Mass Spectrometric Study of Dissociative Electron Attachment in Carbon Dioxide.

The DA efficiency curve of O- in CO2 has been studied mass spectrometricaly. Combining the use of the convolution of theoretical models and the deconvolution of the experimental curves, beside the previously reported DA peaks, some new DA processes have been determined at (6.0+/-0.3) eV and (13.3+/-0.4) eV for O- in CO2. A progressive conversion of electronic into vibrational excitation of diatomic radicals and into kinetic energy of the fragments is postulated as responsible for the threshold at (6.0+/-0.3) eV.