Ion mobilities and clustering in SF₆at high pressures

Using a time-resolved technique (uniform field), ion transients in SF 6 at low E/p 20 (2.5-80 V cm -1 Torr -1 ) and a high gas pressures (70.1, 192.8 Torr) have been analysed by curve fitting to an expression derived from a simplified discharge scheme which considers complete stabilisation of unstable (SF 6 - )*, followed by a saturated reaction leading to the formation of predominantly SF 6 - (SF 6 ) clusters. Reduced mobilities for this ion are reported, together with an 'apparent' stabilisation rate constant.