US2858972A - Ionic vacuum pump - Google Patents

Ionic vacuum pump Download PDF

Info

Publication number
US2858972A
US2858972A US574226A US57422656A US2858972A US 2858972 A US2858972 A US 2858972A US 574226 A US574226 A US 574226A US 57422656 A US57422656 A US 57422656A US 2858972 A US2858972 A US 2858972A
Authority
US
United States
Prior art keywords
gas
working gas
pressure
pump
ionic
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
US574226A
Inventor
Anatole M Gurewitsch
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.)
General Electric Co
Original Assignee
General Electric Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Priority to US574226A priority Critical patent/US2858972A/en
Application granted granted Critical
Publication of US2858972A publication Critical patent/US2858972A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • 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

  • This invention relates to ionic vacuumpumps and, more particularly, to a method whereby the elficiency. of such devices is increased for the pumping of inert gases at very low pressures by means of a working gas, a gas which may be added to the system and removed at a later time by gettering action without any resulting net increase in the amount of gas in the system.
  • Such a pump may comprise a ring-shaped anode and opposed cold cathode plates enclosed in a vacuum tight envelope and means to provide a magnetic field axially of the electrodes.
  • the ring electrode is energized at a positive potential relative to the cathodes to initiate a cold-cathode electric gas discharge. Free electrons accelerated toward the anode are constrained to move along spiral paths by the axial magnetic field. Gas molecules from the system under evacuation are ionized by electron bombardment and the resulting positively charged ions are accelerated into and absorbed by the cold cathodes. Since the pumping action does not necessarily depend upon any chemical gettering, 'it is especially adapted to the removal of inert gas residues.
  • a limitation of the operation of such devices is that the pumping speed depends upon the discharge current which is a function of the gas pressure in the system. Consequently, for given values of accelerating potential and magnetic field strength, there is a limiting pressure below which the discharge current becomes irregular and tapers oif, resulting in a decreased and ineffectual pumping speed.
  • a working gas which may be gettered chemically is introduced into a system being evacuated by an ionic pump when the limiting pressure for the cold cathode gas discharge is approached.
  • the amount of this working gas is controlled to maintain optimum pumping of the mixture of the working gas and the system gas until the partial pressure of the system gas has been reduced to the desired limit.
  • the working gas is then gettered chemically to produce the final vacuum.
  • Fig. 1 is an elevational view partially broken away inert gases in a system under evacuation.
  • the ionic pump may comprise a pill-box-shaped evacuable envelope 3, a ring electrode 4, and disc electrodes 5 and 6 of a gas absorbing material such as carbon.
  • Soft iron pole pieces 7 and 8 and permanent magnet 9 supply a magnetic field axially of electrode 4.
  • Communication between the pump 1, auxiliary device 2, and the system to be evacuated (not shown) is by means of tubulations 10 and 11.
  • the high voltage source 12 is provided to maintain the ring electrode 4 at a positive potential relative to cold cathode discs 5 and 6 which are in contact with the envelope at ground potential.
  • Connection to the ring electrode 4 is by means of a metallic cap 13 and electrode support 14, the cap 13 being insulated from the envelope 1 by a glass member 15.
  • the pumping speed for the ionic pump is substantially proportional to the dischargecurrent, which is a function, ia(V,B,[7), of the anode voltage V, the magnetic field strength B and the pressure p.
  • the limiting pressure, p; is.about 0.006 micron in a closed helium system.
  • V 10,000 volts
  • 11 is found to be 0.0025 micron. It is seen that, to a certain extent, an increased discharge current and hence a lower limiting pressure is obtained by increasing the anode voltage.
  • a working gas may be employed to reduce the otherwise limiting pressure for Apparatus 2, for the supply and removal of the working gas may comprise, for example, a foil 16 of titanium or other material containingan adsorbed gas.
  • the working gas such as hydrogen is chosen from those gases which are not inert, especially hydrogen, oxygen and nitrogen, which are known to be easily gettered-chemically.
  • gases suitable as working gases and of getters therefor may be found described in the text by Saul Dushman entitled, Scientific Foundations of Vacuum Technique, published in 1949 by John Wiley & Sons, Inc.
  • a current is passed through the leads 17 and 18 to heat the foil 16 and evolve a portion of the absorbed gas, so that the sum of the partial pressures of this working gas and the gas of the system is suflicient for the maintenance of a satisfactory discharge current. Pumping may then be continued at an efficient speed.
  • the working gas is removed from the system by means of a getter 19, for example a titanium filament, in the case of hydrogen, which is cycled through a suitable temperature range by a current supplied through the leads 20v and 21 according to conventional steps.
  • the free hydrogen or other shown) of the working gas which'again may advantageously be hydrogen, oxygen, or nitrogen.
  • Supply of the working gas may be regulated to maintain the discharge current at some optimum value while the pumping is continued to produce the desired evacuation.
  • the valve 22 is then closed and a getter 24, illustrated as a nickel tube 25 having a thin wall portion 26 and containing barium 27 is heated as by passing current through the leads 28 and 29.
  • the barium permeates the thin wall portion 26 and is evaporated upon the surrounding surfaces to getter the working gas.
  • the method of evacuating a system containing inert gases by means of an ionic vacuum pump requiring sufficient gas pressure for the maintenance of an electric discharge for efficient pumping speed comprises the steps of reducing the pressure of the system falls below an-optimum value, introducing into the system a working gas which can be gettered chemically to increase the total pressure in the system to a level where an electric discharge within the pump is readily maintained to restore and maintain the pumping speed at an optimum value, pumping the mixture of the system gases and the working gas until the partial pressure of the system gases has been reduced to a predetermined value, and removing the working gas from the system by means of a getter.
  • the method of evacuating a system containing inert gases by means of an ionic vacuum pump requiring sufiicient gas pressure for the maintenance of an electric discharge for etficient pumping speed comprises the steps of reducing the pressure of the system gases by means of the pump until the pumping speed falls below an optimum value, introducing into the system a flow of a working gas to restore the pumping speed to an optimum value,'maintaining the flow of the working gas into the system at a rate to maintain the pressure in the system at a level where an electric discharge is readily maintained to maintain the pumping speed at an optimum value, pumping the mixture of the system gases and the working gas until the partial pressure of the system gases has been reduced to a predetermined value, interrupting the flow of the working gas into the system, and removing the working gas remaining in the system by means of a getter.

Landscapes

  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
  • Electron Tubes For Measurement (AREA)
  • Treating Waste Gases (AREA)
  • Plasma Technology (AREA)
  • Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Description

. 1958 A. M. ukEwlTscl-y 2,358,972
IONIC VACUUM PUMP Filed March 27, 1956 In ve ntorz- A na to/e M Gu rsewitsch,
/"//'s Attorney.
United tates Patent IONIC VACUUM PUMP Anatole M. Gurewitsch, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application March 27, 1956, Serial No. 574,226
2 Claims. (CL 230-69) This invention relates to ionic vacuumpumps and, more particularly, to a method whereby the elficiency. of such devices is increased for the pumping of inert gases at very low pressures by means of a working gas, a gas which may be added to the system and removed at a later time by gettering action without any resulting net increase in the amount of gas in the system.
In the copending application, Serial No. 350,964, filed April 24, 1953, now Patent 2,755,014, dated July 17, 1956, of Willem F. Westendorp and Anatole M. Gur'ewitsch, and assigned to the same assignee as this application, there is disclosed an ionic pump of the type to which this invention is applicable. p
Such a pump may comprise a ring-shaped anode and opposed cold cathode plates enclosed in a vacuum tight envelope and means to provide a magnetic field axially of the electrodes. In operation, after a rough vacuum has been established by a separate fore pump, the ring electrode is energized at a positive potential relative to the cathodes to initiate a cold-cathode electric gas discharge. Free electrons accelerated toward the anode are constrained to move along spiral paths by the axial magnetic field. Gas molecules from the system under evacuation are ionized by electron bombardment and the resulting positively charged ions are accelerated into and absorbed by the cold cathodes. Since the pumping action does not necessarily depend upon any chemical gettering, 'it is especially adapted to the removal of inert gas residues.
A limitation of the operation of such devices is that the pumping speed depends upon the discharge current which is a function of the gas pressure in the system. Consequently, for given values of accelerating potential and magnetic field strength, there is a limiting pressure below which the discharge current becomes irregular and tapers oif, resulting in a decreased and ineffectual pumping speed.
Therefore, it is an object of this invention to provide a method whereby the efiiciency of an ionic pump is increased for the pumping of inert gases at extremely low pressures.
According to this invention, a working gas which may be gettered chemically is introduced into a system being evacuated by an ionic pump when the limiting pressure for the cold cathode gas discharge is approached. The amount of this working gas is controlled to maintain optimum pumping of the mixture of the working gas and the system gas until the partial pressure of the system gas has been reduced to the desired limit. The working gas is then gettered chemically to produce the final vacuum.
The features of the invention desired to be protected herein are pointed out with particularity in the appended claims. The invention itself, together with further objects and advantages thereof, may best be understood by reference to the following description taken in comiection with the accompanying drawings, in which:
Fig. 1 is an elevational view partially broken away inert gases in a system under evacuation.
sure decreases the discharge current also decreases. is found in practice that the pumping speed diminishes asymptotically as the pressure is reduced to the limiting 2,858,972 Patented Nov. 4, 1958 of an ionic vacuum pump and apparatus for performing the method of this invention; and
, invention.
The ionic pump may comprise a pill-box-shaped evacuable envelope 3, a ring electrode 4, and disc electrodes 5 and 6 of a gas absorbing material such as carbon.
Soft iron pole pieces 7 and 8 and permanent magnet 9 supply a magnetic field axially of electrode 4. Communication between the pump 1, auxiliary device 2, and the system to be evacuated (not shown) is by means of tubulations 10 and 11. The high voltage source 12 is provided to maintain the ring electrode 4 at a positive potential relative to cold cathode discs 5 and 6 which are in contact with the envelope at ground potential. Connection to the ring electrode 4 is by means of a metallic cap 13 and electrode support 14, the cap 13 being insulated from the envelope 1 by a glass member 15.
The pumping speed for the ionic pump is substantially proportional to the dischargecurrent, which is a function, ia(V,B,[7), of the anode voltage V, the magnetic field strength B and the pressure p. In general, as the prespressure for a given pump and gaseous system. For example, with V=5,000 volts and B=800 gauss, the limiting pressure, p;,, is.about 0.006 micron in a closed helium system. Under the same conditions, with the voltage increased to V=10,000 volts, 11 is found to be 0.0025 micron. It is seen that, to a certain extent, an increased discharge current and hence a lower limiting pressure is obtained by increasing the anode voltage. However, this control is limited by attendant difficulties in the supply of such high voltages and because an increase of potential beyond a certain limit without an accompanying increase in magnetic field causes electrons to be collected at the anode before they are able to produce a sufficient number of ions. This results in a net loss in efficiency.
Applicant has discovered that a working gas may be employed to reduce the otherwise limiting pressure for Apparatus 2, for the supply and removal of the working gas may comprise, for example, a foil 16 of titanium or other material containingan adsorbed gas. The working gas such as hydrogen is chosen from those gases which are not inert, especially hydrogen, oxygen and nitrogen, which are known to be easily gettered-chemically. The properties of gases suitable as working gases and of getters therefor may be found described in the text by Saul Dushman entitled, Scientific Foundations of Vacuum Technique, published in 1949 by John Wiley & Sons, Inc.
As the pressure in the system is reduced by the pump 1 to a point where the discharge current becomes insufiicient for satisfactory pumping speeds, a current is passed through the leads 17 and 18 to heat the foil 16 and evolve a portion of the absorbed gas, so that the sum of the partial pressures of this working gas and the gas of the system is suflicient for the maintenance of a satisfactory discharge current. Pumping may then be continued at an efficient speed. When the desired partial pressure of the system gas has been reached, the working gas is removed from the system by means of a getter 19, for example a titanium filament, in the case of hydrogen, which is cycled through a suitable temperature range by a current supplied through the leads 20v and 21 according to conventional steps. The free hydrogen or other shown) of the working gas which'again may advantageously be hydrogen, oxygen, or nitrogen. Supply of the working gas may be regulated to maintain the discharge current at some optimum value while the pumping is continued to produce the desired evacuation. The valve 22 is then closed and a getter 24, illustrated as a nickel tube 25 having a thin wall portion 26 and containing barium 27 is heated as by passing current through the leads 28 and 29. The barium permeates the thin wall portion 26 and is evaporated upon the surrounding surfaces to getter the working gas. 1
While the invention has been described by reference to particular embodiments thereof, it will be understood that numerous changes can be made by those skilled in the art without actually departing from the invention, and it is the aim of the appended claims to 'cover all such equivalent variations as come within the true spirit and scope of the foregoing disclosure.
What I claim as new and desire to secure by Letters Patent of the United States is:
1. The method of evacuating a system containing inert gases by means of an ionic vacuum pump requiring sufficient gas pressure for the maintenance of an electric discharge for efficient pumping speed, which method comprises the steps of reducing the pressure of the system falls below an-optimum value, introducing into the system a working gas which can be gettered chemically to increase the total pressure in the system to a level where an electric discharge within the pump is readily maintained to restore and maintain the pumping speed at an optimum value, pumping the mixture of the system gases and the working gas until the partial pressure of the system gases has been reduced to a predetermined value, and removing the working gas from the system by means of a getter.
2. The method of evacuating a system containing inert gases by means of an ionic vacuum pump requiring sufiicient gas pressure for the maintenance of an electric discharge for etficient pumping speed, which method comprises the steps of reducing the pressure of the system gases by means of the pump until the pumping speed falls below an optimum value, introducing into the system a flow of a working gas to restore the pumping speed to an optimum value,'maintaining the flow of the working gas into the system at a rate to maintain the pressure in the system at a level where an electric discharge is readily maintained to maintain the pumping speed at an optimum value, pumping the mixture of the system gases and the working gas until the partial pressure of the system gases has been reduced to a predetermined value, interrupting the flow of the working gas into the system, and removing the working gas remaining in the system by means of a getter.
References Cited in the file of this patent UNITED STATES PATENTS 1,651,386 Gustin Dec. 6, 1927
US574226A 1953-04-24 1956-03-27 Ionic vacuum pump Expired - Lifetime US2858972A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US574226A US2858972A (en) 1953-04-24 1956-03-27 Ionic vacuum pump

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US350964A US2755014A (en) 1953-04-24 1953-04-24 Ionic vacuum pump device
US574226A US2858972A (en) 1953-04-24 1956-03-27 Ionic vacuum pump
CH6340958A CH363756A (en) 1953-04-24 1958-08-29 Method for manufacturing an ion vacuum pump

Publications (1)

Publication Number Publication Date
US2858972A true US2858972A (en) 1958-11-04

Family

ID=25737786

Family Applications (3)

Application Number Title Priority Date Filing Date
US350964A Expired - Lifetime US2755014A (en) 1953-04-24 1953-04-24 Ionic vacuum pump device
US574309A Expired - Lifetime US2925214A (en) 1953-04-24 1956-03-27 Ionic vacuum pump
US574226A Expired - Lifetime US2858972A (en) 1953-04-24 1956-03-27 Ionic vacuum pump

Family Applications Before (2)

Application Number Title Priority Date Filing Date
US350964A Expired - Lifetime US2755014A (en) 1953-04-24 1953-04-24 Ionic vacuum pump device
US574309A Expired - Lifetime US2925214A (en) 1953-04-24 1956-03-27 Ionic vacuum pump

Country Status (7)

Country Link
US (3) US2755014A (en)
BE (1) BE528321A (en)
CH (1) CH363756A (en)
DE (2) DE1000960B (en)
FR (3) FR1101015A (en)
GB (2) GB753264A (en)
NL (1) NL112031C (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2904665A (en) * 1957-06-18 1959-09-15 Applied Radiation Corp Vacuum trap
US3085739A (en) * 1960-09-20 1963-04-16 Ibm Vacuum method
US3104049A (en) * 1959-12-30 1963-09-17 Ibm High purity vacuum systems
US3146849A (en) * 1959-10-20 1964-09-01 Tennyson James Joseph Method and apparatus for acoustically silencing high velocity gases
US3152752A (en) * 1962-04-30 1964-10-13 Gen Electric Apparatus and method of removing organic vapors from low pressure vacuum systems
US3177672A (en) * 1960-03-31 1965-04-13 Martin Marietta Corp Space simulating apparatus and method
US3181775A (en) * 1962-03-20 1965-05-04 Wisconsin Alumni Res Found Pumping apparatus
US3201188A (en) * 1961-03-29 1965-08-17 Varian Associates Rotary exhaust apparatus
US3383032A (en) * 1967-01-31 1968-05-14 Atomic Energy Commission Usa Vacuum pumping method and apparatus

Families Citing this family (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2755014A (en) * 1953-04-24 1956-07-17 Gen Electric Ionic vacuum pump device
US2894679A (en) * 1953-11-23 1959-07-14 Wisconsin Alumni Res Found Pump
US2850225A (en) * 1955-11-10 1958-09-02 Wisconsin Alumni Res Found Pump
US2841324A (en) * 1955-12-30 1958-07-01 Gen Electric Ion vacuum pump
DE1065561B (en) * 1957-02-27
US2897036A (en) * 1957-04-18 1959-07-28 High Voltage Engineering Corp Method of evacuation
US2993638A (en) * 1957-07-24 1961-07-25 Varian Associates Electrical vacuum pump apparatus and method
NL131436C (en) * 1957-07-24
DE1089112B (en) * 1958-02-13 1960-09-15 Thomson Houston Comp Francaise Vacuum pump
US3081020A (en) * 1958-02-13 1963-03-12 Thomson Houston Comp Francaise Ion pumps
DE1090815B (en) * 1958-03-07 1960-10-13 Nihon Shinku Gijitsu Kabushiki Method and pump for continuously generating high vacuums
US3204860A (en) * 1958-04-16 1965-09-07 Csf High-vacuum pump
US3120363A (en) * 1958-09-11 1964-02-04 Electronatom Corp Flying apparatus
NL243654A (en) * 1958-09-25
US3070283A (en) * 1959-06-15 1962-12-25 Ultek Corp Vacuum pump
DE1113283B (en) * 1959-08-14 1961-08-31 Balzers Vakuum G M B H Process for the operation of ultra-high vacuum pumping systems
NL256013A (en) * 1959-09-25
US3095163A (en) * 1959-10-13 1963-06-25 Petroleum Res Corp Ionized boundary layer fluid pumping system
NL131435C (en) * 1959-11-12
NL266745A (en) * 1960-07-08
FR1281403A (en) * 1960-12-01 1962-01-12 Thomson Houston Comp Francaise Advanced Evaporative Ionization Type Vacuum Pump System
US3293490A (en) * 1961-07-25 1966-12-20 Robert A Cornog Apparatus for obtaining controlled production of charged particles
US3147910A (en) * 1961-08-30 1964-09-08 Varian Associates Vacuum pump apparatus
FR80795E (en) * 1961-12-15 1963-06-14 Thomson Houston Comp Francaise Advanced Evaporative Ionization Type Vacuum Pump System
US3293491A (en) * 1962-02-13 1966-12-20 Robert A Cornog Apparatus for producing charged particles
US3216652A (en) * 1962-09-10 1965-11-09 Hughes Aircraft Co Ionic vacuum pump
GB1053215A (en) * 1963-04-15
US3241740A (en) * 1963-10-16 1966-03-22 Cons Vacuum Corp Vacuum pumping methods and apparatus
US3236442A (en) * 1964-01-20 1966-02-22 Morris Associates Ionic vacuum pump
US3309010A (en) * 1964-02-10 1967-03-14 Varian Associates Getter ion vacuum pump
US3311776A (en) * 1964-08-27 1967-03-28 Varian Associates Multifilar sublimation filament for getter vacuum pumps
JPS59123152A (en) * 1982-12-28 1984-07-16 Hajime Ishimaru Ion pump
US7182295B2 (en) 2002-11-12 2007-02-27 Scott D. Redmond Personal flight vehicle and system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1651386A (en) * 1927-12-06 Evacuation of bulbs and other vessels

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1845777A (en) * 1929-01-05 1932-02-16 Argco Tube And Television Corp Metal electrode and method of making the same
DE596017C (en) * 1932-06-24 1934-04-25 Linde Eismasch Ag Process for achieving a pumping effect in gases
US2282401A (en) * 1938-01-06 1942-05-12 Rca Corp Electrical vacuum pump
DE885763C (en) * 1942-07-24 1953-08-06 Telefunken Gmbh Powdery, non-evaporating trapping material for electrical discharge vessels
US2464702A (en) * 1944-11-04 1949-03-15 Hartford Nat Bank & Trust Co Process for manufacturing cathodes for electron discharge tubes
US2460175A (en) * 1945-07-31 1949-01-25 Hazeltine Research Inc Ionic vacuum pump
US2578009A (en) * 1947-12-23 1951-12-11 Rca Corp Electronic high vacuum apparatus
US2636664A (en) * 1949-01-28 1953-04-28 Hertzler Elmer Afton High vacuum pumping method, apparatus, and techniques
US2715993A (en) * 1952-06-06 1955-08-23 W M Welch Mfg Company Ionization pump
US2755014A (en) * 1953-04-24 1956-07-17 Gen Electric Ionic vacuum pump device
US2796555A (en) * 1954-06-29 1957-06-18 High Voltage Engineering Corp High-vacuum pump

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1651386A (en) * 1927-12-06 Evacuation of bulbs and other vessels

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2904665A (en) * 1957-06-18 1959-09-15 Applied Radiation Corp Vacuum trap
US3146849A (en) * 1959-10-20 1964-09-01 Tennyson James Joseph Method and apparatus for acoustically silencing high velocity gases
US3104049A (en) * 1959-12-30 1963-09-17 Ibm High purity vacuum systems
US3177672A (en) * 1960-03-31 1965-04-13 Martin Marietta Corp Space simulating apparatus and method
US3085739A (en) * 1960-09-20 1963-04-16 Ibm Vacuum method
US3201188A (en) * 1961-03-29 1965-08-17 Varian Associates Rotary exhaust apparatus
US3181775A (en) * 1962-03-20 1965-05-04 Wisconsin Alumni Res Found Pumping apparatus
US3152752A (en) * 1962-04-30 1964-10-13 Gen Electric Apparatus and method of removing organic vapors from low pressure vacuum systems
US3383032A (en) * 1967-01-31 1968-05-14 Atomic Energy Commission Usa Vacuum pumping method and apparatus

Also Published As

Publication number Publication date
US2925214A (en) 1960-02-16
GB834655A (en) 1960-05-11
FR71662E (en) 1960-01-13
FR71663E (en) 1960-01-13
NL112031C (en) 1965-10-15
BE528321A (en) 1957-03-01
DE1094401B (en) 1960-12-08
US2755014A (en) 1956-07-17
FR1101015A (en) 1955-09-27
GB753264A (en) 1956-07-18
DE1000960B (en) 1957-01-17
CH363756A (en) 1962-08-15

Similar Documents

Publication Publication Date Title
US2858972A (en) Ionic vacuum pump
CA1039860A (en) Double chamber ion source
US4739214A (en) Dynamic electron emitter
US2988657A (en) Ion pump
US4691109A (en) Apparatus and method for producing ions
Bloomer et al. Some effects of gases upon vacuum breakdown initiated by field emission of electrons
US6114694A (en) Device having field emission type cold cathode and vacuum tank exhausting method and system in the same
US2888189A (en) Vacuum pump
US2925504A (en) High-vacuum pumps for high-voltage acceleration tubes
US2956195A (en) Hollow carbon arc discharge
US2919380A (en) Electron discharge devices
US5480286A (en) Exhaust apparatus and vacuum pumping unit including the exhaust apparatus
US3080104A (en) Ionic pump
JPS6130372B2 (en)
US2134710A (en) Method and apparatus for exhausting tubes
US3310226A (en) Vacuum device
US3684401A (en) Cathode-getter materials for sputter-ion pumps
US2805365A (en) Gas-filled amplifying tube
US3152752A (en) Apparatus and method of removing organic vapors from low pressure vacuum systems
US1374679A (en) Degasifying process
US3042824A (en) Improved vacuum pumps
JPH02121233A (en) Ion source
US1950008A (en) Evacuating process
US1895437A (en) Method of degassing cathodes of electron discharge tubes
WO2017046886A1 (en) Vacuum device