Abstract:
This paper deals with the measurement of the mobility of negative ions in the mixtures of CCl4 with Ar with the CCl4 ratio up to 33.3%. The pulsed Townsend technique was employed to produce an integrated ionic avalanche over a range of the density-reduced electric field E/N for which ionization is either negligible or absent, and attachment processes are dominant, leading to the formation of mostly CCl4-. The E/N range of measurement was 1-50 Td (1 Td=10(-17) V cm(2)). Our measurements strongly suggest that attachment is the dominant process and only negative ions are formed.