With Specific Cathode Patents (Class 378/136)
  • Publication number: 20110280363
    Abstract: An X-ray tube includes a target and a cathode assembly. The cathode assembly includes a first filament configured to emit a first beam of electrons toward the target, a first gridding electrode coupled to the first filament, a second filament configured to emit a second beam of electrons toward the target, and a second gridding electrode coupled to the second filament.
    Type: Application
    Filed: May 12, 2010
    Publication date: November 17, 2011
    Inventors: Yun Zou, Brian Lounsberry, Carey Shawn Rogers, Sergio Lemaitre, Xiaoye Wu, Jizhong Chen, Floribertus P. Heukensfeldt Jansen
  • Publication number: 20110280377
    Abstract: In a thermionic surface emitter and an associated method to operate an x-ray tube, the surface emitter has a conductor path in its emission surface, the conductor path having at least one current entrance point and at least one current exit point. In the thermionic surface emitter, the width of the conductor path is variable i.e. is non-constant or non-uniform. The electrical resistance of the emitter structure thus varies along the heating current path, with the consequence that a symmetrical emission structure can be achieved at a working point established by the hardware geometry.
    Type: Application
    Filed: May 6, 2011
    Publication date: November 17, 2011
    Inventors: Joerg Freudenberger, Gunter Roehrich
  • Publication number: 20110280371
    Abstract: A device is provided for the generation of x-ray emission from an x-ray source based on titanium dioxide (TiO2) nanotubes grown by electrochemical oxidation. TiO2 nanotubes are used as a cold cathode in x-ray tubes.
    Type: Application
    Filed: May 12, 2011
    Publication date: November 17, 2011
    Inventors: Sabee Molloi, Yahya Alivov
  • Publication number: 20110255667
    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.
    Type: Application
    Filed: April 14, 2010
    Publication date: October 20, 2011
    Applicant: General Electric Company
    Inventor: Sergio Lemaitre
  • Patent number: 8031839
    Abstract: According to one embodiment, a distance from an X-ray tube central axis to an outer side surface of a cathode electron gun in a direction perpendicular to the longitudinal direction of a filament coil is made less than a distance from the X-ray tube central axis to an outer side surface of the cathode electron gun in the longitudinal direction of the filament coil, and a distance from the X-ray tube central axis to an X-ray radiation window in the direction perpendicular to the longitudinal direction of the filament coil is made less than a distance from the X-ray tube central axis to an X-ray radiation window in the longitudinal direction of the filament coil.
    Type: Grant
    Filed: July 15, 2010
    Date of Patent: October 4, 2011
    Assignees: Kabushik Kaisha Toshiba, Toshiba Electron Tubes & Devices Co., Ltd.
    Inventor: Takashi Shimono
  • Patent number: 8026674
    Abstract: An electron source has an electron emitter with an electron emission cathode, a high voltage unit provided for power supply of the electron emission cathode, and a low voltage unit provided to control the high voltage unit. Data are transmitted non-electrically (in particular optically) between the high voltage unit and the low voltage unit.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: September 27, 2011
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jan Berk, Josef Deuringer
  • Publication number: 20110228909
    Abstract: An embodiment of the invention relates to a cathode cup (20) comprising a receptacle for holding an electron emitter (21), wherein the cathode cup is provided at least in the area facing the electron emitter (21) with a surface comprising a plurality of cavities (23). Further, the invention provides an electron source and an x-ray system comprising such a cathode cup (20).
    Type: Application
    Filed: December 1, 2009
    Publication date: September 22, 2011
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventors: Stefan Hauttmann, Zoryana Terletska
  • Patent number: 8000449
    Abstract: It is described an emitter (26, 40) for X-ray tubes comprising: a flat foil with an emitting section (30, 46); and at least two electrically conductive fixing sections (31-34; 41-44); wherein the emitting section (30, 46) is unstructured.
    Type: Grant
    Filed: October 10, 2007
    Date of Patent: August 16, 2011
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Stefan Hauttmann, Wolfram Maring
  • Publication number: 20110188634
    Abstract: An x-ray generation device and a cathode thereof are provided. The x-ray generation device comprises the cathode, a focusing device, an anode target, and a glass container. The cathode comprises a container and an electron beam generator. The container has a base and a side wall surrounding the base, and both of them define a trench. The electron beam generator comprises at least one metal unit, each of the at least one metal unit is chemical-vapor-deposited a carbon layer, and each of the at least one metal unit is disposed on a bottom of the trench. The at least one metal unit is electrically connected to an outer metal unit of the x-ray generation device. The glass container contains the cathode, the focusing device, and the anode target in sequence. Each of the at least one carbon layer faces the anode target. The glass container has a valve for evacuating and a window for emitting an x-ray.
    Type: Application
    Filed: February 4, 2010
    Publication date: August 4, 2011
    Applicants: ENERGY RESOURCES INTERNATIONAL CO., LTD.
    Inventors: Pu-Jen LEE, Wen-How LAN
  • Publication number: 20110188637
    Abstract: The disclosed embodiments include embodiments such as an X-ray tube cathode filament system. The X-ray tube cathode filament system includes a substrate and a coating disposed on the substrate. In this cathode filament system, an electron beam is emitted from the coating but not from the substrate. The electron beam is produced through the use of the thermionic effect.
    Type: Application
    Filed: February 2, 2010
    Publication date: August 4, 2011
    Applicant: General Electric Company
    Inventors: Sergio Lemaitre, Julin Wan, Sergiy Zalyubovsky, Andrey Ivanovich Meshkov
  • Patent number: 7983394
    Abstract: A multiple wavelength x-ray source includes a multi-thickness target, having at least a first and a second thickness. The first thickness can substantially circumscribe the second thickness. An electron beam can be narrowed to impinge primarily upon second thickness or expanded to impinge primarily upon the first thickness while maintaining a constant direction of the beam. This invention allows the target thickness to be optimized for the desired output wavelength without the need to redirect or realign the x-rays towards the target.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: July 19, 2011
    Assignee: Moxtek, Inc.
    Inventors: Krzysztof Kozaczek, Sterling Cornaby, Steven Liddiard, Charles Jensen
  • Patent number: 7965818
    Abstract: Disclosed herein is an x-ray field emission apparatus, system and method, the apparatus having a hollow probe held at vacuum; a cathode enclosed within the probe, the cathode producing an electron stream when connected to a high negative potential; an anode enclosed within the probe and separated from the cathode by a gap, said the providing a target for the electron stream; and a shield assembly comprising a hollow shield electrode positioned within the probe and about the cathode.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: June 21, 2011
    Assignee: Minnesota Medical Physics LLC
    Inventors: Ali Jaafar, Victor I. Chornenky
  • Patent number: 7940894
    Abstract: The system uses an X-ray imaging system having an elongated lifetime. Further, the system uses an X-ray beam that lies in substantially the same path as a charged particle beam path of a particle beam cancer therapy system. The system creates an electron beam that strikes an X-ray generation source located proximate to the charged particle beam path. By generating the X-rays near the charged particle beam path, an X-ray path running collinear, in parallel with, and/or substantially in contact with the charged particle beam path is created. The system then collects X-ray images of localized body tissue region about a cancerous tumor. Since, the X-ray path is essentially the charged particle beam path, the generated image is usable for precisely target the tumor with a charged particle beam.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: May 10, 2011
    Inventor: Vladimir Balakin
  • Patent number: 7924983
    Abstract: 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: Grant
    Filed: June 30, 2008
    Date of Patent: April 12, 2011
    Assignee: Varian Medical Systems, Inc.
    Inventor: Paul D. Moore
  • Patent number: 7907700
    Abstract: The present invention aims to suppress calorific value and prolong a lifetime of an apparatus that generates soft X-rays. Thus, the present invention provides a static elimination apparatus that includes an emitter as an electron emitting portion and a target, in which a thin film formed of diamond particles each having a particle size of 2 nm to 100 nm is formed on a surface of the emitter. The thin film has a diamond XRD pattern in an XRD measurement and, in a Raman spectroscopic measurement, a ratio of an sp3 bonding component to an sp2 bonding component within the film of 2.5 to 2.7:1. When a DC voltage is applied to the emitter, with a threshold electric field intensity of 1 V/?m or less, electrons larger in number than the prior art are emitted from the emitter and moreover, a temperature of the emitter is hardly increased, thus obtaining a longer lifetime.
    Type: Grant
    Filed: April 10, 2007
    Date of Patent: March 15, 2011
    Assignees: Casio Computer Co., Ltd., Kochi Industrial Promotion Center
    Inventors: Hitoshi Inaba, Yoshinori Okubo, Yoshiyuki Yagi, Shunichi Sato, Kazuhito Nishimura
  • Publication number: 20110058643
    Abstract: In one embodiment, an X-ray tube is provided. The X-ray tube comprises at least one thermionic cathode configured to generate an electron beam, a target assembly configured to generate X-rays when impinged with the electron beam emitted from the thermionic cathode, a high voltage supply unit for establishing an output voltage across the thermionic cathode and the target assembly for establishing an accelerating electric field between the thermionic cathode and the target assembly and a mesh grid disposed between the thermionic cathode and the target assembly, the mesh grid configured to operate at a voltage so as to lower the electric field applied at the surface of the thermionic cathode. Further, the voltage at the mesh grid is negatively biased with respect to the voltage at the thermionic cathode.
    Type: Application
    Filed: September 4, 2009
    Publication date: March 10, 2011
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Sergio Lamaitre, Carey Rogers, Yun Zou, Jizhong Chen
  • Patent number: 7903789
    Abstract: An X-ray tube includes an emitter wire enclosed in a suppressor. An extraction grid comprises a number of parallel wires extending perpendicular to the emitter wire, and a focusing grid comprises a number of wires parallel to the grid wires and spaced apart at equal spacing to the grid wires. 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 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: Grant
    Filed: February 16, 2009
    Date of Patent: March 8, 2011
    Assignee: Rapiscan Systems, Inc.
    Inventors: Edward James Morton, Russell David Luggar, Paul De Antonis
  • Patent number: 7903788
    Abstract: 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 having a plurality of substantially parallel emission surfaces that collectively emit a beam of electrons for impingement on the target anode. In one aspect, the plurality of substantially parallel emission surfaces are angled relative focusing region so as to provide a substantially uniform thermal load on the target anode. In another aspect, the electron emitter includes a plurality of cut-outs that accommodate thermal expansion in the plane of the emitter. Accommodating thermal expansion in the plane of the emitter prevents distortions to the emitter that would tend to alter the focusing of the electrons on the target anode.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: March 8, 2011
    Assignee: Varian Medical Systems, Inc.
    Inventors: Paul D. Moore, James Russell Boye
  • Publication number: 20110051895
    Abstract: X-ray systems for use in high-resolution imaging applications with an improved power rating are provided. An X-ray source comprises at least one integrated actuator unit (206, 206?, 206a or 206b) for performing at least one translational and/or rotational displacement by moving the position of the X-ray source's anode (204, 204?, 204a? or 204b?) relative to a stationary reference position. This helps to overcome power limitations due to an overheating of the anode at its focal ?spot position (205). In addition to that, a focusing unit (203) for allowing an adapted focusing of the anode's focal spot (205) which compensates deviations in the focal spot size resulting from said anode displacements and/or a deflection means (211, 21 Ia or 21 Ib) for generating an electric and/or magnetic field deflecting the electron beam (202, 202a or 202b) in a direction opposite to the direction of the rotary anode's displacement movement may be provided.
    Type: Application
    Filed: May 4, 2009
    Publication date: March 3, 2011
    Inventors: Gereon Vogtmeier, Rainer Pietig, Astrid Lewalter, Rolf Karl Otto Behling
  • Publication number: 20110026681
    Abstract: An x-ray imaging system includes a detector positioned to receive x-rays, and an x-ray tube coupled to a mount structure. The x-ray tube is configured to generate x-rays toward the detector and includes a target, a cathode cup, an emitter attached to the cathode cup and configured to emit a beam of electrons toward the target, the emitter having a length and a width, and a one-dimensional grid positioned between the emitter and the target and attached to the cathode cup at one or more attachment points. The one-dimensional grid includes a plurality of rungs that each extend in a direction of the width of the emitter, and the plurality of rungs are configured to expand and contract relative to the one or more attachment points without substantial distortion with respect to the emitter.
    Type: Application
    Filed: July 29, 2009
    Publication date: February 3, 2011
    Inventors: Yun Zou, Carey Shawn Rogers, Sergio Lemaitre, Mark Alan Frontera, Edward Emaci, Vance Robinson
  • Patent number: 7864924
    Abstract: 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: Grant
    Filed: June 13, 2008
    Date of Patent: January 4, 2011
    Assignee: L-3 Communications Security and Detection Systems, Inc.
    Inventors: Vitaliy Ziskin, Boris Oreper, Andrew Dean Foland
  • Patent number: 7864925
    Abstract: 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: Grant
    Filed: February 27, 2009
    Date of Patent: January 4, 2011
    Assignee: Siemens Aktiengesellschaft
    Inventor: Wolfgang Kutschera
  • Patent number: 7860219
    Abstract: A cathode shield can comprise a shield body, a pair of tabs for defining a focal spot length, and a lip for concentrically aligning the cathode shield relative to a mounting element and/or an electron source of a cathode assembly. The tabs may be integral with the shield body and spaced a distance apart from each other. The distance may at least partially define the focal spot length of the electron source associated with the cathode assembly. The lip may also be integral with the shield body and extend from the shield body around at least a portion of a perimeter of the shield body so as to define a recess that is configured to receive the mounting element of the cathode assembly.
    Type: Grant
    Filed: September 26, 2008
    Date of Patent: December 28, 2010
    Assignee: Varian Medical Systems, Inc.
    Inventors: Scott M. Clark, Gregory C. Andrews
  • Publication number: 20100316192
    Abstract: It is described an emitter (26, 40) for X-ray tubes comprising: a flat foil with an emitting section (30, 46); and at least two electrically conductive fixing sections (31-34; 41-44); wherein the emitting section (30, 46) is unstructured.
    Type: Application
    Filed: October 10, 2007
    Publication date: December 16, 2010
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventors: Stefan Hauttmann, Wolfram Maring
  • Patent number: 7839978
    Abstract: 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: Grant
    Filed: December 22, 2006
    Date of Patent: November 23, 2010
    Assignee: Nederlandse Organisatie voor toegepast-natuurwetenschappelijk Onderzoek TNO
    Inventors: Godefridus Hendricus Maria Gubbels, Johannes Petrus Zijp
  • Publication number: 20100284519
    Abstract: An electron emitter assembly, and methods of assembly, is disclosed. The emitter assembly includes an electron emitter that is secured to a support device in a manner such that the emitter is substantially thermally isolated from the support device.
    Type: Application
    Filed: September 25, 2008
    Publication date: November 11, 2010
    Applicant: VARIAN MEDICAL SYSTEMS, INC.
    Inventors: Paul D. Moore, Christopher F. Artig, Robert C. Treseder
  • Patent number: 7831020
    Abstract: The present invention relates to an X-ray tube, having a structure for realizing improvement of a magnification factor of a magnified transmission image, and an X-ray source that includes the X-ray tube. The X-ray tube includes: a target housing unit, housing an X-ray target; and an electron gun housing unit, one end of which is mounted to a side wall portion of the target housing unit. The electron gun housing unit is disposed so that a tube axis thereof intersects a tube axis of the target housing unit. The electron gun housing unit holds an electron gun while a center of an electron emission exit of the electron gun is shifted more toward an X-ray emission window side, disposed at one end of the side wall portion of the target housing unit, than the tube axis of the electron gun housing unit.
    Type: Grant
    Filed: October 3, 2006
    Date of Patent: November 9, 2010
    Assignee: Hamamatsu Photonics K.K.
    Inventor: Tutomu Inazuru
  • Publication number: 20100278308
    Abstract: According to one embodiment, a distance from an X-ray tube central axis to an outer side surface of a cathode electron gun in a direction perpendicular to the longitudinal direction of a filament coil is made less than a distance from the X-ray tube central axis to an outer side surface of the cathode electron gun in the longitudinal direction of the filament coil, and a distance from the X-ray tube central axis to an X-ray radiation window in the direction perpendicular to the longitudinal direction of the filament coil is made less than a distance from the X-ray tube central axis to an X-ray radiation window in the longitudinal direction of the filament coil.
    Type: Application
    Filed: July 15, 2010
    Publication date: November 4, 2010
    Applicants: KABUSHIKI KAISHA TOSHIBA, Toshiba Electron Tubes & Devices Co., Ltd.
    Inventor: Takashi Shimono
  • Publication number: 20100278307
    Abstract: 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 having a plurality of substantially parallel emission surfaces that collectively emit a beam of electrons for impingement on the target anode. In one aspect, the plurality of substantially parallel emission surfaces are angled relative focusing region so as to provide a substantially uniform thermal load on the target anode. In another aspect, the electron emitter includes a plurality of cut-outs that accommodate thermal expansion in the plane of the emitter. Accommodating thermal expansion in the plane of the emitter prevents distortions to the emitter that would tend to alter the focusing of the electrons on the target anode.
    Type: Application
    Filed: September 25, 2008
    Publication date: November 4, 2010
    Applicant: VARIAN MEDICAL SYSTEMS, INC.
    Inventors: Paul D. Moore, James Russell Boye
  • Patent number: 7826594
    Abstract: A system and method for addressing individual electron emitters in an emitter array is disclosed. The system includes an emitter array comprising a plurality of emitter elements arranged in a non-rectangular layout and configured to generate at least one electron beam and a plurality of extraction grids positioned adjacent to the emitter array, each extraction grid being associated with at least one emitter element to extract the at least one electron beam therefrom. The field emitter array system also includes a plurality of voltage control channels connected to the plurality of emitter elements and the plurality of extraction grids such that each of the emitter elements and each of the extraction grids is individually addressable. In the field emitter array system, the number of voltage control channels is equal to the sum of a pair of integers closest in value whose product equals the number of emitter elements.
    Type: Grant
    Filed: May 1, 2008
    Date of Patent: November 2, 2010
    Assignee: General Electric Company
    Inventors: Yun Zou, Mark E. Vermilyea, Louis Paul Inzinna, Antonio Caiafa
  • Patent number: 7809115
    Abstract: A flash radiography diode includes a cathode and an anode. The cathode includes a frustum member with a bore extending through the frustum member. The anode is a tapered anode made of an electrically conductive material and oriented toward the cathode. The anode and the cathode are housed in a chamber with a gap between the anode and the cathode. The cathode is configured to emit electrons to the tapered anode, which electrons strike the anode and create an anode plasma. The anode plasma creates X rays which propagate from the anode.
    Type: Grant
    Filed: September 9, 2008
    Date of Patent: October 5, 2010
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Raymond J Allen, Gerald Cooperstein, Joseph W Schumer
  • Publication number: 20100246766
    Abstract: A miniature X-ray source device for effecting radiation therapy at least comprising a vacuum tube containing a cathode and an anode spaced apart at some distance from each other; emitting means for emitting free electrons from the cathode; electric field generating means for applying during use a high-voltage electric field between the cathode and the anode for accelerating the emitted free electrons towards the anode, as well as an exit window for X-ray radiation being generating at the anode. The present invention provides an improved miniature X-ray source device, that can also properly be used in treating skin cancer and which is easy to handle. The anode is provided with a flat X-ray emitting surface. In particular, the cathode exhibits a concave shaped surface having a center part surrounded by an upright circumferential edge, wherein the center part of the concave shaped surface is provided with an electron emitting material.
    Type: Application
    Filed: June 17, 2008
    Publication date: September 30, 2010
    Inventors: Johann Kindlein, Evert Hendrik Agterhuis, Godefridus Hendricus Maria Gubbels, Frank Simonis
  • Patent number: 7795792
    Abstract: An apparatus and method comprising a cathode structure which can be a cylindrical filament coiled in a helix or which can be constructed of a ribbon or other suitable shape. The cathode structure can be heated by passage of an electrical current, or by other means such as bombardment with energetic electrons. Selected portions of the surface of the cathode structure have an altered property with respect to the non-selected portions of the surface. In one embodiment, the altered property is a curvature. In another embodiment, the altered property is a work function. By altering the property of the selected portions of the surface, the electron beam intensity is increased, and the width is decreased.
    Type: Grant
    Filed: February 8, 2006
    Date of Patent: September 14, 2010
    Assignee: Varian Medical Systems, Inc.
    Inventors: James T. Arnold, Steve Bandy, Gary Virshup
  • Patent number: 7782999
    Abstract: Systems and methods for data acquisition in computed tomography (CT) applications are provided. The systems and methods are particularly adapted for scanning and acquiring/processing data in connection with high-power cone-beam CT applications. The electron beam is moved/scanned along the anode surface to multiple focal positions. Data acquisition for a full projection at one focus position and one view angle is achieved by activating each focus position multiple times during the data acquisition for one angle of the gantry. The detector array and associated data processing system are adapted to rapidly switch between the different focus positions during the acquisitions for one view angle and to collect all data belonging to the same projection into the same data set. Adaptive electron optics are utilized to move/scan the electron beam along the anode surface to the various focus positions.
    Type: Grant
    Filed: September 16, 2006
    Date of Patent: August 24, 2010
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Astrid Lewalter, Rainer Pietig, Guenter Zeitler, Kai Eck, Christoph Herrmann, Rainer Kiewitt, Christoph Loef, Oliver Muelhens, Carolina Ribbing, Georg Rose, Matthias Simon, Olaf Wischhusen
  • Patent number: 7778391
    Abstract: A field emission cathode has a field emitter and an extraction grid, and the field emitter and the extraction grid can be moved relative to one another. Such a field emission cathode is highly durable and exhibits a longer lifespan. An x-ray tube has a field emission cathode composed of a field emitter and an extraction grid that can be moved relative to one another. Such an x-ray tube is highly durable and exhibits a longer lifespan.
    Type: Grant
    Filed: June 4, 2009
    Date of Patent: August 17, 2010
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jens Fuerst, Stefan Popescu, Georg Wittmann
  • Publication number: 20100195797
    Abstract: A thermionic electron emitter (1) is proposed comprising an inner part (2) including a heatable flat emission surface (3) and an outer part (4) including a surrounding surface (6) substantially enclosing the emission surface and a heating arrangement for heating the emission surface to a temperature for thermionic electron emission. The outer part is mechanically connected to the inner part in a connection region (10) apart from the emission surface. Furthermore, the surrounding surface is thermally isolated, e.g. by a gap (14), from the emission surface in an isolation region apart from the connection region. By providing a surrounding surface enclosing the emission surface which may be on a similar electrical potential as the emission surface but which can have a substantially lower temperature than the emission surface without influencing the temperature distribution within the emission surface, an improved electron emission distribution and homogeneity can be obtained.
    Type: Application
    Filed: July 17, 2008
    Publication date: August 5, 2010
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventor: Stefan Hauttmann
  • Publication number: 20100195798
    Abstract: An apparatus and method comprising a cathode structure which can be a cylindrical filament coiled in a helix or which can be constructed of a ribbon or other suitable shape. The cathode structure can be heated by passage of an electrical current, or by other means such as bombardment with energetic electrons. Selected portions of the surface of the cathode structure have an altered property with respect to the non-selected portions of the surface. In one embodiment, the altered property is a curvature. In another embodiment, the altered property is a work function. By altering the property of the selected portions of the surface, the electron beam intensity is increased, and the width is decreased.
    Type: Application
    Filed: April 13, 2010
    Publication date: August 5, 2010
    Inventors: James T. Arnold, Steve Bandy, Gary Virshup
  • Patent number: 7759663
    Abstract: A radiation source having self-shading electrodes is disclosed. Debris originating from the electrodes is reduced. The path from the electrodes to the EUV optics is blocked by part of the electrodes themselves (termed self-shading). This may significantly reduce the amount of electrode-generated debris.
    Type: Grant
    Filed: December 6, 2006
    Date of Patent: July 20, 2010
    Assignee: ASML Netherlands B.V.
    Inventors: Maarten Marinus Johannes Wilhelmus Van Herpen, Wouter Anthon Soer
  • Publication number: 20100150315
    Abstract: An X-ray source with a cathode (2) that includes a first wire (4) having optionally thermal loops (12, 14) between an emission loop (10) and first and second ends (6, 8). A spiral second wire (30) is wound around the wire (4) and a low work function coating (32) is provided on both wires. The first and second wires may be of refractory material, such as tungsten, and the low work function coating may include barium oxide.
    Type: Application
    Filed: April 18, 2008
    Publication date: June 17, 2010
    Inventors: Bart Filmer, Maurice Lambers
  • Patent number: 7738632
    Abstract: An x-ray tube has a cathode that generates free electrons; an anode on which the free and accelerated electrons strikes so that x-ray radiation is generated; a cooling channel with coolant flowing therethrough to cool the anode; a vacuum region between the cathode and the anode; and an exit window through which the x-ray radiation exits from the x-ray tube. The anode is fashioned as a transmission anode; with the transmission anode arranged between the vacuum region and the cooling channel, with the cooling channel arranged between the transmission anode and the exit window; so the useful x-ray radiation passes through the coolant.
    Type: Grant
    Filed: September 26, 2008
    Date of Patent: June 15, 2010
    Assignee: Siemens Aktiengesellschaft
    Inventors: Stefan Popescu, Georg Wittmann
  • Patent number: 7734014
    Abstract: A gas discharge source, in particular, for generating extreme ultraviolet and/or soft X-radiation, has a gas-filled intermediate electrode space located between two electrodes, devices for the admission and evacuation of gas, and one electrode that has an opening that defines an axis of symmetry and is provided for the discharge of radiation. A diaphragm exhibits at least one opening on the axis of symmetry and operates as a differential pump stage, between the two electrodes.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: June 8, 2010
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Klaus Bergmann, Willi Neff
  • Patent number: 7693265
    Abstract: The invention relates the field of electron emitter of an X-ray tube. More specifically the invention relates to flat thermionic emitters to be used in X-ray systems with variable focus spot size and shape. The emitter provides two main terminals (3, 5) which form current conductors and which support at least two emitting portions (7, 9). The emitting portions are structured in a way so that they are electron optical identical or nearly identical increasing the emergency operating options in case of emitter damage.
    Type: Grant
    Filed: May 2, 2007
    Date of Patent: April 6, 2010
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Stefan Hauttmann, Jens Peter Kaerst
  • Publication number: 20100067663
    Abstract: A cathode HAS a cathode head in which a surface emitter is arranged that emits electrons upon application of a heating voltage. The surface emitter is fashioned as a parallel surface emitter with at least two emitter surfaces spaced apart from one another, to which at least one electrically conductive cutoff electrode is fed that is galvanically separated from the parallel surface emitter. Such a cathode has a good cutoff capability.
    Type: Application
    Filed: September 11, 2009
    Publication date: March 18, 2010
    Inventors: Joerg Freudenberger, Wolfgang Kutschera, Gunter Roehrich, Karin Soeldner
  • Publication number: 20100061517
    Abstract: A flash radiography diode includes a cathode and an anode. The cathode includes a frustum member with a bore extending through the frustum member. The anode is a tapered anode made of an electrically conductive material and oriented toward the cathode. The anode and the cathode are housed in a chamber with a gap between the anode and the cathode. The cathode is configured to emit electrons to the tapered anode, which electrons strike the anode and create an anode plasma. The anode plasma creates X rays which propagate from the anode.
    Type: Application
    Filed: September 9, 2008
    Publication date: March 11, 2010
    Inventors: Raymond J. Allen, Gerald Cooperstein, Joseph W. Schumer
  • Patent number: 7668296
    Abstract: 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: Grant
    Filed: June 14, 2007
    Date of Patent: February 23, 2010
    Assignee: General Electric Co.
    Inventors: Thomas Schaefer, Ron Hockersmith, Ethan Westcot
  • Publication number: 20100040201
    Abstract: One or more components of an x-ray cathode assembly are manufactured using a metal deposition process. The deposition process is carried out by providing a cathode shield and a cathode head with a cathode cup and a filament slot fabricated from a first metal, and forming a coating comprising a second metal on at least a portion of at least one of the filament slot, cathode cup, cathode head, and/or cathode shield using a deposition process so as to yield the x-ray cathode assembly. The deposition process is continued until a desired thickness of metal is achieved. Example deposition processes include electroforming, chemical vapor deposition, physical vapor deposition, plasma spray, high velocity oxygen fuel thermal spray, and detonation thermal spraying.
    Type: Application
    Filed: August 14, 2008
    Publication date: February 18, 2010
    Applicant: VARIAN MEDICAL SYSTEMS, INC.
    Inventor: David S.K. Lee
  • Patent number: 7657003
    Abstract: 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: Grant
    Filed: September 4, 2008
    Date of Patent: February 2, 2010
    Assignee: Thermo Niton Analyzers LLC
    Inventor: William L. Adams
  • Patent number: 7657002
    Abstract: A cathode assembly including certain features designed to protect the integrity of a filament contained therein is disclosed. In particular, the cathode assembly is configured to prevent damage to the filament should it inadvertently contact another portion of the cathode assembly. In an example embodiment, an x-ray tube incorporating features of the present invention is disclosed. The x-ray tube includes an evacuated enclosure containing a cathode assembly and an anode. The cathode assembly includes a head portion having a head surface. A slot is defined on the head surface and an electron-emitting filament is included in the slot. A protective surface is defined on the head surface proximate to a central portion of the filament. The protective surface in one embodiment is composed of tungsten and is configure to prevent fusing of the filament to the protective surface should the filament inadvertently contact the protective surface.
    Type: Grant
    Filed: January 31, 2006
    Date of Patent: February 2, 2010
    Assignee: Varian Medical Systems, Inc.
    Inventors: James Burke, Charles Lynn Chidester, Bruce A Cain, Rob Treseder, James Boye, Ray Daly, Ricky Smith, Paul Gene Christean
  • Publication number: 20100020936
    Abstract: An x-ray tube has a vacuum housing supported so that it can rotate around a rotation axis, an anode that is arranged within the vacuum housing and that is connected in a rotationally fixed manner with the vacuum housing. The anode has an anode surface fashioned substantially in the shape of a ring. The center axis of which anode surface corresponds to the rotation axis. A cathode is mounted within the vacuum housing such that it can be rotated around the rotation axis. The cathode has a cathode surface fashioned substantially in the shape of a ring. The center axis of which cathode surface corresponds to the rotational axis. The cathode surface is arranged opposite the anode surface. A first actuator rotates the vacuum housing around the rotation axis with a first rotation speed ?1. A second actuator rotates the cathode around the rotation axis with a second rotation speed ?2, wherein ?2<?1.
    Type: Application
    Filed: July 24, 2009
    Publication date: January 28, 2010
    Inventors: SVEN FRITZLER, STEFAN POPESCU, GEORG WITTMANN
  • Patent number: RE41741
    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.
    Type: Grant
    Filed: March 1, 2004
    Date of Patent: September 21, 2010
    Assignee: Carl Zeiss AG
    Inventor: Mark Dinsmore