An external grid-controlled hot cathode array electron gun, including an insulated cathode base, a filament, a plurality of hot cathode emission elements, and a grid-controlled structure is disclosed. In one aspect, the grid-controlled structure includes an insulated grid-controlled structure body and a plurality of through holes. One side of the grid-controlled structure body abuts against the cathode base to clamp the filament between the grid-controlled structure body and the cathode base and the plurality of hot cathode emission elements are inserted into the plurality of through holes respectively.

A flat emitter, in an embodiment, includes an emitter surface to emit electrons when a filament current is applied; a first end region including at least one first connection leg; and a second end region including at least one second connection leg. According to an embodiment, at least one connection leg is embodied as a band-type connection leg and is torsioned at an angle in a longitudinal axis. According to an embodiment, the first connection leg and the second connection leg are embodied as band-type connection legs and in each case are torsioned at a definable angle in a longitudinal axis. As a result, a simply constructed flat emitter in terms of design is achieved, with a longer service life and a high level of electron emission.

A flat emitter, in an embodiment, includes an emitter surface to emit electrons when a filament current is applied; a first end region including at least one first connection leg; and a second end region including at least one second connection leg. According to an embodiment, at least one connection leg is embodied as a band-type connection leg and is torsioned at an angle in a longitudinal axis. According to an embodiment, the first connection leg and the second connection leg are embodied as band-type connection legs and in each case are torsioned at a definable angle in a longitudinal axis. As a result, a simply constructed flat emitter in terms of design is achieved, with a longer service life and a high level of electron emission.

An emitter with a diameter of 100 nm or less is used with a protective cap layer and a diffusion barrier between the emitter and the protective cap layer. The protective cap layer is disposed on the exterior surface of the emitter. The protective cap layer includes molybdenum or iridium. The emitter can generate an electron beam. The emitter can be pulsed.

An external grid-controlled hot cathode array electron gun, including an insulated cathode base, a filament, a plurality of hot cathode emission elements, and a grid-controlled structure is disclosed. In one aspect, the grid-controlled structure includes an insulated grid-controlled structure body and a plurality of through holes. One side of the grid-controlled structure body abuts against the cathode base to clamp the filament between the grid-controlled structure body and the cathode base and the plurality of hot cathode emission elements are inserted into the plurality of through holes respectively.

In the present invention, a flat emitter is formed by the formation of emitter material wires into a unitary non-porous flat emitter structure. The wires are formed with increased yield and tensile strength as a result of the manner of the formation of the emitter material or metal into the wires that is transferred to the flat emitter. To form the flat emitter, the wires are encapsulated and subjected to sufficient temperatures and pressure in a hot isostatic pressing treatment/process to increase the density of the wires into a solid sheet without the presence of voids or pores in the sheet. In forming the emitter sheet in this manner, the strength properties from the wires are retained within the sheet to provide the emitter with increased creep resistance and a consequently longer useful life in the x-ray tube.

A method for manufacturing an electron source includes steps of sandwiching a welding object in which a tip of an electron emission material and a tungsten filament overlap in direct contact between a pair of welding electrodes, and welding the tip and the tungsten filament by causing a current to flow while pressing forces are applied to the welding object by the pair of welding electrodes. A thickness of the welding object is within a range of 50 to 500 m.

A method for manufacturing an electron source includes steps of sandwiching a welding object in which a tip of an electron emission material and a tungsten filament overlap in direct contact between a pair of welding electrodes, and welding the tip and the tungsten filament by causing a current to flow while pressing forces are applied to the welding object by the pair of welding electrodes. A thickness of the welding object is within a range of 50 to 500 m.

A pair of straight or angularly oriented flat emitters formed of an electron emissive material are positioned on an emitter support structure and are electrically connected to one another regardless of the mounting structure on which the emitters are positioned. The electrical connections between the emitters are formed directly between the emitters using electrically conductive material members that are placed between and affixed to the emitters to provide the electrical pathway or connection therebetween the emitters after formation of the emitters. These electrical connection members form an electrical connection between the angled pair of emitters separately from an emitter support structure on the cathode, such that the electrical connection members and angled emitters including the connection members can separate the mechanical architecture of the cathode assembly from the electrical architecture, thereby creating a simplified construction for the cathode assembly and associated x-ray tubes.

An electron source according to the present disclosure includes a columnar portion made of a first material having an electron emission characteristic; and a tubular portion that is disposed to surround the columnar portion and made of a second material having a higher work function than the first material, wherein a hole that extends in a direction from one end face toward the other end face and has a substantially circular cross-sectional shape is formed in the tubular portion, and the columnar portion has a substantially triangular or substantially quadrangular cross-sectional shape and is fixed to the tubular portion in an abutting engagement with an inner surface of the hole.