Absorption of Oxygen and Carbon Monoxide by Barium Alloy Getters

Abstract

WAGENER¹ has described a novel method of finding both the pumping speed and capacity of getters, and has made measurements^2,3 with common gases and barium alloy getters of the type used in radio valves. The results obtained were conflicting. In the earlier paper² it was reported that the speed of pumping depended upon the amount of ionizing electron current in a nearby diode or ionization gauge. Wagener's measurements were made in a range of electron current from 5 m.amp. to 20 m.amp. If these measurements are extrapolated to zero current they show that the speed of pumping is not then zero, contrary to the hypothesis suggested in the paper. In the later publication³ it was reported that the speed of pumping was about the same without, as with, an ionizing electron discharge. The present work was undertaken to decide between these contrary findings. It was decided to study the pumping of oxygen, because the chemical affinity of barium for this gas would make more remarkable any necessity for electron current.