Hydrogen adsorption characteristics of Zr57V36Fe7 non-evaporable getters at low operating temperatures

Non-evaporable getter is commonly used to remove active gases in vacuum chambers, especially H-2 at ambient temperature. In this work, the getter was applied to low operating temperatures where a vacuum chamber is cooled to a temperature of 100 K, and maintained under a pressure of approximately 1 x 10(-3) Pa, in which the residual gas is mainly hydrogen. The test temperatures ranged from 100 K to 293 K. Using constant volume method, the hydrogen sorption capacity of Zr57V36Fe7 at different temperatures and equilibrium pressures are determined. In addition, the corresponding adsorption isotherms of the getter from 10(-4) Pa to 10 Pa are obtained. In contrast with its properties at ambient temperature, Zr57V36Fe7 displays a lower hydrogen adsorption rate but a higher hydrogen sorption capacity at low temperature conditions. From that, it is reasonable to recommend the use of Zr57V36Fe7 for hydrogen degassing of vacuum chambers at low temperatures.