Knowledge Bank

The mobilities of a number of ions $(ArD+,N2+,SD+$ and $SD-$) have been studied on the basis of their Doppler shifts in a positive discharge colum. The technique of infrared velocity modulation and precise microwave $measurementsa$ were employed to investigate the mobilities of spectroscopically identified ions over a broad range of E/N values in an argon buffer gas. For $E/N>100$ Td, the reduced mobilities exhibit substantial differencies for particular ions which could not be explained using the classical Langevin and kinetic theories. The experimental results and a simple model based on influence of an inhomogenous electric field will be presented.