Modes into Plasma-Chemical Dissociation Process

Contribution of Asymmetric and Symmetric CO2 Vibrational Modes into Plasma-Chemical Dissociation Process 

The W-exchange process proceeds at low levels of vibrational excitation independently along symmetric and asymmetric CO2 vibrational modes. The symmetric and asymmetric CO2 vibrational modes can be characterized by individual vibrational temperatures and 

as well as by individual vibrational energy distribution functions. A major contribution to the population of highly vibrationally excited states of CO2 and, hence, to dissociation is related to the excitation of the asymmetric vibrational modes (Rusanov et al., 1985b Rusanov, Fridman, Sholin, 1986). This important statement is based on the following three effects of CO2 plasma-chemical kinetics  

The asymmetric vibrational mode of CO2 is 1, which can be predominantly excited by plasma electrons at electron temperatmes Te = 1-3 eV (see Fig. 5-5). Discharge energy localization within that vibrational mode becomes stronger when CO2 is mixed with CO, which is a product of its dissociation (see Fig. 5-12). 

The VT-relaxation rate from the asymmetric vibrational mode is much slower than that of symmetric vibrations, which helps to accumulate more energy within the asymmetric mode. 

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