The Mobility of K+ Ions in Helium and Argon

Abstract

Abstract'A drift tube-mass spectrometer has been used to measure the mobility of K + ions in helium at 294 and 80 K over the EIN range 5-60 Td and in argon at 295 K over the EIN range 3-120 Td. The zero field reduced mobility KO for K + in He was determined to be 21· 14 ± 0 . 11 cm 2 Y -1 s -1 at 294 K and 17 ·32±0·26 cm 2 y-1 s-l at 80 K. The value of KO obtained for K+ in Ar at 295 K is 2 ·640±0·013 cm 2 y-1 s -1. The results are compared with those obtained in previous measurements.

Diffusion and interaction potentials for K+ions in the noble gases

“…The values available for neon, krypton and xenon are, however, of too low accuracy to be very useful. We therefore restrict the check to the K + -argon system, where we can use the precision mobility data of Cassidy and Elford (1986). The result is shown in figure 7, where the experimental and calculated relative mobilities µ/µ pol are shown.…”

“…For reference, we show in table 4 the predicted relative mobilities µ/µ pol for K + in neon, argon, krypton and xenon. Cassidy and Elford (1986); full curve, calculated from the present model potential.…”

“…For the other K + -noble-gas systems, there seems to be a lack of accurate experimental transport data. High-precision measurements of the mobility for K + in argon were performed by Cassidy and Elford in 1986, but for neon, krypton and xenon only experimental mobilities with substantially lower accuracy are available (James et al 1975, Lamm et al 1981. Ong and co-workers have reported values for D T /µ in argon (Ong and Hogan 1991) and krypton (Hogan and Ong 1991).…”

Spectroscopy of K+⋅Rg and transport coefficients of K+ in Rg (Rg=He–Rn)

“…It is also the case that the mobility data from Ref. 42 is not well represented by the SLT model potential 29 or the two current potentials.…”

“…42 shows considerable scatter, as evinced by large values of , and they are poorly described by every potential studied, as indicated by ␦ values substantially below Ϫ1, probably indicating that these values are not too reliable.…”