Evaluation of Zr–V–Fe getter pump for UHV system

The nonevaporable getter pump St707(Zr–V–Fe) from SAES Getters, Inc. may be activated and operated at lower temperatures than those for the St101 getter. However, its application to a UHV system has not been reported yet. This paper reports the characteristics of the St707 getter strip in a UHV system as a linearly distributed pump. The getter is activated at ∼400 °C for 30 min. The pumping behavior of the getter strip for H2 and CO is studied. The initial pumping speeds per meter of the getter strip for H2 and CO are 300 and 190 ℓ/s, respectively; the H2 speed decreases slowly with increasing gas load to ∼90 ℓ/s at H2 gas loading of ∼50 Torr ℓ/m. Hydrogen equilibrium pressure at temperature <500 °C does not follow the Sieverts law and is higher that that predicted by SAES Getter, Inc. The application of St707 getter strip to the UHV system of ISABELLE is also discussed.