Mobility of Hydrogen and Deuterium Positive Ions in their Parent Gases

Abstract

The mobilities of positive ions in H2 and D2 have been measured, using a pulsed Townsend technique. For hydrogen, the mobility μ0 corrected to 0°C was 11.8 (cm2/v×sec) at E/p0=26(v/sec×mm Hg), increasing to a maximum of 15.3 at E/p0=48, then decreasing to 11.6 at E/p0=150. For deuterium, the mobility was about 0.75 the value for hydrogen throughout the range of E/p0. The experiment was performed with uranium-purified gas in an ultra-high vacuum system. Ions were not identified as atomic, diatomic, or triatomic; there was no conclusive evidence of more than one ion at any value of E/p0. The H2 mobility data are significantly lower than those attributed to Mitchell in the range 20<E/p0<40, and lower than the value ≈12.5 for zero-field mobility generally reported.