The surface adsorption of gas molecules is a key factor limiting the secondary electron yield(SEY)of a material in many areas of applied physics.The influence of O_(2)adsorption on the SEY of metallic Ag is investigat...The surface adsorption of gas molecules is a key factor limiting the secondary electron yield(SEY)of a material in many areas of applied physics.The influence of O_(2)adsorption on the SEY of metallic Ag is investigated in this work.To account for the particle distribution,we propose a BET theory based on multilayer O_(2)physisorption model.Furthermore,based on the phenomenological model of secondary electron(SE)emission and by taking into account the different scattering processes between electrons and particles in the adsorbed layer,we develop a numerical model of SEY in the adsorbed state using Monte Carlo simulations.The relationships among O_(2)adsorption,adsorption layer thickness,and SEY variation characteristics are then examined through a series of experiments.After 12-h exposure to O_(2),the clean samples increases12%-19%of the maximum value of SEY and 2.3 nm in thickness of the adsorbed layer.Experimental results are also compared with the results from the MC model to determine whether the model is accurate.展开更多
基金Project supported by the Fund from the National Key Laboratory of Science and Technology on Space Mircrowave,China(Grant No.6142411112205)the National Natural Science Foundation of China(Grant No.62001376)。
文摘The surface adsorption of gas molecules is a key factor limiting the secondary electron yield(SEY)of a material in many areas of applied physics.The influence of O_(2)adsorption on the SEY of metallic Ag is investigated in this work.To account for the particle distribution,we propose a BET theory based on multilayer O_(2)physisorption model.Furthermore,based on the phenomenological model of secondary electron(SE)emission and by taking into account the different scattering processes between electrons and particles in the adsorbed layer,we develop a numerical model of SEY in the adsorbed state using Monte Carlo simulations.The relationships among O_(2)adsorption,adsorption layer thickness,and SEY variation characteristics are then examined through a series of experiments.After 12-h exposure to O_(2),the clean samples increases12%-19%of the maximum value of SEY and 2.3 nm in thickness of the adsorbed layer.Experimental results are also compared with the results from the MC model to determine whether the model is accurate.
