the plasma mantle the particle motions in the deep nightside are adiabatic and penetrated solar wind plasma elements are frequently observed. The dayside boundary layer consists of poorly mixed magnetosheath and magnetosphere plasmas, with impulsive penetration of the magnetosphere by magnetosheath plasma. The boundary layer electric field has a strong radial component. The O+ ions dominate the dayside magnetospheric plasma during magnetic storms for energies up to 17 keV. Strongly peaked ion spectra are found in the inner ring current.