Upper air neutral composition measurements by a mass spectrometer

Abstract

A quadrupole mass spectrometer with an ion source designed to minimize recombination effects was flown on a Nike-Cajun rocket, NASA 10.91 UA, from Wallops Island (latitude 37°50′N, longitude 75°29′W) at 1302 EST, May 18, 1962, to an altitude of 134.5 km. The results indicate a ratio of O/O2 number densities of 3.1 at apogee with a rms error estimated at 0.3. At apogee, the ratio of N/N2 number densities was less than 0.05, and the ratio of ion currents due to constituents of mass greater than 40 was less than 0.04 of the total ion current. The mean molecular weight computed from the data at 133 km is 25.5 with a rms error estimated at 0.4. These data are uncorrected for effects of the motion of the instrument package. On the basis of a simplified geometrical model, bounds on the dynamic effects are established.