Temperature dependence of electron-ion recombination and ion mobilities in nitrogen afterglows

Abstract

A microwave cavity method has been used to measure the temperature dependence of electron density decay rates in nitrogen afterglows, over the range 295–694°K. At low gas pressures the afterglows, being diffusion controlled, yield the reduced ion mobility μ 0 for the various gas temperatures. At 295°K, a value of (3.8 ± 0.1) cm 2/Vsec was found for the ion mobility. The value of μ 0 increases over the whole temperature range rising to (4.8 ± 0.1) cm 2/Vsec at 694°K. Results at higher pressures (>10 mm Hg) indicate that the afterglows are recombination controlled. The measured values of the electron-ion recombination coefficient α yields a T g −1.07 temperature dependence law. The coefficient at 295°K is 2.0 × 10 −6 cm 3/sec which is in good alphaeement with previous microwave cavity measurements.