%0 Journal Article
%A Rat, V.
%A Andre, P.
%A Aubreton, Jacque
%A Elchinger, M. F.
%A Fauchais, Pierre
%A Lefort, A.
%D 2011
%I Begell House
%K SF_{6} plasma composition, multi-temperature
%N 2
%P 105-113
%R 10.1615/HighTempMatProc.v15.i2.30
%T COMPARATIVE STUDY BETWEEN KINETIC AND THERMODYNAMIC CALCULATION OF COMPOSITION IN SF_{6} PLASMAS
%U http://dl.begellhouse.com/journals/57d172397126f956,3f6f76556f45e3c7,3042a5f3273cae6a.html
%V 15
%X In this paper we compare the compositions calculated in chemical equilibrium for an SF_{6} plasma at atmospheric pressure, in the multi-temperature model and using kinetics (33 reactions involving 18 species). The ratio of the electron temperature T_{e} to that of heavy species T_{h} was calculated as a function of electron density and an intermediate temperature T* between T_{e} and T_{h} was introduced to cope with the relationship k_{f} (T*)/k_{r}(T*) = K_{X}(T*) where k_{f} and k_{r} are the reaction rate coefficients (forward and reverse) and K_{X} the equilibrium constant. The main difference between equilibrium and kinetic calculations lies in the densities of S^{+}, S_{2}^{+}, SF^{+}, F^{−} and S^{−} species between 2,000 and 6,000 K. The multi-temperature method gives results very different from those of the kinetic calculations even when the charge loss reactions are neglected. This is in contrast to what happens with H_{2} or N_{2}.
%8 2012-03-26