Determination of the vibrational excitation cross-section for the F₂ molecule in a plasma discharge simulation

The electron collision cross-section for a fluorine molecular gas, which is necessary for modeling electron diffusion in a plasma reactor, has been determined included. This cross-section includes the vibrational excitation cross-section for F₂ molecule. We have calculated the electron drift velocities in two F2-He mixtures (with 0.2% and 1% fluorine) and in pure F2 by using the determined crosssections and a two-term approximation of the Boltzmann equation for the energies. The results agree well with available experimental data for the electron drift velocity over a wide range of E/N (ratio of the electric field, E, to the neutral number density N). The present cross-sections may be important for quantitatively modeling plasma discharges for processing procedures with materials containing fluorine molecules.