Sticking probabilities of simultaneously adsorbed deuterium and nitrogen on thin iron film at 78 K

Abstract

A flow technique has been applied to measure the partial sticking probabilities of deuterium and nitrogen, simultaneously interacting with thin iron films at 78 K. The features of sticking probability dependence on the quantity of nitrogen and deuterium consumed have been analysed for both simultaneous and post-dosing D 2 and N 2 adsorption and then have been compared with the corresponding dependencies measured for D 2 and N 2 separately adsorbed on clean iron film. It was found that simultaneously dosed N 2 and D 2 adsorb on Fe film with high sticking probabilities (≤1) at low coverage. A part of co-adsorbed nitrogen admolecules is removed from the Fe surface due to competitive adsorption of deuterium at higher coverage. The population of nitrogen simultaneously adsorbed with deuterium on the Fe film surface is similar to that found for the D 2 adsorption on Fe film pre-covered with strongly adsorbed nitrogen admolecules and much higher than the population obtained after the post-dosing N 2 adsorption on Fe film pre-covered with deuterium adspecies.