Theoretical Study of Influence of H2O on Parameters of LowTemperature Plasmas in Humid Mixtures
Janda M., Hensel K., Martišovitš V., Morvová M. Czech. J. Phys. 56, B774B780 (2006)
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Abstract: Monte Carlo (MC) electron dynamic simulations in dry and humid N2, O2, CO2 and
air were performed in order to obtain electron energy distribution functions (EEDFs),
mean free path (λ), drift velocity (vd) and collision frequency of electrons (ν), their mean
energy (ε) 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. λ and ν are
more sensitive than ε and vd, 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.
