With Evacuating Pump Patents (Class 313/7)
  • Patent number: 10550829
    Abstract: An ion pump includes an anode, a backing surface having at least one surface structure extending toward the anode and a cathode positioned between the anode and the backing surface and having an opening such that the at least one surface structure is aligned with and extends from the backing surface towards the opening.
    Type: Grant
    Filed: September 8, 2016
    Date of Patent: February 4, 2020
    Assignee: Edwards Vacuum LLC
    Inventors: Anthony Wynohrad, Joel Langeberg
  • Patent number: 10460917
    Abstract: A system for ion pumping including an anode, a cathode, and a magnet. The magnet comprises a Halbach magnet array.
    Type: Grant
    Filed: May 26, 2016
    Date of Patent: October 29, 2019
    Assignee: AOSense, Inc.
    Inventors: Chandra S. Raman, Thomas H. Loftus, Mark A. Kasevich, Thang Q. Tran, William D. Weis
  • Patent number: 9699881
    Abstract: A diaphragm flange for connecting the tubes in a particle accelerator while minimizing beamline impedance. The diaphragm flange includes an outer flange and a thin diaphragm integral with the outer flange. Bolt holes in the outer flange provide a means for bolting the diaphragm flange to an adjacent flange or beam tube having a mating bolt-hole pattern. The diaphragm flange includes a first surface for connection to the tube of a particle accelerator beamline and a second surface for connection to a CF flange. The second surface includes a recessed surface therein and a knife-edge on the recessed surface. The diaphragm includes a thickness that enables flexing of the integral diaphragm during assembly of beamline components. The knife-edge enables compression of a soft metal gasket to provide a leak-tight seal.
    Type: Grant
    Filed: May 14, 2015
    Date of Patent: July 4, 2017
    Assignee: JEFFERSON SCIENCE ASSOCIATES, LLC
    Inventor: George Herman Biallas
  • Patent number: 9404827
    Abstract: An ionization gauge to measure pressure and to reduce sputtering yields includes at least one electron source that generates electrons. The ionization gauge also includes a collector electrode that collects ions formed by the collisions between the electrons and gas molecules. The ionization gauge also includes an anode. An anode bias voltage relative to a bias voltage of a collector electrode is configured to switch at a predetermined pressure to decrease a yield of sputtering collisions.
    Type: Grant
    Filed: February 6, 2014
    Date of Patent: August 2, 2016
    Assignee: MKS Instruments, Inc.
    Inventor: Gerardo A. Brucker
  • Patent number: 9310596
    Abstract: A compound microscope device allows simultaneous observation of one specimen by a transmission electron microscope and an optical microscope. The compound microscope device 1 of the present invention has a transmission electron microscope 2 and an optical microscope 4. A specimen 10 and a reflection mirror 41 are disposed on an electron optical axis C of an electron ray. The reflection mirror 41 is inclined from the electron optical axis C toward the optical object lens 43 and the specimen 10. Light from the specimen 10 (fluorescent light, reflection light, and the like) is reflected by the reflection mirror 41 and enters into the optical object lens 43. The electron ray from the electron microscope 2 passes through a mounting center hole 42 of the reflection mirror 41. This makes it possible to observe one specimen simultaneously by the electron microscope 2 and the optical microscope 4.
    Type: Grant
    Filed: April 6, 2011
    Date of Patent: April 12, 2016
    Assignees: INTER-UNIVERSITY RESEARCH INSTITUTE CORPORATION NATIONAL INSTITUTE OF NATURAL SCIENCES, JEOL LTD.
    Inventors: Kuniaki Nagayama, Yoshihiro Arai, Hirofumi Iijima, Susumu Terakawa
  • Patent number: 8642949
    Abstract: An ion transfer arrangement for transporting ions between higher and lower pressure regions of the mass spectrometer comprises an ion transfer conduit 60. The conduit 60 has an inlet opening towards a relatively high pressure chamber 40 and an outlet 70 opening towards a relatively low pressure chamber. The conduit 60 also has at least one side wall surrounding an ion transfer channel 115. The side wall includes a plurality of apertures 140 formed in the longitudinal direction of the side wall so as to permit a flow of gas from within the ion transfer channel 115 to a lower pressure region outside of the side wall of the conduit 60.
    Type: Grant
    Filed: March 6, 2012
    Date of Patent: February 4, 2014
    Assignee: Thermo Fisher Scientific (Bremen) GmbH
    Inventors: Alexander A. Makarov, Reinhold Pesch, Robert Malek, Viacheslav Kozlovskiy
  • Publication number: 20130234025
    Abstract: A field-emission electron gun including an electron emission tip, an extractor anode, and a mechanism creating an electric-potential difference between the emission tip and the extractor anode. The emission tip includes a metal tip and an end cone produced by chemical vapor deposition on a nanofilament, the cone being aligned and welded onto the metal tip. The electron gun can be used for a transmission electron microscope.
    Type: Application
    Filed: September 16, 2011
    Publication date: September 12, 2013
    Applicant: CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE (CNRS)
    Inventors: Marc Monthioux, Florent Houdellier
  • Publication number: 20120081097
    Abstract: High voltage high current regulator circuit for regulating current is interposed between first and second terminals connected to an external circuit and comprises at least one main-current carrying cold-cathode field emission electron tube conducting current between the first and second terminals. First and second grid-control cold-cathode field emission electron tubes provide control signals for first and second grids of the at least one main-current carrying cold-cathode field emission electron tube for positive and negative excursions of voltage on the first and second terminals, respectively. The current regulator circuit may be accompanied by a voltage-clamping circuit that includes at least one cold-cathode field emission electron tube.
    Type: Application
    Filed: October 5, 2011
    Publication date: April 5, 2012
    Applicant: ADVANCED FUSION SYSTEMS LLC
    Inventor: Curtis A. Birnbach
  • Patent number: 8148679
    Abstract: An ion transfer arrangement for transporting ions between higher and lower pressure regions of the mass spectrometer comprises an ion transfer conduit 60. The conduit 60 has an inlet opening towards a relatively high pressure chamber 40 and an outlet 70 opening towards a relatively low pressure chamber. The conduit 60 also has at least one side wall surrounding an ion transfer channel 115. The side wall includes a plurality of apertures 140 formed in the longitudinal direction of the side wall so as to permit a flow of gas from within the ion transfer channel 115 to a lower pressure region outside of the side wall of the conduit 60.
    Type: Grant
    Filed: November 7, 2007
    Date of Patent: April 3, 2012
    Assignee: Thermo Fisher Scientific (Bremen) GmbH
    Inventors: Alexander Makarov, Reinhold Pesch, Robert Malek, Viacheslav Kozlovskiy
  • Patent number: 8148680
    Abstract: A method of transporting gas and entrained ions between higher and lower pressure regions of a mass spectrometer comprises providing an ion transfer conduit 60 between the higher and lower pressure regions. The ion transfer conduit 60 includes an electrode assembly 300 which defines an ion transfer channel. The electrode assembly 300 has a first set of ring electrodes 305 of a first width D1, and a second set of ring electrodes of a second width D2 (?D1) and interleaved with the first ring electrodes 305. A DC voltage of magnitude V1 and a first polarity is supplied to the first ring electrodes 205 and a DC voltage of magnitude V2 which may be less than or equal to the magnitude of V1 but with an opposed polarity is applied to the second ring electrodes 310. The pressure of the ion transfer conduit 60 is controlled so as to maintain viscous flow of gas and ions within the ion transfer channel.
    Type: Grant
    Filed: November 7, 2007
    Date of Patent: April 3, 2012
    Assignee: Thermo Fisher Scientific (Bremen) GmbH
    Inventors: Alexander Makarov, Reinhold Pesch, Robert Malek, Viacheslav Kozlovskiy
  • Patent number: 7982183
    Abstract: An ion transfer arrangement for transporting ions between higher and lower pressure regions of a mass spectrometer includes an electrode assembly (120) with a first plurality of ring electrodes (205) arranged in alternating relation with a second plurality of ring electrodes (210). The first plurality of ring electrodes (205) are narrower than the second plurality of ring electrodes (210) in a longitudinal direction, but the first plurality of ring electrodes have a relatively high magnitude voltage of a first polarity applied to them whereas the second plurality of ring electrodes (210) have a relatively lower magnitude voltage applied to them, of opposing polarity to that applied to the first set of ring electrodes (205). In this manner, ions passing through the ion transfer arrangement experience spatially alternating asymmetric electric fields that tend to focus ions away from the inner surface of the channel wall and towards the channel plane or axis of symmetry.
    Type: Grant
    Filed: November 7, 2007
    Date of Patent: July 19, 2011
    Assignee: Thermo Fisher Scientific (Bremen) GmbH
    Inventors: Alexander Makarov, Reinhold Pesch, Robert Malek, Viacheslav Kozlovskiy
  • Patent number: 7635943
    Abstract: An image display apparatus is provided with a vacuum chamber consisting of an electron source substrate and an image display substrate, and an ion pump which is attached to an electron-emitting substrate or the image display substrate and exhausts air from the vacuum chamber by the action of a magnet, wherein the magnet is attached and fixed to the substrate to which the ion pump has been attached. Thereby, the image display apparatus prevents the magnet from applying an excessive force to the ion pump by its weight, and acquires a stable structure without causing a vacuum leak.
    Type: Grant
    Filed: August 17, 2005
    Date of Patent: December 22, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaru Kamio, Ihachiro Gofuku, Hisanori Tsuda, Yasue Sato
  • Patent number: 7615765
    Abstract: There is provided a compact charged particle beam apparatus with a non-evaporable getter pump which maintains high vacuum even during emission of an electron beam without generating foreign particles. The apparatus comprises: a charged particle source; a charged particle optics which focuses a charged particle beam emitted from the charged particle source on a sample and performs scanning; and means of vacuum pumping which evacuates the charged particle optics. The means of vacuum pumping has a differential pumping structure with two or more vacuum chambers connected through an opening in series. A pump made of non-evaporable getter alloy is placed in an upstream vacuum chamber with a high degree of vacuum, and a gas absorbing surface of the non-evaporable getter alloy is fixed without contact with another part.
    Type: Grant
    Filed: October 31, 2006
    Date of Patent: November 10, 2009
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Souichi Katagiri, Takashi Ohshima, Toshihide Agemura, Mitsugu Sato
  • Publication number: 20080143228
    Abstract: The invention relates to a gas discharge source, in particular for generating extreme ultraviolet and/or soft X-radiation, in which a gas-filled intermediate electrode space (3) is located between two electrodes (1, 2), in which devices for the admission and evacuation of gas are present, and in which one electrode (1) exhibits an opening (5) that defines an axis of symmetry (4) and is provided for the discharge of radiation. The proposed improvements constitute the presence of a diaphragm (6), which exhibits at least one opening (7) on the axis of symmetry (4) and operates as a differential pump stage, between the two electrodes (1, 2).
    Type: Application
    Filed: July 29, 2004
    Publication date: June 19, 2008
    Applicant: Koninklijke Philips Electronics N.V.
    Inventors: Klaus Bergmann, Willi Neff
  • Patent number: 7242135
    Abstract: A high voltage direct current contact for a vacuum electron device (VED), including (a) an outer cathode line having a first hollow cylinder having a first VED connection end, (b) a contact block removably positioned within the outer cathode line, having a heater contact and a first threaded stem extending towards the first VED connection end, (c) an inner cathode line removably positioned within the first hollow cylinder and placed in contact with the contact block, the inner cathode line including a second hollow cylinder and a support plate having an opening removably receiving the first threaded stem, and (d) a heater contact line in contact with the heater contact, including a third hollow cylinder and a flange on an exterior thereof, the flange being in contact with the support plate, the third hollow cylinder having a threaded end removably coupled with the first threaded stem.
    Type: Grant
    Filed: March 7, 2006
    Date of Patent: July 10, 2007
    Assignee: Communication and Power Industries, Inc.
    Inventors: Wilson Wai Toy, Christopher Paul Yates, Paul Allen Krzeminski, Robert N. Tornoe, Edmund Thomas Davies
  • Publication number: 20040062659
    Abstract: An one pump is formed with its housing made of titanium so that the housing can form the cathode of the ion pump. Cylindrical anodes may be formed inside the housing. Spikes or posts may be formed on the walls of the housing and may extend into the inside of the anodes.
    Type: Application
    Filed: July 14, 2003
    Publication date: April 1, 2004
    Inventor: Mahadeva P. Sinha
  • Patent number: 6616417
    Abstract: The sputter ion pump includes a vacuum chamber that includes an inner wall having a cylindrical section which is rugged in cross section. The rugged cylindrical section has outer recesses each of which is provided with a permanent magnets, each magnet having a same shape and a same characteristic so that a magnetic pole is directed to a same direction. The rugged cylindrical section has also inner recesses each of which is provided with a cylindrical anode electrode member spaced from the vacuum chamber wall. The rugged cylindrical section of the vacuum chamber wall is formed as a cathode electrode. A cylindrical shield member having a peripheral portion provided with evacuating bores is provided coaxially to the permanent magnets and anode electrodes. The permanent magnets and anode electrode members are arranged with equal spacing in an axis symmetrical configuration.
    Type: Grant
    Filed: November 9, 2001
    Date of Patent: September 9, 2003
    Assignee: ULVAC, Inc.
    Inventor: Guo Hua Shen
  • Publication number: 20020185947
    Abstract: A miniature ion pump, and method for fabricating the miniature ion pump, that may be included within a low-pressure microdevice microenclosure. The miniature ion pump comprises two charge plates separated by a constant distance, fabricated by well-known microchip fabrication techniques, to which a voltage potential difference is applied in order to create a perpendicular electric field that ionizes gas molecules. The resulting positively charged ions are adsorbed to charge plates, thus removing gas molecules from the interior of the low-pressure microenclosure and maintaining a low-pressure environment surrounding the enclosed microdevice.
    Type: Application
    Filed: June 11, 2001
    Publication date: December 12, 2002
    Inventors: Donald W. Schulte, Terry E. McMahon, Douglas Jay Edwards
  • Patent number: 5980212
    Abstract: A sputter ion pump in which the ratio of the length L to the diameter D of each anode cell forming a multi-cell anode inserted between two cathodes is defined within a certain range, thereby increasing a critical vacuum level to be evacuated and achieving a higher exhaust speed.
    Type: Grant
    Filed: December 26, 1996
    Date of Patent: November 9, 1999
    Assignee: Nihon Shinku Gijutsu Kabushiki Kaisha
    Inventors: Guo Hua Shen, Nozomu Takagi, Toshihiro Terasawa, Tsuyoshi Kotani, Hiroyuki Kinpara, Katsuji Nakajima, Hiroyuki Miho
  • Patent number: 5655886
    Abstract: An ion pump permits the continuous evacuation of a small-envelope vacuum chamber while drawing a relatively small amount of power (micro watts). In a preferred embodiment, the present ion pump, due to its small size and integration within the vacuum chamber, enables the device in which the vacuum chamber is incorporated to be portable and to retain its original dimensions.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: August 12, 1997
    Assignee: Color Planar Displays, Inc.
    Inventor: Richard K. Alderson
  • Patent number: 5563407
    Abstract: An X-ray image intensifier incorporates a pair of opposed electrodes and an ion pump within a vacuum vessel. The ion pump supplies a magnetic field to a space between the opposed electrodes. At least one of the opposed electrodes is connected to focusing electrodes in the vacuum vessel. With this structure, the vacuum vessel can be maintained in a high vacuum for a long period of time.
    Type: Grant
    Filed: September 20, 1994
    Date of Patent: October 8, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Shirofumi Yamagishi
  • Patent number: 5548183
    Abstract: In a magnetic field immersion type electron gun for controlling an electron beam emitted by an electron gun (51) with the use of an electric lens (56) and a magnetic field lens formed by permanent magnets (57, 58) of a coaxial ion pump (53), the ion pump magnets are a pair of cylindrical permanent magnets (57, 58) disposed coaxially with an optical axis (52) of the electron gun (51) in such a way as to sandwich a cylindrical ion pump anode (61) of the coaxial ion pump; the two permanent magnets are magnetized in a mutually opposing direction; a hollow cylindrical yoke (60) is disposed also coaxially with the optical axis (52) in such a way as to enclose the two permanent magnets (57, 58) within a hollow portion thereof; and the yoke (60) is formed with an annular yoke gap (63) in a radially inner circumferential surface of the yoke (60) to leak out a magnetic flux flowing through the yoke toward the optical axis.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: August 20, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Motosuke Miyoshi, Katsuya Okumura, Yuichiro Yamazaki
  • Patent number: 5150001
    Abstract: An electron beam system comprises a vacuum enclosure, a source of electrons within the enclosure, and a passive pump located within or in communication with the enclosure for pumping gases from the enclosure. A supplemental active pump is coupled to the vacuum enclosure and functions simultaneously with the passive pump for pumping from the enclosure gases not removed, or not removed efficiently, therefrom by the passive pump.
    Type: Grant
    Filed: April 10, 1990
    Date of Patent: September 22, 1992
    Assignee: Orchid One Corporation
    Inventor: Albert V. Crewe
  • Patent number: 5111054
    Abstract: A heat-actuated valve is inserted between a first vacuum space and a further vacuum space in a particle beam apparatus. The valve is preferably activatable by the temperature required for evacuating first vacuum chamber by heating. Preferably, the valve device itself is also evacuatable by heating; this can be readily realized by avoiding the use of non-metal valve members when the valve is inserted between two spaces wherebetween a compartively small absolute difference in pressure exists, in the closed condition of the valve.
    Type: Grant
    Filed: January 4, 1991
    Date of Patent: May 5, 1992
    Assignee: U.S. Philips Corp.
    Inventor: Hendrik N. Slingerland
  • Patent number: 5036290
    Abstract: Synchrotron radiation is generated when a base of charged particles is bent by a bending magnet. The synchrotron radiation passes down a lead-out duct as the total number of pumps is limited by the size of the apparatus and many pumps are needed in order to achieve a good vacuum. An ion pump has a main magnetic field, normally generated by a magnet of the ion pump which controls the behavior of the electrons in the ion pump. However, the leakage magnetic field of the bending magnet affects the ion pump, and therefore the ion pump is arranged so that its main magnetic field is aligned with the leakage magnetic field at the ion pump, or at least with a main component thereof. In this way, the effect of the leakage magnetic field on the ion pump is reduced. Indeed, it is possible to use the leakage magnetic field as the main magnetic field of the ion pump.
    Type: Grant
    Filed: March 8, 1990
    Date of Patent: July 30, 1991
    Assignees: Hitachi, Ltd., Nippon Telegraph and Telephone Corp.
    Inventors: Tadasi Sonobe, Mamoru Katane, Takashi Ikeguchi, Manabu Matsumoto, Shinjiro Ueda, Toshiaki Kobari, Takao Takahashi, Toa Hayasaka, Toyoki Kitayama
  • Patent number: 5021702
    Abstract: An electron beam apparatus has a cylindrical chamber, ion pump exhaust zones arranged in a substantially ring-like array, and an electron gun located on the center axis of the ring-like array, thereby minimizing the distance between the exhaust zone of an ion pump and the electron gun for generating an electron beam. Since the ion pump exhaust zones are located immediately next to the electron gun, it is therefore possible to achieve substantially the same vacuum level at the location of the electron gun as that at the ion pump per se.
    Type: Grant
    Filed: August 15, 1989
    Date of Patent: June 4, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Motosuke Miyoshi, Katsuya Okumura
  • Patent number: 4890029
    Abstract: An electron beam apparatus is disclosed which comprises a cylindrical chamber, ion pump exhaust zones arranged in a substantially ring-like array, and an electron gun located on the center axis of the ring-like array, thereby minimizing the distance between the exhaust zone of an ion pump and the electron gun for generating an electron beam. Since the ion pump exhaust zones are located immediately next to the electron gun, it is therefore possible to achieve substantially the same vacuum level at the location of the electron gun as that at the ion pump per se.
    Type: Grant
    Filed: August 3, 1987
    Date of Patent: December 26, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Motosuke Miyoshi, Katsuya Okumura
  • Patent number: 4853640
    Abstract: An industrial compact synchrotron radiation source which can improve vacuum evacuation performance to prolong life-time of a charged particle beam and supply highly intensive stable synchrotron radiation. In the source, a charged particle beam bending duct forming a vacuum chamber through which the charged particle beam circulates is encompassed by a bending electromagnet, and at least one SR guide duct for guiding the radiation to outside extends from the outer circumferential wall of the bending duct. The SR guide duct is connected through a gate valve to an SR beam line duct for guiding the SR beam to an object to be worked and a vacuum pump is disposed on the side, close to an orbit of the charged particle beam, of the gate valve. The SR guide duct extending from the outer circumferential wall of the bending duct takes a form of a divergent duct which is widened in accordance with a spreading angle of the SR beam traveling through the SR guide duct.
    Type: Grant
    Filed: February 11, 1988
    Date of Patent: August 1, 1989
    Assignees: Hitachi, Ltd., Nippon Telephone & Telegraph, Hitachi Service Engineering, Ltd.
    Inventors: Manabu Matsumoto, Takashi Ikeguchi, Shinjiroo Ueda, Tadasi Sonobe, Toru Murashita, Satoshi Ido, Kazuo Kuroishi, Yoshiaki Kazawa, Shunji Kakiuchi, Toshiaki Kobari
  • Patent number: 4833362
    Abstract: An encapsulated high brightness source for use in or with an electron beam system such as an electron beam microscope. The source preferably includes a field emitter. The source includes source enclosure means which defines an ultra high vacuum enclosure for the field emitter. A lens which serves as part of the ultra high vacuum enclosure for the source defines a differential pressure aperture. Other lens elements draw electrons from the field emitter and form a focus on axis in the vicinity of the differential pressure aperture, which serves as an effective point source for the associated electron beam system. The source may be permanently built-in or modular; if modular, it may be assembled, tested, and stored in an ultra high vacuum operative condition for OEM assembly or as a replacement part.
    Type: Grant
    Filed: April 19, 1988
    Date of Patent: May 23, 1989
    Assignee: Orchid One
    Inventor: Albert V. Crewe
  • Patent number: 4785254
    Abstract: A vacuum-to-air interface (10) is provided for a high-powered, pulsed particle beam accelerator. The interface comprises a pneumatic high speed gate valve (18), from which extends a vacuum-tight duct (26), that termintes in an aperture (28). Means (32, 34, 36, 38, 40, 42, 44, 46, 48) are provided for periodically advancing a foil strip (30) across the aperture (28) at the repetition rate of the particle pulses. A pneumatically operated hollow sealing band (62) urges foil strip (30), when stationary, against and into the aperture (28). Gas pressure means (68, 70) periodically lift off and separate foil strip (30) from aperture (28), so that it may be readily advanced.
    Type: Grant
    Filed: June 18, 1987
    Date of Patent: November 15, 1988
    Assignee: The United States of America as represented by The United States Department of Energy
    Inventors: Gilbert E. Cruz, William F. Edwards
  • Patent number: 4636680
    Abstract: An ionization gauge of the type including a source of electrons, an accelerating electrode for accelerating said electrons through a volume generally defined by said accelerating electrode and a collector electrode, disposed in the volume. Ions are collected by the collector electrode. The accelerating electrode comprises a substantially closed anode having an internal cavity to precisely define the volume. An aperture is disposed to admit said electrons from the source into the closed volume.
    Type: Grant
    Filed: May 24, 1983
    Date of Patent: January 13, 1987
    Assignee: Granville-Phillips Company
    Inventors: Daniel G. Bills, Paul C. Arnold, Stephen L. Dodgen, Craig B. Van Cleve
  • Patent number: 4389165
    Abstract: An ion pump for producing an ultrahigh degree of vacuum comprising a space formed between a first perforated flat plate-shaped electrode and a second flat plate-shaped electrode and having a high frequency electric source connected between the first and second electrodes, said space being operative to induce multipactor effect between said first and second electrodes, and an ionization space adjacent to one of said first and second electrodes and formed between a first perforated getter electrode and a second getter electrode applied with a negative potential, said ionization space being operative to cause the moving electrons produced by the multipactor effect to collide with gas molecules and ionize the latter.
    Type: Grant
    Filed: September 26, 1980
    Date of Patent: June 21, 1983
    Assignee: Tohoku University
    Inventors: Shoichi Ono, Kuniyoshi Yokoo
  • Patent number: 4307323
    Abstract: A hot filament ionization gauge is provided with a very small diameter and/or very short collector to limit interception of X-ray flux. Suitable gauge sensitivity is achieved by additionally collecting ions at the collector support, which is shielded from the X-ray flux by a shield. Collection of ions by the shield is avoided by maintaining the shield at grid potential.
    Type: Grant
    Filed: April 4, 1980
    Date of Patent: December 22, 1981
    Assignee: Granville-Phillips Company
    Inventors: Daniel G. Bills, Paul C. Arnold
  • Patent number: 4302679
    Abstract: An ion gauge having a reduced "x-ray limit" and means for measuring that limit. The gauge comprises an ion gauge of the Bayard-Alpert type having a short collector and having means for varying the grid-collector voltage.The "x-ray limit" (i.e. the collector current resulting from x-rays striking the collector) may then be determined by the formula: ##EQU1## where: I.sub.x ="x-ray limit",I.sub.l and I.sub.h =the collector current at the lower and higher grid voltage respectively; and,.alpha.=the ratio of the collector current due to positive ions at the higher voltage to that at the lower voltage.
    Type: Grant
    Filed: August 7, 1979
    Date of Patent: November 24, 1981
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: David Edwards, Jr., Christopher P. Lanni
  • Patent number: 4295072
    Abstract: In a field emission electron gun including heating means for heating an anode to prevent gas emission from the anode due to bombardment thereof by the electron beam emitted from the cathode, the present invention provides a field emission electron gun including first exhaust means for defining a first chamber including the cathode and for exhausting said chamber to vacuum, and second exhaust means separate from said first exhaust means defining a chamber including said anode heating means for exhausting said chamber to vacuum independently of the first exhaust means. This construction makes it possible to maintain the chamber including the cathode constantly in the high vacuum state.
    Type: Grant
    Filed: February 1, 1979
    Date of Patent: October 13, 1981
    Assignee: Hitachi, Ltd.
    Inventors: Hideo Todokoro, Yoshio Sakitani
  • Patent number: 4121128
    Abstract: Ions are generated in a vacuum condition of an ion accelerator and injected hrough three aerodynamic windows to atmosphere pressure. In its travel through the windows the coil provides a magnetic field to prevent the ion beam from dissipating while it is traveling to the atmosphere.
    Type: Grant
    Filed: August 15, 1977
    Date of Patent: October 17, 1978
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Thomas G. Roberts