US2988657A - Ion pump - Google Patents

Ion pump Download PDF

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Publication number
US2988657A
US2988657A US826961A US82696159A US2988657A US 2988657 A US2988657 A US 2988657A US 826961 A US826961 A US 826961A US 82696159 A US82696159 A US 82696159A US 2988657 A US2988657 A US 2988657A
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US
United States
Prior art keywords
cathode
ion pump
anode
discharge
ion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US826961A
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English (en)
Inventor
Klopfer Anton Martin
Ermrich Winfried Georg
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Philips Corp
North American Philips Co Inc
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US Philips Corp
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Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US2988657A publication Critical patent/US2988657A/en
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Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J41/00—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas; Discharge tubes for evacuation by diffusion of ions
    • H01J41/12—Discharge tubes for evacuating by diffusion of ions, e.g. ion pumps, getter ion pumps
    • H01J41/18—Discharge tubes for evacuating by diffusion of ions, e.g. ion pumps, getter ion pumps with ionisation by means of cold cathodes
    • H01J41/20—Discharge tubes for evacuating by diffusion of ions, e.g. ion pumps, getter ion pumps with ionisation by means of cold cathodes using gettering substances
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/94—Selection of substances for gas fillings; Means for obtaining or maintaining the desired pressure within the tube, e.g. by gettering
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J41/00—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas; Discharge tubes for evacuation by diffusion of ions
    • H01J41/12—Discharge tubes for evacuating by diffusion of ions, e.g. ion pumps, getter ion pumps
    • H01J41/14—Discharge tubes for evacuating by diffusion of ions, e.g. ion pumps, getter ion pumps with ionisation by means of thermionic cathodes
    • H01J41/16—Discharge tubes for evacuating by diffusion of ions, e.g. ion pumps, getter ion pumps with ionisation by means of thermionic cathodes using gettering substances

Definitions

  • the present invention relates to ion pumps, in which the discharge path extends between a substantially ringshaped anode and cathode parts situated at both sides of the ring plane, provision being made of a magnetic field, the lines of force of which connect the two cathode parts without these lines of force reaching the anode, While during operation a gas-binding metal is constantly precipitated in the proximity of the discharge path.
  • the invention further comprises a discharge system for use in such ion pumps.
  • the invention concerns a method of operating such pumps.
  • Ion pumps of the aforesaid type are known per se.
  • the gas-binding metal precipitating in the proximity of the discharge path originates from two cathode plates which are disintegrated by the discharge.
  • ion pumps are known in which, in contrast to the aforesaid pump, no disintegration is to occur, but in which the produced ions are collected by the cathode plates or by an other electrode.
  • cathode plates provision is made of a particular incandescent cathode, presumably for maintaining the discharge at low pressures, when no further discharge occurs with a cold cathode. Since the gas is collected by the electrodes, the latter may sometimes readily give oil gases such as is in the case of known similarly constructed gasdischarge manometers (Penning).
  • a metal such as titanium in ion pumps comprising incandescent cathodes
  • a metal such as titanium in ion pumps comprising incandescent cathodes
  • a titanium wire is evaporated by unwinding it in contact with a graphite block heated by the discharge.
  • the device used is very complicated and suitable only for large and stationary installations.
  • the present invention has for its object to provide an ion pump combining the advantages of conventional ion pumps and, moreover, having a simple construction so as to permit, without prohibitive cost, any appropriate electron discharge tube to be equipped with such a dis charge system which constitutes the main part of such ion pumps.
  • the discharge path extends between a substantially ring-shaped anode and cathode parts situated at both sides of the ring plane, and in which provision is made of a magnetic field, the lines of force which connect the two cathode parts without reaching the anode, while during operation a gas-binding metal is permanently precipitated in the proximity of the discharge path, at least one of the two cathode parts is, according to the invention, an incandescent cathode pvith a supply of gas-binding metal which is evaporated :during operation of the cathode.
  • the construction according to the invention has the. following advantages.
  • the gas-binding metal evaporating from the incandescent cathode combines with existing or supplied gas already during evaporation. At very low pressures the electrons emitted by the incandescent cathode permit a heavy discharge which would otherwise not be obtainable and, moreover, the metal evaporating from the cathode may contribute to the discharge.
  • the precipitated layer of the metal may be conductively connected to the cathode or a voltage which is negative relatively to the cathode, may be applied to said layer.
  • the precipitated getter-layer constitutes at the same time a collecting surface for the ions.
  • the ion pump according to the invention may be used for evacuating an electron tube, which has been exhausted to a preliminary vacuum of approximately 0.1 mm. Hg and sealed oii, further evacuation being taken over by the ion pump.
  • a preliminary vacuum of approximately 0.1 mm. Hg and sealed oii, further evacuation being taken over by the ion pump.
  • the cathode may be temporarily heated to a slightly higher temperaturein order to accelerate evaporation of the gas-binding metal.
  • one cathode or both cathodes preferably consist of a tungsten wire spun with a wire of titanium or other metal. It is advantageous to provide the two cathode parts with barium and titanium respectively for evaporation.
  • one cathode part consists of an incandescent cathode spun with the metal to-be vaporized, while the other cathode part is a. solid plate consisting of themetal. tobe vaporized, and the anode likewise consists of a solid ring of the metal to be vaporized.
  • This ion pump permits a substantially constant rate of pumping with minimum consumption of energy in a considerable pressure range.
  • rate of vaporization or the disintegration fraction should be proportional to the pressure.
  • the incandescent cathode When using such an ion pump in the pressure range between 0.5 mm. and 0.01 mm. the incandescent cathode is sufiiciently heated to obtain a considerable vaporization fraction of the getter metal. Any hydrocarbons are thermally dissociated at the incandescent cathode. At pressures below 0.01 mm. of Hg the pump, working only by disintegration, can be operated economically for a considerable time only until the pressure decreases to a point such that the discharge, with cold incandescent cathode, is no longer maintained.
  • this electron-emission of the hot incandescent cathode may be used for heating the anode sufficiently by electron bombardment, preferably without a magnetic field, so that evaporation of the anode material and consequently an adequate pumping rate are obtained.
  • FIG. 1 shows the discharge system of an ion pump according to the invention
  • FIG. 2 shows the circuit arrangement of the discharge system
  • FIG. 3 shows an electron-discharge tube sealed to an ion pump
  • FIGS. 4 and 5 represent ion pumps with titanium and barium evaporation.
  • the reference numeral 1 designates the bulb of the discharge system, and 2 denotes a ring-shaped molybdenum wire constituting the anode.
  • Two bent tungsten wires 3 are spun with titanium wire 4 and together constitute the cathode of the discharge path.
  • a contact spring 5 serves for establishing the potential of the layer of titanium 6 precipitated on the wall of the bulb.
  • the reference numeral 7 denotes the battery heating one of the two cathode halves 3. Alternatively, the cathode may be heated by means of alternating current.
  • the anode voltage battery is denoted by 8.
  • the reference numeral 9 designates the source of voltage for establishing the potential of the layer of titanium 6 on the bulb 1.
  • the bulb 1 is situated between two schematically shown pole shoes 10 of a permanent magnet for producing a magnetic field of approximately 500. to 1000 gauss.
  • FIG. 3 represents schematically a cathode-ray tube 11 having sealed to it a discharge system 1 for use in an ion pump.
  • the ion pump is connected according to want, in the case of an excessive quantity of gas developing in the tube 11.
  • the ion pump may also be used in manufacturing the tube 11 for completing evacuation of the tube after sealing it off.
  • one of both cathode parts consists of three V-shaped incandescent wires 12 of tungsten spun with barium-nickel sheath wire.
  • the other cathode part consists of two V-shaped parts 13 spun with titanium.
  • one part of the cathode or both of them are heated.
  • the anode in contrast to FIG. 4, the anode consists of two double rings 15 of barium-ring getter.
  • the glass bulb is designated by 10.
  • the electrodes are mounted on a number of lead-through pins.
  • the heatable part 3 of the cathode consists of 4 three V-shaped' tungsten wires spun with titanium wire.
  • the cold cathode part is a solid titanium plate 30.
  • The. anode 40 is a loop of thick titanium band.
  • a contact spring serves for fixing the potential layer deposited on the wall of the bulb.
  • An ion pump comprising an envelope, a ring-shaped anode within said envelope, an incandescible cathode comprising two portions disposed on opposite-sidesof the plane of the anode, at least one of said cathode portions being provided with a supply of gas-binding metal which is evaporated during operation of the cathode which is precipitated on the wall of the envelope, and means to produce a magnetic field the lines of force of which extend between the portions of the cathode without intercepting the anode.
  • one of the cathode portions is a tungsten wire spun with a wire consisting of metal to be evaporated.
  • An ion pump as claimed in claim 2 in which oneof the cathode portions is spun with titanium wire and the other cathode portion is spun with barium-sheath wire.

Landscapes

  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
  • Electron Tubes For Measurement (AREA)
  • Discharge Lamp (AREA)
US826961A 1958-08-02 1959-07-14 Ion pump Expired - Lifetime US2988657A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DEN15430A DE1089505B (de) 1958-08-02 1958-08-02 Ionenpumpe mit von einem Magnetfeld verlaengerter Entladungsbahn sowie Verfahren zur Verwendung einer derartigen Ionenpumpe
DEN16498A DE1103515B (de) 1958-08-02 1959-04-03 Ionenpumpe mit von einem Magnetfeld verlaengerter Entladungsbahn sowie Verfahren zur Verwendung einer derartigen Ionenpumpe

Publications (1)

Publication Number Publication Date
US2988657A true US2988657A (en) 1961-06-13

Family

ID=25988627

Family Applications (1)

Application Number Title Priority Date Filing Date
US826961A Expired - Lifetime US2988657A (en) 1958-08-02 1959-07-14 Ion pump

Country Status (5)

Country Link
US (1) US2988657A (fr)
CH (1) CH379046A (fr)
DE (2) DE1089505B (fr)
FR (1) FR1235712A (fr)
GB (1) GB909640A (fr)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3131983A (en) * 1959-05-14 1964-05-05 John H O Harries Evacuation of vacuum and gas filled envelopes
US3181775A (en) * 1962-03-20 1965-05-04 Wisconsin Alumni Res Found Pumping apparatus
US3198422A (en) * 1962-06-08 1965-08-03 Heraeus Gmbh W C Vacuum sputtering pump
US3221197A (en) * 1961-05-15 1965-11-30 Gen Electric Scavenging system
US3244933A (en) * 1961-08-24 1966-04-05 Philips Corp Device of the kind comprising a highpower klystron with getter ion pump connected thereto
US3259772A (en) * 1963-12-23 1966-07-05 Nat Res Corp Cold cathode gauge for measuring vacuum
US3280365A (en) * 1963-04-15 1966-10-18 Gen Electric Penning-type discharge ionization gauge with discharge initiation electron source
US3338507A (en) * 1965-03-22 1967-08-29 Perkin Elmer Corp Ionic vacuum pump
US3338506A (en) * 1965-03-05 1967-08-29 Varian Associates Vacuum pump apparatus
US3343781A (en) * 1965-04-28 1967-09-26 Gen Electric Ionic pump
US4334829A (en) * 1980-02-15 1982-06-15 Rca Corporation Sputter-ion pump for use with electron tubes having thoriated tungsten cathodes
EP1028450A1 (fr) * 1999-02-11 2000-08-16 Marconi Medical Systems, Inc. Getter utilisé dans un tube sous vide
US20030159929A1 (en) * 2000-06-30 2003-08-28 Werner Blev Grosse Sensor for helium or hydrogen

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2605431A (en) * 1950-03-30 1952-07-29 Westinghouse Electric Corp Ionization vacuum gauge
US2727167A (en) * 1952-04-18 1955-12-13 Westinghouse Electric Corp Ion pump
US2758233A (en) * 1951-09-12 1956-08-07 Gen Electric Electric discharge device for gas pressure determination
US2790949A (en) * 1954-05-13 1957-04-30 Oscar H Ottinger Thermionic ionization vacuum gauge
US2796555A (en) * 1954-06-29 1957-06-18 High Voltage Engineering Corp High-vacuum pump
US2836790A (en) * 1953-05-25 1958-05-27 Westinghouse Electric Corp Ionization tube

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE540617C (de) * 1929-06-29 1931-12-28 C H F Mueller Akt Ges Verfahren zur Erzeugung und Erhaltung des Vakuums in Entladungsgefaessen
US2167852A (en) * 1935-10-22 1939-08-01 Rca Corp Electron discharge device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2605431A (en) * 1950-03-30 1952-07-29 Westinghouse Electric Corp Ionization vacuum gauge
US2758233A (en) * 1951-09-12 1956-08-07 Gen Electric Electric discharge device for gas pressure determination
US2727167A (en) * 1952-04-18 1955-12-13 Westinghouse Electric Corp Ion pump
US2836790A (en) * 1953-05-25 1958-05-27 Westinghouse Electric Corp Ionization tube
US2790949A (en) * 1954-05-13 1957-04-30 Oscar H Ottinger Thermionic ionization vacuum gauge
US2796555A (en) * 1954-06-29 1957-06-18 High Voltage Engineering Corp High-vacuum pump

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3131983A (en) * 1959-05-14 1964-05-05 John H O Harries Evacuation of vacuum and gas filled envelopes
US3221197A (en) * 1961-05-15 1965-11-30 Gen Electric Scavenging system
US3244933A (en) * 1961-08-24 1966-04-05 Philips Corp Device of the kind comprising a highpower klystron with getter ion pump connected thereto
US3181775A (en) * 1962-03-20 1965-05-04 Wisconsin Alumni Res Found Pumping apparatus
US3198422A (en) * 1962-06-08 1965-08-03 Heraeus Gmbh W C Vacuum sputtering pump
US3280365A (en) * 1963-04-15 1966-10-18 Gen Electric Penning-type discharge ionization gauge with discharge initiation electron source
US3259772A (en) * 1963-12-23 1966-07-05 Nat Res Corp Cold cathode gauge for measuring vacuum
US3338506A (en) * 1965-03-05 1967-08-29 Varian Associates Vacuum pump apparatus
US3343780A (en) * 1965-03-05 1967-09-26 Varian Associates Vacuum pump apparatus
US3338507A (en) * 1965-03-22 1967-08-29 Perkin Elmer Corp Ionic vacuum pump
US3343781A (en) * 1965-04-28 1967-09-26 Gen Electric Ionic pump
US4334829A (en) * 1980-02-15 1982-06-15 Rca Corporation Sputter-ion pump for use with electron tubes having thoriated tungsten cathodes
EP1028450A1 (fr) * 1999-02-11 2000-08-16 Marconi Medical Systems, Inc. Getter utilisé dans un tube sous vide
US6192106B1 (en) 1999-02-11 2001-02-20 Picker International, Inc. Field service flashable getter for x-ray tubes
US20030159929A1 (en) * 2000-06-30 2003-08-28 Werner Blev Grosse Sensor for helium or hydrogen
US7266991B2 (en) * 2000-06-30 2007-09-11 Inficon Gmbh Sensor for helium or hydrogen

Also Published As

Publication number Publication date
CH379046A (de) 1964-06-30
DE1103515B (de) 1961-03-30
DE1089505B (de) 1960-09-22
FR1235712A (fr) 1960-07-08
GB909640A (en) 1962-10-31

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