Measurement of concentration and study of recombination of atomic hydrogen by Wrede-Harteck method

Abstract

The dissociation efficiency of molecular hydrogen was measured using a Wrede-Harteck gauge, at nine different pressures from 0.2 to 1 Torr with discharge/flow tubes of different sizes. The maximum dissociation efficiency was measured at 0.4 to 0.5 Torr pressure of molecular hydrogen. The effect of recombination of hydrogen atoms on the walls of the flow system and in the gas volume was considered in detail and the dissociation efficiency in the discharge region was calculated. Also, γ, the fraction of surface collisions leading to recombination, was measured by the same method and was found to be 6.4× 10^-5 and 4.3× 10^-4 for clean Pyrex and quartz tubes, respectively. This may be a new and relatively accurate method for measuring γ for atomized gases in discharge tubes of different materials.