Abstract: A computed tomography apparatus and a method for influencing a position of a focal spot in an x-ray radiation source having a centering device to center an electron beam and a focus are provided. The method includes positioning a reference object into a beam path of x-ray radiation between the x-ray radiation source and an x-ray radiation detector, the x-ray radiation detector having detector elements to generate an x-ray image, capturing an x-ray image of the reference object at different powers, reducing a focal spot displacement occurring at the different powers based on a comparison of the x-ray images captured at the different powers with one another, by setting at least one altered electric current to operate the centering device or the centering devices of the x-ray radiation source, and operating the computed tomography apparatus with the altered electric current, by which the focal spot displacement was reduced.

Abstract: A method in an X-ray source configured to emit, from an interaction region, X-ray radiation generated by an interaction between an electron beam and a target, the method including the steps of: providing the target; providing the electron beam; deflecting the electron beam along a first direction relative the target; detecting electrons indicative of the interaction between the electron beam and the target; determining a first extension of the electron beam on the target, along the first direction, based on the detected electrons and the deflection of the electron beam; detecting X-ray radiation generated by the interaction between the electron beam and the target; and determining a second extension of the electron beam on the target, along a second direction, based on the detected X-ray radiation.

Abstract: A distributed X-ray light source comprises: a plurality of arranged cathode assemblies used for emitting electron beams; an anode target used for receiving the electron beams emitted by the cathode assemblies; and compensation electrodes and focusing electrodes provided in sequence between the plurality of the cathode assemblies and the anode target, the compensation electrode being used for adjusting electric field strength at two ends of a grid structure in each cathode assembly, and the focusing electrode being used for focusing the electron beams emitted by the cathode assemblies, wherein the focusing electrode corresponding to at least one cathode assembly in the plurality of the cathode assemblies comprises a first electrode and a second electrode which are separately provided, and an electron beam channel is formed between the first electrode and the second electrode.

Abstract: A distributed X-ray light source comprises: a plurality of arranged cathode assemblies used for emitting electron beams; an anode target used for receiving the electron beams emitted by the cathode assemblies; and compensation electrodes and focusing electrodes provided in sequence between the plurality of the cathode assemblies and the anode target, the compensation electrode being used for adjusting electric field strength at two ends of a grid structure in each cathode assembly, and the focusing electrode being used for focusing the electron beams emitted by the cathode assemblies, wherein the focusing electrode corresponding to at least one cathode assembly in the plurality of the cathode assemblies comprises a first electrode and a second electrode which are separately provided, and an electron beam channel is formed between the first electrode and the second electrode.

Abstract: An X-ray generation apparatus includes an electron gun configured to emit an electron beam, a rotary anode unit having a target generating an X-ray by receiving the electron beam and configured to rotate the target, a magnetic lens having a coil configured to generate a magnetic force acting on the electron beam between the electron gun and the target, and a wall portion disposed between the target and the coil so as to face the target. The wall portion is formed with an electron passage hole through which the electron beam passes and a flow path configured to allow a coolant to flow.

Abstract: At least one power supply produces a voltage between a cathode and an anode. The cathode and anode are operable such that electrons emitted from the cathode interact with the anode with energies corresponding to the voltage. The electrons interact with the anode at a focal spot to generate X-rays. The power supply provides the cathode with a cathode current. An electron detector is positioned relative to the anode, and a backscatter electron signal is measured from the anode. The measured backscatter electron signal is provided to a processing unit, which determines a cathode current correction and/or a correction to the voltage between the cathode and the anode using the measured backscatter electron signal and a correlation between anode surface roughness and backscatter electron emission.

Abstract: An electron source that can be used stably for a long time even when hexaboride is used, and an electron beam device using the electron source are provided. The invention is directed to an electron source which includes a filament made of a metal, a metal tube that is fixed to the filament and has a plurality of recesses disposed at least in two axial directions so as to surround a central axis at an outer periphery, and a columnar hexaboride tip that emits an electron, is disposed so as to protrude from the inside of the metal tube to a side opposite to the filament, and is in contact with a bottom of each of the plurality of recesses of the metal tube.

Abstract: A method for determining a CT focal point includes determining a first intensity of first radiation incident on a first detector unit of a scanner, wherein the scanner may include a non-uniform anti-scatter grid (ASG) and a radiation source, and the non-uniform ASG may be configured according to a first focal point of the radiation source. The method also includes determining a second intensity of second radiation incident on a second detector unit of the scanner, wherein the first radiation and the second radiation are emitted from the radiation source with a second focal point. The method further includes determining a displacement of the second focal point from the first focal point based on the first intensity and the second intensity.

Abstract: Methods and an x-ray source for sweeping an x-ray beam across an object of inspection. A beam of electrons is emitted by a cathode, while a sweep controller applies a signal to a beam controller in a prescribed path on an anode, thereby causing an x-ray beam to be emitted from an aperture disposed at one apex of a snout of variable length. The aperture may be a Rommel aperture that allows for forming a scanning x-ray of desired size and flux independently of the angle at which the beam is emitted. Scanning rate may be varied during the course of a scan. Multiple x-ray beams may be formed simultaneously, where one beam is inside a conveyance while the other is outside the conveyance, for example.

Abstract: Three dimensional beam forming X-ray source includes an electron beam generator (EBG) to generate an electron beam. A target element is disposed a predetermined distance from the EBG and positioned to intercept the electron beam. The target element is responsive to the electron beam to generate X-ray radiation. A beam former is disposed proximate to the target element and comprised of a material which interacts with the X-ray radiation to form an X-ray beam. An EBG control system controls at least one of a beam pattern and a direction of the X-ray beam by selectively varying a location where the electron beam intersects the target element to control an interaction of the X-ray radiation with the beam-former.

Abstract: An X-ray emitter includes an anode rotatably mounted arranged inside a vacuum housing. It can be set into rotation by an electric drive. In the region of a focal spot, the anode can be exposed to an electron beam emitted by a cathode. According to an embodiment of the invention, a control unit is configured to activate an electromagnetic deflection unit that deflects the electron beam as a function of at least one operating parameter of the electric drive such that a movement of the focal spot, caused by electromagnetic fields of the electric drive, can be at least partly compensated for. An embodiment of the invention further relates to a method for compensating for a focal spot movement when X-ray emitters in operation.

Abstract: Methods for maintaining a specified beam profile of an x-ray beam extracted from an x-ray target over a large range of extraction angles relative to the target. A beam of electrons is generated and directed toward a target at an angle of incidence with respect to the target, with the beam of electrons forming a focal spot corresponding to the cross-section of the electron beam. At least one of a size, shape, and orientation of the electron beam cross-section is dynamically varied as the extraction angle is varied, and the extracted x-ray beam is collimated. Dynamically varying the size, shape or orientation of the electron beam cross-section may be performed using focusing and stigmator coils.

Abstract: An x-ray device is presented. The x-ray device includes a cathode configured to emit an electron beam. Further, the x-ray device includes an anode having an anode surface configured to generate x-rays in response to the emitted electron beam impinging on a focal spot on the anode surface. Also, the x-ray device includes a reciprocating assembly including a drive shaft operatively coupled to the anode and a first bearing unit operatively coupled to the drive shaft, where the first bearing unit is configured to translate the anode via the drive shaft to distribute heat generated in the anode. Moreover, the x-ray device includes a first diaphragm disposed between the anode and the first bearing unit and configured to cease a flow of one or more first lubricants from the first bearing unit towards the anode.

Abstract: Methods and systems for evaluating and ranking the measurement efficacy of multiple sets of measurement system combinations and recipes for a particular metrology application are presented herein. Measurement efficacy is based on estimates of measurement precision, measurement accuracy, correlation to a reference measurement, measurement time, or any combination thereof. The automated the selection of measurement system combinations and recipes reduces time to measurement and improves measurement results. Measurement efficacy is quantified by a set of measurement performance metrics associated with each measurement system and recipe. In one example, the sets of measurement system combinations and recipes most capable of measuring the desired parameter of interest are presented to the user in rank order based on corresponding values of one or more measurement performance metrics. A user is able to select the appropriate measurement system combination in an objective, quantitative manner.

Abstract: A dual-mode rapidly-passing type moving target radiation inspection system comprises a radiation source, a collimator, sensor units, a control module, a radiation detector and a radiation imaging device, wherein the sensor units are used for identifying the type of a moving target and monitoring the position of the moving target in an inspection channel; the control module is used for controlling the radiation source to emit rays in a preset working mode on the basis of the type and the position of the moving target; the preset working mode corresponds to the type of the moving target, and the rays emitted by the radiation source in different working modes differ in dosage rate. Also disclosed is a dual-mode rapidly-passing type moving target radiation inspection method. The inspection system and method described above are capable of radiation inspection of the entire moving targets such as vehicles.

Abstract: An x-ray generator may include a plurality of electron field emitters; a target material; a plurality of energizable solenoid coils; and an electronic power and timing circuit. The generator may provide electrical current to at least one individual solenoid coil to create a magnetic field to cause the path of electrons emitted from the emitter closest to the energized solenoid coil to be defocused and/or deflected before the electrons reach the target material. The target material may comprise a low atomic number material and a high atomic number material, the high atomic number material being arranged in a regular pattern, such that, in use, the electrons may be aimed at either the high or the low atomic number material.

Abstract: An X-ray generation device which can be efficiently used is provided. The X-ray generation device has an electron gun, a target unit, a tubular portion, a reflected electron detector, and a coil unit. The target unit includes a plurality of targets and a plurality of mark portions having a predetermined relationship with the targets, wherein each mark portion having a surface area larger than a surface area of the target when said target unit is viewed from a direction which is normal to principal faces of the target unit.

Abstract: An apparatus is provided for generating X-ray radiation in an outer magnetic field, which may be generated by a magnetic field device. The apparatus includes a cathode configured to generate an electron beam and an anode configured to retard the electrons of the electron beam and generate an X-ray beam. The apparatus further includes a device configured to generate an electric field orientated from the anode in the direction of the cathode and substantially collinear to the outer magnetic field, wherein the cathode, as an electron emitter, includes a cold cathode that passively provides free electrons by field emission.

Abstract: An X-ray tube comprising: a cathode including an emitter; an anode; a first magnetic quadrupole formed on a first yoke and having a magnetic quadrupole gradient for focusing an electron beam in a first direction and defocusing the beam in a second direction; a second magnetic quadrupole formed on a second yoke and having a magnetic quadrupole gradient for focusing the electron beam in the second direction and defocusing the electron beam in the first direction; wherein a combination of the first and second magnetic quadrupoles provides a net focusing effect in both first and second directions of a focal spot of the electron beam; and a pair of opposing quadrupole electromagnetic coils having alternating current offset being configured to deflect the electron beam in order to shift the focal spot of the electron beam on a target.

Abstract: A capacitive fingerprint sensor, including: a dielectric structure having a contact surface and a sensor surface; an array of capacitive sensing elements held on or near the sensor surface of the dielectric structure; and an electrostatic lens formed within the dielectric structure.

Abstract: Disclosed is an X-ray tube that has a simple configuration and is capable of irradiating multiple different X-rays while switching them at a high rate, as well as an X-ray CT device using the X-ray tube. The X-ray tube comprises first and second electron generators, a deflection means, and a target. The deflection means switches the direction in which first and second electron beams are transmitted between first and second directions. The target comprises first, second, third, and fourth surfaces. The first surface receives a first electron beam transmitted toward the first direction and irradiates a first X-ray toward the irradiation field. The second surface receives a second electron beam transmitted toward the first direction and irradiates a second X-ray toward a direction different from the irradiation field. The third surface receives a first electron beam transmitted toward the second direction and irradiates the first X-ray toward a direction different from the predetermined irradiation field.

Abstract: The invention relates to a method and a system for using photofission to probe an article containing potentially radiation-emitting elements. The article is bombarded by a beam of electrons of sufficient energy, and they are converted into photons by bremsstrahlung directly within the article to be probed, which article is likely to contain photofissile material. No target is added to the package to perform this conversion. Preferably, the article to be probed is a package of radioactive waste, in which the container is made of thick absorbent concrete.

Abstract: The present invention pertains to a system for electronic brachytherapy wherein a layer of target material can produce reflection and transmission X-rays when struck by electrons from a cathode. An alternative system can have a fixed-size containment structure around a miniature X-ray source, with X-ray attenuating coolant fluid between the source and containment structure. A balloon can be around the fixed-size containment structure and can be inflated with an X-ray inert gas.

Abstract: The strain at different locations in a subject's heart is determined by acquiring a series of MR images using a tagging pulse sequence (SPAMM) that produces a grid of lines in the reconstructed images. Circumferential strain, longitudinal strain, and the minimum principal strain angle, are all calculated at locations in the heart. These raw strain values are normalized by comparing them with corresponding values in a stored reference heart model. The normalized values at each location are combined to form a composite multiparametric strain index that is indicative of myocardial contractile function and these values are employed to modulate the color at corresponding locations in an anatomical image of the subject's heart.

Abstract: The invention relates to an X-ray device comprising an x-ray sensitive camera for creating tomograms, especially panoramic tomograms. Means for creating 3D shots of a partial volume of the mandibular arch are also provided, said 3D shots being created especially by a second image receiver for creating a 2D shot and means for taking a plurality of 2D shots from different directions and creating a 3D shot therefrom, preferably according to conebeam technology with the associated reconstruction algorithms. The x-ray sensitive camera comprises a first x-ray sensitive image receiver for creating a tomogram, and a second x-ray sensitive image receiver for creating plane shots.

Abstract: A method for generating an X-ray includes the steps of: disposing at least a target in a chamber; irradiating an electron beam onto the target from an electron beam source disposed in or outside the chamber so as to satisfy a relation of ??60 degrees if an incident angle of the electron beam is defined as “?”; and generating and taking an X-ray out of the target so as to satisfy a relation of ?30 degrees?????60 degrees if an output angle of the X-ray relative to a surface of the target is defined as “?”.

Abstract: An x-ray tube with a vacuum housing includes a cathode chamber with a cathode arrangement, an anode chamber with an anode arrangement, and a drift path disposed between the cathode chamber and the anode chamber. The drift path is surrounded by a magnet arrangement. The magnet arrangement is a self-supporting construction.

Abstract: An X-ray generation device is provided with an electron gun unit for emitting an electron beam, and a target unit having a substrate comprised of diamond, and a target body comprised of a material for generating X-rays with incidence of the electron beam thereto and buried in close contact in the substrate. An outer diameter of the target body is in the range of 0.05 to 1 ?m. An outer diameter of an irradiation field of the electron beam on the target unit is in the range of 1.1 to 2.5 times the outer diameter of the target body. The X-ray generation device irradiates the target body with the electron beam so that the target body is included in the irradiation field, thereby to generate X-rays from the target body.

Abstract: The invention relates to an X-ray source (100) with an electron-beam-generator (120) for generating electron beams (B, B?) that converge towards a target (110). Thus the spatial distribution of X-ray focal spots (T, T?) on the target (110) can be made denser than the distribution of electron sources (121), wherein the latter is usually dictated by hardware limitations. The electron-beam-generator (120) may particularly comprise a curved emitter device (140) with a matrix of CNT based electron emitters (141) and an associated electrode device (130).

Abstract: The present invention relates to monoscopic and stereoscopic X-ray viewing. In order to provide an improved fluent work flow for X-ray viewing with an improved visual perception of depth information, it is provided to generate an electron beam from a cathode arrangement towards a target area of an anode; to deflect the electron beam such that the electron beam hits the anode at different target spots (94a, 94b), wherein the variation is provided as gradual variation of an impinging direction of the electrons such that a stepless transition between monoscopic and stereoscopic viewing is provided. In the monoscopic viewing, X-ray radiation is generated from a single focal spot position, and wherein in the stereoscopic viewing, X-ray radiation is generated from two focal spot positions spaced apart from each other in a first stereo-direction transverse to a viewing direction (92).

Abstract: The present invention discloses an X-ray source which uses a rectangular cavity resonator, which is excited with a microwave TE10p mode. The present invention also can be used as a source of cyclotron radiation, using the cylindrical cavity, but carrying out some structural changes thereof to achieve this purpose. This system allows significantly increasing the energy of the electron beam by compensating the diamagnetic force by an axially symmetric electrostatic field. The electrostatic field is generated longitudinally by ring-type electrodes placed inside the cavity, preferably in the node planes of the TE11p electric field. The electrodes should be made transparent to the microwave field, such as graphite.

Abstract: The present invention relates to simulated spatial live viewing of an object. In order to provide spatial information to the user with reduced requirements concerning to maintain a particular position e.g. with respect to a 3D display or to wear or activate additional components, such as 3D glasses, it is provided to generate an electron beam (38) from a cathode (32) arrangement towards a target area of an anode (34) and to control the electron beam such that the electron beam hits the anode at a moving focal spot (44), wherein the electron beam is controlled such that the focal spot moves at least in a first moving direction (46) transverse to a viewing direction (48). Thus, X-ray radiation (42) is generated by the electron beam impinging on the moving focal spot. Further, it is provided to detect X-ray radiation at least partially passing an object and to generate respective X-ray detection signals.

Abstract: A source of X-rays including at least two cathodes and at least one common anode configured and arranged so as to generate at least two spaced apart beams of X-rays emanating from respectively different locations of the anode, and separately controlled so as to be generated independently of one another. The staggered focal spots can be generated simultaneously or alternately as required. An X-ray imaging system comprising such an X-rays source, and a method utilizing such a source are also disclosed.

Abstract: An X-ray testing device for generating high-resolution geometric projections of a test object, includes a highly focusing X-ray source having: a rotary anode assembly formed by a rotatably mounted anode plate, an anode plate drive connected to rotate the anode plate and a rotational angle encoder detecting the rotation angle of the anode plate; an electron gun producing a focused electron beam; and an electron beam control unit having an electron beam deflecting unit and a control unit, the electron beam deflecting unit controlling the point of incidence of the electron beam generated by the electron gun on the anode plate. The control unit controlling the electron beam deflecting unit dependent on the detected rotation angle of the anode plate minimizing the positional change of the point of incidence on the anode plate relative to a reference point on a bracket holding the test object located in a fixed position.

Abstract: A segmented thermionic emitter is provided. The segmented thermionic emitter has, among other features, a plurality of segments substantially spanning an entire length of the thermionic emitter and aligned substantially parallel with one another. In one embodiment, the segmented thermionic emitter may allow milli-amp modulation of an X-ray tube at voltages less than approximately 2 kV.

Abstract: A dual energy X-ray source for use in Homeland Security, Medical, Non-destructive Testing, and other markets includes a power supply, and a single x-ray tube. The X-ray tube includes two cathodes, and a single anode. The electrons from the cathodes travel predominantly along the axis of the x-ray tube, and impact the anode. The grid and/or focus coil direct the electrons so that electrons can pass by the cathode. The cathodes are kept at different potential, such that the tube can rapidly switch energies, and can rapidly switch output flux from each cathode.

Abstract: A motion correction system and method for motion correction for an x-ray tube is presented. One embodiment of the motion correction system includes a sensing unit coupled to an x-ray tube to determine a distance with which an impingement location of an electron beam generated by the x-ray tube deviates from a determined location due to motion of the x-ray tube. The motion correction system further includes a control unit coupled to the sensing unit to generate a control signal corresponding to the distance with which the impingement location of the electron beam deviates. Also, the motion correction system includes a deflection unit coupled to the control unit to steer the electron beam to the determined location based on the generated control signal.

Abstract: The present invention relates to an apparatus (10) as well as a method for generating X-ray radiation, in particular for generating an X-ray radiation field, comprising an electron source (11) for generating an electron beam (12) as well as a target (13) for generation of X-ray radiation, in particular of an X-ray radiation field by electrons of the electron beam (12) impinging on the target (13). The present invention is characterized in that, the apparatus (10) is designed for generating an adjustable and/or changeable X-ray radiation, in particular for generating an adjustable and/or changeable X-ray radiation field, and in that the apparatus (10) has a variation appliance (15) for varying of at least one parameter of the electron beam source (11) and/or the electron beam (12) for influencing the X-ray radiation, in particular the X-ray radiation field.

Abstract: Provided is an X-ray generator for generating X-rays from an X-ray focal point that is a region in which electrons emitted from a filament impinge upon a rotating anode. The X-ray generator has a Wehnelt electrode for surrounding the filament, an attachment part formed integrally with the Wehnelt electrode, a pedestal to which the attachment part is attached, and a casing for housing the pedestal and the anticathode. The width of the space in which the anticathode is housed by the casing is less than the width of the space in which the pedestal is housed by the casing. The Wehnelt electrode extends into the space in which the anticathode is housed by the casing, in a state in which the attachment part is attached to the pedestal.

Abstract: An x-ray tube is described that includes components for increasing x-ray image clarity in the presence of a moving x-ray source by modifying focal spot characteristics, including focal spot size and focal spot position. In a first arrangement a static focal spot is moved in a direction contrary to the movement of the x-ray source so that an effective focal spot position is essentially fixed in space relative to one of the imaged object and/or detector during a tomosynthesis exposure. In a second arrangement, the size of the static focal spot is increased, and the resulting increase in tube current reduces the exposure time and concomitant blur effect. The methods may be used alone or in combination; for example an x-ray tube with a larger, moveable static focal spot will result in a system that fully utilizes the x-ray tube generator, provides a high quality image with reduced blur and, due to the decrease in exposure time, may scan the patient more quickly.

Abstract: Provided is a high-output X-ray generation tube in which thermal damage to a target is reduced. The X-ray generation tube includes a target, an electron source, and a grid electrode having multiple electron passage apertures disposed between the target and the electron source. A source-side electron beam on the electron source side with respect to the grid electrode has a current density distribution, and the grid electrode has an aperture ratio distribution so that a region of the source-side electron beam in which a current density is largest is aligned with a region of the grid electrode in which an aperture ratio is smallest.

Abstract: During operation of an x-ray source, an electron source emits a beam of electrons. Moreover, a repositioning mechanism selectively repositions the beam of electrons on a surface of a target based on a feedback parameter, where a location of the beam of electrons on the surface of the target defines a spot size of x-rays output by the x-ray source. In response to receiving the beam of electrons, the target provides a transmission source of the x-rays. Furthermore, a beam-parameter detector provides the feedback parameter based on a physical characteristic associated with the beam of electrons and/or the x-rays output by the x-ray source. This physical characteristic may include: at least a portion of an optical spectrum emitted by the target, secondary electrons emitted by the target based on a cross-sectional shape of the beam of electrons; an intensity of the x-rays output by the target; and/or a current from the target.

Abstract: A radiation irradiation device is provided that includes: a metal target that emits bremsstrahlung X-rays as a radiation beam due to irradiation with an electron beam; a radiation shielding member that includes a slit-shaped radiation passage portion and that is disposed downstream of the metal target in the radiation beam emission direction and is disposed such that a portion of the radiation beam passes through the radiation passage portion and the radiation beam incident to regions other than the radiation passage portion is blocked; and an electron beam generating device that irradiates, onto the metal target, an electron beam such that a diameter at a generation point of the emitted radiation beam is smaller than a length of an entry portion of the radiation passage portion along a length direction of the entry portion.

Abstract: A method and device for control of an electron beam flux, electron spot size, and/or electron spot location. Electromagnetic radiation from an anode of the x-ray tube can be focused on a detector. The detector can send a signal to a control module based on the electromagnetic radiation focused on the detector. The control module can control the electron beam with a beam control device and/or a current control device. The signal can also indicate anode temperature at the electron spot.

Abstract: An apparatus for X-ray CT imaging including an X-ray irradiation unit configured to irradiate an X-ray toward a subject, an X-ray detector having a plurality of X-ray detection elements along a channel direction and a row direction, a couch on which the subject can be arranged, a rotation unit on which the X-ray irradiation unit and the X-ray detector are oppositely disposed and rotate around the couch, a controller configured to execute a helical scan while fluctuating an X-ray focal spot along a body axis direction of the subject by controlling the X-ray irradiation unit, and an image processing unit configured to generate a reconstructed image based on data acquired by the helical scan, wherein the controller is further configured to set a magnitude of fluctuation of the X-ray focal spot so that data acquisition loci of the helical scan do not overlap each other.

Abstract: The disclosure relates to systems and methods for fast-switching operating of a standing wave linear accelerator (LINAC) for use in generating x-rays of at least two different energy ranges with advantageously low heating of electronic switches. In certain embodiments, the heating of electronic switches during a fast-switching operation of the LINAC can be kept advantageously low through the controlled, timed activation of multiple electronic switches located in respective side cavities of the standing wave LINAC, or through the use of a modified a side cavity that includes an electronic switch.

Abstract: An apparatus and method to generate distributed x-rays. A hot cathode of an electron gun is used in vacuum to generate electron beams having certain initial movement energy and speed. Periodic scanning is performed with the initial low-energy electron beams, which are thus caused to be reciprocally deflected. A current-limiting device is provided in the travel path of the electron beams along the direction of the reciprocal deflection. Through holes arranged in an array on the current-limiting device, only part of the electron beams targeting specific positions can pass to form sequential electron beam currents distributed in an array. These electron beam currents are accelerated by a high-voltage electric field to obtain high energy, bombard an anode target, and thus sequentially generate corresponding focus spots and x-rays distributed in an array at the anode target.

Abstract: For X-ray tubes of the rotary-anode type for generating a fan beam of X-rays, compensation is afforded for system-related disturbances of the focal spot position on a target area of the rotating anode, and particularly for the anode wobble in an X-ray tube, which occurs as a periodically wobbling inclination angle of the anode disk's rotational plane with respect to an ideal rotational plane, the latter being oriented normal to the rotational axis of the rotary shaft on which the anode disk is inclinedly mounted due to an inaccuracy during its production process. For this purpose, the electron beam generated by a thermionic or other type of electron emitter of the tube's cathode and thus the focal spot position on a target area of the anode disk's X-ray generating surface are steered such that the focal spot stays within the plane of the central X-ray fan beam.

Abstract: An X-ray tube assembly is provided including an emitter configured to emit an electron beam, an emitter focusing electrode, an extraction electrode, and a downstream focusing electrode. The emitter focusing electrode is disposed proximate to the emitter and outward of the emitter in an axial direction. The extraction electrode is disposed downstream of the emitter and the emitter focusing electrode. The extraction electrode has a negative bias voltage setting at which the extraction electrode has a negative bias voltage with respect to the emitter. The downstream focusing electrode is disposed downstream of the extraction electrode, and has a positive bias voltage with respect to the emitter. When the extraction electrode is at the negative bias voltage setting, the electron beam is emitted from an emission area that is smaller than a maximum emission area from which electrons may be emitted.

Abstract: A piece of scientific/technological equipment is presented for the generation of a convergent photon beam for radiotherapy or other applications. This equipment consists of adequately modifying the trajectory of an electron beam from a linear accelerator (LINAC) by applying magnetic and/or electric fields. These electrons perpendicularly impact the surface of a curved material that has a particular curvature ratio (anode), thus generating X-rays. The interaction of the electrons with the atoms of the anode's material generate X-rays with a non-isotropic angular-spatial distribution, with a greater concentration in the focal direction, which is defined by the geometry of the anode. A curved collimator with an adequate curvature ratio is attached to the back of the anode. The collimator is made up of an array of a great number of small holes that point toward the focal point. This device transmits X-rays solely in the focal direction.