US2889478A - Electron discharge apparatus - Google Patents

Electron discharge apparatus Download PDF

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Publication number
US2889478A
US2889478A US439713A US43971354A US2889478A US 2889478 A US2889478 A US 2889478A US 439713 A US439713 A US 439713A US 43971354 A US43971354 A US 43971354A US 2889478 A US2889478 A US 2889478A
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United States
Prior art keywords
cathode
electron
tube
electrode
electron discharge
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Expired - Lifetime
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US439713A
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English (en)
Inventor
Rogers Douglas Cecil
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International Standard Electric Corp
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International Standard Electric Corp
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Filing date
Publication date
Application filed by International Standard Electric Corp filed Critical International Standard Electric Corp
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Publication of US2889478A publication Critical patent/US2889478A/en
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Classifications

    • 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
    • H01J41/02—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas
    • H01J41/04—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas with ionisation by means of thermionic cathodes

Definitions

  • the present invention relates to electron discharge apparatus employing electron beams.
  • the method of testing an electron discharge device comprising collecting and measuring the positive ion current flowing towards the cathode during operation of the said device.
  • an electron discharge device comprising an electron gun for producing an electron beam and having an indirectly heated cathode, the emissive portion of which contains a central aperture, and an electrode insulated from the cathode situated behind the cathode aperture to collect positive ions accelerated along the electron beam path through the said central aperture.
  • the residual gas pressure can be measured in terms of the positive ion current and from a further aspect, the invention provides the method of measurement of the residual gas pressure in an electron discharge device comprising the measurement of the positive ion current flowing through a central aperture in the cathode of the said device in the opposite direction to the normal electron current to an ion collector electrode disposed behind the said central aperture.
  • an indirectly heated cathode 1 is formed by a tubular metallic member 2 mounted upon an insulator 3 which is clamped between ceramic rings 4 and 5, which are shown partly cut away.
  • the emissive surface of the cathode is provided by a spherically shaped end cap 6 fitting into the end of the tube 2.
  • the end cap 6 is coated with electron emissive material, and contains a central aperture 7.
  • a heater winding 8 is shown supported inside the end of the tube 2, adjacent the cap 6.
  • a focussing electrode 9 and accelerating anode 10, which is apertured at 11, are indicated fragmentarily.
  • a metallic rod 12. is mounted behind the aperture 7 within the tube 2 by means of an eyelet 13, secured to the insulator 3 so as to be insulated from the cathode.
  • the tocussing electrode 9 is maintained at cathode potential by means such as the connection 14 and the anode 10 is maintained at a positive potential with respect to the cathode by means of a source of DC. potential indicated by the battery 15.
  • a convergent beam of electrons is drawn towards the anode 10 and passes through the aperture 11, to be utilised in the remainder of tube which is not shown.
  • the collector electrode 12 is preferably maintained at a negative potential with respect to the cathode by means such as a source indicated by the battery 16. Positive ions flowing towards the cathode will tend to be focussed through the aperture 7 and be collected by the collector electrode 12. The resulting ion current may then be measured in a suitable manner such as by means of a microammeter indicated at 17.
  • the negative polarising potential of electrode 12 is not essential; the source 16 may be omitted, if desired, at the expense of somewhat less satisfactory operation.
  • the positive ion current generated in an electron beam tube can be continuously measured both during factory processing and testing, and also, if desired, during subsequent operation of the discharge device.
  • An electron discharge device comprising an electron gun for producing an electron beam and having an indirectly heated cathode, the emissive portion of which contains a central aperture, an accelerating electrode for accelerating electrons emitted from said cathode, and an electrode insulated from the cathode situated behind the cathode aperture to collect positive ions accelerated along the electron beam path through the said central aperture and means for biasing said electrode negative with respect to said cathode.
  • An electron gun comprising an indirectly heated cathode, a focussing electrode, an anode and an ion collector electrode in which the said cathode comprises a tubular metallic member mounted upon an insulator, a

Landscapes

  • Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
US439713A 1953-07-02 1954-06-28 Electron discharge apparatus Expired - Lifetime US2889478A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB18323/53A GB780478A (en) 1953-07-02 1953-07-02 Improvements in or relating to electron discharge apparatus

Publications (1)

Publication Number Publication Date
US2889478A true US2889478A (en) 1959-06-02

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Family Applications (1)

Application Number Title Priority Date Filing Date
US439713A Expired - Lifetime US2889478A (en) 1953-07-02 1954-06-28 Electron discharge apparatus

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US (1) US2889478A (en(2012))
BE (1) BE530043A (en(2012))
GB (1) GB780478A (en(2012))

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2956192A (en) * 1959-01-02 1960-10-11 Eitel Mccullough Inc Gettering electron gun
US2967260A (en) * 1957-05-31 1961-01-03 Eitel Mccullough Inc Electron tube
US3038118A (en) * 1958-07-21 1962-06-05 Wesix Electric Heater Co Ion collecting and measuring apparatus
US3132275A (en) * 1960-05-31 1964-05-05 Eitel Mccullough Inc Electron gun and cathode heater assembly therefor
US4687964A (en) * 1985-05-09 1987-08-18 The United States Of America As Represented By The Administrator National Aeronautics & Space Administration Apparatus for mounting a field emission cathode
US4798993A (en) * 1984-03-09 1989-01-17 Thomson-C.S.F. Electron gun for electronic tubes

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2308800A (en) * 1941-02-15 1943-01-19 Bell Telephone Labor Inc Electron discharge device
US2445811A (en) * 1941-12-22 1948-07-27 Sperry Corp High-frequency tube structure
US2547200A (en) * 1945-09-15 1951-04-03 Hartford Nat Bank & Trust Co Getter structure for electric discharge tubes
US2625586A (en) * 1950-04-14 1953-01-13 Bell Telephone Labor Inc Apparatus for measuring gas pressures
US2639397A (en) * 1949-06-04 1953-05-19 Collins Radio Co Vacuum gauge of the ionization producing type
GB709266A (en) * 1950-02-09 1954-05-19 Post Office Improvements in or relating to ionisation gauges

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2308800A (en) * 1941-02-15 1943-01-19 Bell Telephone Labor Inc Electron discharge device
US2445811A (en) * 1941-12-22 1948-07-27 Sperry Corp High-frequency tube structure
US2547200A (en) * 1945-09-15 1951-04-03 Hartford Nat Bank & Trust Co Getter structure for electric discharge tubes
US2639397A (en) * 1949-06-04 1953-05-19 Collins Radio Co Vacuum gauge of the ionization producing type
GB709266A (en) * 1950-02-09 1954-05-19 Post Office Improvements in or relating to ionisation gauges
US2625586A (en) * 1950-04-14 1953-01-13 Bell Telephone Labor Inc Apparatus for measuring gas pressures

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2967260A (en) * 1957-05-31 1961-01-03 Eitel Mccullough Inc Electron tube
US3038118A (en) * 1958-07-21 1962-06-05 Wesix Electric Heater Co Ion collecting and measuring apparatus
US2956192A (en) * 1959-01-02 1960-10-11 Eitel Mccullough Inc Gettering electron gun
US3132275A (en) * 1960-05-31 1964-05-05 Eitel Mccullough Inc Electron gun and cathode heater assembly therefor
US4798993A (en) * 1984-03-09 1989-01-17 Thomson-C.S.F. Electron gun for electronic tubes
US4687964A (en) * 1985-05-09 1987-08-18 The United States Of America As Represented By The Administrator National Aeronautics & Space Administration Apparatus for mounting a field emission cathode

Also Published As

Publication number Publication date
BE530043A (en(2012))
GB780478A (en) 1957-08-07

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