A vacuum tube insert assembly includes a flared insert piece having an annular flange and a stem each constructed of glass. The stem extends axially from the flange. The flange surrounds a perimeter edge of a plug concavity defined by the stem. Feed-through pins pass axially through the stem and are sealed thereto. The pins terminate inside of the concavity to form a plug. A socket connects to the plug within the concavity and includes receptacles that removably couple to the pins, with an engagement feature preventing erroneous plug and socket connections. A method includes axially inserting the pins through the stem at a fixed relative position such that the pins are arranged within the plug concavity, sealing the stem such that the stem is vacuum-sealed to the pins, thereby forming the plug, and removably coupling mating receptacles of the socket to the pins.

The present invention relates to a rotary anode X-ray source. In addition to a primary cathode of a rotary anode X-ray tube, an auxiliary cathode is provided in the rotary anode X-ray tube. Electrons from the auxiliary cathode are focused into an area on the anode, from which X-rays cannot enter the used X-ray beam generated by the primary cathode. An emission current controlling device is used to control the electron emission of the auxiliary cathode. Thus, the voltage down-ramp for dual energy scanning is kept constant even though the primary X-ray output changes for the sake of dose modulation or during a transient of the primary electron current.

The present invention relates to a rotary anode X-ray source. In addition to a primary cathode of a rotary anode X-ray tube, an auxiliary cathode is provided in the rotary anode X-ray tube. Electrons from the auxiliary cathode are focused into an area on the anode, from which X-rays cannot enter the used X-ray beam generated by the primary cathode. An emission current controlling device is used to control the electron emission of the auxiliary cathode. Thus, the voltage down-ramp for dual energy scanning is kept constant even though the primary X-ray output changes for the sake of dose modulation or during a transient of the primary electron current.

An electron source (2) for generating an electron beam (8) having a cathode (1) and an anode (4) in the form of a graphene layer (6, 12) epitaxially grown on a silicon carbide substrate (5). The invention is suitable for monolithic preparation of a miniaturized source of a high-energy focused electron beam, including its use as an on-chip X-ray source. All components can be prepared from or on a single silicon carbide chip.

A method of manufacturing a CNT paste emitter in accordance with an exemplary embodiment of the present disclosure includes a process of mixing first CNT powder, graphite nanoparticles, SiC nanoparticles, Ni nanoparticles, a dispersant and distilled water and then performing a dispersion process by means of ultrasonication, a process of acquiring second CNT powder by filtering a solution dispersed during the dispersion process, a process of mixing the second CNT powder with a graphite binder and then preparing a CNT paste by means of ball milling, and a process of forming an interface layer on a metal or graphite substrate and then bonding the CNT paste.

It is a CNT device (1) (carbon-metal structure) equipped with a carbon nanotube layer (2) (CNT layer 2; same hereafter) on a metal pedestal (4). The metal pedestal (4) is brazed to the CNT layer (2) with a brazing material layer (3) interposed therebetween. When manufacturing the CNT device (1), firstly, the CNT layer (2) is formed on a heat-resistant textured substrate (6). Next, the metal pedestal (4) is brazed to the CNT layer (2) that is on the heat-resistant textured substrate (6) with the brazing material layer (3) interposed therebetween. Then, the metal pedestal (4) (and the CNT layer 2) is peeled off the heat-resistant textured substrate (6) to transfer the CNT layer (2) from the heat-resistant textured substrate (6) to the metal pedestal (4).

The present invention provides an emitter, which comprises carbon nanotubes and is excellent in the efficiency of electron emission, and an X-ray tube comprising the same.

The present disclosure provides a cathode emission device. The cathode emission device may comprise a cathode assembly, including: a first filament, a second filament, and a grid electrode. The grid electrode may be operably connected to the first filament and surrounding the first filament and the second filament. The cathode assembly may be configured to be operably connected to a high-voltage generator and switchable between a first connection configuration and a second connection configuration.

The present disclosure provides a cathode emission device. The cathode emission device may comprise a cathode assembly, including: a first filament, a second filament, and a grid electrode. The grid electrode may be operably connected to the first filament and surrounding the first filament and the second filament. The cathode assembly may be configured to be operably connected to a high-voltage generator and switchable between a first connection configuration and a second connection configuration.

An x-ray generating unit includes an x-ray tube that is substantially transparent to x-rays. A cathode is within the x-ray tube and defines a plurality of spaced apart cavities. An anode includes a material that emits x-rays when impacted by electrons. A plurality of filaments is each disposed in a different one of the cavities. Each of the filaments is electrically coupled to each other and to an activating voltage source in parallel. Each of the filaments emits a focused electron beam directed to a different predetermined spot on the anode upon application of a predetermined voltage between the cathode and the anode, thereby causing the anode to generate x-rays. Each of the plurality of spaced apart cavities is aimed at the anode so that each predetermined spot on the anode is separated from each other spot by a gap that is not impacted by an electron beam.