US3201640A - Electron gun in the form of a multipactor - Google Patents

Electron gun in the form of a multipactor Download PDF

Info

Publication number
US3201640A
US3201640A US178129A US17812962A US3201640A US 3201640 A US3201640 A US 3201640A US 178129 A US178129 A US 178129A US 17812962 A US17812962 A US 17812962A US 3201640 A US3201640 A US 3201640A
Authority
US
United States
Prior art keywords
electrode
electrons
anode
cathode
electron
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
US178129A
Other languages
English (en)
Inventor
Philo T Farnsworth
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.)
TDK Micronas GmbH
International Telephone and Telegraph Corp
Original Assignee
Deutsche ITT Industries GmbH
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
Priority to NL289897D priority Critical patent/NL289897A/xx
Priority to BE629274D priority patent/BE629274A/xx
Application filed by Deutsche ITT Industries GmbH filed Critical Deutsche ITT Industries GmbH
Priority to US178129A priority patent/US3201640A/en
Priority to GB8317/63A priority patent/GB1030708A/en
Priority to DE19631464682 priority patent/DE1464682A1/de
Priority to FR927150A priority patent/FR1354373A/fr
Application granted granted Critical
Publication of US3201640A publication Critical patent/US3201640A/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
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/48—Electron guns
    • H01J29/481—Electron guns using field-emission, photo-emission, or secondary-emission electron source
    • 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
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/48—Electron guns
    • H01J29/482—Electron guns using electron multiplication

Definitions

  • the present invention relates to an electron gun, and more particularly to an electron gun for use in a cathode ray or similar tube and having high perveance and mutual conductance characteristics.
  • Conventional electron guns comprise a thermionic cathode as a source of electrons, a control electrode for varying beam current, and a set of focusing electrodes for focusing the beam.
  • the perveance of such guns is dependent upon the electron-emitting capabilities of the cathode inasmuch as perveance is defined in the general case as beam cui-ent divided by the three-halves power of the laccelerating anode voltage.
  • the mutual conductance of such guns is also dependent upon the electronemitting capabilities of the cathode, since it is defined as the change in beam current obtained by a given change in voltage on the control electrode.
  • perveance and mutual conductance have values which are limited by cathode eiiciency.
  • high values of perveance and mutual conductance are obtained by providing an electron emitter of exceptionally high eiiiciency whereby an extremely high density beam is generated in the first instance for control by the control and accelerating electrodes.
  • This electron emitter takes the form of an electron multiplier or multipactor wherein a high intensity electron space current is generated and controlled in such a manner as to form a high density electron beam of small cross-section.
  • an electron gun comprising a cathode having an extended active surface capable of emitting secondary electrons a-t a ratio greater than unity, an annular anode which is spaced from and disposed opposite said active surface, an electrode disposed on the side of said anode opposite said cathode and having an aperture therethrough, the area of the active surface being larger than the area of the aforementioned aperture, means including the cathode, the anode and the aforesaid electrode for converging electrons from the cathode active surface toward the aforesaid electrode in the vicinity of said aperture, means electrically connecting the cathode and electrode together, means for imposing an oscillating potential between the anode and the cathode and electrode of a frequency having a half period approximately equal to electron transit time (or an odd multiple of this frequency) between the cathode and electrode, the oscillating potential being of such magnitude as to impart to electrons a velocity suicient to cause secondary emission from said active surface
  • FG. l is a longitudinal sectional illustration of one embodiment of this invention.
  • FIG. 2 is a similarillustration of another embodiment of this invention.
  • FIG. 3 is a geometric illustration of the electron optics and is used in explaining the operating principles thereof.
  • FIG. 4 is a graph used in explaining the operation of the invention.
  • an evacuated glass envelope 1 shown in part section, is of the conventional shape employed in cathode ray display tubes.
  • an electron gun In the neck portion 2 of the envelope is mounted an electron gun, this gun comprising, in general, a subassembly for generating and emitting electrons, a control electrode, and focusing and accelerating electrodes.
  • the electron-emitting subassembly is, in the general sense, an electron multiplier or multipactor and comprises a cathode or electrode 3 mounted in the left-hand end of the envelope neck 2, an anode ring 4 mounted opposite the cathode 3, and an end electrode 5 mounted on the side of the anode 4 opposite the cathode 3. All of these parts are symmetrically formed about the tube axis 6.
  • Cathode 3 has an active surface 7 which is spherically concave inwardly toward the anode 4 and has its center of curvature on the axis 6.
  • the cathode sould be fabricated of a material having a secondary emission ratio of greater than unity, beryllium copper being an example.
  • the anode 4 is formed of metal and is securely mounted in the neck 2 of the tube envelope. It is provided with a frusto-conically shaped opening 8 which is coaxial about the axis 6, the larger diameter end 9 facing the cathode 3 and the smaller diameter end 1t) facing the electrode 5.
  • the electrode 5 is a metallic disc securely mounted in the neck 2 and is provided with a centrally projecting convex portion 11 having a coaxial aperture 12 therethrough.
  • This electrode S may be formed of a metal having a secondary emission greater than unity; however, as will appear from the following description, this emission characteristic is not absolutely necessary.
  • the remaining elements in the electron gun to the righthand side of the electrode 5 are conventional, the first one being a control electrode 13 secured in the neck 2 and having a coaxial limiting aperture 14 therethrough. Adjacent to this is mounted an accelerating anode structure 15 having a pair of limiting apertures i6.
  • anode 15 To ⁇ the right-hand side of the anode 15 'may be mounted the usual additional electrodes utilized in electron guns of cathode ray tubes.
  • the cathode 3 and electrode 5 are electrically connected together through a resonant tank circuit 13 having the center tap grounded as shown.
  • a coil 19 constitutes a part of a radio frequency voltage input circuit and is coupled directly to the tank circuit 18 as shown.
  • A. power supply or battery 2@ has its positive terminal connected to the anode 4 and the negative terminal.
  • the control electrode 13 has the usual biasing potentiais applied thereto and also means for coupling an input signal.
  • a biasing battery 2i has its positive terminal grounded as shown and a potentiometer 22 connected thereacross which is coupled to the control electrode 13.
  • An accelerating anode battery or power supply 23 has its positive terminal connected to the anode and the negative terminal grounded.
  • an oscillatory electron space current is developed between the two end plates or cathode 3 and electrode 5 of the electron multiplier or multipactor section of the electron gun.
  • a certain portion of this space current which occupies the conically shaped region between the two electrodes 3 and 5 penetrates through the aperture l2 and preferably is focused onto a cross-over point in the aperture 14 of the control electrode 13. From this point forward, the electrons are formed into a pencil-like beam by the apertures i4 and 16 in the usual manner.
  • the formation and control of the beam after it leaves the control electrode 13 is conventional, only that portion of the structure to the left-hand side of the control electrode 13 needs to be described and elaborated further.
  • operation of the multipactor section of the electron gun is based upon electrons oscillating back and forth between the cathode 3 and electrode 5 and releasing additional electrons by repeated impacts with the cathode 3. If the electrode 5 is fabricated of material having a secondary emission ratio greater than unity, impacts of electrons with this electrode will also result in the creation of secondary electrons.
  • the impacts are with the cathode 3 and in part with the electrode 5, and the multiplication occurs by secondary electron emission from either the cathode 3 or electrode 5 or both.
  • a high frequency potential which may be of the order of SO-megacycles, is applied between the cathode 3 and electrode 5, this potential being preferably relatively small as compared with the direct potential of the battery 2l) on the anode 4.
  • electrons present in the tube strike at least the active surface 7 of the cathode 3, liberating secondary electrons, which are accelerated toward the opposite electrode 5 by the anode potential 20.
  • the electrode 5 is provided with a coaxial aperture 12, it is obvious that electrons approaching this aperture which would otherwise strike the electrode 5 will penetrate through the aperture and pass onward to the control electrode 13.
  • the electrode S can be considered as being solid for the purpose of determining what happens between this electrode .and the cathode 3.
  • FIG. 4 wherein the .anode to cathode voltage is represented by the graph.
  • the straight line 24 represents the anode potential as .applied by the battery 20.
  • the sine wave Z5 represents the oscillating potential applied between the electrodes 3 and 5 via the coil 19.
  • the oscillating potential 25 as superimposed upon the constant potential 24 provides a varying potential between the anode 4 and each of the electrodes 3 and 5.
  • the secondary electrons then travel backwardly toward the anode 4 and electrode 5, reaching the electrode 5 at the end of the next half period, following which the electrons are again returned toward the cathode 3 to impact the same so as to liberate more secondaries.
  • This action continues until the number of electrons multiplies to an equilibrium value as determined, in general by space charge at the cathode 3 and electrode S which prevents all but the faster secondary electrons from escaping therethrough.
  • the space current between the electrodes 3 and 5 becomes stabilized. It is thus seen that the space current in the chamber between the two electrodes 3 and 5 builds to an unusually high value in comparison to the current iowing to the lanode 4.
  • This point A is chosen on the periphery of the cathode surface 7 for the reason that it represents an external ray and one for which the probability of striking anode 4 is greatest.
  • This electron is accelerated along the radius AC of the active surface 7.
  • a divergent lens at the opening 9 of the anode cone 8 refracts the electron away from the cone axis so that it leaves the cone along the line BD. This lens is divergent, because the electron moves from Ia region of high gradient into a region of lower gradient.
  • the electron path EF is not quite along a radius. There is a small component of non-radial velocity directed toward the axis of the cone. The electron is reflected from the cathode 3 but retains the non-radial component of velocity.
  • the space charge which develops when the number of released electrons becomes very large drives the peripheral electrons, i.e., the electrons more remote from Ithe center of the cloud traversing the chamber, toward the anode, making their collection by the anode possible.
  • the electron optics as just explained in connection with iFIG. 3, the electron can be guided between the two electrodes 3 and 5 for a repeated number of trips before they eventually will be collected by the anode 4.
  • This multiplication process continues until the number of electrons collected -by the anode 4 equals the number of secondaries being emitted from the active surface 7.
  • the electrons in the beams formed between the two diametrically opposite electrodes 3 and 5 have periods of oscillation and t-ransit time which are related to the D.C. anode voltage and the frequency of the radio -frequency voltage applied between the cathode 3 and the electrode 5, the frequency of this voltage being adjusted to correspond.
  • the electrons leaving either the cathode 3 or electrode S at one instant of time absorb power from the field established by the radio frequency voltage andthe oneS leaving at another instant of time give up energy to the field.
  • the electrons are said to be in-phase with .the applied voltage, whereas in the latter instance they are out-of-phase.
  • the electrons oscillate between the two electrodes 3 and 5 at approximately the same frequency as the radio frequency ⁇ and they make one trip between the electrodes in a half period of the radio frequency.
  • the fact that the electrons are so accelerated insures that they strike the 'active surface .-7.
  • the returning electrons also make the trip in slightly less than one-half cycle. The result is that the fastest electrons very rapidly get out of phase with the radio frequency voltage.
  • the process results in electrons being fed from the multiplication phase (in-phase) into the oppos-ite phase wherein an electron is decelerated rather than accelerated by the radio frequency. Electrons in this phase do not strike the electrodes 3 and 5 at all, but continue to oscillate between them, delivering energy to the external .circuit as they are slowed down by the radio frequency.
  • This 'action is a phenomenon well known in the art of elect-ron multipliers of the multipactor type, typical multipactors being disclosed in my Patents Nos. 2,189,358, 2,107,782 and 2,071,515.
  • the electrons which are in-phase have .an oscillatory swing which carries for a distance greater than that between the two facing electrodes 3 and 5 such that .the electrons impact the active surface 7 with enough force t0 eject secondaries and to provide electron multiplacation; however, the out-of-phase electrons will be decelerated and will never quite reach the electrode surfaces.
  • the decelerated electrons do not -strike the electrodes 3 and 5 but continue to oscillate between them and in doing so form a space charge which results in potential minima in front of the facing surface, the position of which being indicated by the dashed liners 27 and 28, respec-tively.
  • Other groupsof ele-ctrons which do not have as great an oscillatory swing will be reflected inwardly of the surfaces 27 and 28.
  • the electrode 5 will appear as a solid plate.
  • those electrons having a swing sufficient to impact the active surface 7 and also to penetrate the surface 28 will pass through the aperture 12 and will converge into ⁇ the aperture 14 of the control elect-rode 13. From this point forward, the electrons are collected into a pencil-like beam and are handled conventionally by the various accelerating, focusing and deflecting 4electrodes in a .cathode ray tube.
  • FIG. 2 A second and preferred embodiment of the invention is illustrated in FIG. 2 wherein like numerals indicate like parts.
  • the multipactor composed of the cathode 3, the anode 4 and the electrode 5 are encased in .a resonant cavity .as generally indicated by the numeral 29.
  • the cavity 29 preferably is of cylindrical conguration and has two opp-osite end plates 3u and 31 which are spaced apart and parallel.
  • the cavity 29 is of course made out of metal such that it is electrically conductive from one end to the other.
  • the cathode 3 is conductively mounted securely in the end plate 30, and the electrode 5 is similarly mounted in the end plate 31.
  • the Acathode 3 and the electrode 5 are electrically ⁇ connected together. They are otherwise spaced apart and disposed with respect to each other .and the anode 4 the same as already described in connection with the embodiment of FIG. 1.
  • the anode 4 is supported inside the resonant cavity 29 by means of an annular support 32 of insulating materlal.
  • a wire 33 feeds through the end plate 3) and is soldered to the inside wall ofthe cavity 29 for the purpose of applying a ⁇ radio frequency voltage to the cavity 29.
  • the multipactor portion of the elec-tron gun operates the same as that already described in connection with FIG. 1. The only difference in operation resides in the fact that this multipactor of FIG. 2 is excited by means of the oscillating field set -up inside the resonant cavity 29, the cavity itself being excited by loop 33. The intense beam emerges from the aperture 12 and is concentrated in the region of the aperture 14 of the control electrode 13, thereby producing a high density beam of small crosssect-ion already described.
  • Invan electron gun comprising an envelope, a pair of spaced-apart electrodes therein, a first of said electrodes being adapted to emit secondary electrons on impact by a primary electron, a second of said electrodes having an aperture through which electrons may flow, means for converging said electrons toward said second electrode in the vicinity of said aperture, said means including a concave surface on said first electrode, an intermediate electrode having a conically shaped opening tapering toward said aperture, an oscillatory circuit connected to said pair of electrodes, means for supplying alternating current to said oscillatory circuit to cause said electrons to oscillate between said pair of electrodes and to make repeated secondary electron-generating impacts with said first electrode and cause a portion of said electrons to penetrate said aperture.
  • a cathode having an extended active surface capable of emitting secondary electrons at a ratio greater than unity
  • an electron permeable anode having a first aperture and disposed opposite said cathode, an electrode disposed on the side of said anode opposite said cathode and having a second aperture therethrough, the area of said active surface being larger than the area of said second aperature
  • means including said cathode, said anode and said electrode for converging electrons from said active surface toward said electrode in the vicinity of said second aperture and means applying a positive potential to said anode with respect 'to said cathode and said electrode for oscillating electrons between said cathode and said electrode
  • a cathode having an extended active surface capable of emitting secondary electrons at a ratio greater than unity, an anode of annular shape positioned opposite said active surface, an electrode disposed on the side of said anode opposite said cathode and having an aperture therethrough, said active surface being concave facing said anode and having a center of curvature on the axis of said anode, said electrode being convex facing said anode with said aperture coaxial with said axis, said anode having a frusto-conically shaped second aperture wherein the larger diameter portion is adjacent to said active surface and the smaller diameter portion is adjacent to said electrode, said cathode surface and anode and electrode apertures having progressively diminishing areas; constituting an electron lens which converges electron flow from said active surface 'toward said electrode in the vicinity of said aperture, and a control element disposed on the side of said electrode opposite said anode, said control element having a beamforming aperture coaxial with said axis.
  • a cathode having an extended active surface capable of emitting secondary electrons at a ratio greater than unity, an anode of annular shape positioned opposite said active surface, an electrode disposed on the side of said anode opposite said cathode and having an aperture therethrough, said active surface being spherically concave facing said anode and having a center of curvature on the axis of said anode, said electrode being convex facing said anode with said aperture coaxial with said axis, said anode having a frusto-conically shaped inner periphery wherein the larger diameter portion is adjacent to said active surface and the smaller diameter portion is adjacent to said electrode, said cathode, anode and electrode constituting an electron lens which converges electron flow from said active surface toward said electrode in the vicinity of said aperture, means for applying a constant positive potential to said anode with respect to said cathode and said electrode for oscillating electrons between the latter, and means for imposing an oscillatory potential
  • an electron gun comprising an envelope, a cathode having an extended active surface capable of emitting secondary electrons at a ratio greater than unity, an anode of annular shape positioned opposite said active surface, an electrode disposed on the side of said anode opposite said cathode and having an aperture therethrough, said active surface being spherically concave facing said anode and having a center of curvature on the axis of said anode, said electrode being convex facing said anode with said aperture coaxial With Vsaid axis, said anode having a frustoconically shaped inner periphery wherein the larger diameter portion is adjacent to said active surface and the smaller diameter portion is adjacent to said electrode, said cathode, anode and electrode constituting an electron lens which converges electron ow from said active surface toward said electrode in the vicinity of said aperture, a resonant cavity having conductive Walls with opposite ends closed within the envelope, said cathode and said electrode being mounted in said ends, respectively, and electrical
  • an electron gun comprising an envelope, a cathode having an extended active surface capable of emitting secondary electrons at a ratio greater than unity, an anode of annular shape positioned opposite said active surface, an electrode disposed on the side of said anode opposite said cathode and having an aperture therethrough, said active surface being spherically concave facing said anode and having a center of curvature on the axis of said anode, said electrode being'convex facing said anode with said aperture coaxial with said axis, said anode having a frusto-conically shaped inner periphery wherein the larger diameter portion is adjacent to said active surface and the smaller diameter portion is adjacent to said electrode, said cathode, anode and electrode constituting an electron lens which converges electron flow from said active surface toward said electrode in the vicinity of said aperture, a resonant cavity having conductive walls of cylindrical shape enclosed within said envelope with opposite ends which are substantially flat and parallel, said cathode and electrode being mounted in said

Landscapes

  • Electron Sources, Ion Sources (AREA)
  • Particle Accelerators (AREA)
  • Microwave Tubes (AREA)
US178129A 1962-03-07 1962-03-07 Electron gun in the form of a multipactor Expired - Lifetime US3201640A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
NL289897D NL289897A (es) 1962-03-07
BE629274D BE629274A (es) 1962-03-07
US178129A US3201640A (en) 1962-03-07 1962-03-07 Electron gun in the form of a multipactor
GB8317/63A GB1030708A (en) 1962-03-07 1963-03-01 Electron gun
DE19631464682 DE1464682A1 (de) 1962-03-07 1963-03-06 Elektronenstrahlerzeugungssystem
FR927150A FR1354373A (fr) 1962-03-07 1963-03-07 Canon à électrons

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US178129A US3201640A (en) 1962-03-07 1962-03-07 Electron gun in the form of a multipactor

Publications (1)

Publication Number Publication Date
US3201640A true US3201640A (en) 1965-08-17

Family

ID=22651321

Family Applications (1)

Application Number Title Priority Date Filing Date
US178129A Expired - Lifetime US3201640A (en) 1962-03-07 1962-03-07 Electron gun in the form of a multipactor

Country Status (5)

Country Link
US (1) US3201640A (es)
BE (1) BE629274A (es)
DE (1) DE1464682A1 (es)
GB (1) GB1030708A (es)
NL (1) NL289897A (es)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3457490A (en) * 1965-02-25 1969-07-22 Lockheed Aircraft Corp Multipactor rectifier
US3521146A (en) * 1964-12-17 1970-07-21 Gen Electric Microwave power rectifier with multipactor discharge
US3543135A (en) * 1964-12-09 1970-11-24 Hughes Aircraft Co Microwave to electrical energy converter utilizing multipactor discharge between differing secondary electron emissive surfaces
US3649868A (en) * 1969-03-31 1972-03-14 Thomson Csf Pulse electron gun
US3718836A (en) * 1970-11-18 1973-02-27 Itt Multipactor ion generator
US20050253837A1 (en) * 2002-07-09 2005-11-17 Koninklijke Philips Electronics N.V. Matrix display device

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL8403537A (nl) * 1984-11-21 1986-06-16 Philips Nv Kathodestraalbuis met ionenval.
US8159118B2 (en) 2005-11-02 2012-04-17 United Technologies Corporation Electron gun

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2240713A (en) * 1936-07-07 1941-05-06 Aeg Electron multiplier
US2416303A (en) * 1941-02-05 1947-02-25 Bell Telephone Labor Inc Secondary emissive shell resonator tube
US2817033A (en) * 1955-04-08 1957-12-17 Hughes Aircraft Co Electron gun

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2240713A (en) * 1936-07-07 1941-05-06 Aeg Electron multiplier
US2416303A (en) * 1941-02-05 1947-02-25 Bell Telephone Labor Inc Secondary emissive shell resonator tube
US2817033A (en) * 1955-04-08 1957-12-17 Hughes Aircraft Co Electron gun

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3543135A (en) * 1964-12-09 1970-11-24 Hughes Aircraft Co Microwave to electrical energy converter utilizing multipactor discharge between differing secondary electron emissive surfaces
US3521146A (en) * 1964-12-17 1970-07-21 Gen Electric Microwave power rectifier with multipactor discharge
US3457490A (en) * 1965-02-25 1969-07-22 Lockheed Aircraft Corp Multipactor rectifier
US3649868A (en) * 1969-03-31 1972-03-14 Thomson Csf Pulse electron gun
US3718836A (en) * 1970-11-18 1973-02-27 Itt Multipactor ion generator
US20050253837A1 (en) * 2002-07-09 2005-11-17 Koninklijke Philips Electronics N.V. Matrix display device

Also Published As

Publication number Publication date
BE629274A (es)
DE1464682A1 (de) 1968-12-05
GB1030708A (en) 1966-05-25
NL289897A (es)

Similar Documents

Publication Publication Date Title
US2632130A (en) High current density beam tube
US3453482A (en) Efficient high power beam tube employing a fly-trap beam collector having a focus electrode structure at the mouth thereof
US3201640A (en) Electron gun in the form of a multipactor
US2452075A (en) Velocity modulation electron discharge tube
US2411913A (en) Electron discharge device
US2852715A (en) High frequency structure
US2852716A (en) Cathode ray tube and electron gun therefor
US2071515A (en) Electron multiplying device
US3432722A (en) Electromagnetic wave generating and translating apparatus
US3780336A (en) High power beam tube having depressed potential collector containing field-shaping probe
US3312857A (en) Microwave amplifier utilizing multipaction to produce periodically bunched electrons
US3258633A (en) High density plasma generator
US3700945A (en) High power pulsed electron beam
US2517726A (en) Ultra high frequency electron tube
US3649868A (en) Pulse electron gun
US3274507A (en) Electron beam plasma amplifier with a wave-guide coupling
US2794931A (en) Retarding field oscillators
US2794146A (en) Ultra-high frequency amplifying tube
US4087720A (en) Multi-beam, multi-aperture ion sources of the beam-plasma type
US2936393A (en) Low noise traveling-wave tube
US3210669A (en) Charged particle flow control apparatus
US3772551A (en) Cathode ray tube system
US2886738A (en) Electron beam system
US2867687A (en) Cathode ray reproduction tube having auxiliary function of synchronizing signal separation
US2801362A (en) Amplification of microwaves