US2198329A - Electric discharge tube - Google Patents

Electric discharge tube Download PDF

Info

Publication number
US2198329A
US2198329A US195567A US19556738A US2198329A US 2198329 A US2198329 A US 2198329A US 195567 A US195567 A US 195567A US 19556738 A US19556738 A US 19556738A US 2198329 A US2198329 A US 2198329A
Authority
US
United States
Prior art keywords
discharge tube
metal
metals
electric discharge
oxide
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
US195567A
Inventor
Bruining Hajo
Boer Jan Hendrik De
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.)
RCA Corp
Original Assignee
RCA Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by RCA Corp filed Critical RCA Corp
Application granted granted Critical
Publication of US2198329A publication Critical patent/US2198329A/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
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/32—Secondary-electron-emitting electrodes

Definitions

  • discharge tube according to the present invention which comprises a secondaryemission electrode coated, at least on part of its surface, with a layer which is not thicker than 1 micron and which consists of one or more compounds of the alkali, alkaline earth or earth metals which do practically .not contain free metal.
  • alkali metals are meant the metals: lithium, sodium, potassium, rubidium and caesium, by alkaline earth metals the metals calcium, strontium, barium and in the present case also magnesium and by the earth metals: aluminium, scandium, yttrium, lanthanum and the rare earth metals, furthermore, zirconium, titanium, hafnium and thorium.
  • the generally accepted opinion that materials which have a satisfactory primary emission also will have the best secondary emission is incorrect but that the best secondary emission is only obtained it use is made of a layer which consists of one or more compounds in which there is practically no free metal, that is to say of a layer which would be completely unsuitable to act as a primary emitter.
  • the invention consists in the use of layers which consist or compounds which practically contain no free metal and which have a small thickness, which is necessary as theconductivity of such layers is smaller than that of layers which contain a more or less large amount of free metal.
  • diflerent materials may be utilised for the purpose above referred to, use should preferably be made of oxides, or halogenides of the alkali metals, or alkaline earth metals such, for example, as barium oxide, caesium oxide, sodium chloride, potassium chloride, sodium fluoride, sodium bromide, potassium iodide, aluminium oxide, etc.
  • the table below indicates the values of the secondary emission for the abovementioned compounds and for the pure metals.
  • the accompanying drawing illustrates diagrammatically one embodiment of myinvention as a tube comprising an envelope l enclosing a source of primary electrons, such as a thermionic cathode 2, a conventional control grid 3, an output electrode 4, and a secondary electron emitter 5 constructed in accordance with my invention and. having a layer 6 of alkaline earth oxide on the surface facing the cathode.
  • the primary electron stream fiows, as indicated by a single arrow, from the source 2 to the emitter 5, and the secondary electron stream flows, as indicated by several arrows, from the emitter 5 to the output electrode 4.
  • An electron discharge tube comprising a source of primary electrons, a collector electrode, and a secondary electron emitting electrode having on the surface exposed to said source a layer no thicker than one micron and consisting of an oxygen compound of a metal selected from the group consisting of the alkali and the alkaline earth metals and substantially. free from the metal of the compound,
  • a secondary electron emitter for an electron discharge device comprising an electrode, and a coating on said electrode thinner than one micron and consisting of an oxide of an alkali or alkaline earth metal and free from the metal of the oxide.
  • a secondary electron emitter for an electron discharge device comprising an electrode, and a coating on said electrode no thicker than one micron and consisting of an oxide of an alkaline earth metal and free from said metal.

Description

April 23, 1940.
H. BRUINING ET AL ELECTRIC DISCHARGE TUBE Filed March 12, 1938 SECONDARY ELECTRON EMITTER WITH LAYER UFALKAL/NE EARTH METAL OXIDE N0 TH/CKER THAN ONE MICRON AND SUBS TAN TIALL Y FREE OF METAL OF THE OXIDE INVENTORS HAJO BRU/NING AND BY v HENDR/K'DE 305R fl w ATTORNEY.
Patented Apr. 23, 1940 UNITED STATES PATENT OFFIC ELECTRIC DISCHARGE TUBE Hajo Bruining and Jan Hendrik de Boer, Eindhoven, Netherlands, signments, to Radio assignors, by mesne as- Corporation of America,
New York, N. Y., a corporation of Delaware Application March 12,
1938, Serial N0. 195,567
In the Netherlands March 25, 1937 3 Claims.
made to metals and to compounds of alkali metals and alkaline earth metals, metallic caesium absorbed to caesium oxide being very customary.
Applicants have made extensive investigations on this subject and have found that, as regards the value of the secondary emission, it is by no means indifferent whether use is made of compounds or of metals but that a very high secondary emission is only obtained if use is made of an electric. discharge tube according to the present invention which comprises a secondaryemission electrode coated, at least on part of its surface, with a layer which is not thicker than 1 micron and which consists of one or more compounds of the alkali, alkaline earth or earth metals which do practically .not contain free metal. By alkali metals are meant the metals: lithium, sodium, potassium, rubidium and caesium, by alkaline earth metals the metals calcium, strontium, barium and in the present case also magnesium and by the earth metals: aluminium, scandium, yttrium, lanthanum and the rare earth metals, furthermore, zirconium, titanium, hafnium and thorium.
Applicants have found, in fact, that the generally accepted opinion that materials which have a satisfactory primary emission also will have the best secondary emission is incorrect but that the best secondary emission is only obtained it use is made of a layer which consists of one or more compounds in which there is practically no free metal, that is to say of a layer which would be completely unsuitable to act as a primary emitter. Based on this recognition the invention consists in the use of layers which consist or compounds which practically contain no free metal and which have a small thickness, which is necessary as theconductivity of such layers is smaller than that of layers which contain a more or less large amount of free metal.
Although diflerent materials may be utilised for the purpose above referred to, use should preferably be made of oxides, or halogenides of the alkali metals, or alkaline earth metals such, for example, as barium oxide, caesium oxide, sodium chloride, potassium chloride, sodium fluoride, sodium bromide, potassium iodide, aluminium oxide, etc. The table below indicates the values of the secondary emission for the abovementioned compounds and for the pure metals.
Material Sec. emission Voltage As may be seen .from this table the secondary emission of the compounds is materially greater than that of the pure metal.
The accompanying drawing illustrates diagrammatically one embodiment of myinvention as a tube comprising an envelope l enclosing a source of primary electrons, such as a thermionic cathode 2, a conventional control grid 3, an output electrode 4, and a secondary electron emitter 5 constructed in accordance with my invention and. having a layer 6 of alkaline earth oxide on the surface facing the cathode. The primary electron stream fiows, as indicated by a single arrow, from the source 2 to the emitter 5, and the secondary electron stream flows, as indicated by several arrows, from the emitter 5 to the output electrode 4.
What we claim is:
1. An electron discharge tube comprising a source of primary electrons, a collector electrode, and a secondary electron emitting electrode having on the surface exposed to said source a layer no thicker than one micron and consisting of an oxygen compound of a metal selected from the group consisting of the alkali and the alkaline earth metals and substantially. free from the metal of the compound,
2. A secondary electron emitter for an electron discharge device comprising an electrode, and a coating on said electrode thinner than one micron and consisting of an oxide of an alkali or alkaline earth metal and free from the metal of the oxide.
3. A secondary electron emitter for an electron discharge device comprising an electrode, and a coating on said electrode no thicker than one micron and consisting of an oxide of an alkaline earth metal and free from said metal.
HAJO BRUINING. JAN HENDRIK ns BOER.
US195567A 1937-03-25 1938-03-12 Electric discharge tube Expired - Lifetime US2198329A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL207131X 1937-03-25

Publications (1)

Publication Number Publication Date
US2198329A true US2198329A (en) 1940-04-23

Family

ID=19778610

Family Applications (1)

Application Number Title Priority Date Filing Date
US195567A Expired - Lifetime US2198329A (en) 1937-03-25 1938-03-12 Electric discharge tube

Country Status (4)

Country Link
US (1) US2198329A (en)
BE (1) BE427143A (en)
CH (1) CH207131A (en)
FR (1) FR835633A (en)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2457947A (en) * 1942-12-21 1949-01-04 Albert G Thomas High-frequency oscillation tube
US2472189A (en) * 1941-07-03 1949-06-07 Hartford Nat Bank & Trust Co Thermionic tube having a secondary-emission electrode
US2540635A (en) * 1948-05-27 1951-02-06 Rca Corp Cesiated monoscope
US2548514A (en) * 1945-08-23 1951-04-10 Bramley Jenny Process of producing secondaryelectron-emitting surfaces
US2585534A (en) * 1945-11-07 1952-02-12 Emi Ltd Secondary electron emissive electrode and its method of making
US2600112A (en) * 1948-06-30 1952-06-10 Sylvania Electric Prod Electron emitter
US2708726A (en) * 1948-12-04 1955-05-17 Emi Ltd Electron discharge device employing secondary electron emission and method of making same
US2722490A (en) * 1950-07-24 1955-11-01 Bell Telephone Labor Inc Germanium elements and methods of preparing same
US2730640A (en) * 1951-08-08 1956-01-10 Gen Electric Secondary electron emitting system
US2802127A (en) * 1954-02-03 1957-08-06 Dobischek Dietrich Dynode coating
DE1015947B (en) * 1951-10-23 1957-09-19 Telefunken Gmbh Amplifier tubes with high electronic input resistance
US2846338A (en) * 1954-08-03 1958-08-05 William G Shepherd Secondary electron emitter
US2887597A (en) * 1955-10-27 1959-05-19 Hughes Aircraft Co Storage screen for direct-viewing storage tube
DE1078240B (en) * 1953-12-17 1960-03-24 Siemens Ag Electron tubes for amplifying signals, e.g. B. in the manner of a hexode
US3410716A (en) * 1965-04-01 1968-11-12 Trw Inc Coating of refractory metals with metal modified oxides

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE874176C (en) * 1939-03-25 1953-04-20 Sueddeutsche Telefon App Secondary electron multiplier with glow cathode
DE857535C (en) * 1939-08-08 1952-12-01 Telefunken Gmbh Impact electrode for secondary electron multiplication
DE895629C (en) * 1940-07-31 1953-11-05 Zeiss Ikon Ag Process for the manufacture of secondary emission cathodes

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2472189A (en) * 1941-07-03 1949-06-07 Hartford Nat Bank & Trust Co Thermionic tube having a secondary-emission electrode
US2457947A (en) * 1942-12-21 1949-01-04 Albert G Thomas High-frequency oscillation tube
US2548514A (en) * 1945-08-23 1951-04-10 Bramley Jenny Process of producing secondaryelectron-emitting surfaces
US2585534A (en) * 1945-11-07 1952-02-12 Emi Ltd Secondary electron emissive electrode and its method of making
US2540635A (en) * 1948-05-27 1951-02-06 Rca Corp Cesiated monoscope
US2600112A (en) * 1948-06-30 1952-06-10 Sylvania Electric Prod Electron emitter
US2708726A (en) * 1948-12-04 1955-05-17 Emi Ltd Electron discharge device employing secondary electron emission and method of making same
US2722490A (en) * 1950-07-24 1955-11-01 Bell Telephone Labor Inc Germanium elements and methods of preparing same
US2730640A (en) * 1951-08-08 1956-01-10 Gen Electric Secondary electron emitting system
DE1015947B (en) * 1951-10-23 1957-09-19 Telefunken Gmbh Amplifier tubes with high electronic input resistance
DE1078240B (en) * 1953-12-17 1960-03-24 Siemens Ag Electron tubes for amplifying signals, e.g. B. in the manner of a hexode
US2802127A (en) * 1954-02-03 1957-08-06 Dobischek Dietrich Dynode coating
US2846338A (en) * 1954-08-03 1958-08-05 William G Shepherd Secondary electron emitter
US2887597A (en) * 1955-10-27 1959-05-19 Hughes Aircraft Co Storage screen for direct-viewing storage tube
US3410716A (en) * 1965-04-01 1968-11-12 Trw Inc Coating of refractory metals with metal modified oxides

Also Published As

Publication number Publication date
BE427143A (en)
CH207131A (en) 1939-09-30
FR835633A (en) 1938-12-27

Similar Documents

Publication Publication Date Title
US2198329A (en) Electric discharge tube
US3387161A (en) Photocathode for electron tubes
US3197662A (en) Transmissive spongy secondary emitter
GB648955A (en) Improvements in electron-emitting electrodes for electric discharge tubes
US2144249A (en) Cathode for electron discharge devices
US2620287A (en) Secondary-electron-emitting surface
US3986065A (en) Insulating nitride compounds as electron emitters
US2185189A (en) Gaseous discharge tube
US2159774A (en) Secondary electron emitter and method of making it
US2548514A (en) Process of producing secondaryelectron-emitting surfaces
US2144250A (en) Cathode for electron discharge devices
US2147669A (en) Secondary electron emitting electrode
GB496556A (en) Improvements in electrodes for electron discharge devices
US1871363A (en) Electrode construction
GB413166A (en) Improvements in and relating to controllable gas or vapour filled discharge tubes
US1843244A (en) Incandescent cathode for electron discharge devices
Good et al. Design of Beta‐Ray and Gamma‐Ray Geiger‐Müller Counters
US2189971A (en) Secondary electron emitting electrode
US2159946A (en) Electron discharge device
US2151783A (en) Secondary electron discharge tube
US2190695A (en) Secondary electron emitter and method of making it
US2663824A (en) Vapor-electric device
US1980702A (en) Phototube
US2677070A (en) Coated grid tube
US2698397A (en) Electron discharge device