Back Diffusion of Electrons in Ar, $\hbox {SF}_{6}$ , and $\hbox {Ar} + \hbox {SF}_{6}$ Binary

The back diffusion processes in Ar, SF₆, and Ar + SF₆ binary mixtures are analyzed by a Monte Carlo simulation method employing realistic collision cross sections of the respective component gases in the E/N range from 50 to 500 Td. The escape factors in pure Ar are always higher than that of those in pure SF₆, and as the SF₆ content in the binary mixture increases, the escape factors decrease accordingly. Furthermore, the number of collisions observed for the backscattered electrons before returning to cathode in SF₆ are smaller than that of those in Ar, and as the SF₆ content in the binary mixture increases, the mean number of collisions of the backscattered electrons decrease accordingly.