An ion detector includes a first dynode, a second dynode, a scintillator, a conductive layer, and a photomultiplier tube. The first dynode is configured to emit a charged particle in response to the incidence of the ion. The second dynode is configured to be given a negative potential and emit a secondary electron in response to incidence of the charged particle from the first dynode. The scintillator includes an electron incident surface arranged to receive the secondary electron from the second dynode, and is configured to convert the secondary electron into light. The conductive layer is disposed on the electron incident surface. The photomultiplier tube is configured to detect the light from the scintillator.

An ion detector includes a first dynode, a second dynode, a scintillator, a conductive layer, and a photomultiplier tube. The first dynode is configured to emit a charged particle in response to the incidence of the ion. The second dynode is configured to be given a negative potential and emit a secondary electron in response to incidence of the charged particle from the first dynode. The scintillator includes an electron incident surface arranged to receive the secondary electron from the second dynode, and is configured to convert the secondary electron into light. The conductive layer is disposed on the electron incident surface. The photomultiplier tube is configured to detect the light from the scintillator.

An electron multiplier includes a series of discrete electron emissive surfaces or a continuous electron emissive resistive surface configured to provide an electron amplification chain; and a housing surrounding the series of electron emissive surfaces or the continuous electron emissive resistive surface and separating the environment inside the housing from the environment outside the housing. The housing includes an electron-transparent, gas-impermeable barrier configured to allow electrons to pass through into the housing to reach a first discrete electron emissive surface of the series of discrete electron emissive surfaces or a first portion of the continuous electron emissive resistive surface.

An electron multiplier includes a series of discrete electron emissive surfaces or a continuous electron emissive resistive surface configured to provide an electron amplification chain; and a housing surrounding the series of electron emissive surfaces or the continuous electron emissive resistive surface and separating the environment inside the housing from the environment outside the housing. The housing includes an electron-transparent, gas-impermeable barrier configured to allow electrons to pass through into the housing to reach a first discrete electron emissive surface of the series of discrete electron emissive surfaces or a first portion of the continuous electron emissive resistive surface.

An electron multiplier includes a series of discrete electron emissive surfaces or a continuous electron emissive resistive surface configured to provide an electron amplification chain; and a housing surrounding the series of electron emissive surfaces or the continuous electron emissive resistive surface and separating the environment inside the housing from the environment outside the housing. The housing includes an electron-transparent, gas-impermeable barrier configured to allow electrons to pass through into the housing to reach a first discrete electron emissive surface of the series of discrete electron emissive surfaces or a first portion of the continuous electron emissive resistive surface.

An electron multiplier includes a series of discrete electron emissive surfaces or a continuous electron emissive resistive surface configured to provide an electron amplification chain; and a housing surrounding the series of electron emissive surfaces or the continuous electron emissive resistive surface and separating the environment inside the housing from the environment outside the housing. The housing includes an electron-transparent, gas-impermeable barrier configured to allow electrons to pass through into the housing to reach a first discrete electron emissive surface of the series of discrete electron emissive surfaces or a first portion of the continuous electron emissive resistive surface.

A photomultiplier includes a housing including a proximal end and a distal end, an optical window disposed at the proximal end of the housing, an end-wall plate disposed at the distal end of the housing, a feedthrough that penetrates through the end-wall plate, and a gas electron multiplier (GEM) board disposed between the optical window and the end-wall plate.

A photomultiplier includes a housing including a proximal end and a distal end, an optical window disposed at the proximal end of the housing, an end-wall plate disposed at the distal end of the housing, a feedthrough that penetrates through the end-wall plate, and a gas electron multiplier (GEM) board disposed between the optical window and the end-wall plate.

Disclosed herein is a photomultiplier comprising: an electron ejector; a detector; a substrate; and a first electrode in the substrate; a second electrode in the substrate; a third electrode in the substrate; wherein each of the first, second and third electrodes comprises a flat or curved surface at an angle to a normal direction of the substrate; wherein each of the first, second and third electrodes comprises a first end and a second end, the first end being closer to the electron ejector than the second end; wherein the first, second and third electrodes are spatially arranged such that the second ends of the first, second and third electrode are on a same plane, or such that a plane the second ends of the first and third electrodes are on crosses the second electrode.

Disclosed herein is a photomultiplier comprising: an electron ejector; a detector; a substrate; and a first electrode in the substrate; a second electrode in the substrate; a third electrode in the substrate; wherein each of the first, second and third electrodes comprises a flat or curved surface at an angle to a normal direction of the substrate; wherein each of the first, second and third electrodes comprises a first end and a second end, the first end being closer to the electron ejector than the second end; wherein the first, second and third electrodes are spatially arranged such that the second ends of the first, second and third electrode are on a same plane, or such that a plane the second ends of the first and third electrodes are on crosses the second electrode.