We have used a drift tube with double mass spectrometry to measure the mobility of ${\mathrm{He}}^{+},$ ${\mathrm{Ne}}^{+},$ ${\mathrm{Ar}}^{+},$ ${\mathrm{N}}_2^{+},$ ${\mathrm{O}}_2^{+},$ and ${\mathrm{CO}}_2^{+}$ in their parent gas over a wide range of the density-normalized electric field, $E/N,$ from 70 to $12500\times {10}^{-21}{\mathrm{V}\mathrm{}\mathrm{m}}^2.$ In all cases, the $E/N$ ranges have exceeded those hitherto found in the literature, especially those of ${\mathrm{Ar}}^{+}$ in Ar and ${\mathrm{N}}_2^{+}$ in ${\mathrm{N}}_2.$ Our mobility data are in fair to excellent agreement with previous experimental data in the overlap range. Recent calculated data for the mobility of ${\mathrm{Ar}}^{+}$ in Ar show excellent agreement with our data at high $E/N,$ while fair agreement was observed for the calculated data of the systems ${\mathrm{N}}_2^{+}$ in ${\mathrm{N}}_2$ and ${\mathrm{O}}_2^{+}$ in ${\mathrm{O}}_2.$ Also, the ${\mathrm{Ar}}^{+}$ in Ar mobilities for $E/N>\mathrm{}10\mathrm{}\mathrm{kTd}$ were found in excellent agreement with those derived from the measurement of the mean ion energy in diffuse Townsend discharges $\left(1\mathrm{}{\mathrm{T}\mathrm{d}=1\mathrm{}\mathrm{}\mathrm{t}\mathrm{o}\mathrm{w}\mathrm{n}\mathrm{s}\mathrm{e}\mathrm{n}\mathrm{d}=10\mathrm{}}^{\mathrm{-}21}{\mathrm{}\mathrm{V}\mathrm{}\mathrm{m}}^2\right).\mathrm{}$ To the best of our knowledge, over some $E/N$ ranges, our data were found to be the first to be reported.

• Received 17 September 1999

DOI:https://doi.org/10.1103/PhysRevE.61.3053