Cross sections for resonant vibrational excitation ofN2by electron impact

We report the results of a theoretical study of resonant vibrational-excitation of ${\mathrm{N}}_2$ by low-energy electrons. The vibrational-excitation cross sections were calculated using ab initio fixed-nuclei resonance parameters in the complex-potential or "boomerang" model of Dubé and Herzenberg. The electronic resonance energy and decay width were extracted from several ab initio calculations of the ${}_{}{}^2{}_{}{}^{}\Pi _g^{}{}_{}{}^{}$ shape resonance of ${\mathrm{N}}_2^{-}$. The good agreement between the present cross sections and those obtained recently with the $R$-matrix technique indicates that the assumptions underlying the complex-potential model are valid for the case of ${{\mathrm{N}}_2}^{-}\left({}_{}{}^2{}_{}{}^{}\Pi _g^{}{}_{}{}^{}\right)$. The present results also show the sensitivity of the computed vibrational-excitation cross sections to the fixed-nuclei resonance parameters employed in the calculations. The differential vibrational-excitation cross sections at 90° and the total integrated cross section which we have obtained agree resonably well with the available experimental data.