Study of the dielectric breakdown properties of CO₂-O₂ mixtures by considering electron detachments from negative ions

The dielectric breakdown properties of CO₂-O₂ mixtures at different O₂ concentrations and gas pressures were studied in this paper, with electron detachments from negative ions taken into consideration. The influences of the electron detachment on the reduced effective ionization coefficients α_eff/N, the critical reduced electric fields (E/N)_cr, the critical electron temperature T_cr, the breakdown reduced electric fields (E/N)_breakdown, and the breakdown electron temperature T_breakdown were analyzed for the CO₂-O₂ mixture. Based on the results, it was found that an enhancement in α_eff/N and a decrease in (E/N)_cr and T_cr were caused by the electron detachment, which appeared to be more significant at relatively low E/N and low gas pressures. With the increase in the pd product, both (E/N)_breakdown and T_breakdown in the CO₂-O₂ mixture decreased first and then tended to be a constant at relatively high pd products.