Total cross sections for dissociative electron attachment to ozone caused by the²a<inf>2</inf> feshbach resonance

Total resonant cross sections for electron collision with ozone are presented. The results are based on ab initio calculations for the X 1 A1 target ground state and the 2A 2 negative-ion state potential energy surfaces close to the Franck-Condon region. The fixed-nuclei resonance width as a function of collision energy and internuclear distances has been obtained from R-matrix calculations. The nuclear motion has been taken into account employing the Franck-Condon reflection principle. In order to determine the information which is significant for the parametrization of resonant scattering cross sections, the calculations have been carried out at different levels of accuracy. The lifetime of the anionic state with respect to electron detachment was found to be long compared with the fragmentation process. Therefore, the fragmentation probability can be assumed to be equal to 1 and the total cross sections for the formation of the ion can be compared with the experimental cross sections for dissociative electron attachment (DEA). The results confirm the assumption that the prominent structure in the DEA cross sections at 1.3 eV is caused by a metastable 2A2 state of O3-.