An electron gun includes: a cathode, which has a cathode holder and a cathode body; and a Wehnelt cylinder. The cathode holder receives the cathode body and the Wehnelt cylinder is suitable for bundling free electrons, which can escape from the cathode body toward the Wehnelt cylinder, to form an electron beam. The Wehnelt cylinder is interlockingly arranged, at least in some parts along a first inner surface facing the cathode holder, on an outer surface of the cathode holder and at least partly extends around the cathode holder.

A light modulated electron source utilizes a photon-beam source to modulate the emission current of an electron beam emitted from a silicon-based field emitter. The field emitter's cathode includes a protrusion fabricated on a silicon substrate and having an emission tip covered by a coating layer. An extractor generates an electric field that attracts free electrons toward the emission tip for emission as part of the electron beam. The photon-beam source generates a photon beam including photons having an energy greater than the bandgap of silicon, and includes optics that direct the photon beam onto the emission tip, whereby each absorbed photon creates a photo-electron that combines with the free electrons to enhance the electron beam's emission current. A controller modulates the emission current by controlling the intensity of the photon beam applied to the emission tip. A monitor measures the electron beam and provides feedback to the controller.

The present invention addresses the problem of providing a method for automatically adjusting an electron beam emitted from an electron gun equipped with a photocathode to the incident axis of an electron optical system. [Solution] An incident axis alignment method for an electron gun equipped with a photocathode, the electron gun being capable of emitting an electron beam in a first state due to the photocathode being irradiated with excitation light, and the method including at least an excitation light radiation step, a first excitation light irradiation position adjustment step for changing the irradiation position of the excitation light on the photocathode and adjusting the irradiation position of the excitation light, and an electron beam center detection step for detecting whether a center line of the electron beam in the first state coincides with an incident axis of an electron optical system.

A light modulated electron source utilizes a photon-beam source to modulate the emission current of an electron beam emitted from a silicon-based field emitter. The field emitter's cathode includes a protrusion fabricated on a silicon substrate and having an emission tip covered by a coating layer. An extractor generates an electric field that attracts free electrons toward the emission tip for emission as part of the electron beam. The photon-beam source generates a photon beam including photons having an energy greater than the bandgap of silicon, and includes optics that direct the photon beam onto the emission tip, whereby each absorbed photon creates a photo-electron that combines with the free electrons to enhance the electron beam's emission current. A controller modulates the emission current by controlling the intensity of the photon beam applied to the emission tip. A monitor measures the electron beam and provides feedback to the controller.

An electron emission source is provided. The electron emission source includes a first electrode, an insulating layer, and a second electrode. The first electrode, the insulating layer, and the second electrode are successively stacked with each other. the second electrode is a graphene layer, and the graphene layer is an electron emission end to emit electron. A thickness of the graphene layer ranges from about 0.1 nanometers to about 50 nanometers.

The present invention addresses the problem of providing an electron beam generator and an electron beam applicator for which maintenance is facilitated. The electron beam generator comprises a vacuum chamber, a photocathode holder, an activation vessel, and an internal motive power transmission member. The photocathode holder is capable of moving relative to the activation vessel.

An electron gun includes an emitter, an electron gun electrode, and a short-circuiting mechanism for setting the emitter and the electron gun electrode at the same potential. The short-circuiting mechanism includes a first switch member provided with a first switch electrode that is connected to the emitter and a second switch electrode that is connected to the electron gun electrode, a second switch member provided with a third switch electrode, and a drive unit that operates at least one of the first switch member and the second switch member to switch between a state in which the first switch electrode and the second switch electrode are in contact with the third switch electrode and a state in which the first switch electrode and the second switch electrode are separated from the third switch electrode. The short-circuiting mechanism has the same potential as a predetermined voltage.

Controlling total emission current of an electron emitting construct in an x-ray emitting device by providing a cathode, providing multiple active areas each active area having a gated cone electron source, including multiple emitter tips arranged in an array, a gate electrode, and a gate interconnect lead connected to the gate electrode, providing an x-ray emitting construct comprising an anode, the anode being an x-ray target, situating the x-ray emitting construct facing the active areas face each other, selecting a set of active areas, and activating selected active areas by conductively connecting a voltage source to their associated the gate electrode interconnect lead.

A charged particle gun for a charged particle beam device is described. The charged particle gun includes a gun housing; an emitter provided in the gun housing, the emitter being configured to emit a charged particle beam along an axis; an emitter power supply connected to the emitter; a trapping electrode provided in the gun housing, the trapping electrode at least partially surrounding the axis; a trapping power supply connected to the trapping electrode; and a shielding element shielding an electrostatic field of the trapping electrode from the axis during operation of the gun housing.

The apparatus includes: a photocathode including a substrate and a photoelectric film formed on the substrate; a light source configured to emit a pulsed excitation light; a condenser lens facing the substrate of the photocathode and configured to condense the pulsed excitation light toward the photocathode; a first anode electrode and a second anode electrode facing the photoelectric film of the photocathode; a first power supply configured to apply a first control voltage between the first anode electrode and the second anode electrode; and a second power supply configured to apply an acceleration voltage between the photocathode and the second anode electrode. The first anode electrode is disposed between the photocathode and the second anode electrode. A surface of the first anode electrode facing the second anode electrode has a recessed shape, and a surface of the second anode electrode facing the first anode electrode has a protruding shape.