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The electron drift velocity has been measured in xenon over the range of reduced field strength 1 Td

The velocities of negative ions drifting in mixtures of methane and sulphur hexafluoride have been measured. Measurements were made as a function of gas composition, reduced electric field strength between 3 and 185 Td, and total gas pressure in the range 100-600 Torr at 300K. The data indicate that SF6- (SF6) ions are the dominant ion in all of the gas mixtures studied. Extrapolation of the data using Blanc's Law was used to determine the velocity of sulphur hexafluoride ions drifting in pure methane.

Recombination of ions in mixtures of methane and sulphur hexafluoride has been simulated in Monte Carlo technique. The results of the simulation can be directly compared with experimental measurements. As a function of gas pressure, the recombination rate has a maximum of approximately 10-6 cm3 s-1 at a pressure of 1 atm, in good agreement with experimental results.

We have measured the recombination rate for positive and negative ions in sulphur hexafluoride and in mixtures of methane and sulphur hexafluoride in an electron beam sustained discharge. Measurements were made as a function of gas composition, gas pressure in the range 100 to 600Torr, and reduced electric field strength in the range 12 to 150Td. When plotted as a function of an effective ion temperature, defined by the drift velocities of the ions in the applied electric field, the rates in each of the gas mixtures follow the same T;d.6 power law. From comparisons with theories appropriate to the recombination of positive ions with electrons it is suggested that the index of the power law might indicate that the recombination process follows an indirect path, with the approaching ions being initially trapped in stable orbits before final stabilisation of the collision.