Cold Ionospheric Ions in the External Dayside Magnetosphere

摘要: During periods of quiet magnetic activity, a cold plasma layer with densities reaching 1–3 cm′3 is encountered on the magnetospheric side dayside magnetopause. Direct density measurements from frequency indicate that this can have width exceeding 1 RE in direction normal to Plasma composition major detected ions are H+, He+ and O+. These ionospheric show repetitive pattern energy changes. While magnetopause approaching satellites, their increases below detector low-energy threshold up about 100 eV for protons. After passage satellites into magnetosheath just following re-entry magnetosphere, ion decreases protons down lowest detectable energy. This behavior interpreted as effect electric field associated motion. The motion set when compressed relaxed boundary going out. Altogether clearly there hidden populations inside at least during geomagnetic conditions. paper emphasizes importance use determination probe density. biased particle detectors located far enough satellite body should allow distribution function these future missions.