US3663853A - Triode electron gun with positive grid and modular cathode - Google Patents

Triode electron gun with positive grid and modular cathode Download PDF

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Publication number
US3663853A
US3663853A US59224A US3663853DA US3663853A US 3663853 A US3663853 A US 3663853A US 59224 A US59224 A US 59224A US 3663853D A US3663853D A US 3663853DA US 3663853 A US3663853 A US 3663853A
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United States
Prior art keywords
anode
grid
electrons
axis
gun
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Expired - Lifetime
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US59224A
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English (en)
Inventor
Jean Sommeria
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Alcatel Lucent SAS
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Alcatel SA
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    • 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

  • ABSTRACT Triode electron gun with positive control grid, with emitting cathode, and with acceleration anode, providing a concentration and emission of electrons directed along straight and parallel paths.
  • gun includes several elementary guns distributed around a single axis, the axes of the guns converging toward one and the same point on the axis situated at the entrance to an axial conical conduit drilled in the anode.
  • the electrons produced in each elementary gun by an emitting pellet go through a concentrator and then through a conduit in alignment with the axis of each gun and perforated in a single thick grid.
  • the invention can be applied in metallurgy for melting and heating.
  • the method involved consists in clearly separating the space for the extraction of the electrons from the acceleration space. We thus get a straight electron flow in an extraction space by creating a large electrical field between the cathode and a control acceleration grid but the voltage difference between the anode and this control acceleration grid remains within the usual limits.
  • the invention is intended to improve this process by making the emission zones on the emitting cathode even more homogeneous and absolutely straight and the trajectories of the electrons in the extraction zone more parallel to each other.
  • the improvement is based on the following considerations.
  • the improvement involves making these electrons pass into cylindrical conduits whose cross-section is small and whose length is rather great.
  • the mesh of the screen-grid and the mesh of the polarized grid have identical forms and are placed one above the other so as to make up cylindrical studs. But, to obtain a large electrical field without using very great potential differences, we must move the grids closer together which damages the parallel arrangement of the trajectories of the electrons.
  • an electron gun thus improved involving an emitting cathode, a control grid, an acceleration anode, and in which the place where the physical phenomenon of the extraction of the electrons occurs is separated from the place where the physical phenomenon of the acceleration of these electrons occurs by placing each of these phenomena in an electrically defined space, the spaces being contiguous and their separation being perfectly defined is characterized by the fact that the extraction place is constituted by the assembly of several identical emitting cathodes, each having its own heating unit and the place of acceleration is constituted by a grid that is polarized with respect to the emitting cathodes, said grid being very thick and, in front of each of the emitting cathodes, representing a cylindrical conduit with a relatively narrow cross-section, the direction of said conduits being that of the axes of emission of the cathodes and the axes of emission of the cathodes and of the cylindrical conduits converging at a point situated on the axis of the acceleration anodes.
  • the advantage offered by the electron gun, thus improved, is that the speeds of emission of the electrons in the elementary guns are made more uniform than in the modular single gun described in U.S. Pat. application No. 818,735. In the improved gun it is therefore easier to concentrate the electrons on the entrances of the conduits hollowed out in the control grid.
  • Another advantage of the improved electron guns is to constitute rather very narrow and relatively long conduits which force the path of the electrons to be parallel and to constitute very essentially monokinetic electron flows.
  • Another advantage is the ability to concentrate on the level of the acceleration anode and on the axis of this anode all of the electron beams coming from elementary guns and the ability to obtain great electrical power in the overall beam of the modular gun.
  • the gun of the present invention involves a tight cylindrical metallic gear-case l in which it is possible to create a vacuum and whose axis is that of the modular gun.
  • a crown 2 attached to the wall of gear-case 1 serves as support for a circular support 3, made of insulating material, which carries a metallic socket 4 involving wide openings allowing passage to the electrical conductors to which voltage is applied.
  • the gun has six elementary guns 6, only two of which are visible in the figure and which are arranged around the axis of the gear-case in such a fashion that their axes are in planes passing through said axis and constituting angles of 60 among themselves, the axes of the elementary guns forming an angle of 20 with the axis of the gear-case.
  • the refractory blocks 9 carry the heating units made up, in the example considered, of the heating windings or filaments 11 of the elementary guns which are connected in parallel to conductors 12 and 13.
  • Metal tubes 14, which have the same axis as the corresponding elementary gun, are attached to in sulating sleeves 10.
  • Each of the tubes 14 is closed off by a pellet 16 made up of a material for emitting hot electrons.
  • the interior of each pellet 16 has the shape of a spherical segment.
  • a thick and circular grid 18 is attached to the side of case 5 so that the axis of this grid may be situated in the proximity of the cathodes of guns 6.
  • Cylindrical conduits 19, with a small cross-section, are formed in the grid 18 so that the axis of each one of them coincides with the axis of the adjacent elementary gun 6.
  • a circular anode 20 is attached to gear-case l.
  • a conical conduit 21 is perforated in the anode 20 so that its axis coincides with that of gear-case l and so that the axes of the elementary guns 6 pass through a common point on the axis of the gear-case situated at the entrance to conduit 21.
  • anode 20 is grounded.
  • Grid 18 is brought by conductor 7 and case to a potential of 40,000 V with respect to the ground, and cathodes 16 are brought, by conductor 15, to a potential of 5,000 V with respect to grid 18.
  • Filaments ll are brought to a potential of 3,000 V with respect to the cathode by conductors l2 and 13.
  • the electrons come out of cathodes 16 and are forced back toward the axis of these cathodes by concentrators 17.
  • the electrical field between cathodes 16 and grid 18 is large and the electrons take on a relatively great speed and penetrate into conduits 19.
  • the electrons, whose trajectories are not parallel to the axis of passages 19, are captured by grid 18 which can be cooled by the circulation of a fluid (not shown). Finally, essentially monokinetic parallel electron flows emerge from this grid.
  • This improved electron gun can have many applications in metallurgy for melting or heating operations requiring very great power as well as for all other operations requiring a very strong energy density concentrated in the form of a narrow and orientable beam.
  • An electron triode gun comprising an emitting cathode formed of several annularly spaced, identical tubular modules, each provided with a heating means and an emitting surface, a single very thick control grid disposed adjacent to said modules and having converging openings of small cross section therethrough in alignment with said emitting surfaces to receive electrons therefrom, and an acceleration anode disposed adjacentto said control grid and positioned on the side thereof opposite to said modules, said anode having an opening therethrough positioned to receive the electrons passing through said converging gn'd openings, the axes of said grid openings converging at a point situated on the axis of said anode opening, and each of said modules being disposed at an angle to the axis of said anode opening so that the electrons from said emitting surfaces are directed in a converging manner through said grid openings to a point situated on the axis of said anode opening, the extraction of the electrons being effected in the space between the cathode and the control grid, and the
  • each of said modules comprises an emissive pellet surrounded by a concentrator.

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  • Electron Sources, Ion Sources (AREA)
US59224A 1969-07-29 1970-07-29 Triode electron gun with positive grid and modular cathode Expired - Lifetime US3663853A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR6925987A FR2030536A6 (enrdf_load_stackoverflow) 1969-07-29 1969-07-29

Publications (1)

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US3663853A true US3663853A (en) 1972-05-16

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US59224A Expired - Lifetime US3663853A (en) 1969-07-29 1970-07-29 Triode electron gun with positive grid and modular cathode

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US (1) US3663853A (enrdf_load_stackoverflow)
DE (1) DE2037629A1 (enrdf_load_stackoverflow)
FR (1) FR2030536A6 (enrdf_load_stackoverflow)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4529048A (en) * 1982-10-06 1985-07-16 Megadiamond Industries, Inc. Inserts having two components anchored together at a non-perpendicular angle of attachment for use in rotary type drag bits
IL119841A (en) * 1996-12-16 2000-02-29 Iscar Ltd Cutting inserts

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2803778A (en) * 1947-03-06 1957-08-20 Philips Corp Device for generating electrical oscillations
US3107313A (en) * 1959-10-30 1963-10-15 Johann R Hechtel Velocity modulated electron tube with cathode means providing plural electron streams
US3497743A (en) * 1967-06-16 1970-02-24 United Aircraft Corp Annular multiple beam contoured cathode device
US3558967A (en) * 1969-06-16 1971-01-26 Varian Associates Linear beam tube with plural cathode beamlets providing a convergent electron stream

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2803778A (en) * 1947-03-06 1957-08-20 Philips Corp Device for generating electrical oscillations
US3107313A (en) * 1959-10-30 1963-10-15 Johann R Hechtel Velocity modulated electron tube with cathode means providing plural electron streams
US3497743A (en) * 1967-06-16 1970-02-24 United Aircraft Corp Annular multiple beam contoured cathode device
US3558967A (en) * 1969-06-16 1971-01-26 Varian Associates Linear beam tube with plural cathode beamlets providing a convergent electron stream

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Publication number Publication date
DE2037629A1 (de) 1971-02-04
FR2030536A6 (enrdf_load_stackoverflow) 1970-11-13

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