Cross sections for production of O2− and C− by dissociative electron attachment in CO2: An observation of the Renner-Teller effect

Using monoenergetic electron beams and mass analysis, we have measured the cross sections for production of O2− and C− by dissociative attachment in CO2. The cross section for O2− production has two peaks of the order of 10−24 cm2 at 11.3 ± 0.2 and 12.9 ± 0.2 eV incident electron energy. The double peaked nature of the cross section is interpreted as a manifestation of the Renner-Teller effect. The positions of these two peaks are in good agreement with INDO calculations. The cross section for C− production has three peaks at 16.0 ± 0.2, 17.0 ± 0.2, and 18.7 ± 0.1 eV, the largest of which, at 18.7 eV, has magnitude of approximately 2 × 10−21 cm2.