An updated set of electron-impact cross sections for CO₂: untangling dissociation and application to CO₂ with Ar and N₂ admixtures

Abstract This work proposes an updated set of electron-impact cross sections (CSs) for carbon dioxide (CO 2 ) by quantitatively identifying CO 2 dissociation within the two electronic excitation channels proposed by Phelps. In particular, the CS with energy threshold at 7 eV is considered with a 15% dissociation branching ratio and is associated with dissociation into O( 1 D) + CO(X), while the one with threshold at 10.5 eV is used entirely for dissociation into O( 3 P) + CO(a 3 Π r ). Experimental data on CO 2 dissociation rate coefficients at moderate reduced electric field ( E / N ), CO 2 conversion efficiencies at high E / N , and electron transport coefficients for E/N ∈[10 −2 , 10 3 ] Td are used to validate the updated set and demonstrate its completeness and consistency over a wide range of E / N . Notably, the updated CS set enables the full coupling between the electron and chemical kinetics, a feature lacking in most existing CS sets. The updated set is applied to study electron kinetics in CO 2 –Ar and CO 2 –N 2 mixtures, revealing significant modifications in the electron energy distribution function and CO 2 dissociation rate coefficient due to mixture composition. The updated CS set is made available at the IST-Lisbon database within LXCat.