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US3500110A - Noncurrent intercepting electron beam control element - Google Patents

Noncurrent intercepting electron beam control element Download PDF

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Publication number
US3500110A
US3500110A US662766A US3500110DA US3500110A US 3500110 A US3500110 A US 3500110A US 662766 A US662766 A US 662766A US 3500110D A US3500110D A US 3500110DA US 3500110 A US3500110 A US 3500110A
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United States
Prior art keywords
grid
electron
electrode
mask
elements
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
US662766A
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English (en)
Inventor
Donald L Winsor
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Raytheon Co
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Raytheon Co
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J25/00—Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons
    • H01J25/02—Tubes with electron stream modulated in velocity or density in a modulator zone and thereafter giving up energy in an inducing zone, the zones being associated with one or more resonators
    • H01J25/04—Tubes having one or more resonators, without reflection of the electron stream, and in which the modulation produced in the modulator zone is mainly density modulation, e.g. Heaff tube
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
    • 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
    • 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
    • H01J3/029—Schematic arrangements for beam forming
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
    • H01J2893/0012—Constructional arrangements
    • H01J2893/0019—Chemical composition and manufacture
    • H01J2893/0022—Manufacture

Definitions

  • Planar laminar flow type electron guns may utilize control elements to assist in the modulation of the electron beam.
  • Such elements are disposed in close proximity to the electron emitter and may comprise a grid-type electrode having an independently variable biasing voltage supply connected thereto with, desirably, a negative bias with respect to the emitter. When said bias is applied no-beam current flows.
  • the device is activated subsequently by application of a positive voltage to the grid electrode of an appropriate waveform, beam current flows and the device functions to amplify and produce output power.
  • Neutralizing means should desirably be provided adjacent to the electron emitter of the gun to offset the effects of a positively biased grid electrode element.
  • a positively biased grid electrode element Such a structure is often referred to in the art as a shadow mask and is biased at the emitter electrode potential. Perfect registry or alignment, however, of the mask and grid electrode is necessary, particularly in the convergent 3,500,110 Patented Mar. 10, 1970 Summary of the invention
  • a grid electrode and shadow mask arrangement to collectively define a control element is provided in such a manner that substantially all electrons emitted from the emitter electrode will pass through the control element without interception and restriction of the average power provided by the electron gun beam.
  • a plurality of diaphragm members is rigidly secured together in a structure tailored to provide the final grid-mask spatial relationship in the over-all gun assembly.
  • the unitary grid electrode and shadow mask assembly is provided with precisely aligned radially extending rib elements of any desired dimension by means of electrically actuated discharge machining of both the grid and mask element in one sequential operation by an accompanying tool bearing the final configuration of the resultant structure.
  • the grid and mask elements In the spherical concave embodiment of a convergent electron gun, the grid and mask elements have differing curvatures of radius oriented to and concentrically disposed about a common point.
  • FIG. 1 is a diagrammatic representation of a prior art traveling wave electron discharge device
  • FIG. 2 is an enlarged partial cross-sectional view of a prior art electron gun assembly of the convergent type
  • FIG. 3 is a diagrammatic presentation of the equipotential planes and electron trajectories of an illustrative high convergence electron gun structure
  • FIG. 4 is a schematic representation illustrative of the sitting of the grid and mask electrode elements in the nonuniform electric field configuration of a convergent electron gun wherein the 0 as well as the trajectory components must be resolved;
  • FIGS. 5A and 5B are, respectively, front elevational and cross-sectional views of an illustrative grid-mask structure in accordance with the present invention.
  • FIG. 6 is a schematic view of the reference lines to assist in an explanation of the invention.
  • FIG. 7 is a cross-sectional view of a component of the over-all grid-mask assembly in one of the stages of fabrication
  • FIG. 8 is an exploded view illustrative of the method of fabricating the illustrative embodiment of the invention.
  • FIG. 9 is a cross-sectional view of the completed machined grid-mask assembly components in one of the subassembly stages.
  • FIG. is a perspective view, partially broken away, showing the principal elements of the electron gun of the present invention.
  • FIG. 1 of the drawings a schmatic representation of a traveling wave tube embodiment is shown and designated 10.
  • a slow wave periodic electromagnetic energy propagating structure in the form of a helix 12 is aligned along the longitudinal axis of an envelope 14.
  • the wave propagating structure may, of course, assume any of the well known periodic structure configurations such as a ring and bar line, interdigital finger delay line, coupled cavity line, or a bifilar helix, as desired.
  • the electron beam generation means 16 is disposed at one end of the tube envelope to propel and direct an electron beam designated collectively by the numeral 18. Surrounding the over-all tube envelope is the magnetic field producing means 20.
  • a longitudinal magnetic field parallel to the path of the electron stream is provided by the magnetic means 20 which may comprise a permanent magnet or electromagnetic solenoid arangement.
  • Microwave energy is coupled into and out of the respective ends of the slow wave structure by an input transmission line 22 and an output transmission line 24.
  • the electron beam generation means 16 comprises an emissive cathode member 26 having an internal heater coil 28 with conventional leads 30 and 32 extending through the tube envelope for connection to an appropriate voltage supply.
  • Anode member 34 is disposed in the intermediate region between the input end of the slow wave periodic structure and the electron beam generation means. This member is conventionally provided with a sufiiciently high positive voltage to accelerate and direct the emitted electrons formed in a beam of the desired configuration along the interaction path adjacent to the slow Wave structure.
  • a grid control member 36 is disposed in close proximity to the emissive cathode member and is suitably biased by a voltage supply 38 connected by means of lead 40 to the grid electrode. The supply 38 may be varied from a negative to a positive biasing potential with respect to the cathode electrode.
  • a collector electrode 42 is disposed adjacent to the opposing end of the envelope and provides a terminal for the electron beam traversing the longitudinal axis of the device.
  • FIG. 2 a convergent electron gun assembly 44 is disclosed.
  • a spherical concave emitting surface 46 at the outer end of cathode electrode member 48.
  • a heater coil 50 is supported on a rod member 52 to indirectly heat the emissive surface.
  • an anode member 54 biased positively with respect to the cathode electrode adjacent to the emitting surface and provided with a central aperture 56 conforms and shapes the thermal electrons into a beam of reducing diameter represented by the numeral 58.
  • a beam-forming electrode 60 surrounds the emitting surface. This electrode creates a potential along the edge of the electron beam which desirably matches as nearly as possible the theoretical potential inside the beam. Ceramic member 62 supports the beam-forming electrode and inwardly extending diaphragm or lip 64 assists in exerting the constrictive forces on the electron beam. Generally the beamforming electrode is biased at the cathode potential by the voltage supply means 66 also connected to the anode electrode 54.
  • the illustrative electron gun is referred to in the art as the Pierce electron gun. Appreciably high perveance which is defined as the ratio of total beam cur rent to the three halves power of the beam voltage may be realized with this structure. Expressed in terms of amperes/volts values in the order of 5.9 10 may be attained.
  • FIG. 3 a theoretical calculated plot of the electron trajectories 68 and equi-potential planes 70 for a high convergence electron gun having an emitter surface 72, anode electrode 74 with central aperture 76 and focusing element 78 is displayed.
  • the lack of orthogonality is evident and is nearly always present in an electron gun which produces a well behaved resulting electron beam.
  • This lack of orthogonal electron flow from the emitter surface makes the design and sitting of a nonelectron intercepting grid, other than as described herein, most difiicult.
  • FIG. 4 reference numerals relating to similar structure shown in FIG.
  • the radius 82 and symbol r indicates the radius of the emitter surface 72 from a focal point along the electron beam axis 80.
  • a honeycomb grid electrode disposed adjacent to the emitter surface illustratively comprising elements may utilize such elements provided in the plane 86 as well as the 0 plane 88.
  • a mask 92 would be required in an offsetting relationship to neutralize the force of the grid potential. Any grid-mask structure, therefore, will require complex calculations of the spatial relationship and each gun would have to be carefully individually tailored.
  • the problem is further amplified by the fact that the critical spatial orientations must be maintained at the elevated temperatures at which the electron gun is conventionally operated.
  • the present invention teaches the provision of a substantially perfect registration of the grid-mask elements utilizing solely the directed elements which leads to the provision of a unitary structure in a spherical concave embodiment having a bursting sunrise effect when viewed in a front elevation.
  • a grid-mask assembly comprises two juxtapositioned diaphragms 94 and 96 having pie-shaped segmented openings 98 in each of the concave surfaces. Between each of the piece-shaped openings a radially extending rib element 100 is defined. Further, an aperture 102 may be provided in the composite grid-mask assembly through the technicque of fabrication.
  • FIG. 6 explains the orientation of the rib elements with respect to the beam axis 80 and the spherical configuration along the plane referred to by the symbol and numeral 86 will be evident. The orthogonal axis 88 would have no grid elements disposed therealong.
  • an exemplary structure of solid diaphragm members 104 and 106 of a high temperature resistant metal such as, for example, molybdenum, is maintained in the desired shape during the forming operation to provide the spherical concave surface by member 108 of a relatively softer metal such as copper sandwiched between the diaphragms.
  • a high temperature resistant metal such as, for example, molybdenum
  • FIG. 8 the components of a suggested method of processing are illustrated.
  • the substantially rigid concave metallic diaphragms 104 and 106 are permanently secured, illustratively by brazing, to a cylindrical support member 112 which forms a permanent part of the over-all electron gun assembly.
  • a space 110 between the diaphragms is maintained bycera'rnic spacers 117.
  • a portion of the reentrant passageway 114 is utilized in the final assembly as the beam-forming electrode.
  • a circular lip member not shown for the fsake of clarity in the explanation of the present invention, would be secured to the outer planar surface 115 adjacent the end of the passageway 114 by the similar technique of brazing.
  • the diaphragm members are joined within a recessed portion 116 disposed adjaceht to'the opposing end of the support member 112 and ceramic spacer members 117 and 118 form an integral part of this sub-assembly for providing electrical isolation of the grid members from the cathode member.
  • an annular member 120 secures the lower diaphragm member 106 or what eventually will be considered the mask electrode in position. It is therefore evident that with the diaphragm members securely positioned and the fact that they are fabricated of a rather rigid metal such as molybdenum, it is now permissible to fabricate the diaphragm members as an integral unitary body to secure the final grid-mask structure illustrated in FIGS. A and 5B.
  • a tool or arc element 122 is provided with radially disposed notches 124 together with raised pie-shaped segmented portions 126 disposed therebetween.
  • the notches 124 eventually define the rib elements 100, and the portions 126 provide for the erosion of the pie-shaped segments 98 between the respective radial rib elements.
  • the tool element is a carbon composition and oil is disposed between this element and'the component to be machined to provide for transmission of the high intense electrical arc. Travel of the tool element 122 in the direction indicated by the arrow 128 will cause the erosion of, successively, the diaphragm members 104 and 106 to thereby result in the desired grid electrode member 94 and the mask member 96.
  • FIGS. 9 and a still further evolution in the, manufacture of the electron gun assembly in accordance with the practice of the present invention is noted.
  • the subassembly heretofore described with reference to FIG. 8 has now been modified by the provision of the grid and mask elements 94 and 96 respectively, together with the central aperture 102 and rib elements 100.
  • the subassembly designated generally by the numeral 130 has a further collar member 132 afiixed to, the shoulder 134 defined in the support member 112.
  • the cathode support member 136 having a passageway 138 defining a separate shoulder portion 140 and flange 142 is joined to the subassembly 130.
  • the cathode electron emitter together with a heater coil is supported having a shape and construction closely similar to that shown in FIG. 2 and designated by numerals 46, 48, 50 and 52.
  • Voltage biasing connections may be afiixed to the member 136 at the cathode potential.
  • the mask element 96 may also be biased at this potential.
  • Grid electrode 94 is preferably biased through support member 112 at the slightly positive potential relative to the cathode for optimum convergence.
  • an electron emissive cathode electrode for generating and projecting a converging beam of electrons along a predetermined axis
  • control electrode disposed along said axis in spaced apart relationship from said cathode electrode
  • control electrode defining a plurality of grid elements oriented in a predetermined manner
  • said masking electrode being electrically biased at said cathode electrode potential.
  • grid elements comprise a plurality of substantially rigid radially converging conductive members terminating in an apertured apex portion.
  • controland second electrodes are of a substantially concave spherical configuration.
  • a traveling wave type electron discharge device comprising:
  • a periodic slow wave electromagnetic propagating structure disposed along the longitudinal axis of said envelope
  • a high perveance high convergence ratio electron gun for producing a converging beam of electrons directed along the envelope axis adjacent to said slow wave structure
  • said electron gun comprising an electrically biased electron emitting member
  • a conductive masking member of spherical concave configuration positioned anterior to said emitting member and biased at a"'substantially similar electric potential as said electron gun;
  • said conductive masking member defining a plurality of radially disposed metallic elements with openings therebetween for passage of emitted electrons
  • a grid control electrode of substantially identical configuration and positioned anterior to said conductive masking member and defining a plurality of substantially identical metallic elements in register with the underlying elements;
  • a high perveance high convergence ratio electron gun assembly adapted to produce a converging electron beam having an electron emissive surface, means for directing and projecting emitted electrons along a predetermined path comprising:
  • first and second conductive members of spherical concave configuration spaced apart a rigidly maintained uniform dimension and disposed with said first member nearest to said emissive surface;
  • said conductive members defining substantially identical grid elements with apertures therebetween for passage of electrons;

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US662766A 1967-08-23 1967-08-23 Noncurrent intercepting electron beam control element Expired - Lifetime US3500110A (en)

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Application Number Priority Date Filing Date Title
US66276667A 1967-08-23 1967-08-23

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US (1) US3500110A (fr)
JP (1) JPS4818024B1 (fr)
DE (1) DE1764860B1 (fr)
FR (1) FR1577744A (fr)
GB (1) GB1220630A (fr)
NL (1) NL141700B (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2201535A1 (fr) * 1972-09-28 1974-04-26 Varian Associates
US3818260A (en) * 1973-03-05 1974-06-18 Sperry Rand Corp Electron gun with masked cathode and non-intercepting control grid
US3852633A (en) * 1972-12-13 1974-12-03 Varian Associates Gridded electron gun
US3859552A (en) * 1972-03-02 1975-01-07 Siemens Ag Electron beam generator for transit-time electron discharge tubes
US3963955A (en) * 1974-04-15 1976-06-15 Varian Associates Means and method for suppressing oscillations in electron guns
US4031425A (en) * 1974-10-19 1977-06-21 U.S. Philips Corporation Dispenser cathode for a grid-controlled electron tube and method of manufacturing same
FR2544547A1 (fr) * 1983-04-18 1984-10-19 Litton Systems Inc Canon a electrons
EP0154591A1 (fr) * 1984-03-09 1985-09-11 Thomson-Csf Canon à électrons pour tube électronique
US4634925A (en) * 1983-10-07 1987-01-06 Mitsubishi Denki Kabushiki Kaisha Electron gun for a high power klystron
US5623183A (en) * 1995-03-22 1997-04-22 Litton Systems, Inc. Diverging beam electron gun for a toxic remediation device with a dome-shaped focusing electrode

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4593230A (en) * 1982-03-29 1986-06-03 Litton Systems, Inc. Dual-mode electron gun
US4947467A (en) * 1988-03-24 1990-08-07 Manoly Arthur E Traveling-wave tube slow-wave structure with integral conductively-loaded barrel and method of making same
US5990622A (en) * 1998-02-02 1999-11-23 Litton Systems, Inc. Grid support structure for an electron beam device
GB9809819D0 (en) * 1998-05-09 1998-07-08 Eev Ltd Electron gun assembly
FR2853450B1 (fr) * 2003-04-04 2006-09-08 Thales Sa Grille de commande d'un tube electronique
CN108666188B (zh) * 2013-12-30 2020-06-12 Asml荷兰有限公司 阴极配置、电子枪以及包括此电子枪的光刻系统
JP7533658B1 (ja) * 2023-03-15 2024-08-14 株式会社明電舎 電子ビーム放出構造及び電界放射装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2811667A (en) * 1954-12-09 1957-10-29 Hughes Aircraft Co Electron gun
US2939993A (en) * 1957-01-07 1960-06-07 Gen Electric Traveling-wave tube attenuators
US3195006A (en) * 1960-04-08 1965-07-13 Varian Associates Travelling wave tube output coupling
US3278779A (en) * 1962-05-17 1966-10-11 Rauland Corp Cathode-ray tube having an insulating spacer between the cathode and the control grid
US3377492A (en) * 1965-08-03 1968-04-09 Hughes Aircraft Co Flood gun for storage tubes having a dome-shaped cathode and dome-shaped grid electrodes

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2811667A (en) * 1954-12-09 1957-10-29 Hughes Aircraft Co Electron gun
US2939993A (en) * 1957-01-07 1960-06-07 Gen Electric Traveling-wave tube attenuators
US3195006A (en) * 1960-04-08 1965-07-13 Varian Associates Travelling wave tube output coupling
US3278779A (en) * 1962-05-17 1966-10-11 Rauland Corp Cathode-ray tube having an insulating spacer between the cathode and the control grid
US3377492A (en) * 1965-08-03 1968-04-09 Hughes Aircraft Co Flood gun for storage tubes having a dome-shaped cathode and dome-shaped grid electrodes

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3859552A (en) * 1972-03-02 1975-01-07 Siemens Ag Electron beam generator for transit-time electron discharge tubes
FR2201535A1 (fr) * 1972-09-28 1974-04-26 Varian Associates
US3852633A (en) * 1972-12-13 1974-12-03 Varian Associates Gridded electron gun
US3818260A (en) * 1973-03-05 1974-06-18 Sperry Rand Corp Electron gun with masked cathode and non-intercepting control grid
US3963955A (en) * 1974-04-15 1976-06-15 Varian Associates Means and method for suppressing oscillations in electron guns
US4031425A (en) * 1974-10-19 1977-06-21 U.S. Philips Corporation Dispenser cathode for a grid-controlled electron tube and method of manufacturing same
FR2544547A1 (fr) * 1983-04-18 1984-10-19 Litton Systems Inc Canon a electrons
US4634925A (en) * 1983-10-07 1987-01-06 Mitsubishi Denki Kabushiki Kaisha Electron gun for a high power klystron
EP0154591A1 (fr) * 1984-03-09 1985-09-11 Thomson-Csf Canon à électrons pour tube électronique
FR2561039A1 (fr) * 1984-03-09 1985-09-13 Thomson Csf Canon a electrons pour tube electronique
US4798993A (en) * 1984-03-09 1989-01-17 Thomson-C.S.F. Electron gun for electronic tubes
US5623183A (en) * 1995-03-22 1997-04-22 Litton Systems, Inc. Diverging beam electron gun for a toxic remediation device with a dome-shaped focusing electrode

Also Published As

Publication number Publication date
JPS4818024B1 (fr) 1973-06-02
FR1577744A (fr) 1969-08-08
DE1764860B1 (de) 1971-07-08
GB1220630A (en) 1971-01-27
NL6811981A (fr) 1969-02-25
NL141700B (nl) 1974-03-15

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