Motion of SFx+ (x=1-3,5) and ion conversion in SF6-N2 mixtures -: art. no. 026412

This paper reports on the mass-analyzed measurement of the drift velocity of the positive SF6 daughter ions, SFx+ (x = 1-3,5) in the mixture of SF6 with N-2 for SF6 concentrations of 10% and 50%. A double mass spectrometer-drift tube was used for these measurements. The density-normalized electric field intensity E/N, was varied from 30 to 360 Td (1 Td = 10(-17) V cm(2)). We have found an increasingly monotonic dependence of the drift velocity with E/N, and an inverse dependence of the above parameter with the decrease of the SF6 content in the mixture. A test of Blanc's law for the zero-field reduced mobilities of the above ions shows a fair qualitative agreement. No drift velocities of these ionic species could be measured in pure N-2, since we found that these ions reacted strongly with the nitrogen molecules. The cases for SF3+ and SF5+ are discussed. A similar behavior was observed for the nitrogen ions drifting in pure SF6.