Ion Generation Patents (Class 250/423R)
  • Patent number: 4562351
    Abstract: The invention consists of a mass spectrometer having a sample insertion probe on which a reference compound and an unknown sample can be simultaneously introduced without mixing into a field ionization or ion or neutral particle bombardment ion source. An insulated support is mounted by a parallel hinge on the end of the probe shaft. Two or more separated segments or emitter wires, one carrying the unknown sample, another carrying an appropriate reference compound, are mounted on a base member which is fitted to the support. A drive shaft, concentric with the outer probe shaft, has an eccentric peg on the end, which engages with a cam on the support, so that rotation of the drive shaft results in an oscillating motion of the segments or emitters, alternately positioning them in the optimum position for ionization. A spectrum of the sample or the reference compound can be obtained when required by selecting the appropriate position of the drive shaft.
    Type: Grant
    Filed: November 9, 1983
    Date of Patent: December 31, 1985
    Assignee: VG Instruments Group Limited
    Inventors: Paul Atherton, Peter Burns, Brian N. Green
  • Patent number: 4562355
    Abstract: A high current ion source for generating ion beams from gases and non-volatile materials which comprises a furnace-cathode unit for generating vapor to be ionized, a major source unit for ionizing the vapor generated in the furnace-cathode chamber and an extraction unit for removing the ions from the major source unit. The three units are removably sealed to each other by vacuum-tight seals. The furnace-cathode unit includes a furnace chamber, the major source unit includes a discharge chamber and the extraction unit a source outlet electrode. Connecting means couple the furnace chamber to the discharge chamber, and suspension means are provided for suspending the components from surrounding flanges.
    Type: Grant
    Filed: February 28, 1985
    Date of Patent: December 31, 1985
    Assignee: Gesellschaft fur Schwerionenforschung mbH Darmstadt
    Inventors: Roderich Keller, Fritz Nohmayer
  • Patent number: 4560879
    Abstract: An ion implantation apparatus and method are disclosed for reducing contamination of doubly-charged ions by singly-charged ions. A liner, with a grooved or smooth surface, formed of beryllium or graphite reduces secondary electron scattering into the ion beam. Solid red phosphorus reduces the operating vacuum thereby reducing contamination.
    Type: Grant
    Filed: September 16, 1983
    Date of Patent: December 24, 1985
    Assignee: RCA Corporation
    Inventors: Chung P. Wu, Frank Kolondra
  • Patent number: 4549082
    Abstract: An improved crossed-beam charge-exchange ion gun in which a synthetic plasma is formed by injecting an electron beam into a collimated molecular beam just before the molecules are ionized by charge exchange with a crossed primary ion beam, thereby forming a secondary ion beam from the ionized but space-charge-neutralized and substantially undeflected molecular beam. The plasma thus formed extends to an aperture stop in an aperture tube which extends upstream from an anode downstream of which anode a cathode is placed. A field is formed within the cathode/anode space and within the aperture tube into which the plasma extends. The sheath edge of the plasma within the tube is curved by the field to form a meniscus, and the aperture, being smaller in area than the secondary ion beam upstream of the aperture, both collimates the secondary ion beam and acts as a lens stop for the subsequent immersion lens formed by the meniscus and the field region.
    Type: Grant
    Filed: April 19, 1983
    Date of Patent: October 22, 1985
    Inventor: Michael R. McMillan
  • Patent number: 4546253
    Abstract: Apparatus for producing sample ions comprising means of producing metastable species by corona discharges in the carrier gas, a needle-shaped emitter whose pointed end is inserted into the stream of carrier gas which transports said metastable species, means for applying a high potential to said needle emitter, wherein sample is arranged adjacent to or deposited on the pointed end of said emitter. Its value is further enhanced when it is combined with a mass spectrometer.
    Type: Grant
    Filed: July 28, 1983
    Date of Patent: October 8, 1985
    Assignee: Masahiko Tsuchiya
    Inventors: Masahiko Tsuchiya, Hirofumi Kuwabara
  • Patent number: 4542321
    Abstract: The present invention provides, in a preferred embodiment, a cylindrical stainless steel cathode with end pieces thereon to form a cathode chamber within. In addition, in a preferred embodiment, there is a stainless steel rod which passes axially through the cathode chamber and which is electrically insulated therefrom at the end pieces. The stainless steel cathode has first and second apertures formed therein with the first to be connected to a source of ionizable gas and the second to act as the opening through which there passes a stream of ions to an ion beam target. A magnetic flux source is coupled to the cathode chamber to pass magnetic flux therethrough and a voltage source is connected between the anode and the cathode to provide an electrostatic field therebetween whereby when ionizable gas is fed into the cathode chamber, it is ionized and a stream of ions emanates from the second aperture.
    Type: Grant
    Filed: July 12, 1982
    Date of Patent: September 17, 1985
    Assignee: Denton Vacuum Inc
    Inventors: Bawa Singh, David Boyarsky
  • Patent number: 4529571
    Abstract: A single-ring magnetic cusp low gas pressure ion source designed for use in a sealed, nonpumped neutron generator utilizes a cathode and an anode, three electrically floating electrodes (a reflector behind the cathode, a heat shield around the anode, and an aperture plate), together with a single ring-cusp magnetic field, to establish and energy-filtering mechanism for producing atomic-hydrogen ions.
    Type: Grant
    Filed: October 27, 1982
    Date of Patent: July 16, 1985
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Frank M. Bacon, John P. Brainard, James B. O'Hagan, Robert J. Walko
  • Patent number: 4521719
    Abstract: The invention relates to an ion beam gun having a pair of electrodes for applying a high-frequency high voltage to ionize an ionization gas, the ions produced being extracted by an extraction electrode arranged behind the pair of electrodes in the direction of the ion beam (FIG. 1).
    Type: Grant
    Filed: August 27, 1982
    Date of Patent: June 4, 1985
    Assignee: Technics GmbH Europa
    Inventor: Gerhard Liebel
  • Patent number: 4514363
    Abstract: Isotope enrichment, particularly .sup.235 U enrichment, is achieved by irradiating an isotopically mixed vapor feed with radiant energy at a wavelength or wavelengths chosen to selectively excite the species containing a desired isotope to a predetermined energy level. The vapor feed if simultaneously reacted with an atomic or molecular reactant species capable of preferentially transforming the excited species into an ionic product by a chemiionization reaction. The ionic product, enriched in the desired isotope, is electrostatically or electromagnetically extracted from the reaction system.
    Type: Grant
    Filed: September 15, 1981
    Date of Patent: April 30, 1985
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: James W. Dubrin
  • Patent number: 4507588
    Abstract: A radio frequency wave ion generating apparatus which provides a thin disc shaped plasma adjacent an ion attracting means is described. The radio frequency waves are preferably microwaves. Several improvements to microwave plasma generation are described including the steps of generation of a resonantly sustained microwave discharge inside a microwave/plasma coupler or cavity (11) to ignite the plasma; probe (14) and length tuning of the microwave/plasma coupler by means of a sliding short (12) during operation of the plasma and minimization of the plasma volume inside the coupler in a chamber (15) to produce the disc plasma. The apparatus is particularly useful for internal ion or free radical irradiation of various materials provided in the plasma or for ion acceleration outside the cavity for use as an ion engine or as an ion source for irradiation of the materials.
    Type: Grant
    Filed: February 23, 1983
    Date of Patent: March 26, 1985
    Assignee: Board of Trustees operating Michigan State University
    Inventors: Jes Asmussen, Joseph J. Root
  • Patent number: 4506160
    Abstract: A gas is introduced into a discharge chamber of an ion source apparatus, and a gas discharge is performed between a thermionic cathode and an anode. Ions are extracted from the plasma formed in this gas discharge by a grid electrode. The thermionic cathode has a hollow cylindrical shape. A cathode chamber is defined by the thermionic cathode and a cylindrical partition wall supporting it. A columnar auxiliary electrode is coaxially inserted in the thermionic cathode. An A.C. voltage from a power source unit is supplied between the thermionic cathode and the auxiliary electrode such that effective power for keeping the thermionic cathode at a positive potential with respect to the auxiliary electrode is higher than that for keeping the auxiliary electrode at a positive potential with respect to the thermionic cathode.
    Type: Grant
    Filed: May 17, 1983
    Date of Patent: March 19, 1985
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Toru Sugawara, Yasuyuki Ito
  • Patent number: 4501965
    Abstract: A plasma is generated within an induction coil and the plasma is sampled through an orifice into a vacuum chamber for mass analysis of trace ions in the plasma. Arcing at the orifice is prevented by grounding the induction coil at or near its center, thus eliminating ultraviolet noise and reducing average ion energies and ion energy spread, as well as preventing destruction of the orifice. The elimination of arcing at the orifice allows the use of a sharp edge orifice structure to prevent formation of a cool boundary layer over the orifice and also permits direct sampling of the plasma. The direct sampling and the lack of cooling prevent recombination and reaction of the ions with oxygen and improve the response to elements of high ionization potential, increasing the desired ion signal and greatly reducing the presence of oxides which would otherwise complicate the spectrum.
    Type: Grant
    Filed: January 14, 1983
    Date of Patent: February 26, 1985
    Assignee: MDS Health Group Limited
    Inventor: Donald J. Douglas
  • Patent number: 4500787
    Abstract: Method and device for furnishing an ion stream by causing gas to flow through a discharge aperture having a diameter of at most 20 .mu.m into an evacuated chamber and ionizing said gas by means of one or a plurality of focused electron beams downstream of said aperture in which the ionization is effected immediately downstream of said discharge aperture.
    Type: Grant
    Filed: August 2, 1982
    Date of Patent: February 19, 1985
    Assignee: Nederlandse Centrale Organisatie Voor Toegepast Natuurwetenschappelijk Onderzoek
    Inventors: Jan B. Le Poole, Pieter Kruit
  • Patent number: 4496843
    Abstract: The invention provides a method for producing metal ions, having the steps of: producing a gas containing a metal element by evaporation of a liquid organic metal compound; introducing the gas containing the metal element and an auxiliary gas for cleaning into the ionization chamber; and producing the metal ions by ionizing the metal element by a discharge. According to this method, the metal ions are produced easily and quickly with good controllability.
    Type: Grant
    Filed: May 27, 1982
    Date of Patent: January 29, 1985
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Kei Kirita, Katuo Koike
  • Patent number: 4491735
    Abstract: Means are provided to produce plasma in a chamber. A diaphragm having an externally small aperture permits ions to flow out of the chamber. The ions are focused to produce an ion beam of high current density in a very small area.
    Type: Grant
    Filed: December 15, 1983
    Date of Patent: January 1, 1985
    Assignee: The Perkin-Elmer Corporation
    Inventor: Donald L. Smith
  • Patent number: 4488045
    Abstract: A reservoir containing a material to be ionized has in its bottom a capillary extending outwardly in symmetrical with the optical axis of an ion source, and has a needle extending coaxially through said capillary in said reservoir so that the apex end of the needle projects slightly beyond the exterior surface of the reservoir. Intensive electric field at the apex end of the needle is formed by an extracting electrode disposed in facing the needle. An electric current is supplied through conductive wires or filaments supporting the reservoir for heating the reservoir. As a result, the liquid material to be ionized in the reservoir seeps smoothly through the capillary of the reservoir toward the apex end of the needle for field evaporation and ionization.
    Type: Grant
    Filed: August 27, 1982
    Date of Patent: December 11, 1984
    Assignee: JEOL Ltd.
    Inventors: Norimichi Anazawa, Masahiko Okunuki, Ryuzo Aihara
  • Patent number: 4486665
    Abstract: An ionization vessel is divided into an ionizing zone and an extraction zone by a magnetic filter. The magnetic filter prevents high-energy electrons from crossing from the ionizing zone to the extraction zone. A small positive voltage impressed on a plasma grid, located adjacent an extraction grid, positively biases the plasma in the extraction zone to thereby prevent positive ions from migrating from the ionizing zone to the extraction zone. Low-energy electrons, which would ordinarily be dragged by the positive ions into the extraction zone, are thereby prevented from being present in the extraction zone and being extracted along with negative ions by the extraction grid. Additional electrons are suppressed from the output flux using ExB drift provided by permanent magnets and the extractor grid electrical field.
    Type: Grant
    Filed: August 6, 1982
    Date of Patent: December 4, 1984
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Ka-Ngo Leung, Kenneth W. Ehlers
  • Patent number: 4481062
    Abstract: An electron-bombardment ion source includes means defining a chamber for containing an ionizable gas together with means for introducing such gas into that chamber. Disposed therein is an anode and an electron-emissive cathode. The potential impressed between the anode and the cathode to effect electron emission at a sufficient velocity to ionize the gas. Also included are means for accelerating ions out of the chamber together with means for establishing a magnetic field within the chamber that increases the efficiency of ionization of the gas by the electrons. Mounted within the chamber is an anode of non-magnetic material that defines an essentially continuous and smooth surface which encloses substantially all of the volume within which the ionization occurs except the exit for the accelerated ions out of the chamber. The entire design is such as to ensure ready removability of the different components for quick and easy cleaning.
    Type: Grant
    Filed: February 7, 1984
    Date of Patent: November 6, 1984
    Inventors: Harold R. Kaufman, Raymond S. Robinson, William E. Hughes
  • Patent number: 4476392
    Abstract: An ionization source is disclosed for use with mass spectrometers and electron capture species detectors having an ionization light source excited so as to illuminate a fluid sample which flows past the light source whereby electrons are photoelectrically generated by a light source. Means are also provided to accelerate the photoelectrons and to extract heavy ions generated by the accelerated photoelectrons from the fluid sample. Further means are provided to focus the extracted heavy ions so that they may be detected. Also included is a means to maintain a vacuum between the light source and the sample and the detector.
    Type: Grant
    Filed: December 28, 1981
    Date of Patent: October 9, 1984
    Inventor: Robert A. Young
  • Patent number: 4471224
    Abstract: Method and apparatus for generating high current, negative ion beams. A plasma source of ions of one charge polarity includes an accelerator for accelerating the ions toward a target having a plurality of apertures. An electric field directs the ions exiting the apertures against a target surface which is arranged to emit ions of an opposite polarity. The electric field directs the opposite polarity ions away from the target forming a stream of oppositely charged ions.
    Type: Grant
    Filed: March 8, 1982
    Date of Patent: September 11, 1984
    Assignee: International Business Machines Corporation
    Inventors: Jerome J. Cuomo, Harold R. Kaufman
  • Patent number: 4468564
    Abstract: The invention relates to an ion source.This source comprises a gas ionization chamber, an electron source and means for oscillating the electrons in the chamber, so as to produce an ionization zone of the gas. The means for oscillating the electrons comprise two identical electron lenses, whose axes coincide with the oscillation direction, two spherical concave mirrors turned towards one another and positioned respectively on either side of the two lenses and whose centers respectively coincide with the foci of the lenses, the electron source being positioned at the focus of one of the two lenses.Application to the analysis of gases by mass spectrometry.
    Type: Grant
    Filed: October 18, 1982
    Date of Patent: August 28, 1984
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Robert Boyer, Jean-Pierre Journoux
  • Patent number: 4453077
    Abstract: A thin freestanding oil film is produced in vacuum by directing an oil stream radially inward to the hollow-ground sharp outer edge of a rotating disc. The sides of the edge are roughened somewhat to aid in dispersing oil from the disc. Oil is removed from the surface of disc to prevent formation of oil droplets which might spin off the disc and disrupt the oil film. An ion beam is directed through the thin oil film so that electrons are stripped from the ions to increase their charge.
    Type: Grant
    Filed: March 9, 1982
    Date of Patent: June 5, 1984
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Beat T. Leemann, Roland B. Yourd
  • Patent number: 4447761
    Abstract: A negative ion generator is formed from a magnetically insulated transmission line having a coating of graphite on the cathode for producing negative ions and a plurality of apertures on the opposed anode for the release of negative ions. Magnetic insulation keeps electrons from flowing from the cathode to the anode. A transverse magnetic field removes electrons which do escape through the apertures from the trajectory of the negative ions.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: May 8, 1984
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Regan W. Stinnett
  • Patent number: 4447728
    Abstract: An ionizer for ionizing a sample by bombardment with energetic particles. The ionizer incudes an ion chamber and an adjacent gas discharge region formed with an electrode cooperating wih the ion chamber. Said region serving to discharge a gas to form neutral and charged gas particles. The cooperation of the electrode and chamber accelerates the charged particles and causes charged and uncharged particles to flow into the ion chamber to strike and ionize a sample in the ion chamber.
    Type: Grant
    Filed: February 5, 1982
    Date of Patent: May 8, 1984
    Assignee: Finnigan Corporation
    Inventors: George C. Stafford, Donald C. Bradford
  • Patent number: 4447724
    Abstract: An apparatus for the chemical analysis of a sample ejects neutral and charged particles from the sample by ion bombardment from a primary ion source. An electric diaphragm passes only the ejected neutral particles for ioniziation in a plasma which is separate from the primary ion source and which serves only for the post-ionization of the neutral particles. The ionized particles are then analyzed by mass spectrometry. Charging of insulating samples by primary ions is prevented by rendering the diaphragm permeable to plasma electrons.
    Type: Grant
    Filed: January 7, 1982
    Date of Patent: May 8, 1984
    Assignee: Leybold Heraeus GmbH
    Inventor: Hans Oechsner
  • Patent number: 4446403
    Abstract: A compact ion source plug connected to a socket is provided. The source uses a magnetic pole piece which includes a center pole piece and a surrounding circumferential pole piece to form an arcuate fringe field. Cathode elements and anode elements are located within the fringe field for producing a plasma. A source body terminates at one end with at least one grid and forms a plasma chamber with a base member. All of the electrical connections to the plasma generator and the gas connection are through a plug formed on the opposite side of the base member.
    Type: Grant
    Filed: May 26, 1982
    Date of Patent: May 1, 1984
    Assignee: International Business Machines Corporation
    Inventors: Jerome J. Cuomo, James M. E. Harper, Harold R. Kaufman
  • Patent number: 4430570
    Abstract: A variable shaping type electron beam exposing apparatus is provided which comprises an electron gun which irradiates an electron beam from the front end of a cathode chip; shaping plates having openings of variable shapes for shaping the electron beam irradiated from the electron gun into the shapes of these openings; and an objective lens for focusing the electron beam passed through the shaping plates into a predetermined shape on a sample. In this apparatus, the cathode chip is made of single-crystal lanthanum hexaboride whose axial orientation is <310>, the front end of it is formed into a circular conical shape, and half the vertical angle of the front end is set to be between 60.degree. and 85.degree.. The maximum area of the image on the sample is between 2 to 50 .mu.m.sup.2.
    Type: Grant
    Filed: December 4, 1980
    Date of Patent: February 7, 1984
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Tadahiro Takigawa, Isao Sasaki
  • Patent number: 4426582
    Abstract: A liquid metal field ionization source is used in conjunction with a three element asymmetric lens system to provide an ion gun having greater magnitude beam currents focused on a smaller spot size than has been previously possible for intermediate energy beams. An ultra-clean emitter surface is achieved by means of an argon sputtering and/or plasma etching process applied to the emitter surface before liquid metal is applied to the emitter surface to ensure uniform and sufficient flow of liquid metal to the apex of the emitter. The three element asymmetric lens system has a very low chromatic aberration coefficient, enabling precise focusing of beams with large energy spreads. For beam accelerating ratios in the range from 0.2 to 6, the ion gun produces very high current densities in beams focused on very small spot areas, despite the relatively large energy spread of beams produced by liquid metal ionization sources.
    Type: Grant
    Filed: October 2, 1981
    Date of Patent: January 17, 1984
    Assignee: Oregon Graduate Center
    Inventors: Jonathan H. Orloff, Lynwood W. Swanson
  • Patent number: 4423324
    Abstract: A negative ion detector converts negative ions to positive ions by means of a conversion anode which is maintained at a relatively high positive voltage. The resultant positive ions are detected by a standard continuous dynode electron multiplier which has its detection signal output at ground potential.
    Type: Grant
    Filed: July 23, 1979
    Date of Patent: December 27, 1983
    Assignee: Finnigan Corporation
    Inventor: George C. Stafford
  • Patent number: 4409520
    Abstract: A microwave discharge ion source according to this invention comprises a microwave generator, a discharge chamber having ridged electrodes, and a waveguide connecting the microwave generator with the discharge chamber. This waveguide consists of a waveguide having no ridged electrode, and a waveguide having ridged electrodes. Further, a vacuum-sealing dielectric plate is disposed at an intermediate position or an end part of the waveguide having no ridged electrode. A space in the waveguide as extends from the vacuum-sealing dielectric plate to the discharge chamber is filled with a dielectric.As a result, the design and fabrication of the vacuum-sealing dielectric plate are facilitated, and a microwave discharge ion source of high performance is provided.
    Type: Grant
    Filed: March 24, 1981
    Date of Patent: October 11, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Hidemi Koike, Noriyuki Sakudo, Katsumi Tokiguchi, Ichiro Kanomata
  • Patent number: 4391778
    Abstract: To avoid the problem of instrumental drift encountered when using an open-split interface between a temperature-programmed gas-liquid chromatography column and a mass spectrometer, the inert gas supplied to the open-split interface and the interface itself are heated to a temperature above the maximum temperature attained by the chromatography column during the analysis.
    Type: Grant
    Filed: September 30, 1981
    Date of Patent: July 5, 1983
    Assignee: The Ohio State University
    Inventors: Brian D. Andresen, Kwokei J. Ng
  • Patent number: 4388560
    Abstract: Thermionic cathode 12 for a plasma ion source 10 has tungsten wire 64 advanced by wheels 56 from supply 50 to take-up spool 58. In chamber 48, the active cathode region 64 acts with anode 16 to supply electrons for ionizing a fuel gas so the ions are discharged from slit 18 for acceleration, separation and implantation.
    Type: Grant
    Filed: May 26, 1981
    Date of Patent: June 14, 1983
    Assignee: Hughes Aircraft Company
    Inventors: William P. Robinson, Hugh McNulty, Jr., Robert L. Seliger, Weldon S. Williamson
  • Patent number: 4388531
    Abstract: An ionizer adapted to be placed in a vacuum envelope for providing ions of a sample to be analyzed is disclosed herein and includes an electron source, ion accelerating and focusing electrodes and an interchangeable ionization chamber including a first opening for allowing electrons to enter the chamber and an exit opening to allow ions to exit said chamber. The ionization chamber is supported in cooperative relationship with the electron source and accelerating and focusing electrodes whereby electrons enter the chamber through the first opening and form sample ions in the chamber which then exit the chamber through the exit opening toward said accelerating and focusing electrodes.
    Type: Grant
    Filed: March 6, 1981
    Date of Patent: June 14, 1983
    Assignee: Finnigan Corporation
    Inventors: George C. Stafford, David R. Stephens
  • Patent number: 4383177
    Abstract: A plurality of magnetic pole pieces are arranged around the external wall of a high temperature plasma confining structure. The pole pieces are positioned between permanent magnets spaced from one another and the confining structure by distances calculated to produce a minimum field toward the center of the structure with an effective containing field around the periphery of the structure. The magnets and the pole pieces are cooled. An odd number of poles are employed such that the missing pole appears as a virtual pole at the extraction slit used for forming an ion beam for ion implantation. The resulting small package multipole plasma containment functions to provide higher beam current, longer source lifetime, higher voltage stability and reduces maintenance and cleaning operations, with the permanent magnets protected from high temperature and corrosive gases.
    Type: Grant
    Filed: December 24, 1980
    Date of Patent: May 10, 1983
    Assignee: International Business Machines Corporation
    Inventors: John H. Keller, Charles M. McKenna
  • Patent number: 4380720
    Abstract: An electric-wind or static-breeze generating system in which ions are produced in a duct and drift toward a counterelectrode thereby displacing a gas, e.g. air, through the duct at atmospheric pressure. Nozzles can introduce an aerosol to increase the air displacement and an alternating current system can be utilized to energize the device in a bipolar manner.
    Type: Grant
    Filed: November 19, 1980
    Date of Patent: April 19, 1983
    Inventor: Carl M. Fleck
  • Patent number: 4377773
    Abstract: A negative ion source of the type where negative ions are formed by bombarding a low-work-function surface with positive ions and neutral particles from a plasma, wherein a highly ionized plasma is injected into an anode space containing the low-work-function surface. The plasma is formed by hollow cathode discharge and injected into the anode space along the magnetic field lines. Preferably, the negative ion source is of the magnetron type.
    Type: Grant
    Filed: December 12, 1980
    Date of Patent: March 22, 1983
    Assignee: The United States of America as represented by the Department of Energy
    Inventors: Ady Hershcovitch, Krsto Prelec
  • Patent number: 4362936
    Abstract: Apparatus for monitoring a plasma process in which a plasma is formed to occupy a specified region, which apparatus is composed of: a mass spectrometer system including a mass analyzer having an ion inlet and an ion outlet and an ion detector disposed in operative association with the ion outlet; an output device connected to the detector for providing an output signal representative of the mass spectrum of ions observed by the mass spectrometer system; and an ion-optical system having an inlet opening located in the vicinity of the specified region and disposed for extracting ions from the plasma and focussing the ions thus extracted onto the ion inlet of the analyzer, whereby the output signal produced by the output device is representative of the mass spectrum of ions in the plasma.
    Type: Grant
    Filed: November 26, 1980
    Date of Patent: December 7, 1982
    Assignee: Leybold-Heraeus GmbH
    Inventors: Dieter Hofmann, Reiner Wechsung
  • Patent number: 4354113
    Abstract: An ion source comprises a cylindrical chamber having a longitudinal exit slit formed therein and two parallel anode wires extending the length of the chamber in the central region thereof and symmetrically disposed with respect to the longitudinal axis of the chamber and the exit slit, wherein at each end of the exit slit there is positioned at or near the zero potential equipotential a mask, the separation of the inner ends of the masks defining the width of the ion beam emitted by the source.
    Type: Grant
    Filed: December 30, 1980
    Date of Patent: October 12, 1982
    Assignee: United Kingdom Atomic Energy Authority
    Inventors: Philip D. Goode, Michael J. Poole, Gordon W. Proctor
  • Patent number: 4344019
    Abstract: An ion source of the Penning discharge type having a self-cleaning aperture is provided by a second dynode (24) with an exit aperture (12) in a position opposite a first dynode 10a, from which the ions are sputtered, two opposing cathodes (14, 16), each with an anode (18, 20) for accelerating electrons emitted from the cathodes into a cylindrical space defined by the first and second dynode. A support gas maintained in this space is ionized by the electrons. While the cathodes are supplied with a negative pulse to emit electrons, the first dynode is supplied with a negative pulse (e.g., -300 V) to attract atoms of the ionized gas (plasma). At the same time, the second dynode may also be supplied with a small voltage that is negative with respect to the plasma (e.g., -5 V) for tuning the position of the plasma miniscus for optimum extraction geometry. When the negative pulse to the first dynode is terminated, the second dynode is driven strongly negative (e.g.
    Type: Grant
    Filed: November 10, 1980
    Date of Patent: August 10, 1982
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Basil F. Gavin, Robert A. MacGill, Raymond K. Thatcher
  • Patent number: 4329586
    Abstract: An electron energy recovery system for negative ion sources is provided. The system, employs crossed electric and magnetic fields to separate the electrons from ions as they are extracted from a negative ion source plasma generator and before the ions are accelerated to their full kinetic energy. With the electric and magnetic fields oriented 90.degree. to each other, the electrons are separated from the plasma and remain at approximately the electrical potential of the generator in which they were generated. The electrons migrate from the ion beam path in a precessing motion out of the ion accelerating field region into an electron recovery region provided by a specially designed electron collector electrode.
    Type: Grant
    Filed: September 17, 1980
    Date of Patent: May 11, 1982
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: William K. Dagenhart, William L. Stirling
  • Patent number: 4321126
    Abstract: A device for coating a metal or alloy layer onto an electrically conducting workpiece comprises a low pressure chamber having a workpiece support platform mounted therein. An ion producer is connected to the chamber and adapted to receive an ionized carrier gas and spender medium. An electrode of first polarity is connected to the chamber and ion producer. An electrode of opposite polarity is connected to the support platform. Arc discharge means extend into the chamber and a turbulence chamber communicates with the low pressure chamber for creating turbulence in the carrier gas.
    Type: Grant
    Filed: March 3, 1980
    Date of Patent: March 23, 1982
    Assignee: Wolfgang Kieferle
    Inventors: Wolfgang Kieferle, Franz Waschle
  • Patent number: 4321467
    Abstract: A flowing discharge ion source for supplying negative and positive ions to a mass spectrometer has an elongated, confined flow and discharge region through which flow the sample to be analyzed and a reagent gas and in which ionizing discharge electrodes are located. Inlet and outlet gas flow orifices are independently variable so that the reagent gas pressure in the discharge region and flow velocity therethrough are controlled. Controlling flow velocity provides one way for determining reagent and sample gas residence time, which is further controlled by making the position of the discharge electrodes adjustable along the length of the ionization region. A controllable heater is provided upstream of the discharge region to regulate reagent and sample gas temperature.
    Type: Grant
    Filed: June 4, 1980
    Date of Patent: March 23, 1982
    Assignee: SRI International
    Inventor: Sidney E. Buttrill, Jr.
  • Patent number: 4318028
    Abstract: An improved system for generating an ion beam comprises a nozzle through which a gas to be ionized is fed, and a ring electrode encircling the tip of the nozzle. High positive potential and negative potential are applied to the nozzle and ring electrode, respectively, to create a high intensity electric field. The gas atoms passing through the capillary nozzle are ionized, and the ions so created are accelerated in a direction forwardly from the nozzle by the field. The current level or "brightness" of the ion beam so generated may be controlled by varying the pressure of the gas supplied to the nozzle, or the electrical potential difference applied between the nozzle and ring electrode.
    Type: Grant
    Filed: July 20, 1979
    Date of Patent: March 2, 1982
    Assignee: Phrasor Scientific, Inc.
    Inventors: Julius Perel, John F. Mahoney
  • Patent number: 4318029
    Abstract: Liquid metal ion source has cylindrical ceramic tube 12 embraced by strip heater 20 which is held in place by ceramic bushing 26. Apex 28 of the strip heater contains the ion source fuel metal and is pierced by needle 34 having sharp tip 36. Upon heating and electrical bias with respect to a coaxial extraction electrode, tip 36 emits ions.
    Type: Grant
    Filed: May 12, 1980
    Date of Patent: March 2, 1982
    Assignee: Hughes Aircraft Company
    Inventor: Jerg B. Jergenson
  • Patent number: 4318030
    Abstract: Liquid metal ion source has cylindrical ceramic body 12 engaged by one leg of hook shaped strip heater 20 which is held in place by ceramic bushing 24. Apex 18 of the strip heater contains the ion source fuel metal and is pierced by needle 22 having sharp tip 30. Upon heating by heater current flow through needle 22 and heater leg 14 and electrical bias with an extraction electrode, tip 30 emits ions.
    Type: Grant
    Filed: May 12, 1980
    Date of Patent: March 2, 1982
    Assignee: Hughes Aircraft Company
    Inventor: Jerg B. Jergenson
  • Patent number: 4316090
    Abstract: A microwave plasma ion source according to this invention is characterized by the construction of the extracting electrode in contact with the discharge chamber. The electrode is divided into a part substantially exposed to a plasma and a remaining part which is not exposed to the plasma. Moreover, both these parts are held in a state in which they are electrically connected with each other.As a result, very little P or As deposits on the surface of the electrode, and a stable high-current ion beam can be supplied over a long period of time.
    Type: Grant
    Filed: May 30, 1980
    Date of Patent: February 16, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Noriyuki Sakudo, Katsumi Tokiguchi, Hidemi Koike, Ichiro Kanomata
  • Patent number: 4311910
    Abstract: The requisite process chambers for field desorption ionization are annularly arranged and cooperate with electrodes on the inside. Individual electrodes are cyclically and in steps juxtaposed to the process chambers so that the various steps are simultaneously carried out on different electrodes. After a cycle, all electrodes have faced all of the chambers. Alternatively, a single wire is segmentwise placed adjacent to the chambers. The process steps are, in each instance: activating the electrode (or a wire segment); depositing an analyzing substance; ionization; and cleaning.
    Type: Grant
    Filed: April 3, 1980
    Date of Patent: January 19, 1982
    Inventor: Hans B. Linden
  • Patent number: 4303865
    Abstract: A plasma discharge ion source for a mass spectrometer, having a magnet forming an axial magnetic field, two cathodes axially spaced in said field and an annular anode between the cathodes. Ions generated by the source emerge via an opening in one cathode and then pass in succession through axially aligned openings in two planar electrodes. The electrode closest said one cathode has a further disc or cone shaped electrode positioned in the opening of that electrode so as to form an annular gap between the peripheries of the disc shaped electrode and opening.Ions from the source opening pass in succession through the annular gap and then through the electrode opening in the electrode furtherest from the source opening. By applying suitable electric potentials to the electrodes ions of an energy above a predetermined level are prevented from passing through the electrodes.
    Type: Grant
    Filed: August 24, 1979
    Date of Patent: December 1, 1981
    Assignee: Commonwealth Scientific & Industrial Research Organization
    Inventor: Donald L. Swingler
  • Patent number: 4301369
    Abstract: A semiconductor ion emitter for a mass spectrometer, comprises an electrode having semiconductor whiskers provided on the conductive surface of a base. A process for manufacturing such semiconductor ion emitter, includes steps of evaporating gold onto a wire having a diameter of about 60 .mu.m, preheating the coated wire, and supplying a gas containing the semiconductor for growth of the whiskers on the gold plated wire. An apparatus for such process comprises a vacuum vessel for enclosing the wire, means for controllably heating the wire and means for controllably supplying a gas containing the semiconductor into the vacuum vessel.
    Type: Grant
    Filed: February 13, 1979
    Date of Patent: November 17, 1981
    Assignee: The President of Osaka University
    Inventors: Takekiyo Matsuo, Itsuo Katakuse, Hisashi Matsuda
  • Patent number: 4298798
    Abstract: A method and apparatus are described for producing negative deuterium ions for use in controlled thermonuclear reactions such as fusion. Negative ions are obtained by bombarding the surface of an ionization electrode with positive ions and extracting negative ions from the electrode. The unique surface layer of the electrode is formed by depositing onto a substrate the products of thermal decomposition of cesium carbonate. This layer, which is easily formed and renewed, is characterized by a very low value of work function of about 1.05 electron volts, which facilitates formation of large quantities of negative ions. Properties of the surface layer, particularly the low value of work function, are reproducible and relatively insensitive to variations in the thickness of the layer and to the substrate material selected for the electrode.
    Type: Grant
    Filed: November 29, 1979
    Date of Patent: November 3, 1981
    Assignee: Thermo Electron Corporation
    Inventor: Fred N. Huffman