Motion of SF+x (x=1-3,5) and ion conversion in SF6-N2 mixtures

This paper reports on the mass-analyzed measurement of the drift velocity of the positive SF6 daughter ions, SF+x (x=1-3,5) in the mixture of SF6 with N2 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 N2, since we found that these ions reacted strongly with the nitrogen molecules. The cases for SF+3 and SF+5 are discussed. A similar behavior was observed for the nitrogen ions drifting in pure SF6.