Experimental evidence for the presence of helium ions based on Explorer VIII satellite data

Values of positive-ion concentration (N+ = 1.3 ± 0.1 × 104 ions/cm3), electron temperature (Te = 1750° ± 200°K), and the ratio of atomic helium to oxygen ions (He+/O+ = 1.3 ± 0.3), measured by three separate experiments at an altitude of 1630 km on the Explorer VIII satellite, are presented. These together with ionosonde data are shown to be consistent with a model of an isothermal upper ionosphere in diffusive equilibrium. The model infers that hydrogen ions are less important than either helium or oxygen ions at altitudes below 1600 km. The measured ratio of helium to oxygen ions is consistent with that postulated by Nicolet.

[1]  K. Gringauz The structure of the ionized gas envelope of earth from direct measurements in the U.S.S.R. of local charged particle concentrations , 1963 .

[2]  W. B. Hanson Upper‐atmosphere helium ions , 1962 .

[3]  S. Bauer THE ELECTRON DENSITY DISTRIBUTION ABOVE THE F2 PEAK AND ASSOCIATED ATMOSPHERIC PARAMETERS , 1962 .

[4]  J. L. Donley,et al.  Electron Temperature Measurements on the Explorer VIII Satellite , 1961 .

[5]  S. Bauer,et al.  Rocket measurement of a daytime electron‐density profile up to 620 kilometers , 1961 .

[6]  R. Bourdeau Ionospheric Results with Sounding Rockets and the Explorer VIII Satellite (1960 ) , 1961 .

[7]  M. Nicolet Helium, an important constituent in the lower exosphere , 1961 .

[8]  E. Whipple,et al.  Measurements of Sheath Currents and Equilibrium Potential on the Explorer VIII Satellite (1960 xi) , 1961 .

[9]  W. B. Hanson,et al.  An ion‐trap measurement of the ion concentration profile above the F 2 peak , 1961 .

[10]  F. S. Johnson,et al.  Electron Temperatures in the Ionosphere , 1961 .

[11]  J. Jackson,et al.  Ionospheric Measurements Using Environmental Sampling Techniques , 1960 .

[12]  F. S. Johnson,et al.  Charge and magnetic field interaction with satellites , 1960 .

[13]  V. I. Krassovsk Exploration of the Upper Atmosphere with the Help of the Third Soviet Sputnik , 1959, Proceedings of the IRE.

[14]  K. I. Gringauz,et al.  Измерение концентрации положительных ионов вдоль орбиты искусственного спутника Земли , 1957 .