The present invention generally relates to systems and methods for generating controllable beam of electrons using a hollow-cathode triode electron gun that substantially mitigate impact of back-streaming electrons. In one embodiment, a triode hollow-cathode electron gun is configured to provide electrons and substantially mitigates the impact of back-streaming electrons. The triode hollow-cathode electron gun includes a hollow cathode, a heating filament, an anode, a control grid, a shadow grid and a sleeve mechanically coupled to the hollow-cathode. The sleeve is substantially centered on the axis of the triode hollow-cathode electron gun and configured to maintain shape and trajectory of emitted beams of electrons.

A filament assembly can include: a button having a planar emitter region with one or more apertures extending from an emission surface of the planar emitter region to an internal surface opposite of the emission surface; an inlet electrical lead coupled to the button at a first side; an outlet electrical lead coupled to the button at a second side opposite of the first side; and a low work function object positioned adjacent to the internal surface of the planar emitter region and retained to the button. The planar emitter region can include a plurality of apertures. The low work function object can include a porous ceramic material having the barium, and may have a polished external surface. An electron gun can include the filament assembly. An additive manufacturing system can include the electron gun having the filament assembly.

The invention relates to an electron gun for generating a flat electron beam, comprising a cathode with an emission surface which is curved about a central axis and which is designed to emit electrons. The electron gun further comprises an accelerating device for accelerating the electrons in a radial direction towards a target region on the central axis. Furthermore, the emission surface has a width in the azimuth direction and a height oriented perpendicularly to the width, said width being at least ten times greater than the height.

In the present invention, a cathode assembly for an X-ray tube is provided including a cathode cup, a pair of emitters disposed within the cup and each configured to emit an electron beam therefrom and an electrode spaced from the pair of emitters and configured to affect the shape and/or intensity of the electron beams emitted by the pair of emitters. The electrode includes a rod extending across a central aperture defined within the electrode that enables the electrode to grid or focus the electron beam or beams emitted from the emitters using a bias voltage between +10 kV and 10 kV.

An electron gun, an X-ray source and a CT device are provided. The electron gun includes a body having a first end portion and a second end portion opposite to each other, wherein the first end portion is a connecting end portion; an internal cavity is formed in the body and has an opening positioned on the second end portion,d a cathode, a grid, a compensation electrode and a focus electrode, orderly arranged in the internal cavity in a direction from the first end portion to the second end portion.

A system for injecting radio frequency (RF) pulses into an RF linear accelerator (RF LINAC) cavity is described. In accordance with the description an RF power amplifying element, typically a compact planar triode (CPT), is directly mounted to an outside of a hermetically sealed RF cavity. The direct mounting of the RF power amplifying element places the antennaresponsible for coupling power into the RF cavityphysically on the RF cavity side of a hermetic high-voltage (HV) break. The RF input, RF circuitry, biasing circuitry, and RF power amplifier are all outside of the vacuum cavity region. The direct mounting arrangement facilitates easy inspection and replacement of the RF power amplifier, the RF input and biasing circuitry. The direct mounting arrangement also mitigates the deleterious effects of multipactoring associated with placing the RF power amplifier and associated RF circuitry in the vacuum environment of the RF LINAC cavity.

The purpose of the present invention is to provide a charged particle beam device that exhibits high performance due to the use of vanadium glass coatings, and to provide a method of manufacturing a component for a charged particle beam device. Specifically provided is a charged particle beam device using a vacuum component characterized by comprising a metal container, the interior space of which is evacuated to form a high vacuum, and coating layers formed on the surface on the interior space-side of the metal container, wherein the coating layers are vanadium-containing glass, which is to say an amorphous substance. Coating vanadium glass onto walls of a space where it is desirable to form a high vacuum, for example walls in the vicinity of an electron source, reduces gas discharge in the vicinity of the electron source, and the getter effect of the coating layer induces localized evacuation and enables the formation of an extremely high vacuum, even in spaces having a complex structure, without providing a large high-vacuum pump.

Various methods and systems are provided for a cathode of an X-ray imaging system. A method for fabricating the cathode comprises machining a plurality of focusing features on a focusing element and welding the focusing element to a base assembly.

An electron gun supporting member includes an insulating supporting member configured such that its one end is connected to a predetermined member having a ground potential and other end is connected to a high-voltage electrode to which a high potential being a negative high potential for emitting electrons from an electron source is applied, so as to support the high-voltage electrode, and a metal film formed in a partial region, which contacts neither the high-voltage electrode nor the predetermined member, on the outer surface of the insulating supporting member.

Provided is an electron beam source for generating an electron beam comprising a cathode, an anode and a grid for regulating an electron beam current. The cathode has a base and a protrusion with sidewalls and a top surface. The base surface and the top surface are essentially flat. The base surface and the top surface are arranged at a predetermined distance from each other. The base is larger than the protrusion. The electron beam source further comprising a control unit adapted for changing an applied voltage to the grid for switching a spot size of the electron beam on a target surface between at least a first a first spot size corresponding to emission from the top surface of the cathode only and to a second spot size corresponding to emission from the top surface and the base surface of the cathode.