Laboratory Facility for Ionospheric Reaction Studies

Abstract

This paper describes techniques employed in the laboratory investigation of charged and neutral particle reactions of importance in the ionosphere. Atmospheric gases at densities appropriate to the D region, contained in a large reaction chamber, are irradiated by a spatially uniform flux of 1.5 MeV electrons. The resulting reactions are studied by a combination of resonant cavity measurements of electron density, mass analysis of positive and negative ions, and optical emission spectroscopy, both during continuous beam irradiation of the gas and in the radiation afterglow. Mechanisms and rates for molecular production and loss processes have been investigated using this apparatus under conditions resembling those in the ionosphere, with negligible competition from diffusion losses to the container walls. In addition to descriptions of the techniques, the paper includes examples of measurements made with the experimental system.