Ionization gauge with a cold electron source
AssigneeBrooks Automation, Inc.
InventorsRichard A. Knott, Gerardo A. Brucker, Paul C. Arnold
Life of this patent
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Abstract
An ionization gauge that eliminates a hot cathode or filament, but maintains a level of precision of gas density measurements approaching that of a hot cathode ionization gauge. The ionization gauge includes a collector electrode disposed in an ionization volume, an electron source without a heated cathode, and an electrostatic shutter that regulates the flow of electrons between the electron source and the ionization volume. The electrostatic shutter controls the flow of electrons based on feedback from an anode defining the ionization volume. The electron source can be a Penning or glow discharge ionization gauge.
Claims27
An ionization gauge comprising:
- an electron source that generates electrons;
- a collector electrode disposed in an ionization volume, the collector electrode configured to collect ions formed by the impact between the electrons and gas molecules;
- and
- an electrostatic shutter configured to control the flow of electrons between the electron source and the ionization volume.
A method of measuring a gas pressure from gas molecules and atoms, comprising:
- generating electrons in an electron source;
- regulating the flow of electrons between the electron source and an ionization volume;
- and
- collecting ions formed by an impact between the electrons and the gas molecules and atoms in the ionization volume.
An ionization gauge comprising:
- an electron source that generates electrons;
- a first collector electrode, and a second collector electrode with both being disposed in an ionization volume, the first and second collector electrodes configured to collect ions formed by the impact between the electrons and gas molecules;
- and
- an electrostatic shutter configured to control the flow of electrons between the electron source and the ionization volume.
An ionization gauge comprising:
- an electron source that generates electrons;
- a collector electrode disposed in an ionization volume, the collector electrode configured to collect ions formed by the impact between the electrons, and gas molecules;
- an electrostatic shutter configured to control the flow of electrons between the electron source, and the ionization volume;
- and
- an envelope surrounding the electron source, the electrostatic shutter and the envelope permitting electrons from a predetermined electric potential to enter into the ionization volume.
A method of measuring a gas pressure from gas and atoms comprising:
- generating electrons from a source;
- regulating the flow of electrons from the source to the ionization volume;
- controlling the electron energy from the electron source;
- and
- collecting ions formed by an impact between the electrons and gas molecules, and atoms in the ionization volume.
Dependencies are inferred from the claim text.