Dual Pumping Speeds of Some Ionization Pumps

Abstract

IN recent years the phenomenon of ion pumping in ionization gauges has received widespread attention. Work in many laboratories has shown that in an ionization gauge, activated gas molecules interact with the glass walls of the tube and are removed from the gas phase at a rate depending largely upon the pumping history of the gauge. Alpert¹, Nottingham² and others have shown that in the Bayard–Alpert form of gauge, the glass walls assume an electrical potential, slightly negative with respect to the cathode delivering primary electrons, and the pumping action of the gauge is due largely to ions which acquire a high kinetic energy and are driven into the walls.