With Specific Cathode Patents (Class 378/136)
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Publication number: 20100002842Abstract: A cathode assembly for a rotating anode X-ray source comprises two parts: a focusing part that is mechanically connected to the remainder of the X-ray source and permanently aligned with respect to the anode and a separate emission part that holds the electron source and is removably connected to the focusing part. The electron source is permanently mounted in the emission part and precisely aligned to the focusing part. The focusing part and the emission part are mechanically connected aligned relative to one another at the time of replacement. This arrangement allows the emission part, including the electron source to be quickly removed and replaced by an inexperienced user while maintaining the accuracy of the X-ray source alignment.Type: ApplicationFiled: July 1, 2008Publication date: January 7, 2010Applicant: BRUKER AXS, INC.Inventors: Gijsbertus J. Kerpershoek, Leendert J. Seijbel, Chuji Katayama
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Publication number: 20090323898Abstract: An electron emitter assembly for use in an x-ray emitting device or other electron emitter-containing device is disclosed. In one embodiment, an x-ray tube is disclosed, including a vacuum enclosure that houses both an anode having a target surface, and a cathode positioned with respect to the anode. The cathode includes an electron emitter assembly for emitting a beam of electrons during tube operation. The electron emitter assembly comprises a refractory metal foil with a plurality of shaped rung structures for emitting an electron beam that maximizes flux while simultaneously focusing the electron beam in two dimensions. Focusing occurs primarily through an electrical field shaped by the electron emitter assembly and through balancing current density, electrical resistance, and heat loss through thermal conduction to control the regions that emit electrons. Furthermore, the refractory metal foil can be configured with a modified work function for preferential electron emission.Type: ApplicationFiled: June 30, 2008Publication date: December 31, 2009Applicant: VARIAN MEDICAL SYSTEMS, INC.Inventor: PAUL D. MOORE
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Publication number: 20090296888Abstract: Device for generating X-rays, comprising: —a field emission cathode (10) configured to emit electrons when an electrical field is applied to the cathode (10); and—an anode (20), the anode being configured to generate X-rays as a result of receiving electrons from the field emission cathode (10); wherein the cathode (10) comprises an electron emission surface (S) extending opposite the anode (20), the cathode (10) being configured to emit electrons substantially from the electron emission surface (S) during use.Type: ApplicationFiled: December 22, 2006Publication date: December 3, 2009Applicant: Nederlanse Organisatie voor toegepastnatuurwetenschappelijk Onderzoek TNOInventors: Godefridus Hendricus Maria Gubbels, Johannes Petrus Zijp
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Patent number: 7609815Abstract: Techniques for controllably directing beamlets to a target substrate are disclosed. The beamlets may be either positive ions or electrons. It has been shown that beamlets may be produced with a diameter of 1 ?m, with inter-aperture spacings of 12 ?m. An array of such beamlets, may be used for maskless lithography. By step-wise movement of the beamlets relative to the target substrate, individual devices may be directly e-beam written. Ion beams may be directly written as well. Due to the high brightness of the beamlets from extraction from a multicusp source, exposure times for lithographic exposure are thought to be minimized. Alternatively, the beamlets may be electrons striking a high Z material for X-ray production, thereafter collimated to provide patterned X-ray exposures such as those used in CAT scans. Such a device may be used for remote detection of explosives.Type: GrantFiled: June 1, 2007Date of Patent: October 27, 2009Assignee: The Regents of the University of CaliforniaInventors: Ka-Ngo Leung, Qing Ji, William A. Barletta, Ximan Jiang, Lili Ji
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Publication number: 20090220051Abstract: A cathode has a cathode head in which is arranged a surface emitter is arranged that emits electrons upon the application of a heating voltage. At least one electrically conductive barrier plate that is galvanically separated from the surface emitter extends up to the surface emitter. This cathode has a longer lifespan, a high electron emission and a good blocking capability.Type: ApplicationFiled: February 27, 2009Publication date: September 3, 2009Inventor: Wolfgang Kutschera
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Patent number: 7576481Abstract: A method of producing a cathode for use in an x-ray tube assembly is provided including machining an emission aperture into a cup emission surface portion of a cup structure. The cup structure is comprised of a cup base portion opposite the cup emissions surface portion. Electro-discharge machining is used to form an electro-discharge machining slot into the cup structure to provide access to the interior of the cup structure. Electro-discharge machining is used to form a transverse coil chamber within the interior by way of the electro-discharge machining slot such that the transverse coil chamber is formed between the cup base portion and the cup emissions surface portion while retaining an essentially contiguous emissions surface perimeter surrounding the emission aperture.Type: GrantFiled: June 30, 2005Date of Patent: August 18, 2009Assignee: General Electric Co.Inventor: Sergio Lemaitre
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Patent number: 7542549Abstract: An improved x-ray generation system produces a converging or diverging radiation pattern particularly suited for substantially cylindrical or spherical treatment devices. In an embodiment, the system comprises a closed or concave outer wall about a closed or concave inner wall. An electron emitter is situated on the inside surface of the outer wall, while a target film is situated on the outside surface of the inner wall. An extraction voltage at the emitter extracts electrons which are accelerated toward the inner wall by an acceleration voltage. Alternately, electron emission may be by thermionic means. Collisions of electrons with the target film causes x-ray emission, a substantial portion of which is directed through the inner wall into the space defined within. In an embodiment, the location of the emitter and target film are reversed, establishing a reflective rather than transmissive mode for convergent patterns and a transmissive mode for divergent patterns.Type: GrantFiled: July 18, 2007Date of Patent: June 2, 2009Assignee: Cabot Microelectronics CorporationInventors: Stanley D. Lesiak, Heinz H. Busta, Bruce M. Zwicker
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Patent number: 7539286Abstract: A filament assembly for use in an x-ray emitting device or other filament-containing device is disclosed. In one embodiment, an x-ray tube is disclosed, including a vacuum enclosure that houses both an anode having a target surface, and a cathode positioned with respect to the anode. The cathode includes a filament assembly for emitting a beam of electrons during tube operation. The filament assembly comprises a heat sink and a plurality of filament segments. The filament segments are configured for simultaneous emission of an electron beam for impingement on the target surface of the anode, and are electrically connected in series. Each filament segment includes first and second end portions that are thermally connected to the heat sink, and a central portion that can be configured with a modified work function for preferential electron emission.Type: GrantFiled: November 19, 2007Date of Patent: May 26, 2009Assignee: Varian Medical Systems, Inc.Inventors: Steve Bandy, Gary F Virshup, Michael Curzon Green, James Russell Boye, Dennis Runnoe, Robert Clark Treseder, David Humber
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Publication number: 20090129549Abstract: An x-ray tube having a reduced spacing between the focal spot of an anode and an adjacent end wall of an evacuated enclosure is disclosed. This in turn positions the tube relatively closer to the chest wall of a patient during mammography procedures. In one embodiment, the x-ray tube comprises an evacuated enclosure having first and second ends interconnected by a cylindrical side wall. The evacuated enclosure includes a rotor assembly having a bearing assembly and a stem. An anode is rotatably supported by the stem of the rotor assembly and includes a target surface and an opposite second surface. The target surface is positioned to face the bearing assembly, while the second surface is positioned to face the first end of the evacuated enclosure, with no intervening structure interposed therebetween. A cathode is included to emit electrons for impingement on a focal spot of the focal track.Type: ApplicationFiled: November 21, 2007Publication date: May 21, 2009Applicant: Varian Medical Systems Technologies, Inc.Inventor: Gary Fredric Virshup
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Patent number: 7529345Abstract: A cathode header optic for an x-ray tube includes an elongate trench with opposite trench walls. A cup recess is formed in the trench between the opposite trench walls, and has a bounded perimeter. A cathode element is disposed in the trench at the cup recess. The cathode element is capable of heating and releasing electrons. A secondary cathode optic defining a cathode ring can be disposed about the header optic. The cathode optics can form part of an x-ray tube.Type: GrantFiled: July 18, 2007Date of Patent: May 5, 2009Assignee: Moxtek, Inc.Inventors: Erik C. Bard, Steven D. Liddiard, Charles R. Jensen
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Patent number: 7518134Abstract: A radiation source is disclosed that includes an anode and a cathode that are configured and arranged to create a discharge in a substance in a discharge space between the anode and the cathode and to form a plasma so as to generate electromagnetic radiation, the anode and the cathode being rotatably mounted around an axis of rotation, the cathode being arranged to hold a liquid metal. The radiation source further includes an activation source arranged to direct an energy beam onto the liquid metal so as to vaporize part of the liquid metal and a liquid metal provider arranged to supply additional liquid metal so as to compensate for the vaporized part of the liquid metal.Type: GrantFiled: December 6, 2006Date of Patent: April 14, 2009Assignee: ASML Netherlands B.V.Inventors: Vladimir Vitalevitch Ivanov, Vadim Yevgenyevich Banine, Konstantin Nikolaevitch Koshelev, Vladimir Mihailovitch Krivtsun
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Publication number: 20090086898Abstract: An x-ray device and method useful in performing close coupled sample analyses. The x-ray device includes an evacuated enclosure having a window and in which is disposed a cathode assembly, control grid, insulator, and anode arranged so that the anode is interposed between the electron source and the window. The anode includes a target surface oriented toward the window and the anode defines a drift tunnel which is substantially aligned with a hollow defined by the insulator. The control grid can be used to influence the energy of the electrons emitted by the filament of the cathode assembly. A high voltage field between the anode and filament causes electrons emitted by the cathode to accelerate rapidly through the insulator. After accelerating to an energy level consistent with the high voltage field, the electrons then pass through the drift tunnel without gaining any additional appreciable energy.Type: ApplicationFiled: September 27, 2007Publication date: April 2, 2009Applicant: Varian Medical Systems Technologies, Inc.Inventors: John E. Richardson, Robert Clark Treseder
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Patent number: 7512215Abstract: An X-ray tube includes an emitter wire (18) enclosed in a suppressor(14, 16). An extraction grid comprises a number of parallel wires (20) extending perpendicular to the emitter wire, and a focusing grid comprises a number of wires (22) parallel to the grid wires (20) and spaced apart at equal spacing to the grid wires (20). The grid wire are connected by means of switches to a positive extracting potential or a negative inhibiting potential, and the switches are controlled so that at any one time a pair of adjacent grid wires (22) are connected together to form an extracting pair, which produce an electron beam. The position of the beam is moved by switching different pairs of grid wires to the extracting potential.Type: GrantFiled: April 23, 2004Date of Patent: March 31, 2009Assignee: Rapiscan Systems, Inc.Inventors: Edward James Morton, Russell David Luggar, Paul De Antonis
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Patent number: 7508917Abstract: An x-ray radiator has an anode that emits x-rays, a cathode that thermionically emits electrons upon irradiation thereof by a laser beam, a voltage source for application of a high voltage between the anode and the cathode for acceleration of the emitted electrons toward the anode to form an electron beam, a vacuum housing, an insulator that is part of the vacuum housing and that separates the cathode from the anode, an arrangement for cooling components of the x-ray radiator, a deflection and arrangement that deflects the laser beam from a stationary source, that is arranged outside of the vacuum housing, to a spatially stationary laser focal spot on the cathode.Type: GrantFiled: May 23, 2007Date of Patent: March 24, 2009Assignee: Siemens AktiengesellscahftInventors: Ronald Dittrich, Joerg Freudenberger, Sven Fritzler, Manfred Fuchs, Detlef Mattern, Peter Roehrer, Peter Schardt
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Publication number: 20090060142Abstract: An x-ray source produces a well-defined electron beam, without an undesirable halo. The x-ray source includes a housing, a cathode disposed within the housing, an anode spaced apart from the cathode for accelerating electrons emitted from the cathode and an x-ray emitter target disposed within the housing and spaced apart from the cathode for impact by the accelerated electrons. The cathode includes a passivation layer over only a portion of the area of the cathode, leaving an emission portion of the cathode that is not passivated. The passivation layer reduces or prevents emissions from the passivated portion of the cathode, thereby preventing a halo, which would otherwise be produced by lower-level emissions from the portion of the cathode that surrounds the emission portion of the cathode.Type: ApplicationFiled: September 4, 2008Publication date: March 5, 2009Inventor: William L. ADAMS
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Patent number: 7496179Abstract: An x-ray unit has an x-ray radiator having an anode that emits x-rays upon being struck by electrons, a cathode that thermionically emits electrons upon irradiation thereof by a laser beam, electrical connections for application of a high voltage between the anode and the cathode to accelerate the emitted electrons toward the anode as an electron beam, a vacuum housing that can be rotated around an axis, an insulator that is part of the vacuum housing and that separates the cathode from the anode, a drive that rotates the vacuum housing around its axis, an arrangement for cooling components of the x-ray radiator, and an arrangement that directs the laser beam from a stationary source, arranged outside of the vacuum housing, onto a spatially stationary laser focal spot on the cathode and that focuses the laser beam.Type: GrantFiled: May 23, 2007Date of Patent: February 24, 2009Assignee: Siemens AktiengesellschaftInventors: Joerg Freudenberger, Sven Fritzler, Manfred Fuchs, Matthias Maier, Detlef Mattern, Peter Roehrer, Peter Schardt
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Publication number: 20090041195Abstract: A cathode has an emission layer that thermionically emits electrons upon exposure with a laser beam. The material of the emission layer has a product of density (?), measured in kg m 3 , heat capacity (Cp), measured in J kg ? ? K and heat conductivity (?), measured in W mK that is, at room temperature, maximally 500,000 J 2 m 4 ? K 2 ? s . Such a cathode has an improved thermionic emission of electrons.Type: ApplicationFiled: August 8, 2008Publication date: February 12, 2009Inventors: Joerg Freudenberger, Sven Fritzler, Manfred Fuchs, Detlef Mattern, Peter Roehrer, Peter Schardt
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Patent number: 7486774Abstract: An x-ray tube having a removable aperture structure that can be detached from a portion of the x-ray tube without damaging either component is disclosed. The aperture structure includes heat conducting surfaces in communication with a coolant supplied to the fluid reservoir. The removable aperture structure includes a bond surface configured to receive a removable bond with the x-ray tube evacuated enclosure.Type: GrantFiled: May 25, 2005Date of Patent: February 3, 2009Assignee: Varian Medical Systems, Inc.Inventor: Bruce A. Cain
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Patent number: 7479646Abstract: An extreme ultraviolet source with wide-angle vapor containment and reflux is described. In the optical output directions radiating from the source plasma there is an array of tapered buffer gas heat pipes, with wick structures in the walls. In directions toward the insulators separating the discharge electrodes there are disc-shaped buffered gas heat pipes that prevent metal vapor from condensing on these insulators. A preferred electrode configuration has three electrode discs that operate in the star pinch mode. Another electrode configuration comprises two electrode discs and supports a pseudospark discharge. The star pinch variant of this source has efficiently generated 13.5 nm radiation with lithium vapor and helium buffer gas.Type: GrantFiled: December 11, 2006Date of Patent: January 20, 2009Assignee: PLEX LLCInventor: Malcolm W. McGeoch
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Patent number: 7469040Abstract: X-ray tube (11/12) for high dose rates, a corresponding method for generating high dose rates with X-ray tubes (11/12) as well as a method for producing corresponding X-ray devices (11/12), in which an anode (31/32) and a cathode (21/22) are disposed opposite each other in a vacuumized internal chamber (41/42), electrons e? being accelerated to the anode (31/32) by means of impressible high voltage. The anode (31/32) is made of a layer or coating of a metal having a high atomic number, for conversion of the electrons (e?) into X-ray radiation (?) with cooling. The cathode (21/22) comprises a substrate substantially transparent for X-ray radiation (?). In particular, the likewise substantially transparent for X-ray radiation (?). In particular, the cathode (31/32) can close off the vacummized internal chamber (41/42) toward the outside.Type: GrantFiled: March 2, 2004Date of Patent: December 23, 2008Assignee: Comet Holding AGInventors: Kurt Holm, Mark Joachim Mildner, Lars-Ola Nilsson, Adrian Riedo, Toni Waber
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Publication number: 20080310594Abstract: X-ray radiation is generated at a target that emits x-ray radiation in response to being struck by accelerated electrons, the electrons being emitted by a cathode that emits electrons in response to being illuminated by electromagnetic radiation from a source, and the x-ray radiation is moved by orienting a surface that directs the electromagnetic radiation from the source toward the cathode.Type: ApplicationFiled: June 13, 2008Publication date: December 18, 2008Applicant: L-3 Communications Security and Detection Systems, Inc.Inventors: Vitaliy Ziskin, Boris Oreper, Andrew Dean Foland
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Publication number: 20080310593Abstract: In one embodiment, an X ray tube assembly is provided. The X ray tube assembly comprises an evacuated envelope, an anode disposed at a first end of the evacuated envelope and a cathode assembly disposed at a second end of the evacuated envelope. The cathode assembly comprises a cathode filament and a cathode cup defining a plurality of electrically isolated deflection electrodes. Further, the cathode cup comprises at least two portions, a first portion comprising an electrically conductive material and a second portion comprising an electrically insulating material. In another embodiment, a method of manufacturing the X ray tube assembly is provided.Type: ApplicationFiled: June 14, 2007Publication date: December 18, 2008Applicant: GENERAL ELECTRIC COMPANYInventors: Thomas Schaefer, Ron Hockersmith, Ethan Westcot
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Patent number: 7450690Abstract: An x-ray tube assembly is provided comprising a tube casing assembly including a plurality of vertical mount posts. An insulator plate is mounted to the plurality of vertical mount posts such that the insulator plate can translate vertically on the posts. A cathode assembly is mounted to the insulator plate and generates both an eccentric moment and a vertical expansion in response to a cathode power load. A semi-compressible element is positioned between at least one of the vertical mount posts and the insulator plate. The semi-compressible element becomes incompressible at a cathode power threshold such that the vertical expansion is translated into a correction moment countering the eccentric moment.Type: GrantFiled: July 8, 2005Date of Patent: November 11, 2008Assignee: General Electric CompanyInventors: Wayne Frederick Block, Edward Emaci, Sergio Lemaitre, Ron Kent Hockersmith
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Patent number: 7424095Abstract: Modular X-ray tube (10) and method for the production of such an X-ray tube, in which an anode (20) and a cathode (30) are arranged in a vacuumized inner space (40) situated opposite each other, electrons (e?) being produced at the cathode (30) and X-rays (y) at the anode (20). The X-ray tube (10) according to the invention comprises a multiplicity of acceleration modules (41, . . . , 45), complementing one another, and each acceleration module (41, . . . , 45) comprises at least one potential-carrying acceleration electrode (20/30/423/433/443). A first acceleration module (41) thereby comprises the cathode (30), a second acceleration module (45) the anode (20). The X-ray tube (10) further comprises at least one other acceleration module (42, . . . , 44). In particular, the X-ray tube according to the invention can possess a re-closeable vacuum valve, enabling individual defective parts of the tube (10) to be replaced in a simple manner or enabling the tube (10) to be modified in a modular way.Type: GrantFiled: December 2, 2003Date of Patent: September 9, 2008Assignee: Comet Holding AGInventors: Mark Joachim Mildner, Kurt Holm
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Patent number: 7412033Abstract: An x-ray radiator has a vacuum housing that can rotate around an axis, a cathode that thermionically emits electrons upon irradiation thereof by a laser beam, an anode that emits x-rays upon being struck by the electrons, an insulator that is part of the vacuum housing and that separates the cathode from the anode, electrodes or terminals to apply a high voltage between the anode and the cathode to accelerate the emitted electrons toward the anode to form an electron beam, a drive arrangement for rotation of the vacuum housing around its axis, an arrangement for cooling components of the x-ray radiator, and an arrangement that directs and focuses the laser beam from a stationary source that is arranged outside of the vacuum housing onto a spatially stationary laser focal spot on the cathode.Type: GrantFiled: September 12, 2006Date of Patent: August 12, 2008Assignee: Siemens AktiengesellschaftInventors: Jörg Freudenberger, Sven Fritzler, Manfred Fuchs, Detlef Mattern, Peter Röhrer, Peter Schardt
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Publication number: 20080187093Abstract: A method and apparatus are provided for generating high frequency electromagnetic energy using a secondary emission electron source. An x-ray source is therefore provided having a primary electron emitter, a secondary emission member, and an anode. The primary electron emitter provides a primary electron current directed to the secondary emission member. The secondary emission member then generates a secondary electron current which causes x-ray generation when impinging upon the anode.Type: ApplicationFiled: February 6, 2007Publication date: August 7, 2008Inventors: John Scott Price, Loucas Tsakalakos, Pierre-Andre Bui, Bruce Matthew Dunham
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Patent number: 7403595Abstract: Disclosed is an X-ray tube system with a disassembled carbon nanotube substrate for generating micro focusing level electron beams. A housing provides a vacuum space. An anode forms an electric field by a voltage applied from the outside and accelerates the electrons emitted from the cathode to reach the anode itself. A carbon nanotube substrate used as a cathode corresponding to the anode. A cathode plate supports and fixes the carbon nanotube substrate and applies a voltage to the carbon nanotube substrate. A sample probe is installed assemblably/disassemblably in the housing. A grid electrode is installed in front of the carbon nanotube substrate and extracting electrons from the carbon nanotube substrate in an easy manner. An electron focusing lens focuses the electrons passed through the grid electrode to form a micro level focus in the anode. A feed through applies a voltage to the cathode, the grid electrode and the electron focusing lens.Type: GrantFiled: April 5, 2007Date of Patent: July 22, 2008Assignee: Korean Electro Technology Research InstituteInventors: Jong Uk Kim, Hae Young Choi
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Patent number: 7397898Abstract: An x-ray tube comprises an envelope, an anode target rotatably mounted within the envelope, and a cathode and window assembly mounted within the envelope and spaced relative to the anode. The cathode and window assembly includes an electrically insulative ceramic base defining an x-ray transmissive window therethrough, a recess formed within the electrically insulative base adjacent to a peripheral portion of the x-ray transmissive window, a filamentary electrode received within the recess, first and second metalized conductive surfaces formed on a surface of the recess on opposite sides of the filamentary electrode and substantially electrically isolated relative to one another, a first terminal electrically connected to the first metalized conductive surface, a second terminal electrically connected to the second metalized conductive surface, and a high voltage cable receptacle located on a second side of the electrically insulative ceramic base.Type: GrantFiled: March 13, 2006Date of Patent: July 8, 2008Assignee: Parker Medical, Inc.Inventors: William P. Holland, Timothy Holland, Joseph Suffredini
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Patent number: 7352846Abstract: A coiled filament for an X-ray tube has a varied coil pitch to obtain a good uniformity of the longitudinal temperature distribution. The filament has a central region including plural turns having a same coil pitch, and end regions which include plural turns each of which has a coil pitch smaller than the coil pitch of the central region. The coil pitches of the plural turns of the end regions are reduced one by one by a same variation from a turn close to the central region toward an outermost turn. A value of ?p/p is within a range of 0.015 to 0.1 and k/n is within a range of 0.3 to 0.8, where p is the coil pitch of the central region, ?p is the coil pitch variation of the end regions, n is a total number of turns of the filament, and k is a sum of numbers of turns of the end regions. The k/n preferably satisfies the following equation: k/n=0.72?4.66(?p/p)±0.12.Type: GrantFiled: October 19, 2006Date of Patent: April 1, 2008Assignee: Rigaku CorporationInventors: Masaru Kuribayashi, Masahiro Nonoguchi, Naohisa Osaka, Yoji Kobayashi
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Patent number: 7346147Abstract: A linear source of x-rays is disclosed wherein an elongated filament, mounted within a cylindrically formed anode, provides electrons around the filament, and along the length of said filament. The anode that comprises a high Z material such as gold, receives the electrons and emits X-rays in a 360 degree arc and along a substantial length of the anode. In one embodiment the tube is used for irradiation purposes.Type: GrantFiled: July 27, 2005Date of Patent: March 18, 2008Inventors: Randol E. Kirk, Daniel F. Gorzen
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Patent number: 7333592Abstract: An X-ray tube includes an electron gun in which a Wehnelt electrode is formed with an opening asymmetric about an electron emitter. The electron emitter is an elongate coil filament which is disposed inside the elongate opening of the Wehnelt electrode. The opening has two longer sides positioned asymmetrically about a center-of-width line of the filament. Each of the two longer sides is curved in the same direction as viewed in a direction normal to the front face of the Wehnelt electrode. The two longer sides have curvature radii R1 and R2 different from each other, so that an electron-beam-irradiation region on a target is not curved but becomes almost straight.Type: GrantFiled: April 14, 2006Date of Patent: February 19, 2008Assignee: Rigaku Corp.Inventors: Masahiro Nonoguchi, Masaru Kuribayashi
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Patent number: 7327829Abstract: An improved cathode assembly, including a filament for producing an electron stream having a highly uniform cross sectional density. The cathode assembly comprises a support base, a cathode cup affixed to the support base, and a filament disposed in a slot defined on the bottom face of the cup. In one embodiment, the side walls of the slot are shaped so as to allow greater electric field penetration about regions of the filament that typically produce relatively low quantities of electrons, thereby increasing electron emission therefrom. Other embodiments are directed to modifying either the filament winding configuration or the wire from which the filament is formed, in order to equalize electron production by the filament. The uniformly dense electron stream is preferably directed toward the anode of an x-ray tube, thereby producing a superior x-ray beam for a variety of applications.Type: GrantFiled: April 20, 2004Date of Patent: February 5, 2008Assignee: Varian Medical Systems Technologies, Inc.Inventor: Charles Lynn Chidester
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Patent number: 7298826Abstract: An X-ray generator of this invention has an X-ray monitor that monitors a state of an X-ray emitted from a target. Hence the state of the X-ray can be monitored in real time to maintain the X-ray in a constant state. The X-ray monitor is positioned off the path on which an X-ray transmitted from a first exit window travels. Hence, when the X-ray is emitted from the first exit window to an object to be inspected, the X-ray monitor does not obstruct the approaching of the object to the first exit window. This makes it possible to acquire X-ray images of high magnification.Type: GrantFiled: April 25, 2003Date of Patent: November 20, 2007Assignee: Hamamatsu Photonics K.K.Inventor: Tutomu Inazuru
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Patent number: 7280636Abstract: An x-ray source for producing a uniformly intense area x-ray beam. The x-ray source includes a vacuum chamber. An area electron emitter is disposed at a first end of the vacuum chamber. A target material is disposed at a second end of the vacuum chamber and spaced apart from the area electron emitter. The area electron emitter and the target material are correspondingly shaped and/or correspondingly curved. The x-ray source also includes at least one high voltage power source. The area electron emitter is electrically connected to a negative pole of one of the at least one high voltage power source and the target electrically connected to a positive pole of one of the at least one high voltage power source.Type: GrantFiled: October 4, 2004Date of Patent: October 9, 2007Assignee: Illinois Institute of TechnologyInventors: Timothy I. Morrison, Ivan Nesch, Gocha Khelashvili
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Patent number: 7280637Abstract: A cathode cup is provided. The cathode cup includes one or more pockets; and one or more filaments associated with the one or more pockets. A same number of pockets as filaments are present. Each pocket is associated with exactly one filament and is configured to have a length that is tailored to a length of the filament. The cathode cup can be used in an X-ray system having an anode and a cathode. A method of electron beam shaping is provided. The method includes the following steps. A computer-simulated model of a cathode cup is created. The model is used to predict focal spot dimensions. The predicted focal spot dimensions are compared to desired focal spot dimensions. The steps of creating, using and comparing are repeated until the predicted focal spot dimensions match the desired focal spot dimensions. A cathode cup is created based on the computer-simulated model.Type: GrantFiled: March 28, 2006Date of Patent: October 9, 2007Inventors: Jizhong Chen, Sergio Lemaitre, Brian Douglas Lounsberry
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Patent number: 7274772Abstract: An improved x-ray generation system produces a converging or diverging radiation pattern particularly suited for substantially cylindrical or spherical treatment devices. In an embodiment, the system comprises a closed or concave outer wall about a closed or concave inner wall. An electron emitter is situated on the inside surface of the outer wall, while a target film is situated on the outside surface of the inner wall. An extraction voltage at the emitter extracts electrons which are accelerated toward the inner wall by an acceleration voltage. Alternately, electron emission may be by thermonic means. Collisions of electrons with the target film causes x-ray emission, a substantial portion of which is directed through the inner wall into the space defined within. In an embodiment, the location of the emitter and target film are reversed, establishing a reflective rather than transmissive mode for convergent patterns and a transmissive mode for divergent patterns.Type: GrantFiled: May 27, 2004Date of Patent: September 25, 2007Assignee: Cabot Microelectronics CorporationInventors: Stanley D. Lesiak, Heinz H. Busta, Bruce M. Zwicker
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Patent number: 7257194Abstract: A cathode head is provide that is suitable for use in an x-ray device that includes an anode having a target surface configured and arranged to receive electrons emitted by the cathode head. The cathode head may be constructed of magnetic or non-magnetic material and includes an emitter block carrying a filament that defines a longitudinal axis about which is disposed one or more magnetic coils. The filament is configured and arranged to emit an electron beam that defines a focal spot on the target surface of the anode. The magnetic coil, or coils, disposed about the longitudinal axis defined by the filament generate a magnetic field that enables control of the location of the focal spot on the target surface of the anode.Type: GrantFiled: February 9, 2004Date of Patent: August 14, 2007Assignee: Varian Medical Systems Technologies, Inc.Inventor: Ricky Smith
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Patent number: 7236569Abstract: The invention improves an insulating performance of an X-ray tube without increasing an insulation size. An X-ray tube in accordance with the invention keeps a mechanical strength of a glass insulation material and improves an insulation withstand voltage by a concavity and convexity, by forming a concavity and convexity having an arithmetic mean surface roughness of JIS B0601-1994 equal to or more than 1.0 ?m and equal to or less than 10 ?m in a vacuum side surface of a glass insulation material supporting electric conductors within a vacuum chamber for a range equal to or more than 2 mm from a position in an end of the electric conductors.Type: GrantFiled: July 1, 2005Date of Patent: June 26, 2007Assignee: Hitachi, Ltd.Inventors: Ryozo Takeuchi, Yoshiaki Tsumuraya
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Patent number: 7224771Abstract: An x-ray tube (16) suitable for use in a computed tomography (CT) scanner (10) includes an envelope (42) which defines an evacuated chamber. An anode (40) and a cathode assembly (70) are disposed within the chamber. The anode defines a target area (56) which is struck by electrons (52) emitted by a filament (54) of the cathode assembly and emits x-rays (46). The target area lies partially on a first annular portion (80) which is disposed at first angle (a) relative to a plane perpendicular to an axis of rotation (R) of the anode, and partially on a second portion (82,120) which is radially spaced from the first portion and disposed at a second angle (?), relative to the plane. The second angle is greater than the first angle. The portions of different slope allow the x-ray tube to take advantage of a shallow angle, while minimizing the heel effect.Type: GrantFiled: July 16, 2004Date of Patent: May 29, 2007Assignee: Koninklijke Philips Electronics N.V.Inventors: Simha Levene, Gabriel Malamud, Altman Ami
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Patent number: 7218703Abstract: To provide an X-ray microscopic inspection apparatus capable of performing non-destructive inspection with high resolving power equal to or less than 0.1 ?m in a very short period, and largely contributing to the nano-technology field. In the X-ray microscopic inspection apparatus having X-ray generating means for generating an X-ray by allowing an electron beam from an electron source to impinge on a target for X-ray generation, for inspecting an object to be inspected by utilizing the X-ray, a magnetic field superposition lens having a magnetic field generating portion disposed in the vicinity of an electron generating portion of an electron gun is included as a component element of the X-ray generating means. Further, the apparatus includes a liquid metal electron source using liquid metal or a thermal field emission electron source as the electron source, as a component element of the X-ray generating means.Type: GrantFiled: November 21, 2003Date of Patent: May 15, 2007Assignee: Tohken Co., Ltd.Inventors: Keiji Yada, Hiromi Kai, Yasushi Saito
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Patent number: 7218700Abstract: A system and method for forming x-rays. One exemplary system includes a target and electron emission subsystem with a plurality of electron sources. Each of the plurality of electron sources is configured to generate a plurality of discrete spots on the target from which x-rays are emitted. Another exemplary system includes a target, an electron emission subsystem with a plurality of electron sources, each of which generates at least one of the plurality of spots on the target, and a transient beam protection subsystem for protecting the electron emission subsystem from transient beam currents, material emissions from the target, and electric field transients.Type: GrantFiled: February 1, 2005Date of Patent: May 15, 2007Assignee: General Electric CompanyInventors: William Hullinger Huber, Colin Richard Wilson, John Scott Price, Peter Michael Edic, Mark Ernest Vermilyea
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Patent number: 7209544Abstract: An x-ray tube cathode assembly (28) includes a support arm (36) comprising a first metal. A ceramic insulator (70, 82) has a first metalized surface (72, 86) wherein the metalized surfaces comprise a desired amount of the first metal. A first member of filler material (90) is in contact with the support arm (36) and the first metalized surface (72, 86) of the ceramic insulator (70, 82), the first member of filler material comprising at least a second metal (96a, 96b) wherein a first alloy system (FIG. 5) comprising the first and second metals includes an alloy minimum point percentage composition (P) of the first and second metals having a first alloy system minimum melting point (M) for the alloy minimum point percentage composition that is lower than both of the melting point of the first metal and second metal.Type: GrantFiled: February 20, 2004Date of Patent: April 24, 2007Assignee: Koninklijke Philips Electronics, N.V.Inventors: Paul Xu, George Awad, Salvatore Perno, Qing K. Lu
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Patent number: 7203269Abstract: A system and method for forming x-rays. One exemplary system includes a target and electron emission subsystem with a plurality of electron sources. Each of the plurality of electron sources is configured to generate a plurality of discrete spots on the target from which x-rays are emitted. Another exemplary system includes a target, an electron emission subsystem with a plurality of electron sources, each of which generates at least one of the plurality of spots on the target, and a transient beam protection subsystem for protecting the electron emission subsystem from transient beam currents and material emissions from the target.Type: GrantFiled: February 1, 2005Date of Patent: April 10, 2007Assignee: General Electric CompanyInventors: William Hullinger Huber, Colin Richard Wilson, John Scott Price, Peter Michael Edic, Mark Ernest Vermilyea, Forrest Frank Hopkins
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Patent number: 7192031Abstract: 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).Type: GrantFiled: February 5, 2004Date of Patent: March 20, 2007Assignee: General Electric CompanyInventors: Bruce M. Dunham, Colin R. Wilson, John Scott Price
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Patent number: 7149282Abstract: A miniaturized X-ray source is disclosed. It comprises an anode structure (43) and a cathode structure (41), each having an essentially pointed portion (44, 42), wherein at least the pointed portions being directed towards each other and enclosed in a vacuum cavity (49). The anode structure has an essentially dome shaped structure having a first essentially flat part (46) surrounded by a second essentially flat part (48), connected by a wall section (47), such that said first and second parts are located at different levels. The pointed portion is provided on said first flat portion and having an extension such that the apex of said pointed portion does not extend beyond the level of said second essentially flat part. A method of making an X-ray source is also disclosed.Type: GrantFiled: September 7, 2001Date of Patent: December 12, 2006Assignee: Radi Medical Technologies ABInventors: Pelle Rangsten, Carolina Ribbing, Klas Hjort, Jonas Tirén
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Patent number: 7145988Abstract: A sealed electron beam source (12) for an imaging tube (16) is provided. The beam source (12) includes a source housing (50) with a source window (54) having a first voltage potential and a source electrode (52) having a second voltage potential. The source electrode (52) generates electrons and emits the electrons through the source window (54) to a target (32) that is external to the source housing (50). A method of supplying and directing electrons on the target (32) within the imaging tube (16) is also provided. The method includes forming the source housing (50) over the source electrode (52) and sealing the source housing (50). The electrons are generated and emitted from the source electrode (52) and directed through the source window (54) to the target (32).Type: GrantFiled: December 3, 2003Date of Patent: December 5, 2006Assignee: General Electric CompanyInventors: J. Scott Price, Bruce M. Dunham
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Patent number: 7130381Abstract: Methods for connecting electrical potential to an extractor cup at the cathode of a miniature x-ray tube are disclosed. The various connection schemes are designed to form a rugged and conveniently manufacturable connection between the metal extractor cup and one side of the cathode filament, so that the extractor cup shapes the path of electrons as desired en route to the anode of the tube. Some of the disclosed connections involve evaporation of conductive metal or other materials off the filament when the filament is first activated. Others involve applying a paste or paint conductive precursor directly to a base to connect a post and the extractor, the paste being heat-cured after the completion of assembly. Others involve a fine wire or spring strip from one filament post to the walls of the extractor cup. Other schemes include welded or brazed wires or foil, crimping, pinching, swaging and other connections, all made inside the tube enclosure.Type: GrantFiled: November 30, 2005Date of Patent: October 31, 2006Assignee: Xoft, Inc.Inventors: Paul A. Lovoi, Petre H. Vatahov, Earl E. Dozier, Peter C. Smith, Leonard Reed, Robert G. Neimeyer
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Patent number: 7130380Abstract: Methods for connecting electrical potential to an extractor cup at the cathode of a miniature x-ray tube are disclosed. The various connection schemes are designed to form a rugged and conveniently manufacturable connection between the metal extractor cup and one side of the cathode filament, so that the extractor cup shapes the path of electrons as desired en route to the anode of the tube. Some of the disclosed connections involve evaporation of conductive metal or other materials off the filament when the filament is first activated. Others involve applying a paste or paint conductive precursor directly to a base to connect a post and the extractor, the paste being heat-cured after the completion of assembly. Others involve a fine wire or spring strip from one filament post to the walls of the extractor cup. Other schemes include welded or brazed wires or foil, crimping, pinching, swaging and other connections, all made inside the tube enclosure.Type: GrantFiled: March 13, 2004Date of Patent: October 31, 2006Assignee: Xoft, Inc.Inventors: Paul A. Lovoi, Petre H. Vatahov, Earl E. Dozier, Peter C. Smith, Leonard Reed, Robert G. Neimeyer
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Patent number: 7123689Abstract: In accordance with one embodiment, the present technique provides an X-ray source. The X-ray source includes a field emitter array having a plurality of field emitter elements disposed in a vacuum chamber and configured to emit electrons in the vacuum chamber towards an anode assembly. The X-ray source also includes an anode disposed in the vacuum chamber for receiving the electrons emitted by the field emitter array and configured to thereby generate X-ray radiation. The X-ray source further includes a source of cleaning gas coupled to the vacuum chamber, wherein the source of cleaning gas is configured to provide the cleaning gas to the vacuum chamber towards the field emitter array to reduce deposition of contaminants on or to clean contaminates from the field emitter array.Type: GrantFiled: June 30, 2005Date of Patent: October 17, 2006Assignee: General Electric CompanyInventor: Colin Richard Wilson
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Patent number: 7085354Abstract: This invention provides an X-ray tube apparatus which can output X-rays of a dose suitable for radioscopy for a long time. In the apparatus, small focus filaments are provided on respective sides of a large focus filament, such that they have almost equal distances from the center of the large focus filament, and the inclination angles of converging electrodes surrounding the respective small focus filaments with respect to a cathode main body are set to almost equal angles within a range of 20 to 40°.Type: GrantFiled: September 3, 2004Date of Patent: August 1, 2006Assignees: Toshiba Electron Tube & Devices Co., Ltd., Kabushiki Kaisha ToshibaInventor: Masaji Kanagami