Resonant vibrational excitation of the NO ground state by electron impact in the 0.1-3 eV energy range

The cross sections for differential elastic scattering and vibrational excitation of the NO ground state have been studied in an electron impact experiment in the 0.1-3 eV energy range. Strong resonant processes are observed. They are associated with the ³ Sigma ^-, ¹ Delta and ¹ Sigma ⁺ states of NO^-. The vibrational levels of the ³ Sigma ^- state can be observed up to about 1.2 eV. Sudden increases are observed in the peak spacings and widths, and also rapid changes of the angular distribution of the ejected electrons, and these can be explained by the formation of the NO^{- 1} Delta state ( omega _c approximately=185 meV). In order to explain all the observed structure, the third low-lying ¹ Sigma ⁺ state of NO^- must be taken into account from 1.120 eV upwards. Interference effects between these three resonant states strongly affect the structure heights from one exit channel to the next.