Absolute total electron scattering cross sections forN2between 0.5 and 50 eV

Abstract

Absolute total electron scattering cross sections for ${\mathrm{N}}_{2}$ from 0.5 to 50 eV have been measured with an estimated uncertainty of \ifmmode\pm\else\textpm\fi{}3% using a transmission time-of-flight method previously described. The results are compared to previous experimental results and to recent calculations. The positions of the $^{2}\ensuremath{\Pi}_{g}$ resonance peaks were determined with much greater accuracy (\ifmmode\pm\else\textpm\fi{} 15 meV) than in previous transmission measurements. The structure reported by Golden (1966) below the $^{2}\ensuremath{\Pi}_{g}$ resonance was clearly not present, indicating that, if real, these features are not a property of the ${\mathrm{N}}_{2}$ ground vibronic state. The shape resonance predicted at 11 eV by Dill and Dehmer (1977) was not seen, perhaps because it was too weakly manifested in the total cross section. A weak broad band centered at 25 eV may be interpreted as being due to a ${\ensuremath{\sigma}}_{u}$ shape resonance as predicted by Dehmer, Siegel, Welch, and Dill.