92results about "X-ray tube cathode assembly" patented technology

An field emitter array system (10) includes a housing (50). An emitter array (80) generates an electron beam and has multiple emitter elements (81) that are disposed within the housing (50). Each of the emitter elements has multiple activation connections (92).

An x-ray tube comprising an electron gun assembly having an electron gun container housing an electron generator for generating electrons in a first direction along a first axis. The beam of electrons impinges upon an anode which emits x-rays in response to the beam of electrons. The gun container is characterized by having a discharge end comprising a solid spherical shape.

The present invention relates to a radiation generating apparatus which includes an envelope provided with a first window through which radiation is transmitted, a radiation tube housed in the envelope and provided with a second window through which the radiation is transmitted, the second window being located at a position opposite the first window, and an insulating fluid adapted to fill between the inner wall of the envelope and the radiation tube. Plural plates are arranged side by side between the first window including its periphery and the second window including its periphery by overlapping one another via gaps. The gaps is formed among the plates, thereby the withstanding voltage between the first window and second window is made larger.

An apparatus and method for determining the density and other properties of a formation surrounding a borehole using a high voltage x-ray generator. One embodiment comprises a stable compact x-ray generator capable of providing radiation with energy of 260 keV and higher while operating at temperatures equal to or greater than 125° C. In another embodiment, radiation is passed from an x-ray generator into the formation; reflected radiation is detected by a short spaced radiation detector and a long spaced radiation detector. The output of these detectors is then used to determine the density of the formation. In one embodiment, a reference radiation detector monitors a filtered radiation signal. The output of this detector is used to control at least one of the acceleration voltage and beam current of the x-ray generator.

In a radiation imaging apparatus which comprises an envelope which has a first window for transmitting a radiation and is filled with an insulating liquid, a radiation tube in the envelope which has, at a position facing the first window, a second window for transmitting the radiation, and a shielding member, a solid insulating member is arranged between the shielding member and the inner wall of the envelope, an opening is formed at a position on the insulating member corresponding to the first window, and a shortest distance from the shielding member to the first window or the inner wall of the envelope through the opening of the insulating member without the insulating member is made longer than a shortest distance from the shielding member to the first window or the inner wall of the envelope through the insulating member, thereby improving withstand voltage performance without reducing an radiation amount.

An imaging tube (52, 52′) includes a vacuum vessel (96) and an atmospheric-side supply line assembly (104, 104′). The vacuum vessel (96) has an internal vacuum (98). The supply line assembly (104, 104′) has an electromagnetic shield (94, 94′). An insulator (106, 106′) separates the internal vacuum (98) from an external atmosphere (126). A cathode post (92, 92′) resides within the vacuum vessel (96). The cathode post (92, 92′) is in conductive proximity with the electromagnetic shield (94, 94′) and prevents the bending of electrostatic field lines within the imaging tube (52, 52′).

Systems, methods, and devices with improved electrode configuration for downhole nuclear radiation generators are provided. For example, one embodiment of a nuclear radiation generator capable of downhole operation may include a charged particle source, a target material, and an acceleration column between the charged particle source and the target material. The acceleration column may include an intermediate electrode that remains floating at a variable potential, being electrically isolated from the rest of the acceleration column.

An indirectly heated cathode assembly is presented. The indirectly heated cathode assembly includes at least one electron source for generating a first electron beam, an emitter for producing a second electron beam when heated by the first electron beam and a focusing electrode for controlling, and directing the first electron beam towards the emitter.

A transmission type X-ray tube includes an electrode lead (4) holding a cathode filament (7) and a stem unit (1) to which a sealing member (5), an exhaust tube (2), and the like are attached by brazing, and an irradiation widow frame (8) having an X-ray irradiation window (9) attached by brazing. The other end side (52) of the sealing member (5) is attached to an open end (83) of the irradiation window frame (8) by welding. Thus, it is possible to obtain a high-quality transmission type X-ray tube having a long service life at a low cost.

A thermionic flat electron emitter has an emitter arrangement with an emitter plate having slits therein that produce serpentine current paths. The emitter arrangement has a structure that, in operation, causes the electron density of the emitted electrons to be lower in the central region of the emitter plate than in a region adjoining the central region.

In one embodiment, an X-ray tube is provided. The X-ray tube comprises at least one thermionic cathode configured to generate an electron beam, a target assembly configured to generate X-rays when impinged with the electron beam emitted from the thermionic cathode, a high voltage supply unit for establishing an output voltage across the thermionic cathode and the target assembly for establishing an accelerating electric field between the thermionic cathode and the target assembly and a mesh grid disposed between the thermionic cathode and the target assembly, the mesh grid configured to operate at a voltage so as to lower the electric field applied at the surface of the thermionic cathode. Further, the voltage at the mesh grid is negatively biased with respect to the voltage at the thermionic cathode.

An aperture cooling structure (a cooling structure used for the open X-ray source) 10 comprises an aperture unit 31 formed with an aperture 33, a holder 34 for holding the aperture unit 31, and a heat dissipator 36 connected to the holder 34. The aperture 33 restricts an electron beam E from passing therethrough on an electron path 4 of an X-ray generator (open X-ray source). The heat dissipator 36 has a heat dissipation member 37 including a coolant flow path constituent part 41 and a heat dissipation member 38 including a coolant flow path constituent part 42. The coolant flow path constituent part 41 and the coolant flow path constituent part 42 are combined with each other, so as to construct a coolant flow path 43.

A plurality of high atomic number wires are sintered together to form a porous rod that is parted into porous disks which will be used as x-ray targets. A thermally conductive material is introduced into the pores of the rod, and when a stream of electrons impinges on the sintered wire target and generates x-rays, the heat generated by the impinging x-rays is removed by the thermally conductive material interspersed in the pores of the wires.

An x-ray tube for generating a sweeping x-ray beam. A cathode is disposed within a vacuum enclosure and emits a beam of electrons attracted toward an anode. The anode is adapted for rotation with respect to the vacuum enclosure about an axis of rotation. At least one collimator opening corotates with the anode within the vacuum enclosure, such that a swept x-ray beam is emitted.

A transmission-type target includes a target layer and a transmissive substrate. The target layer is configured to generate X-rays in response to irradiation of electrons. The transmissive substrate supports the target layer and is configured to allow the X-rays generated in the target layer to pass therethrough. The transmissive substrate includes polycrystalline diamond in which grain boundaries extend in a substrate thickness direction and a substrate plane direction. The grain boundaries define an electrical potential of the target layer.

An apparatus and method for providing uniform X-Ray irradiation to material carried in a plurality of containers. The apparatus includes an X-Ray tube providing a linear source of irradiation and also a 4pi (360 degrees) irradiation. The material to be irradiated is placed in containers suspended on a vertical carousel wheel type structure. The individual containers are mounted receive irradiation throughout the rotation of the wheel. The tube is mounted approximately at the axis or center of the wheel. In operation, the containers of material are rotated around the tube, and due to their orientation and the 4 pi irradiation from the source, each and all the containers receive a uniform irradiation for the material contained therein.

The present technique provides a method for controlling an electron beam (e-beam) in an X-ray tube. The method comprises emitting electrons from an electron source to form the e-beam, accelerating the e-beam from a cathode through an aperture in a plate, focusing and steering the e-beam from the aperture through a plurality of field generating plates, and accelerating the e-beam from the plurality of the field generating plates to a target. Also provided are X-ray tubes and computed tomography systems.

When the focus of an X-ray tube in an X-rays generator is to be made extremely small, a first electrode closest to a cathode out of two or more intermediate electrodes (2b, 2c, 2d) arranged between a cathode (2a) and a target (3) must be brought as close as possible to the cathode, and thereby causing the problem of temperature rise of the first electrode. In the invention, even if the thermal capacity of the first electrode is increased by applying the same potential as that of a container (1) to the first electrode to allow it to touch the container, the function of the X-rays generator is not damaged. Positional relation between an electron gun and the container is determined by allowing the first electrode to touch the container, and assembling work of the X-rays generator is facilitated. Furthermore, management of a power supply is facilitated because the potentials of the cathode, the intermediate electrodes (e.g. the second electrode, the third electrode) and the target are all at positive polarity with respect to the potential of the first electrode.

The invention relates to key parts in detection equipment, in particular to a high-reliability security check ceramic X-ray tube. The high-reliability security check ceramic X-ray tube comprises an anode assembly and a cathode assembly. An anode head in the anode assembly and a focusing disc in the cathode assembly are oppositely arranged. The high-reliability security check ceramic X-ray tube is characterized in that the anode assembly and the cathode assembly are assembled into a whole in a butt joint mode through a ceramic shell, the anode head and the focusing disc are arranged in the ceramic shell, the anode assembly is provided with a ray output window located outside the ceramic shell, the anode head is of a conical head structure, the focusing disc is provided with a small circular cavity and a large circular cavity and is of a cap structure, the large circular cavity is located at the outer end and is opposite to the anode head, the inner diameter of the large circular cavity is larger than the largest outer diameter of the anode head, and a water cooling sleeve is additionally installed at the tail end of the anode head. The high-reliability security check ceramic X-ray tube solves the problem that an existing security check tube is poor in reliability and short in service life, and is mainly used for various security check devices.