Study of the temperature dependence of the critical electric field strength in SF6 and mixtures of SF6 with C2H6 by the method of laser gas heating

The temperature dependences of the critical reduced electric field strength (E/N)_cr in SF₆ and mixtures of SF₆ with C₂H₆ are obtained in the gas temperature range T_g = 293 – 1500 K in the absence of thermal dissociation. Gases were heated due to the VT relaxation of SF₆ molecules excited by a pulsed CO₂ laser. The values of (E/N)_cr were estimated by the quasi-stationary burning voltage of a self-sustained volume discharge ignited with a delay with respect to the laser pulse. It is shown that in the absence of dissociation, the reduced electric field strength in SF₆ and mixtures of SF₆ with C₂H₆ in the temperature range under study increases with T_g. The obtained temperature dependence of (E/N)_cr in SF₆ is compared with the results reported by other researchers.