Ions with a Mass Number of Two in Mass-Spectrometric Experiments aboard Rockets and Satellites

Abstract

Deuterium ions D+and doubly-charged helium ions He++have the same mass-to- charge ratio (M/Z= 2) and are not distinguished by the mass-spectrometer. On the basis of analysis of published data, Interkosmos-24satellite data, and theoretical estimations, it is shown that in the ionosphere and plasmasphere the ion with a mass number of two is He++and not D+, at least at altitudes of higher than 600–800 km. Arguments in favor of the validity of this assumption at lower altitudes are presented. Regularities of the dependence of the N(He++)/N(He+) ratio on altitude, time of day, season, and solar activity are derived. It is found that in the daytime the N(He++)/N(He+) ratio decreases with increasing solar activity. The seasonal dependence is most pronounced at nighttime in the altitude interval 1000–2000 km, where this ratio decreases in passing from winter to summer. Peculiarities of the latitude distribution of the absolute and relative values of the He++concentration are found in the Interkosmos-24satellite data. On the basis of the same data, a strong longitude effect in the N(He++) concentration occurring under certain heliogeophysical conditions is discovered, an effect amplitude attaining one order of magnitude on adjacent orbits. An interpretation of this effect is given.