Vibrational Excitation of CO2by Electron Impact

Abstract

Vibrational excitation of C${\mathrm{O}}_2$ is studied using a double electrostatic analyzer. The asymmetric stretch vibration (001) exhibits a peak cross section about 3 × ${10}^{-16\mathrm{}}$ ${\mathrm{cm}}^2$ at 0.9 eV, and the 002 mode excitation is an order of magnitude lower. Six energy loss peaks associated with the symmetric stretch mode (100, 200, etc.) are observed in the energy range 3-4.5 eV, with a peak at 3.8 eV. The data are consistent with the existence of two short-lived compound states. The first, around 0.9 eV, exhibits $p$-wave character, and the second, around 3.8 eV, exhibits $s$-wave behavior.