US3250949A - Electron gun - Google Patents

Electron gun Download PDF

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Publication number
US3250949A
US3250949A US205312A US20531262A US3250949A US 3250949 A US3250949 A US 3250949A US 205312 A US205312 A US 205312A US 20531262 A US20531262 A US 20531262A US 3250949 A US3250949 A US 3250949A
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US
United States
Prior art keywords
anode
cathode
electron
gun
electron gun
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
US205312A
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English (en)
Inventor
Weber Cornelis
Hart Paul Anton Herman
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
Original Assignee
US Philips Corp
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 US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3250949A publication Critical patent/US3250949A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J23/00—Details of transit-time tubes of the types covered by group H01J25/00
    • H01J23/02—Electrodes; Magnetic control means; Screens
    • H01J23/06—Electron or ion guns
    • H01J23/065—Electron or ion guns producing a solid cylindrical beam
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J3/00—Details of electron-optical or ion-optical arrangements or of ion traps common to two or more basic types of discharge tubes or lamps
    • H01J3/02—Electron guns
    • H01J3/027—Construction of the gun or parts thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J3/00—Details of electron-optical or ion-optical arrangements or of ion traps common to two or more basic types of discharge tubes or lamps
    • H01J3/02—Electron guns
    • H01J3/029—Schematic arrangements for beam forming

Definitions

  • the invention relates to a device comprising an electron-beam tube for signal amplification 'by the action of an inhomogeneous magnetic or an inhomogeneous electric field on an electron-beam emanating from an electron gun having at least two anodes, which beam is focussed by an axial magnetic field.
  • an electron-beam tube for signal amplification 'by the action of an inhomogeneous magnetic or an inhomogeneous electric field on an electron-beam emanating from an electron gun having at least two anodes, which beam is focussed by an axial magnetic field.
  • the electron beam should be satisfactorily focussed and should have a high space charge density. If this were not the case, the beam would be violently defocussed under the action of the inhomogeneous magnetic field.
  • the electron beam should have a low voltage, since in this case a high amplification per unit length can be obtained.
  • a comparatively high perveance in a given case approximately 3X10- amperes x volts* is obtained already with small dimensions of the gun. It is moreover important that the axial electron velocity should be constant as far as possible throughout the sectional area of the beam. With a high space charge density this cannot be realized because of the potential depression in the beam.
  • the cathode of the electron gun is magnetically screened by the first anode, while the further anodes of the electron gun are located outside this magnetic screening.
  • the gun is built up, accordingly, of a part with low perveance serving as a magnetic screen and a lens system outside the magnetic screen, which system enhances the perveance of the beam-by reducing the voltage of the beam.
  • the first anode operating as a magnetic screen may have a simple shape, which is important with a view to the small distance of the cathode from this anode and to the small opening of this anode.
  • the lens system may be of a simple shape by building it up from a number of anodes instead of using one or more anodes of a particular shape.
  • the first anode serves at the same time as a magnetic screen and may be made from iron.
  • the invention furthermore relates to an electron-beam 3,25%,949 Patented May 10, 1966 tube for use in such device and to an electron gun for use in such an electron-beam tube.
  • This gun comprises a cathode 1 and anodes 2, 3, 4, 5, 6 and 7.
  • the anode 2 is made of iron. It has a very small opening and is prolonged cylindrically in the direction towards the cathode, so that the latter is magnetically screened substantially completely from the external magnetic field focussing the beam in the tube in which this gun is employed.
  • the anodes 3 to 7 are held in ceramic tube 8 and are held at a given distance from each other by the ceramic rings 9.
  • the ceramic tube 8 and the anode 2 are arranged in a constantan sleeve 10.
  • the cathode support 11 of stainless steel is held between two ceramic rings 12, which are held at a given distance from the anode 2 by a molybdenum spacing member 13.
  • cathode voltage was 0 volt and the voltages of the anodes
  • the maximum amplification was 50 db. If in the same tube use was made of the conventional gun, the maximum amplification was 35 db with a maximum beam voltage of 6 v. and a beam current of 35 A. In both cases the beam diameter was 0.4 to 0.5 mm.
  • An electron-beam forming element comprising a cathode, a first anode directly surrounding and magnetically shielding said cathode, said first anode having an aperture smaller than the diameter of the cathode for the passage of an electron-beam therethrough, and a second anode located beyond the first anode and outside the shield provided by the first anode, the space between the first anode and the cathode being free of other electrodes, means applying a positive potential to the first anode relative to the cathode, and means applying another positive potential to said second anode.
  • An electron-beam forming element comprising a cathode, a first anode of ferromagnetic material spaced from and directly surrounding and shielding said cathode from an axial magnetic focussing field, said first anode having an aperture smaller than the diameter of the cathode therein for the passage of an electron beam therethrough, and a second anode located beyond the first anode and outside the shield provided by the first anode, the space between the first anode and the cathode being free of other electrodes, means applying a positive potential to the first anode relative to the cathode, and means applying another positive potential to said second anode.
  • An electron-beam forming element as claimed in claim 2 including a plurality of anodes beyond the first anode and outside the shield provided by the first anode.

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  • Microwave Tubes (AREA)
  • Electron Sources, Ion Sources (AREA)
US205312A 1961-07-07 1962-06-26 Electron gun Expired - Lifetime US3250949A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL266799 1961-07-07

Publications (1)

Publication Number Publication Date
US3250949A true US3250949A (en) 1966-05-10

Family

ID=19753143

Family Applications (1)

Application Number Title Priority Date Filing Date
US205312A Expired - Lifetime US3250949A (en) 1961-07-07 1962-06-26 Electron gun

Country Status (4)

Country Link
US (1) US3250949A (es)
DE (1) DE1299771B (es)
GB (1) GB1013622A (es)
NL (1) NL266799A (es)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2445606A1 (fr) * 1978-12-28 1980-07-25 Axenov Nikolai Dispositif electro-optique pour la formation du faisceau electronique dans un dispositif a faisceau electronique
US5942847A (en) * 1996-07-26 1999-08-24 AEG Elektronische Rohren GmbH Cathode ray tube
US9318309B2 (en) 2011-11-04 2016-04-19 Micromass Uk Limited Mass spectrometers comprising accelerator devices

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3522469A (en) * 1968-04-12 1970-08-04 Varian Associates Magnetic beam focusing structure for a traveling wave tube employing magnetic shunts between the pole pieces and the emitter
US5136161A (en) * 1990-12-03 1992-08-04 Spacelabs, Inc. Rf mass spectrometer
DE19622269A1 (de) * 1996-06-03 1997-12-04 Basf Ag Verfahren zur Reinigung von sterisch gehinderten 4-Aminopiperidinen
DE19622268C1 (de) * 1996-06-03 1997-10-23 Basf Ag Sterisch gehindertes 4-Amino-piperidin mit geringem Dimergehalt, seine Herstellung und Verwendung

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2619611A (en) * 1951-05-29 1952-11-25 Eitel Mccullough Inc Electron tube apparatus

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL89376C (es) * 1950-06-17
US2817035A (en) * 1954-04-26 1957-12-17 Hughes Aircraft Co Brillouin flow electron gun

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2619611A (en) * 1951-05-29 1952-11-25 Eitel Mccullough Inc Electron tube apparatus

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2445606A1 (fr) * 1978-12-28 1980-07-25 Axenov Nikolai Dispositif electro-optique pour la formation du faisceau electronique dans un dispositif a faisceau electronique
US5942847A (en) * 1996-07-26 1999-08-24 AEG Elektronische Rohren GmbH Cathode ray tube
US9318309B2 (en) 2011-11-04 2016-04-19 Micromass Uk Limited Mass spectrometers comprising accelerator devices
US9552975B2 (en) 2011-11-04 2017-01-24 Micromass Uk Limited Mass spectrometers comprising accelerator devices

Also Published As

Publication number Publication date
NL266799A (es)
GB1013622A (en) 1965-12-15
DE1299771B (de) 1969-07-24

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