Infrared Emission from Electron Irradiated Air Laboratory Experiment Feasibility Study

Abstract : A laboratory measurements program to simulate many chemical and radiative processes present at auroral altitudes is evaluated. An electron beam would be used to irradiate O2 - N2 mixtures, either pure or with O3, NO, CO2, or H2O additives and measurements then made of the resultant ultraviolet, visible, and infrared emissions from the gas. The spatial distribution of the electron beam energy deposition would be obtained from the N2(1-) emission. The concentrations of metastable species would be determined from their emission. A major objective would be the investigation of infrared emission from air irradiated by ionizing radiation. Estimates of the infrared emission from NO, O3, NO2 are presented as a function of pressure and electron beam current. The degree of ionization of the gas is low due to rapid dissociative recombination. The operating range of the experiment is also investigated. The low pressure limit has been determined by diffusion losses to the wall. The high pressure limit was set by three-body reactions at low beam power and by thermal convection losses at high power.