Gas and hydrogen ion gettering properties of lithium

Abstract The gettering properties of lithium films for O 2 , CO 2 and H 2 O were examined in a vacuum system with a heater for lithium evaporation. The absorbed amounts of O 2 , CO 2 and H 2 O observed were in the ratio, O 2 /Li=0.2, CO 2 /Li=0.01 and H 2 O/Li=0.12. The gettering action for H 2 O was saturated at a relatively low lithium evaporation amount. The hydrogen uptake of a lithium oxide film was also investigated by using an ion irradiation apparatus with a thermal desorption spectroscopy. The ratio of retained hydrogen was H/Li ≃ 0.7, which was roughly the same as in the case of a fresh lithium film. The helium ion irradiation reduced the hydrogen retention of the lithium oxide film. The retained amount was 50% of that before the helium ion irradiation.