Patent 7295015 was granted and assigned to Brooks Automation on November, 2007 by the United States Patent and Trademark Office.
An ionization gauge for isolating an electron source from gas molecules includes the electron source for generating electrons, a collector electrode for collecting ions formed by the impact between the electrons and gas molecules, and an electron window which isolates the electron source from the gas molecules. The ionization gauge can have an anode which defines an anode volume and decelerates and retains the electrons in a region of the anode. The ionization gauge can have a plurality of electron sources and/or collector electrodes. The collector electrode(s) are be located within the anode volume. The ionization gauge can be a Bayard-Alpert type that measures pressure.