An ionization gauge includes an anode, a cathode, and an electromagnetic wave source. The cathode includes a first cathode plate having a through hole through which the anode passes, a storage portion configured to store the electromagnetic wave source, and a passage arranged between the storage portion and the through hole and configured to pass an electromagnetic wave generated by the electromagnetic wave source.

An ionization gauge includes an anode, a cathode, and an electromagnetic wave source. The cathode includes a first cathode plate having a through hole through which the anode passes, a storage portion configured to store the electromagnetic wave source, and a passage arranged between the storage portion and the through hole and configured to pass an electromagnetic wave generated by the electromagnetic wave source.

An ionization gauge includes an anode, a cathode, and an electromagnetic wave source. The cathode includes a first cathode plate having a through hole through which the anode passes, a storage portion configured to store the electromagnetic wave source, and a passage arranged between the storage portion and the through hole and configured to pass an electromagnetic wave generated by the electromagnetic wave source.

An ionization gauge includes an anode, a cathode, and an electromagnetic wave source. The cathode includes a first cathode plate having a through hole through which the anode passes, a storage portion configured to store the electromagnetic wave source, and a passage arranged between the storage portion and the through hole and configured to pass an electromagnetic wave generated by the electromagnetic wave source.

An ionization gauge includes an anode having a rod shape, and a cathode including a cathode plate having a through hole through which the anode extends. A shape of the through hole on a section along an axial direction of the anode includes a concave portion sandwiched between two convex portions.

An ionization gauge includes an anode having a rod shape, and a cathode including a cathode plate having a through hole through which the anode extends. A shape of the through hole on a section along an axial direction of the anode includes a concave portion sandwiched between two convex portions.

A gauge having a housing formed of a polymer material and one or more electrical feedthrough pins disposed in the housing. The electrical feedthrough pins can be oriented substantially perpendicular to each other and have complex shapes.

A gauge having a housing formed of a polymer material and one or more electrical feedthrough pins disposed in the housing. The electrical feedthrough pins can be oriented substantially perpendicular to each other and have complex shapes.

The disclosure includes an outer electrode and an inner electrode. The outer electrode defines an inner volume and is configured to receive injected electrons through at least one aperture. The inner electrode positioned in the inner volume. The outer electrode and inner electrode are configured to confine the received electrons in orbits around the inner electrode in response to an electric potential between the outer electrode and the inner electrode. The apparatus does not include a component configured to generate an electron-confining magnetic field.

The disclosure includes an ionization chamber, a first electron multiplier, and a second electron multiplier. The ionization chamber is configured to receive gas molecules from an environment at a pressure. The first electron multiplier is configured to receive a plurality of photons from a photon source, generate a first plurality of electrons from the plurality of photons, and discharge the first plurality of electrons into the ionization chamber to generate a plurality of gas ions from at least a portion of the gas molecules. The second electron multiplier is configured to receive the plurality of gas ions from the ionization chamber and generate a second plurality of electrons from the plurality of gas ions that is proportional to a quantity of the plurality of gas ions. A quantity of electrons of the second plurality of electrons is indicative of the pressure.