THE FLUORESCENCE OF AIR AND NITROGEN EXCITED BY ENERGETIC ELECTRONS

Abstract

Abstract : The optical radiation from air and nitrogen bombarded by energetic (kev) electrons was measured over a wide range of gas pressures. Absolute fluorescent efficiencies of spectra from 3,200 to 11,000A are presented for air and nitrogen at both 22 Torr excited by 10 kev electrons and 600 Torr excited by 50 kev electrons. At lower pressures, absolute intensity measurements have been made in the form of electron excitation cross sections for the first negative and Meinel bands of N2(+). The radiative lifetimes of the Meinel bands are also given. The pressure dependence of the first and second positive systems of N2 and the first negative and Meinel systems of N2(+) was analyzed. With the exception of the Meinel bands, the Stern-Volmer collisional quenching mechanism accurately describes the pressure dependence of these systems in nitrogen and air. Based on the Stern-Volmer analysis, the absolute intensity of the electron induced fluorescence is determined for various transitions of these four band systems for any pressure of air or nitrogen.