A kinetic model is presented for decay of an SF6 arc plasma concerning the period when the electrons disappear (the so-called post-arc phase in SF6 circuit breaker operation). The model is based on solution of the rate equations of the 14 species chosen for the study (electrons, atomic ions, atoms, and diatomic molecules and ions). It is applied to a homogeneous medium at constant pressure in which the variation of temperature is taken as being known. The most interesting results concern electron decay and show the possibility of electron overpopulation with respect to the equilibrium composition. The departures from equilibrium remain slight and are analysed by comparing the variation rate constant of electrons with the relaxation times of the electron dissipation reactions, namely electron-ion recombination and dissociative attachment. Pressure has a strong influence on departures from equilibrium, which decreases as the pressure rises.
No takes yet. Share an insight, caveat, or question.
Gleizes et al. (1993) studied this question.