Abstract: An integral cathode for use with x-ray devices. The integral cathode includes an emitter made of a refractory metal such as tungsten, preferably doped with rhenium to afford malleability during construction and assembly. The integral cathode also includes a support cartridge, preferably composed of an electrically non-conductive material such as ceramic, in which the emitter is received. The support cartridge electrically isolates the cathode from the other components and structures of the x-ray device. Additionally, the support cartridge serves to impose, and maintain, a parabolic curve in the emitter. The parabolic form of the emitter naturally shapes an electron beam by causing electrons discharged from the emitter to converge at a focal spot. In this way, both the emission and focusing functions of the cathode are integrated and performed by a single part.

Abstract: To solve a difference in an emitting directions by switching the types of X-rays. An X-ray generator comprises: an anticathode unit 3 in which a plurality of anticathode parts 2 (2A and 2B) that emit X-rays by collision of thermoelectrons are disposed side by side; a cathode 4 for releasing the thermoelectrons toward the anticathode parts 2A and 2B on the anticathode unit 3; and a cathode moving mechanism that switches the anticathode parts, against which the thermoelectrons from the cathode 4 collide by moving the cathode 4 along the diction of aligning anticathode parts 2A and 2B.

Abstract: A miniature X-ray source device connected to a distal end of a guiding wire for insertion towards a desired location within an animal body for effecting radiation thereby. The X-ray source device at least includes a vacuum tube containing a cathode and an anode spaced apart at a distance from each other; an emitter for emitting free electrons from the cathode; an electric field generator for applying a high-voltage electric field between the cathode and the anode for accelerating the emitted free electrons towards the anode; and a getter material located in a high-voltage electric field free region in the vacuum tube. The vacuum tube is at least partly transparent to X-ray radiation emitted by the anode.

Abstract: A miniature x-ray tube capable of intra vascular use, has a micro cathode preferably formed by MEMS techniques. The very fine wire of the cathode filament is formed on a semiconductor base and draws a current sufficiently low that lead wires in a cathode heater circuit, passing through a probe line connected to the x-ray tube, can be very small wires, which helps maintain sufficient dielectric spacing in the high voltage circuit handled by the same probe line. In a preferred embodiment the probe line comprises a glass fiber, held at a small diameter to allow flexibility for navigating small-radius turns within the vessels. In a preferred embodiment the fiber is overcoated with a high-dielectric polymer to significantly increase the dielectric strength of the overall cable, without adding significantly to stiffness. The high voltage ground conductor is a coaxial sheath on the outside of the polymer. Exterior to the ground conductor is a further flexible layer having paths for coolant.

Abstract: The present invention provides apparatus and method for providing a stabilized x-ray output from a field emission x-ray apparatus by monitoring the operating current and adjusting the gap between the anode and cathode to stabilize the output.

Abstract: A method for adjusting a focal spot position during a scan of a computed tomography (CT) imaging system having a z-axis. The CT imaging system includes a detector array having a plurality of detector elements and an x-ray tube configured to direct an x-ray beam towards the detector through an object to be imaged. The method includes turning on the x-ray tube and reading a z-ratio from the detector. A shift in a position of a focal spot of the x-ray tube is then determined utilizing the read z-ratio. The method further includes using a transfer function to determine a compensating electronic deflection value; and applying the electronic deflection value to the x-ray tube as at least one of a deflection voltage or a deflection current to track the focal spot in the z-axis direction.

Abstract: An x-ray generating device includes at least one field-emission cold cathode having a substrate and incorporating nanostructure-containing material including carbon nanotubes. The device further includes at least one anode target. Associated methods are also described.

Abstract: A cathode (38) for an imaging tube (33) is provided. The cathode (38) includes an emitter (74) that emits an electron beam (98) to a focal spot (46) on an anode (44). A backing member (76) is electrically disposed on a second side (78) of the emitter (74) and contributes in formation of the electron beam (98). A deflection electrode (82) is electrically disposed between the backing member (76) and the anode (44) and adjusts position of the focal spot (46) on the anode (44). A non-contact x-ray source component position measuring system (32) is also provided. The position measuring system (32) includes an electromagnetic source (18) having an electromagnetic radiation source component (42) and a probe (50) that directs an emission signal (52) at and receives a return signal from the electromagnetic radiation source component (42). A controller (28) generates the emission signal (52) and determines position of the electromagnetic radiation source component (42) in response to the return signal (54).

Abstract: In a method to detect the pressure in an x-ray tube having a cathode of the x-ray tube that is heated with a heater current, and wherein electrons are accelerated between the cathode and an anode by an applied x-ray tube voltage, the heater current is measured, a tube current corresponding to the tube -ray voltage is measured, the difference between the measured heater current and the measured tube current is determined or the temporal change of the measured heater current or of the measured tube current is determined, the difference or the temporal change is compared with predetermined calibration values, and a value representing the pressure in the x-ray tube is determined from the comparison.

Abstract: An X-ray generating apparatus comprises a semiconductor structure, an emitter formed on the semiconductor structure, with the emitter to emit electrons. The apparatus further comprises an element to generate X-rays in response to impact by the electrons on the element.

Abstract: Described herein are integrated systems for generating neutrons to perform a variety of tasks including: on-line analysis of bulk material and industrial process control (as shown in FIG. 1), security interrogation (as shown in FIG. 2), soil and environmental analysis, and medical diagnostic treatment. These systems are based on novel gas-target neutron generation which embodies the beneficial characteristics of replenishable fusible gas targets for very long lifetime, stability and continuous operation, combined with the advantageous features common to conventional accelerator neutron tubes including: on/off operation, hermetically sealed operation, and safe storage and transport. Innovative electron management techniques provide gas-target neutron production efficiencies that are comparable or surpass existing sources.

Abstract: An apparatus for emitting x-rays comprises a housing which contains an anode having an electron receiving surface and a cathode having an electron emitting surface. A cable couples the anode to a source of high voltage. An optical fiber secured to the cable has a proximal end coupled to a source of optical energy and a distal end configured to direct the optical energy onto the cathode's electron emitting surface. The cathode emits electrons which strike the anode to create x-ray radiation.

Abstract: An X-ray source comprises a cold cathode and an anode. The cold cathode has a curved emission surface capable of emitting electrons. The anode is spaced apart from the cathode. The anode is capable of emitting X-rays in response to being bombarded with electrons emitted from the curved emission surface of the cathode.

Abstract: A multi-beam x-ray generating device includes a stationary field-emission cathode having a plurality of stationary and individually controllable electron-emitting pixels disposed in a predetermined pattern on the cathode, an anode opposing the cathode comprising a plurality of focal spots disposed in a predetermined pattern that corresponds to the predetermined pattern of the pixels, and a vacuum chamber enveloping the anode and cathode.

Abstract: In a method to detect the pressure in an x-ray tube having a cathode of the x-ray tube that is heated with a heater current, and wherein electrons are accelerated between the cathode and an anode by an applied x-ray tube voltage, the heater current is measured, a tube current corresponding to the tube -ray voltage is measured, the difference between the measured heater current and the measured tube current is determined or the temporal change of the measured heater current or of the measured tube current is determined, the difference or the temporal change is compared with predetermined calibration values, and a value representing the pressure in the x-ray tube is determined from the comparison.

Abstract: An apparatus and method for reducing the incidence of electric field stress on portions of insulating structures within high voltage devices is disclosed. Each of the embodiments disclosed herein modifies the conductive properties of the insulating structure surface in a non-uniform manner such that the distribution of voltage potential along the surface thereof is more fully equalized during operation of the high voltage device. This, in turn, reduces the per unit stress on the insulating structure caused by the electric field of the high voltage device. Through embodiments of the present invention are preferably directed to utilization in x-ray tube devices, a variety of high voltage devices may benefit from application of the disclosed matter.

Abstract: The voltage applied to a first grid electrode 71 of an X-ray tube 11 by a grid voltage control section 110 is controlled with reference to a predetermined negative voltage from a negative voltage generating section 112 when an object 5 to be inspected does not exist in an imaging area (irradiation area of an X-ray from an X-ray source 1) so that the pulse outputted from a pulse generator 105 is in its OFF state, and is controlled with reference to a reference positive voltage from a reference voltage generating section 115 when the object 5 to be inspected exists in the imaging area in the X-ray image intensifier 2 (irradiation area of the X-ray from the X-ray source 1) so that the pulse outputted from the pulse generator 105 is in its ON state, whereby both of the cutoff voltage and grid operating voltage are applied in a stable state.

Abstract: A multisource type X-ray CT apparatus including a fixed sensor array, a fixed vacuum chamber, and an X-ray generation unit. The X-ray generation unit includes a cathode and an anode which are fixed in the vacuum chamber so as to surround the sensor array, a gate array including a plurality of grid electrodes which are densely fixed between the cathode and anode and which include holes for passing the electron beams, a power source which applies a bias voltage to the grid electrodes of the gate array, and a controller which controls the power supply operation from the power source so as to select the grid electrode suitable for image pickup from the gate array in accordance with an image pickup portion of the subject and to release the bias voltage applied to the selected grid electrode.

Abstract: A catheter for emitting radiation is disclosed, comprising a catheter shaft and an x-ray unit attached to the distal end of the catheter shaft. The x-ray unit comprises an anode and a cathode coupled to an insulator to define a vacuum chamber. The cathode is preferably a field emission cathode of graphite or graphite coated with titanium carbide, for example. The anode is preferably tungsten and the insulator is preferably pyrolytic boron nitride. The x-ray unit is preferably coupled to a voltage source through a coaxial cable. The anode is preferably a heavy metal such as tungsten. The cathode may also be a ferroelectric material. The x-ray unit can have a diameter less than about 4 mm and a length less than about 15 mm. Methods of use of the catheter are also disclosed. The catheter of the present invention can be used to irradiate the site of an angioplasty procedure to prevent restenosis. It can also be used to treat other conditions in any vessel, lumen or cavity of the body.

Abstract: A method and apparatus for an x-ray tube having an emitter and a differentially biased emitter-cup cathode configured to provide an electron beam of substantially greater perveance and beam compression ratio than otherwise obtainable with conventional cathode designs is disclosed. The method and apparatus include a cathode assembly opposing an anode and spaced apart therefrom. The cathode is maintained during operation of the x-ray tube at a negative potential with respect to the anode. The cathode assembly includes an emitter for emitting an electron beam to a focal spot on the anode during operation of the x-ray tube and a cathode front member having an aperture defined by the cathode front member on a first side of the emitter. A backing is disposed on a second side of the emitter and is operably connected to the cathode front member via a backing insulator. The cathode further includes a means for applying a differential bias in the cathode assembly to variably change the focal spot size.

Abstract: In a hot cathode of an X-ray tube of the kind having a thermoelectronic emitter supported by a heating element, the emitter is comprised of plural emitter regions separated from each other. Each emitter region has the largest measure less than 3 mm, so that no crack occurs on the thermoelectronic emitter. The hot cathode is comprised of a heating element made of glassy carbon and a thermoelectronic emitter supported by the heating element. The emitter is comprised of plural emitter regions made of sintered lanthanum hexaboride. The hot cathode can be produced as described below. The heating element with a thickness of 1 mm is formed, at its thermoelectron-emitting side, with four recesses each of which is 2.6 mm in length, 0.5 mm in width and 0.3 mm in depth. The recesses are filled with lanthanum hexaboride powder, which is then sintered to complete four emitter regions.

Abstract: A cathode assembly (43) for a computed tomography scanning system (10) is provided. The cathode assembly (43) includes a one-piece tab assembly (52) for simple and relatively quick installation on a cathode cup (44). In one embodiment, the one-piece tab assembly (52) has two rail portions (56) extending substantially across its length. These rail portions (56) are intended for insertion into channels (50) formed within the cathode cup (44) and for properly locating the one-piece tab assembly (52) in a desired position relative to the filament (46). The assembly (52) further includes two tab portions (58, 58″) located on opposing ends of the rail portions (56). The tab portions (58, 58″) each include a main body portion (62) and a flap portion (54) extending from the main body portion (62). The main body portion (62) extends between the two rail portions (56) and has a mounting surface for attaching the one-piece tab assembly (52) to the cathode cup (44).

Abstract: An electromagnetic wave energy emitter including a generally cylindrical probe including generally coaxial first and second electrodes, each of the electrodes having an at least partially cylindrical shape, one of the electrodes being energizable to emit electrons and the other of the electrodes being adapted to receive the electrons and generate electromagnetic wave energy. A grid element may be placed between the first and second electrodes. A controller may be in communication with the grid element, adapted to control a potential of the grid element. The grid element may have an at least partially cylindrical shape. The grid element may be placed concentrically or non-concentrically with respect to the first and second electrodes.

Abstract: An electromagnetic wave energy emitter including a generally cylindrical probe including generally coaxial first and second electrodes, each of the electrodes having an at least partially cylindrical shape, one of the electrodes being energizable to emit electrons and the other of the electrodes being adapted to receive the electrons and generate electromagnetic wave energy. A grid element may be placed between the first and second electrodes. A controller may be in communication with the grid element, adapted to control a potential of the grid element. The grid element may have an at least partially cylindrical shape. The grid element may be placed concentrically or non-concentrically with respect to the first and second electrodes.

Abstract: A nondestructive inspection apparatus with integrated power supply comprises a molded power supply section (14) having a resin-molded high voltage (e.g. 160 kV) generating section (15) secured to the base of a tubular section (2). The durability and handlability are improved by omitting a high voltage cable. Since the high voltage generating section (15) is confined in a molding resin, the degree of freedom in the arrangement of the high voltage generating section (15) within the mold is enhanced significantly. Furthermore, an X-ray generating unit (1) can be installed stably in the nondestructive inspection apparatus (70) by disposing the heavy molded power supply section (14) under a target (10).

Abstract: A system for delivering therapeutic radiation, such as x-rays, to a treatment region includes a plurality of individually controllable therapeutic radiation sources. The therapeutic radiation sources are selectively and moveably disposed along one or more axes, or upon a two-dimensional surface, or within a three-dimensional volume, so as to form a one-dimensional or a multi-dimensional array. Each therapeutic radiation source includes an electron source for emitting electrons, and an associated target element adapted to emit therapeutic radiation in response to incident electrons. In one embodiment, each therapeutic radiation source is coupled to a distal end of an associated optical delivery structure, which is adapted to direct a beam of optical radiation to impinge upon a surface of the electron source so as to cause emission of electrons therefrom.

Abstract: The invention relates to an X-ray tube whose cathode arrangement includes a flat electron emitter that is provided with openings. An electrode is arranged on the side of the electron emitter that is remote from the anode of the X-ray tube; this electrode carries a negative potential relative to the electron emitter, which negative potential straightens the electron paths in front of the emitter. These steps result in a favorable ratio of the dimensions of the electron emitter to the dimensions of the focal spot formed on the anode by the emitted electrons.

Abstract: In a hot cathode of an X-ray tube of the kind having a thermoelectronic emitter supported by a heating element, the emitter is comprised of plural emitter regions separated from each other. Each emitter region has the largest measure less than 3 mm, so that no crack occurs on the thermoelectronic emitter. The hot cathode is comprised of a heating element made of glassy carbon and a thermoelectronic emitter supported by the heating element. The emitter is comprised of plural emitter regions made of sintered lanthanum hexaboride. The hot cathode can be produced as described below. The heating element with a thickness of 1 mm is formed, at its thermoelectron-emitting side, with four recesses each of which is 2.6 mm in length, 0.5 mm in width and 0.3 mm in depth. The recesses are filled with lanthanum hexaboride powder, which is then sintered to complete four emitter regions.

Abstract: Methods and apparatus for generating x-ray beams are described. In one embodiment, the method includes operating a cathode to generate an electron beam, directing the electron beam from the cathode through an aperture in an accelerating electrode, and impinging the electron beam on an anode surface to form a focal spot on the anode surface.

Abstract: A field emission array electron source (12) is used to generate an electron beam in a x-ray generating device (10). The field emission array operates at room temperature and has a life expectancy in excess of 12,000 hours and provides a robust, efficient emitter for generating an electron beam in a x-ray generating device cathode (10).

Abstract: A cold emitter x-ray tube is provided comprised of a cathode which is a carbon nanotube or nanostructured carbon film which serves as the electron emission source in an x-ray tube, and is positioned on a suitable substrate. The nanostructured carbon film is selected from a group consisting of nanocyrstalline graphite, carbon nanotubes, diamond, diamond like carbon, or a composite of two or more of members of the group. An extraction/suppression grid may be utilized. A metal anode which functions as the x-ray generating target is positioned within the x-ray tube. A high voltage source with negative contact is connected to the emitter and the positive contact connected to the anode target. This single source of high potential serves to provide the electric field, between the emitter and anode, for extraction of electrons from the emitter and to accelerate the electrons to the target for generation of x-rays. X-rays pass through a beryllium window that is an integral part of the vacuum envelope.

Abstract: A therapeutic radiation source includes a spiral-shaped, laser-heated thermionic cathode. A fiber optic cable directs a beam of radiation, having a power level sufficient to heat at least a portion of the electron-emissive surface to an electron emitting temperature, from a laser source onto the cathode. The cathode generates an electron beam along a beam path by thermionic emission, and strikes a target positioned in its beam path. The target includes radiation emissive material that emits therapeutic radiation in response to incident accelerated electrons from the electron beam. The spiral-shaped conductive element has a plurality of spaced apart turns, and is disposed in a vacuum. An interstitial spacing is defined between adjacent turns, so that heat transfer across the spacing between each adjacent turn is essentially eliminated, thereby substantially reducing heat loss in the cathode caused by thermal conduction.

Abstract: A dual filament x-ray tube assembly (16) includes an evacuated envelope (52) having an anode (54) disposed at a first end of the evacuated envelope (52) and a cathode assembly (62) disposed at a second end of the evacuated envelope (52). The cathode assembly includes a variable-length filament assembly (72, 74; 100) which emits electron beams for impingement on the anode (54) at focal spots having varying lengths. The cathode assembly (62) further includes a cathode cup (64, 66, 68; 110, 112) which is subdivided into a plurality of electrically insulated deflection electrodes (64, 66, 68; 110, 112). A filament select circuit (80) selectively and individually heats a portion of the variable-length filament assembly (72, 74). Electron beams emitted from the filament assembly (72, 74) are electrostatically focused and controlled by applying potentials to different ones of the deflection electrodes (64, 66, 68; 110, 112).

Abstract: A miniaturized, optically driven therapeutic radiation source operates at significantly reduced power levels. The apparatus includes a laser-driven thermionic cathode, a target element, a probe assembly, and a laser source. The probe assembly includes an optical delivery structure, such as a fiber optic cable, that directs a laser beam from the laser source to impinge upon a surface of the thermionic cathode, heating the surface to a temperature sufficient to cause thermionic emission of electrons. The emitted electrons form an electron beam along a beam path. The target element is positioned in the beam path, and includes means for emitting therapeutic radiation, such as x-rays, in response to incident accelerated electrons from the electron beam. Reflector elements may be included to reflect unabsorbed laser radiation back to the thermionic cathode.

Abstract: A therapeutic radiation source includes a optically heated thermionic cathode that is shaped so as to maximize the coupling efficiency of the incident optical radiation to the thermionic cathode. A fiber optic cable directs a beam of radiation, having a power level sufficient to heat at east a portion of the electron-emissive surface to an electron emitting temperature, from a laser source onto the cathode. An electron beam generated by said cathode strikes a target which is positioned in its beam path and which emits therapeutic radiation in response to incident accelerated electrons from the electron beam. The thermionic cathode has a non-planar configuration, such as a conical shape and a concave shape, adapted to allow an incident ray of optical radiation to impinge upon, and undergo absorption from, a plurality of regions within the surface of the cathode in succession.

Abstract: An X-ray source includes a first support member and a second support member joined together so as to form a cavity between them and such that they are electrically insulated from each other. A cathode and an anode are located inside the cavity and opposite each other. The cathode is suitably made of diamond or diamond like material, and includes at least one pointed element.

Abstract: An apparatus provides in-situ radiation treating utilizing a miniature energy transducer to produce x-rays, wherein the energy transducer includes a Schottky cathode tip. More specifically, the energy transducer includes a transducer body, an anode provided at a first end of the transducer body, and a cathode provided at a second end of the transducer body opposite the anode. The energy transducer is coupled to an energy source by a flexible insertion device. The energy source provides electrical and/or light signals to the energy transducer via the flexible insertion device. Light transmitted from the energy source to the energy transducer by the flexible insertion device is focused on a Schottky cathode tip of the cathode by the optical fiber provided in the hollow core of the anode.

Abstract: A portable x-ray fluorescence spectrometer apparatus comprising a housing; a high voltage energized x-ray source operably secured within the housing; and an unheated electron cathode, operably linked to the high voltage energized x-ray source, thereby eliminating the need for a cathodic electron power supply for spectrometric analysis. Another embodiment comprises a portable x-ray fluorescence spectrometer having a housing, an integrated x-ray tube, a high voltage power supply operably linked to the integrated x-ray tube, and a mechanism for controlling the x-ray emissions of the x-ray tube and power supply including an electron suppression grid operably positioned between a filament cathode and a target anode of the x-ray tube.

Abstract: An X-ray generator includes a cathode having an emitter made of carbon nanotubes which emits electrons by field emission and thus becomes a cold cathode electron emission source. In the invention using the carbon nanotubes, any one of the following three forms is adopted to control the tube current apart from the electron-focusing control. The first form is that a takeoff electrode is disposed near the cathode and the Wehnelt potential and the takeoff electrode potential are controlled independently. The second form is that an electron emission source is disposed behind the cathode and the electron emission source emits electrons which collide against the back of the cathode so that the cathode temperature is controlled in a range of the room temperature to about 100 degrees Celsius to regulate an amount of electron emission from the cathode.

Abstract: A dual filament x-ray tube assembly (16) includes an evacuated envelope (52) having an anode (54) disposed at a first end of the evacuated envelope (52) and a cathode assembly (62) disposed at a second end of the evacuated envelope (52). The cathode assembly includes a variable-length filament assembly (72, 74; 100) which emits electron beams for impingement on the anode (54) at focal spots having varying lengths. The cathode assembly (62) further includes a cathode cup (64, 66, 68; 110, 112) which is subdivided into a plurality of electrically insulated deflection electrodes (64, 66, 68; 110, 112). A filament select circuit (80) selectively and individually heats a portion of the variable-length filament assembly (72, 74). Electron beams emitted from the filament assembly (72, 74) are electrostatically focused and controlled by applying potentials to different ones of the deflection electrodes (64, 66, 68; 110, 112).

Abstract: The invention provides a scheme in accordance with which a linear accelerator may be operated in two or more resonance (or standing wave) modes to produce charged particle beams over a wide range of output energies so that diagnostic imaging and therapeutic treatment may be performed on a patient using the same device. In this way, the patient may be diagnosed and treated, and the results of the treatment may be verified and documented, without moving the patient. This feature reduces alignment problems that otherwise might arise from movement of the patient between diagnostic and therapeutic exposure machines. In addition, this feature reduces the overall treatment time, thereby reducing patient discomfort.

Abstract: A radiography system (10) has a solid state x-ray source that includes a substrate with a cathode (58) disposed thereon within a vacuum chamber (52). An anode (68) is spaced apart from cathode within vacuum chamber (52). The system may include a computer (36) that controls an x-ray controller (28) and a plurality of detectors elements (20) which provide data acquisition system (32) with predetermined data in response to x-ray submitted at x-ray source (14). Data acquisition system (32) is used in image reconstructor (34) to provide the desired image. An interface (48) may be used to transmit the image to a remote diagnostic facility. The wireless interface (48) is particularly suitable for communication with a remote diagnostic facility.

Abstract: Disclosed is an X-ray tube for generating X-rays linearly focused in a vertical or horizontal direction in accordance with the orientation of a filament used. The X-ray tube includes a linear filament arranged at a cathode included in the X-ray tube, the linear filament serving to allow an anode included in the X-ray tube to generate line-focused X-rays. The X-ray tube according to the present invention can be applied to a calibration for X-ray spectroscopes, or various applications requiring line-focused X-rays.

Abstract: An X-ray tube 1 in which a cathode 73 is heated to emit electrons 80, and the electrons 80 are bombarded against an anode target 32, thereby generating X-rays 81, includes a stem substrate 4 mounted on an opening 22 of a container 21 housing the cathode 73, a plurality of pins 5 extending through the insulating substrate 4 and adapted to supply a voltage into the container 21, and pin covers 6 mounted on the pins 5 in the container 21 and arranged at positions away from a surface of the stem substrate 4 to cover base portions of the pins 5.

Abstract: A method and apparatus are provided for adjusting a filament set height in a cathode of an x-ray tube. The method for adjusting a filament set height of a cathode comprises providing a cathode cup of an x-ray tube, the cathode cup comprising at least one bore extending therethrough; inserting a filament post through at least one bore such that the filament set height is below a desired filament set height; measuring an actual filament set height that results from the step of inserting; determining a filament set height adjustment distance in which the filament set height adjustment is generally equal to a difference between the actual filament set height and the desired filament set height; contacting an end of the filament lead with an adjustment tool; and moving the adjustment tool a distance substantially equal to the filament set height adjustment distance. Therefore, the filament is positioned at the predetermined filament set height.

Abstract: In an X-ray tube having an anode supported for rotation and an annular target track mounted upon the anode, a cathode spaced apart from the anode projects a beam of electrons onto the target track within a focal spot. The cathode is designed to normalize the impact temperature across the focal spot, as a function of length. In accordance therewith, the cathode comprises a filament and a cathode cup, wherein the filament is disposed to project the electron beam onto the target track to generate X-rays, when a high voltage potential difference is established between the filament and the anode. The filament and the cathode cup are respectively configured to selectively form the electron beam so that the beam provides an electron distribution within the focal point which maintains each point within the focal spot at substantially the same temperature.

Abstract: The invention relates to an X-ray tube whose cathode arrangement includes a flat electron emitter that is provided with openings. An electrode is arranged on the side of the electron emitter that is remote from the anode of the X-ray tube; this electrode carries a negative potential relative to the electron emitter, which negative potential straightens the electron paths in front of the emitter. These steps result in a favorable ratio of the dimensions of the electron emitter to the dimensions of the focal spot formed on the anode by the emitted electrons.

Abstract: The transmission cathode for X-ray generation is a device wherein an electrical current generated by a low voltage power supply produces an electron flow from the transmission cathode that is accelerated by a high voltage power supply towards an anode where X rays are emitted on impact. As the X rays are emitted, a primary beam passes through the cathode striking a sample placed outside the tube. The transmission cathode is X comprised of an electron emitter structure, preferably, an electron field emitter diode or thermionic emitter or a photoemitter or a nanotube or a pyroemitter or a piezoemitter, fabricated, preferably of elements of atomic numbers of 14 (silicon) or below, with electrically conductive components or conductive mechanical structural components, preferably, conductive silicon or diamond or aluminum or beryllium metal, and non-conductive electrical insulators or non-conductive mechanical structural components, preferably, diamond or silicon dioxide or boron carbide.

Abstract: An X-ray tube comprising an anode having a target surface radiating X-rays from a position of an X-ray focal spot by impingement of an electron beam, a focusing electrode and cathodes. The focusing electrode has a bottom portion positioned facing the target surface of the anode and most remote from the X-ray focal spot, at least one inclined wall surface obliquely ascending from the bottom portion in the direction of the anode, and substantially rectangular focusing recesses formed at the inclined wall surface. Each of the cathodes emits electron beams, positioned respectively in the focusing recesses of the focusing electrode. The focusing recess has first and second corners which curve from at least one end wall facing the end of the cathode to two side walls along the direction of the longer side of the cathode, and the first corner located remote from the bottom portion is gentler than the second corner located adjacent to the bottom portion with reference to condition of curving.

Abstract: The present invention related to miniaturized x-ray tubes, that enable radiation treatment by locating the x-ray source within a human body in close vicinity to or inside of the area to be treated with X-rays. Advantageously, the present invention eliminates most of the problems related to the methods based on a radioactive source and offers a method for efficient and controllable radiation treatment.