Ions with a mass number of two in mass-spectrometric experiments aboard rockets and satellites

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-24 satellite data , and theoretical estimations, it is shown that in the ionosphere and plasm asphere the ion with a mass number of two is He++ and not D+, at least at a ltitudes of higher than 600-800 km. Arguments in favor of the validity of t his assumption at lower altitudes are presented. Regularities of the depend ence of the N(He++)/N(He+) ratio on altitude, time of day, season, and sola r 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 t his ratio decreases in passing from winter to summer. Peculiarities of the latitude distribution of the absolute and relative values of the He++ conce ntration are found in the Interkosinos-24 satellite data. On the basis of t he same data, a strong longitude effect in the N(He++) concentration occurr ing under certain heliogeophysical conditions is discovered, an effect ampl itude attaining one order of magnitude on adjacent orbits. An interpretatio n of this effect is given.