Effect of Molecular Dissociation and Vibrational Excitation on Electron Energy Transfer in Co2 Laser Plasmas

The electron energy distribution function has been calculated for CO2 laser plasmas in gas mixtures of CO2, N2, and He using available cross-section data. Electron-molecule energy exchange rates were then calculated and used to evaluate the role of dissociation products in electron energy exchange processes. Under circumstances typical of CO2 lasers, the calculation shows that more than 15% of the electron energy can be transferred to CO vibrational levels. The sensitivity of electron kinetic processes to vibrational temperature variations was also evaluated for plasma systems dominated by N2. Changes in vibrational temperature were found to have a relatively small effect on electron power transfer.