Theoretical study of influence of H2O on parameters of low-temperature plasmas in humid mixtures

Monte Carlo (MC) electron dynamic simulations in dry and humid N-2, O-2,.CO2 and air were performed in order to obtain electron energy distribution functions (EEDFs), mean free path (lambda), drift velocity (v(d)) and collision frequency of electrons (v), their mean energy (if) and rate coefficients of electron impact reactions, as functions of reduced electric field strength (E/N) and concentration Of H2O. The aim was to test the latest compilation of cross-sections for H2O, the applicability of the MC method used, and the effect of the H2O concentration. A sensitivity of various parameters to the presence Of H2O differs, e.g. lambda and v are more sensitive than (epsilon) over bar and V-d, and it depends strongly on the E/N. For E/N > 100 Td the parameters may be approximated as their linear combinations of values in pure gases. The difference is below 10%. For E/N < 100 Td, the difference increases rapidly and MC simulations in mixtures are necessary. The presence of H2O increases the rate coefficients of most studied reactions for E/N > 60 Td. Processes with higher threshold energy imply stronger increase.