A Rocket Borne Mass Spectrometer with Helium Cooled Ion Source

Abstract
A new electron bombardment ion source was developed to reduce the influence of gas‐wall interactions on the measurement of the neutral gas in the upper atmosphere. The ion source is cooled to low temperatures by means of supercritical helium. Ion source, mass spectrometer, cryogen supply system, and their arrangement in a rocket payload are described. The instrument was first successfully launched on 13 October 1970.