TRANSPORT-COEFFICIENTS OF SF+ AND SF2+ IN SF6

The mobility and longitudinal diffusion coefficients of SF+ and SF2+ in SF6 have been measured with a drift tube-mass spectrometer over the combined E/N range 35-580 Td. Low-field reduced mobilities of 0.791 +/- 0.005 and 0.685 +/- 0.009 cm2 V-1 s-1 have been obtained for SF+ and SF2+ respectively. No other data have been found in the literature for the purposes of comparison. The present low-field reduced mobilities, together with those previously measured for SF3+, SF5+ and SF5- with the same apparatus, scale very well according to the polarization-limit equation for the mobility.