US2905844A - Electron discharge device - Google Patents

Electron discharge device Download PDF

Info

Publication number
US2905844A
US2905844A US434467A US43446754A US2905844A US 2905844 A US2905844 A US 2905844A US 434467 A US434467 A US 434467A US 43446754 A US43446754 A US 43446754A US 2905844 A US2905844 A US 2905844A
Authority
US
United States
Prior art keywords
layer
electron
electrons
emissive
dynode
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
US434467A
Other languages
English (en)
Inventor
Ernest J Sternglass
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.)
CBS Corp
Original Assignee
Westinghouse Electric 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
Priority to BE538686D priority Critical patent/BE538686A/xx
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US434467A priority patent/US2905844A/en
Priority to DEW16705A priority patent/DE1037610B/de
Priority to GB15355/55A priority patent/GB792507A/en
Application granted granted Critical
Publication of US2905844A publication Critical patent/US2905844A/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
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/50—Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output
    • H01J31/506—Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output tubes using secondary emission effect
    • 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
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/023—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof secondary-electron emitting electrode arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J43/00—Secondary-emission tubes; Electron-multiplier tubes
    • H01J43/04—Electron multipliers
    • H01J43/06—Electrode arrangements
    • H01J43/10—Dynodes

Definitions

  • This invention relates to electron discharge devices, and more particularly to those devices having secondary electron emissive electrodes.
  • Figure l is a diagrammatic view of an electron multiplier tube embodying my invention.
  • Fig. 2 is a sectional view of a portion of a secondary missive electrode, utilized in the device shown in Fig. 1;
  • Fig. 3 is a front view of the structure shown in Fig. 2.
  • an electron discharge tube comprising an envelope 9 having a cylindrical portion 10 and end plates 13 and 14 positioned at opposite ends thereof.
  • a planar cathode or electron emissive surface 15 is positioned near to or on the end plate 13 and an anode or target element 16 is positioned at the opposite end of the envelope 9 near to or on the end. plate 14.
  • a plurality of the secondary electron emissive electrodes or dynodes 17, 18 and 19 are interspaced. between the cathode 15 and target 16.
  • the planar electron emissive surface 15 positioned near the end plate 13 may be of any suitable type such as thermionic or photoemissive. In my specific embodiment, a photocathode planar surface 15 is utilized as the source of electrons for the discharge device.
  • the photocathode surface 15 may be of a suitable material, such as caesium antimony, capable of emission of electrons upon light impingement.
  • the end plate 13 is of a transparent material such as glass so as to permit passage of light.
  • the photo-emitting surface 15 may be mounted on a suitable supporting transparent conductive surface or may be deposited on the interior surface of the end plate 13. It is desirable in most cases to provide a conductive coating 21 on the end plate 13 prior to the depositing of the photocathode material so as to obtain an electrode for the photo-emitting surface.
  • a suitable transparent conductive coating may be of a material such as Nesa.
  • the target electrode 16 is positioned at the opposite end of the envelope 9 near the face plate 14.
  • the target 16 may be of any electron sensitive material so as to develop a signal representative of the electron bombardment.
  • a phosphor screen is utilized as the target electrode 16 of the electron discharge device.
  • the phosphor screen 16 is of a suitable material such as zinc sulphide which may be placed on a suitable transparent conductive supporting member or deposited on the end plate 14. If the phosphor screen 16 is deposited on the end plate 14 as shown in my specific embodiment, it is desirable that a transparent conductive layer 20 such as Nesa be deposited on the end plate 14 prior to the'phosphor screen 16 to serve as an electrode.
  • the phosphor screen 16 may also be deposited directly on the end plate 14 if desired and a thin electron permeable conductive layer such as aluminum be deposited upon the exposed surface phosphor screen to serve as the voltage electrode.
  • a thin electron permeable conductive layer such as aluminum be deposited upon the exposed surface phosphor screen to serve as the voltage electrode.
  • the aluminum backing will also enhance the light output of the phosphor screen.
  • dynodes 1'7, 18 and 19 Positioned between the cathode 15 and the image screen 16 are a plurality of secondary electron emissive electrodes or dynodes 1'7, 18 and 19 and by way of example, I have shown only 3 dynodes. The number of dynodes Within the envelope 9 is dependent on the amount of amplification desired from the device and a single dynode may be sufficient in some applications.
  • the requisite potential for the electrodes within the envelope 9 may be obtained from a potentiometer, or any other suitable device.
  • a battery 22 having its negative terminal connected by means of a conductor 24 to the conductive layer 21. to supply a potential to the cathode 15 and the positive terminal of the battery 22 is connected by means of a conductor 25 to the conductive layer 20 to supply a potential to the image screen 16.
  • a plurality of resistors 31, 32, 33, and 34 of equal value connected in series are connected across the conductors 24 and 25 so as to be shunted across the battery 22.
  • a lead 39 is provided from the first dynode 17 to a point between resistors 31 and 32 while the second dynode 18 is connected to a point between the resistances 32 and 33, and the third dynode 19 is connected to a point between the resistors 33 and 34.
  • the free end of resistor 31 is connected to the conductor 24 while the free end of resistor 34 is connected to conductor 25.
  • the successive electrodes 17, 18, 19 and 16following the cathode 15' have progressively increasing steps of positive potential with respect to the cathode 15 so as to accelerate the electrons from electrode to electrode.
  • a light image may be projected onto the cathode surface 15 by any suitable means so as to activate the photoemitting cathode 15.
  • any suitable means so as to activate the photoemitting cathode 15.
  • I have shown a kinescope 28 with a suitable lens system 29 between the kinescope 28 and a photocathode surface 15 for purscope onto the photocathode surface 15.
  • the dynode structure is comprised of at least a secondary electron emissive layer 40.
  • the secondary emissive layer 40 is of a crystalline insulator material such as an alkali-halide (For example KCl or NaCl) which has the property of allowing the flow of secondary electrons within the material for a long distance before being absorbed. It has also been found that the higher the atomic number the higher the emission, for example cesium iodide has a high average atomic number.
  • the term average atomic number as used herein refers to the atomic number of the element or the average of the atomic numbers of the elements in a compound.
  • An alkaline earth oxide is also a suitable secondary emissive material.
  • the secondary electron emissive layer 40 is of a thin planar sheet having substantially the same area as the photocathode surface 15 and parallel thereto. The thickness of the secondary emissive layer is of the order of 100s to 1000s of angstrom units, or 10 10 cm.
  • the secondary electron emissive layer 40 may be deposited on an even thinner layer 41 of a high atomic number material such as gold or uranium.
  • the thickness of this heavy metal layer is on the order of 100 angstroms or less.
  • the function of the heavy metal film 41 is to aid in scattering the incident electrons so that the electrons entering the secondary electron emissive layer 49 will be at an angle with the incident electrons trajectory which is normal to the surface of the layer 40 thereby enhancing the secondary emission of the secondary emissive layer on the side opposite to that on which the primaries are incident.
  • the heavy metal layer 41 is in turn supported by a fine mesh grid 42.
  • the grid 42 in the preferred embodiment of the device is fabricated from a thin sheet of conducting material such as copper or nickel.
  • the metal grid 42 may then be pleated or coated if desired with an inert metal such as gold or platinum in order to insure greater resistance of the grid 42 to oxidation and corrosion.
  • the holes or apertures 43 in the grid 42 may be etched in a sheet of suitable material so as to provide a large open area screen of about 70 to 90%.
  • the sides 44 of the apertures 43 are tapered toward the cathode 15.
  • the grid 42 may also be considered as a cellular or honeycomb structure with the sides 44 of the cells or apertures 43 tapered towards the source of incident electrons.
  • the grid 42 By designing the grid 42 in this fashion, many of the incident electrons that would be lost in conventional type grids are scattered by the sloping or tapered sides 44- of the apertures 43 in the grid member 42 so as to produce secondary electrons in the secondary electron emissive layer 40.
  • the tapered grid design permits the grid 42 to be made mechanically quite strong by making the walls 44 of the apertures relatively thick near the heavy metal layer 41 and relatively thin at the opposite side of the grid 42 and thereby still retain a large open area screen of transmission. In my specific device to obtain the desired resolutions in an image intensifier, it is desirable to have on the order of 500 apertures per inch of screen. Fewer apertures per unit distance may be used when no imaging is desired.
  • the dynodes 17, 18 and 19 may be constructed by suitable methods known in the art.
  • an organic film such as nitrocellulose lacquer is settled on the grid structure by covering the grid with water and applying the organic solution with solvent on the surface of the water. As the organic solution spreads out on the surface of the water the solvent evaporates leaving the organic film. The water is then removed allowing the film to settle on the grid.
  • the organic film is dried and the heavy metal film, if used, is evaporated onto the free .4 surface of the organic film.
  • the secondary electron emissive layer is then evaporated onto the organic film or the heavy metal film (if used).
  • the heavy metal film with the alkalihalide of lower average atomic number while it may be omitted with the alkali-halides of higher average atomic number.
  • the higher average atomic number alkali materials sufficiently scatter the incident electrons while the lower atomic numbered require the heavy metal layer.
  • the organic film may then be baked olf leaving the heavy metal layer on the grid and the secondary electron layer upon the heavy metal layer. This is only one of many methods of depositing the layers on the grid.
  • the etched-foil type of mesh for the grid 42 is preferred to the woven mesh structure because of a fiat surface available for supporting the thin layer of secondary electron emissive material.
  • Another method of construction is to deposit the crystalline layer 40 on to a permanent film of a suitable material such as SiO of thickness equal to tens of angstroms previously deposited by techniques similar to that described above for the organic film. It is also possible, if the voltage between dynode structures is sufficiently high, to use a self-supporting thin metallic foil instead of the supporting grid 42 and the secondary electron emissive layer 40. Also the dynodes may be mounted at different angles to the direction of the incident electrons, while at the same time the secondary electron emissive layer may be made thinner, so as to cause incident electrons to have larger angles of incidence with the dynode so that secondaries form close to the surface of the crystalline layer 40.
  • a suitable material such as SiO of thickness equal to tens of angstroms previously deposited by techniques similar to that described above for the organic film.
  • a second grid may be placed in coincidence with the first grid but on the opposite side of the secondary electron emissive layer.
  • Such'a double-grid arrangement has the further advantage of reducing the undesirable emission of electrons at large angles relative to the normal surface. It also may be desirable in some cases to evaporate the secondary electron emissive material over the sides of this second grid supporting mesh in order to further enhance the ratio of secondary electron emission to incident electrons within the dynode structure.
  • an image is projected by the kinescope 28 through the optical means 29 upon the photocathode surface 15.
  • the photocathode layer 15 in response to the light image projected thereon will generate an electron image representative of the light image projected thereon.
  • the electron image emitted from the photocathode layer 15 will be accelerated to a sufficient velocity to the ingressive side of the dynode 17, such that the incident electrons in passing through the secondary emissive layer 40 will be reduced substantially to Zero.
  • the secondary emissive electrons released from the first dynode 17 are accelerated to the second dynode 18 where this procedure is again repeated.
  • the secondary electron emission from the emission side of the secondary emission layer 40 of the second dynode 18 is many times greater than the incident electron thereon.
  • the dispersion of the electron image flowing between the photocathode and theimage screen 16 is limited to a small amount so that substantially .no reduction of details is lost from the original light-image .projected thereon.
  • aclose spacing of the order of a few tenths of an inch betweendynode members 17, it; and 19 also aids in insuring that a satisfactory picture is obtained on the image screen 16 without the aid of electromagnetic focussing. It has been found that by controlling the accelerating voltages .between dynode stages 17, 18 and 19 so thattheincident electrons are not able to completely penetrate thesecondary electron emissive layer 40, an excellent image is obtained on the screen 16.
  • secondary electron multiplier dynode structure may be constructed.
  • Both the metallic supporting grid and thevernployment of high energy electrons are instrumental .in. bringing. about the desired effect in that the grid serves to reduce the conduction path for the replenishment of electrons, and the high energy electrons serve to reduce the electrical resistance by providing conduction electrons throughout the insulating layer.
  • alkali-halide and grid supporting structure requires no special activation procedures nor is it affected by exposure to air unlike the complex surfaces such as cesiated silver presently employed for dynode surfaces.
  • the alkali-halides and the gold or similar metals also possess a high melting point and high work-function and, therefore, do not suffer from most of the disadvantages of presently used complex secondary emitters. It has been found that these features are particularly important for applications to low signal-level operation in that a'greatly reduced thermionic and photoelectric emission as well as leakagecurrent is obtained between stages.
  • This type of secondary emissive surface is also suited to problems of low-level electron-image amplification such as in infrared and X-ray image tubes because of the small loss of definition .to be expected resulting frornthe extreme thinness of the multiplying surfaces and the absence of fast stray electrons. Since the current densi ties encountered in this type of application are extremely low, about 10* amp/cm. or less, and any possible deterioration of the crystalline surfaces as a result of bombardment is a function only of the total charge involved, the life of such a multiplying surface can be shown to be large compared to minimum requirements.
  • An electron multiplier comprising, anenvelope and having therein a cathode, a target and a. plurality of dynodes positioned between said cathode and said target, said dynodes characterized in having a thin secondary emissive layer of insulating material having an ingressive surface and an emissive surface with said ingressive surface facing said cathode, a supporting member for said secondary emissive layer contacting said ingressive surface, said supporting member having a plurality of cellular openings.
  • An electron discharge device comprising an envelope having therein a planar cathode positioned at one end thereof, and a target electrode near the opposite end of the envelope and a plurality of dynodes positioned between said cathode and said target, each of said dynodes being capable of producing secondary electrons transmissively at a ratio greater than unity and comprising a thin layer of secondary electron emissive insulating material of about angstroms in thickness supported on a metallic structure.
  • An electron multiplier comprising an envelope and having therein a planar photo-emissive cathode positioned near one end of said envelope, a planar electron responsive electrode positioned at the opposite end of said envelope, a plurality of dynode structures positioned between said cathode and said electron-responsive electrode, said dynodes comprising a thin secondary emissive layer of insulating material of the order of 100 angstroms in thickness and a thin metallic coating.
  • An electron multiplier comprising an envelope and having located therein a planar photo-emissive cathode, an electron-responsiveelectrode positioned at the opposite end of said envelope with respect to said cathode, a plurality of planar dynode structures positioned between said cathode and said target, said dynode comprising a thin layer of crystalline insulating material and means for supporting said layer.
  • An electric discharge device comprising an enve lope and havin therein, a planar photo-emissive cathode positioned at one end of said envelope, an electron responsive planar target positioned at the opposite end of 'said envelope with respect to said cathode, and a plurality of planar dynodes positioned between said cathode and said target, each of said dynodes being capable of producing transmissive secondary electrons at a ratio greater than unity and comprising a thin layer of alkali halide material supported on a perforated metallic grid structure.
  • An electric discharge device comprising an envelope and having therein a planar cathode positioned at one end thereof, a target electrode positioned near the opposite end of said envelope and a plurality of dynodes positioned between said cathode and said target, each of said dynodes comprisin a thin layer of pure crystalline insulating material exhibiting the properties of producing secondary electrons transmissively and of increasing conductivity upon electron bombardment supported on a metallic grid-like structure.
  • An electron multiplier comprising an envelope and having therein, a planar cathode and electron responsive target positioned at the opposite end of said envelope with respect to said cathode, a plurality of said dynodes positioned between said cathode and said target, each of said dynodes comprising a thin layer of secondary emissive insulating material supported on a metallic planar grid-like member, said grid-like member having a plurality of cellular openings therein with the sides of said openings tapered toward said cathode.
  • a transmissive dynode structure for an electron multiplier comprising a thin layer of a crystalline insulating material characterized in exhibiting the properties of producing transmissive secondary electrons at a ratio greater than unity and of an increasing conductivity upon electrode bombardment, a layer of high average atomic number material deposited on the bombardment side of said insulating layer to scatter bombarding electrons and means for supporting layers.
  • An electron multiplier comprising an envelope and having therein a planar photo-emissive cathode, a planar electron responsive target positioned at the opposite end cathode, each of said dynodes comprisin a thin continuous layer of insulating material mounted on a gridlike metallic supporting structure, means positioning said dynodes in relatively closed spaced relationship, means to focus the electrons from said cathode on the first of said dynodes, means for focusing the secondary electrons from the last dynode upon the electron responsive target and means for maintaining said electrodes at increasingly positive potentials with respect to said cathode.
  • a secondary emissive dynode structure comprising a continuous layer of insulating material capable of the emission of secondary electrons from the opposite surface on which the bombarding electrons impinge, and a continuous layer of a conductive material of a higher average atomic number than said insulating material on the bombardment side of said insulating material for scattering the bombarding electrons into said insulating layer.
  • a transmissive type secondary electron emissive dynode structure comprising a continuous layer of insulating material capable of the emission of secondary electrons from the opposite surface with respect to the surface which is bombarded by primary electrons, said insulating material having a large energy gap between the filled valence band and the conduction band so that secondary electrons within the layer can travel relatively large distances and escape therefrom, electrical conductive means provided on the surface of said layer on which said bombarded electrons impinge to reduce the conduction path for replenishment of electrons over the emissive surface of said insulating layer.

Landscapes

  • Common Detailed Techniques For Electron Tubes Or Discharge Tubes (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
US434467A 1954-06-04 1954-06-04 Electron discharge device Expired - Lifetime US2905844A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
BE538686D BE538686A (de) 1954-06-04
US434467A US2905844A (en) 1954-06-04 1954-06-04 Electron discharge device
DEW16705A DE1037610B (de) 1954-06-04 1955-05-17 Elektronenvervielfacher mit einer zwischen Kathode und Leuchtschirm angeordneten Vielzahl von Dynoden, bei denen die Traeger der Sekundaer-elektronen-Emissionsschichten gitterartige Gebilde sind
GB15355/55A GB792507A (en) 1954-06-04 1955-05-27 Improvements in or relating to electron discharge devices

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US434467A US2905844A (en) 1954-06-04 1954-06-04 Electron discharge device

Publications (1)

Publication Number Publication Date
US2905844A true US2905844A (en) 1959-09-22

Family

ID=23724362

Family Applications (1)

Application Number Title Priority Date Filing Date
US434467A Expired - Lifetime US2905844A (en) 1954-06-04 1954-06-04 Electron discharge device

Country Status (4)

Country Link
US (1) US2905844A (de)
BE (1) BE538686A (de)
DE (1) DE1037610B (de)
GB (1) GB792507A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2979633A (en) * 1958-05-26 1961-04-11 Franklin H Harris Storage electrode
US3197662A (en) * 1960-03-11 1965-07-27 Westinghouse Electric Corp Transmissive spongy secondary emitter
US3553518A (en) * 1967-08-10 1971-01-05 Philips Corp Image intensifiers for night vision
JPS5126465A (en) * 1974-07-03 1976-03-04 Raboratoaaru Derekutoroniku E Maikurochanneruban oyobi sonoseizohoho

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2196278A (en) * 1937-08-31 1940-04-09 Bell Telephone Labor Inc Electron discharge apparatus
US2254128A (en) * 1938-06-02 1941-08-26 Vacuum Science Products Ltd Electron multiplier
US2254616A (en) * 1937-10-26 1941-09-02 Emi Ltd Manufacture of grids for use in electron discharge devices
US2254617A (en) * 1937-10-28 1941-09-02 Emi Ltd Electron discharge device
US2527981A (en) * 1945-08-23 1950-10-31 Bramley Jenny Secondary-electron emission
US2739084A (en) * 1951-04-28 1956-03-20 Emi Ltd Secondary electron emitting coatings and method for producing same

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE884509C (de) * 1936-02-25 1953-07-27 Fernseh Gmbh Einrichtung zur Verstaerkung von Elektronenbildern durch Sekundaerelektronen
DE693296C (de) * 1936-06-27 1940-07-06 Aeg Anordnung zur elektronenoptischen Abbildung von Folien mit Sekundaerelektronen
DE712302C (de) * 1938-01-15 1941-10-16 Walter Heimann Dr Ing Netzfoermige Prallelektrode zur Ausloesung von Sekundaerelektronen
DE706872C (de) * 1938-03-12 1941-06-07 Fernseh Gmbh Anordnung zur punktweisen Abtastung eines auf einer Bildelektrode mit elektronischer Halbleiterschicht gespeicherten Ladungsbildes

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2196278A (en) * 1937-08-31 1940-04-09 Bell Telephone Labor Inc Electron discharge apparatus
US2254616A (en) * 1937-10-26 1941-09-02 Emi Ltd Manufacture of grids for use in electron discharge devices
US2254617A (en) * 1937-10-28 1941-09-02 Emi Ltd Electron discharge device
US2254128A (en) * 1938-06-02 1941-08-26 Vacuum Science Products Ltd Electron multiplier
US2527981A (en) * 1945-08-23 1950-10-31 Bramley Jenny Secondary-electron emission
US2739084A (en) * 1951-04-28 1956-03-20 Emi Ltd Secondary electron emitting coatings and method for producing same

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2979633A (en) * 1958-05-26 1961-04-11 Franklin H Harris Storage electrode
US3197662A (en) * 1960-03-11 1965-07-27 Westinghouse Electric Corp Transmissive spongy secondary emitter
US3553518A (en) * 1967-08-10 1971-01-05 Philips Corp Image intensifiers for night vision
JPS5126465A (en) * 1974-07-03 1976-03-04 Raboratoaaru Derekutoroniku E Maikurochanneruban oyobi sonoseizohoho

Also Published As

Publication number Publication date
DE1037610B (de) 1958-08-28
BE538686A (de)
GB792507A (en) 1958-03-26

Similar Documents

Publication Publication Date Title
Wiley et al. Electron multipliers utilizing continuous strip surfaces
US2898499A (en) Transmission secondary emission dynode structure
US3243628A (en) Electron multiplier with curved resistive secondary emissive coating
US3673457A (en) High gain storage target
US3657596A (en) Electron image device having target comprising porous region adjacent conductive layer and outer, denser region
US3114044A (en) Electron multiplier isolating electrode structure
US3327151A (en) Light amplifier employing an electron multiplying electrode which supports a photocathode
US2928969A (en) Image device
US2717971A (en) Device for storage of images of invisible radiation
US2914690A (en) Electron-emitting surfaces and methods of making them
US3213316A (en) Tube with highly porous target
US2905844A (en) Electron discharge device
US2277246A (en) Electron discharge device
US3213315A (en) High gain storage tube with bic target
US2850657A (en) Cathode ray tube current amplifying means
US2802963A (en) Tube for reproducing invisible images
US2335705A (en) Signal-generating apparatus
US2970219A (en) Use of thin film field emitters in luminographs and image intensifiers
US2818520A (en) Photocathode for a multiplier tube
US3128406A (en) Radiation image pickup tube
US3099764A (en) Photomultiplier tube
US3555345A (en) Radiation pickup device incorporating electron multiplication
US3322999A (en) Image-intensifier tube
US3189781A (en) Image tube utilizing transmissive dynode-type target
US3350594A (en) Image intensifier having continuous conducting layer between porous metallic coating and luminescent layer