High-resolution electron-impact emission spectra and vibrational emission cross sections from 330-1100nm for N2

Abstract

Electron-impact emission cross sections for N2 were measured in the wavelength range of 330-1100nm at 25eV and 100eV impact energies. Cross sections of several molecular emission bands of the first positive band system B3Π g+(ν′)→ A 3Σ g+(ν″) and the second positive band system C3Π u (ν′)→ B 3Π g (ν″) of N2, the first negative band (1NB) system B2Σ u+(ν′) → X2Σ g+(ν″) and Meinel band system A2Π u (ν′)→ X 2Σ g+(ν″) of N2+ ions as well as line emissions of N (N I) and N+ (N II) in the visible-optical-near-IR wavelength range reported in this work were measured for the first time in a single experimental setup at high spectral resolving power (λ/Δλ 10000) under single-collision- scattering geometry and optically thin conditions. Rotational emission lines of N2 and N2+ were observed for strong emission bands at a gas temperature of about 300 K. The absolute cross section of the strongest (0,0) vibrational band at 391.43nm of 1NB was determined using the standard Hα emission cross sections of H2 by electron impact at both 25eV and 100eV electron-impact energies, and the cross sections for the remainder of the emissions were determined using (0,0) 1NB value. A comparison of the present emission cross sections with the earlier published data from both electron energy loss and electron-impact-induced fluorescence emission is discussed. © 2011. The American Astronomical Society. All rights reserved.