This invention concerns a photo-cathode for a vacuum system, wherein the photo-cathode is configured for receiving electromagnetic radiation having an incoming wavelength and for emitting electrons in response thereto. The photo-cathode comprises a conducting structure having a geometry, the geometry comprising a tip section. The tip section is adapted to provide field enhancement, β, when the conducting structure is illuminated with the electromagnetic radiation, wherein β is greater than about 10.sup.2. The photo-cathode further comprising a substrate, the substrate being or comprising a dielectric substrate, the substrate supporting the conducting structure.

This invention concerns a photo-cathode for a vacuum system, wherein the photo-cathode is configured for receiving electromagnetic radiation having an incoming wavelength and for emitting electrons in response thereto. The photo-cathode comprises a conducting structure having a geometry, the geometry comprising a tip section. The tip section is adapted to provide field enhancement, β, when the conducting structure is illuminated with the electromagnetic radiation, wherein β is greater than about 10.sup.2. The photo-cathode further comprising a substrate, the substrate being or comprising a dielectric substrate, the substrate supporting the conducting structure.

An injector arrangement for providing an electron beam. The injector arrangement comprises a first injector for providing electron bunches, and a second injector for providing electrons bunches. The injector arrangement is operable in a first mode in which the electron beam comprises electron bunches provided by the first injector only and a second mode in which the electron beam comprises electron bunches provided by the second injector only.

An injector arrangement for providing an electron beam. The injector arrangement comprises a first injector for providing electron bunches, and a second injector for providing electrons bunches. The injector arrangement is operable in a first mode in which the electron beam comprises electron bunches provided by the first injector only and a second mode in which the electron beam comprises electron bunches provided by the second injector only.

In-situ methods for the batch fabrication of flat-panel micro-channel plate (MCP) photomultiplier tube (PMT) detectors (MCP-PMTs), without transporting either the window or the detector assembly inside a vacuum vessel are provided. The method allows for the synthesis of a reflection-mode photocathode on the entrance to the pores of a first MCP or the synthesis of a transmission-mode photocathode on the vacuum side of a photodetector entrance window.

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 photoinjector system containing modularly-structured waveguide-mode launcher, which is reversibly connected to the RF gun (containing a tubular construction formed with disattachably-affixed to one another structurally-complementary halves); and a solenoid magnet in operation enclosing such tubular structure in a central hollow. The resulting quality, power, and frequency rate of operation as well as cost of manufacturing and operation of the system are superior as compared with those of a related art system.

A photoinjector system containing modularly-structured waveguide-mode launcher, which is reversibly connected to the RF gun (containing a tubular construction formed with disattachably-affixed to one another structurally-complementary halves); and a solenoid magnet in operation enclosing such tubular structure in a central hollow. The resulting quality, power, and frequency rate of operation as well as cost of manufacturing and operation of the system are superior as compared with those of a related art system.

The present invention addresses the problem of providing a device with which it is possible to adjust the focal point of an electron beam both toward a shorter focal point and toward a longer focal point after an electronic gun was fitted on a counterpart device. The aforementioned problem can be solved by an electron gun including a photocathode, and an anode, the electron gun furthermore comprising an intermediate electrode disposed between the photocathode and the anode, the intermediate electrode comprising an electron-beam passage hole through which an electron beam released from the photocathode passes, and the electron-beam passage hole having formed therein a drift space in which, when an electrical field is formed between the photocathode and the anode due to application of a voltage, the effect of the electrical field can be disregarded.

The present invention addresses the problem of providing a device with which it is possible to adjust the focal point of an electron beam both toward a shorter focal point and toward a longer focal point after an electronic gun was fitted on a counterpart device. The aforementioned problem can be solved by an electron gun including a photocathode, and an anode, the electron gun furthermore comprising an intermediate electrode disposed between the photocathode and the anode, the intermediate electrode comprising an electron-beam passage hole through which an electron beam released from the photocathode passes, and the electron-beam passage hole having formed therein a drift space in which, when an electrical field is formed between the photocathode and the anode due to application of a voltage, the effect of the electrical field can be disregarded.