EUV studies of N2 and O2 produced by low energy electron impact

Abstract

The emission spectrum of atomic nitrogen (NI), singly ionized atomic nitrogen (NII), atomic oxygen (OI), singly ionized atomic oxygen (OII), and molecular nitrogen (N2) dominates the day airglow and aurora spectrum in the extreme ultraviolet. However, analysis of the excitation of these lines is not possible due to the lack of laboratory or theoretical data for the relevant processes. Absolute emission excitation cross sections resulting from low energy electron impact on N2 and O2 have been measured in the extreme vacuum ultraviolet (500-1200 Å). Electron energies were from 0 to 300 eV. Numerous bands of N2 were found between 800 and 1000 Å. These band systems are of particular interest because their optical oscillator strengths are unusually large and should have large emission cross sections. Excitation functions were measured for the N2 c′ 1Σu+→X 1Σ g+ ν′=0-ν″-0 band emission, the NII 916 Å multiplet, the OI 879 Å multiplet, and the OII 834 Å multiplet. In addition, cross sections were measured at 200 eV only for several of the band emissions plus the NI 1135 Å, NI 1164 Å, NI 1177 Å, NII 776 Å, NII 1084 Å, OI 1152 Å, OI 1041 Å, OI 1027 Å, OI 999 Å, OI 989 Å, OI 879 Å, OH 834 Å, OII 616 Å, OII 555 Å, OII 539 Å, and OII 718 Å multiplets. © 1983 American Institute of Physics.