A photocathode including a substrate, a photoelectric conversion layer provided on the substrate and generating photoelectrons in response to incidence of light, and an underlayer provided between the substrate and the photoelectric conversion layer and containing beryllium, in which the underlayer has a first underlayer containing a nitride of beryllium.

A photocathode including a substrate, a photoelectric conversion layer provided on the substrate and generating photoelectrons in response to incidence of light, and an underlayer provided between the substrate and the photoelectric conversion layer and containing beryllium, in which the underlayer has a first underlayer containing a nitride of beryllium.

An electron multiplier apparatus of the type used in ion detectors, and modifications thereto for extending the operational lifetime or otherwise improving performance. The electron multiplier includes a series of discrete electron emissive surfaces configured to provide an electron amplification chain, the electron multiplier being configured so as to inhibit or prevent a contaminant from entering into, or passing partially through, or passing completely through the electron multiplier. The electron multiplier may include one or more baffles configured. so as to decrease vacuum conductance of the electron multiplier compared to the same or similar electron multiplier not having one or more baffles.

An electron multiplier apparatus of the type used in ion detectors, and modifications thereto for extending the operational lifetime or otherwise improving performance. The electron multiplier includes a series of discrete electron emissive surfaces configured to provide an electron amplification chain, the electron multiplier being configured so as to inhibit or prevent a contaminant from entering into, or passing partially through, or passing completely through the electron multiplier. The electron multiplier may include one or more baffles configured. so as to decrease vacuum conductance of the electron multiplier compared to the same or similar electron multiplier not having one or more baffles.

A photomultiplier tube (PMT) detector assembly includes a PMT and an analog PMT detector circuit. The PMT includes a photocathode configured to emit an initial set of photoelectrons in response to an absorption of photons. The PMT includes a dynode chain with a plurality of dynodes. The dynode chain is configured to receive the initial set of photoelectrons, generate at least one amplified set of photoelectrons, and direct the at least one amplified set of photoelectrons. The PMT includes an anode configured to receive the at least one amplified set of photoelectrons, with a digitized image being generated based on a measurement of the final amplified set of photoelectrons. The digitized image is corrected by applying an output of the signal measured by the analog PMT detector circuit to the digitized image.

A photomultiplier tube (PMT) detector assembly includes a PMT and an analog PMT detector circuit. The PMT includes a photocathode configured to emit an initial set of photoelectrons in response to an absorption of photons. The PMT includes a dynode chain with a plurality of dynodes. The dynode chain is configured to receive the initial set of photoelectrons, generate at least one amplified set of photoelectrons, and direct the at least one amplified set of photoelectrons. The PMT includes an anode configured to receive the at least one amplified set of photoelectrons, with a digitized image being generated based on a measurement of the final amplified set of photoelectrons. The digitized image is corrected by applying an output of the signal measured by the analog PMT detector circuit to the digitized image.

The effective quantum efficiency of a metal-channel photomultiplier tube can be increased with an optical system. The optical system can direct incident light from areas of low efficiency on the cathode of the metal-channel photomultiplier tube instead to areas of high efficiency on the cathode. These high-efficiency areas of the cathode can correspond to a position between the dynode structure.

The effective quantum efficiency of a metal-channel photomultiplier tube can be increased with an optical system. The optical system can direct incident light from areas of low efficiency on the cathode of the metal-channel photomultiplier tube instead to areas of high efficiency on the cathode. These high-efficiency areas of the cathode can correspond to a position between the dynode structure.

An electron tube includes a housing having a window having an electromagnetic wave transmitting property, an electron emission plate disposed inside the housing, the electron emission plate emitting electrons, and a holding member disposed inside the housing and configured to hold the electron emission plate and to apply a voltage to the electron emission plate. The electron emission plate has a first main surface and a second main surface facing each other. The holding member has a base portion being in contact with the first main surface, and a plurality of electron emission plate biasing portions which are in contact with an edge of the second main surface and are configured to elastically bias the electron emission plate to the base portion. The holding member is electrically connected to the second main surface through the plurality of electron emission plate biasing portions.

An electron tube includes a housing having a window having an electromagnetic wave transmitting property, an electron emission plate disposed inside the housing, the electron emission plate emitting electrons, and a holding member disposed inside the housing and configured to hold the electron emission plate and to apply a voltage to the electron emission plate. The electron emission plate has a first main surface and a second main surface facing each other. The holding member has a base portion being in contact with the first main surface, and a plurality of electron emission plate biasing portions which are in contact with an edge of the second main surface and are configured to elastically bias the electron emission plate to the base portion. The holding member is electrically connected to the second main surface through the plurality of electron emission plate biasing portions.