Measurements of DT/μ of Na+ ions in argon and neon

Abstract

Room temperature measurements of the ratio DT/μ between the transverse diffusion coefficient and the mobility of mass-identified ions in a neutral gas are reported for Na+ ions in argon and neon. A new apparatus was used which, in contrast to previous methods, does not involve mechanical movement which alters the geometry of the drift tube assembly during a measurement scan, or variation of the experimental conditions inside it. Results with an estimated accuracy of better than 3% were obtained at E/N values ranging from 10 to 260 Td with argon and 10 to 200 Td with neon.