The barium evaporable getters are characterized by very high carbon monoxide and carbon dioxide uptake rate and much lower of hydrogen and nitrogen adsorption activity; the sorption of gases by a barium film is practically irreversible. Inert gases (argon, helium, etc.) are not adsorbed by the barium film.
The main working element of the evaporable getter is a highly porous barium film obtained by heating a barium-containing active compound to a temperature of sublimation and chemical reduction of barium. Followed by its precipitation as a film on the inner surface of the housing.
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