US1822359A - High electron emissive cathode - Google Patents

High electron emissive cathode Download PDF

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Publication number
US1822359A
US1822359A US305122A US30512228A US1822359A US 1822359 A US1822359 A US 1822359A US 305122 A US305122 A US 305122A US 30512228 A US30512228 A US 30512228A US 1822359 A US1822359 A US 1822359A
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US
United States
Prior art keywords
cathode
high electron
coating
electron emissive
emitter
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
US305122A
Inventor
Richard E Miesse
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.)
Q R S DE VRY Corp
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Q R S DE VRY CORP
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Filing date
Publication date
Application filed by Q R S DE VRY CORP filed Critical Q R S DE VRY CORP
Priority to US305122A priority Critical patent/US1822359A/en
Application granted granted Critical
Publication of US1822359A publication Critical patent/US1822359A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • H01J1/13—Solid thermionic cathodes
    • H01J1/14—Solid thermionic cathodes characterised by the material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913—Rod, strand, filament or fiber
    • Y10T428/2918—Rod, strand, filament or fiber including free carbon or carbide or therewith [not as steel]
    • Y10T428/292—In coating or impregnation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913—Rod, strand, filament or fiber
    • Y10T428/2933—Coated or with bond, impregnation or core
    • Y10T428/294—Coated or with bond, impregnation or core including metal or compound thereof [excluding glass, ceramic and asbestos]
    • Y10T428/2942—Plural coatings
    • Y10T428/2949—Glass, ceramic or metal oxide in coating

Definitions

  • My invention relates to a high electron emissive cathode and the process of making same.
  • My improved cathode is also better enabled to withstand positive ion bombardment.
  • a suitable metal core having a melting point higher than 1000 C. such as nickel, nlckel silicon, platinum or the like. After this metal has been thoroughly cleaned, it is given a thin in the form of graphite, or the more heavy deposit commonly known as soot, I prefer, however, to use the graphitizing process,
  • the filament is then given a coating of barium, strontium, or calcium oxide, either alone or in combination with one another.
  • a metallic cathode having a thin layer of finely divided carbon, a surrounding thin layer of an emitter and a coating of finely divided carbon. 7
  • a metallic cathode having a thin layer of finely divided carbon, a surrounding thin layer of an alkaline earth emitter and a coating of finely divided carbon.
  • An electrode for gaseous conduction devices consisting of a base metal having barium carbide thereon.
  • An electrode for gaseous conduction devices consisting of a base metal having a coating thereon including a carbide of an alkaline earth metal.
  • a method of making an electrode for gaseousronduction devices which consists in coating a base metal with an oxide of an alkaline earth metal and heating said electrode in the presence of carbon whereby to at Least partially convert the coating to a car:
  • a cathode for positive column gaseous conduction tubes having a surface including a carbide of an alkaline earth metal.
  • An electrode for positive column gaseous conduction tubes consisting of a nickel base having'a discharge surface provided with a compound coating including a carbide of an alkaline earth metal.

Landscapes

  • Solid Thermionic Cathode (AREA)

Description

Patented Sept. 8, 1931 UNITED STATES PATENT OFFICE- RICHARD E. MIESSE, OF CHICAGO, ILLINOIS, A SSIGNOR TO Q. R. S. DE VRY CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS HIGH ELECTRON EMISSIVE CATHODE No Drawing.
My invention relates to a high electron emissive cathode and the process of making same.
In accordance with my inventionI have developed a'cathode of this character which shows a very high rate of electron emission as compared to other types as the thoriated tungsten emitter or the VVehnolt cathode.
My improved cathode is also better enabled to withstand positive ion bombardment. In the manufacture of my improved filament, I use a suitable metal core having a melting point higher than 1000 C. such as nickel, nlckel silicon, platinum or the like. After this metal has been thoroughly cleaned, it is given a thin in the form of graphite, or the more heavy deposit commonly known as soot, I prefer, however, to use the graphitizing process,
The filament is then given a coating of barium, strontium, or calcium oxide, either alone or in combination with one another.
' This combination is then raised in temperature sufficiently so as to form the carbides of the metals used in the coating. The carbides are better emitters than the oxides. I
have produced the carbides by another method in accordance with which I have first graphitized the core metal, then added a coating of the oxides or carbonates of the emitter metals to be employed and then added another coat of graphite. This combination is then mounted in the device where it is to be used and a voltage applied thereto during the pumping stage. This voltagemust be sufiicient so that the filament is raised to incandescence. This procedure will change the oxides or carbonates of the emitter metals to carbides, no matter in which form they have been applied. I
The ability of these cathodes to withstand positive ion bombardment is of exceptional value in connection with positive column tubes where the positive ion bombardment is of great magnitude.
From what has becnthus described, the nature ofmy invention will be readily clear to those skilled in the art and it will also be clear that modifications may be made withcoating of carbon either Application'filed. September 10, 1928. Serial No. 305,122.
put departing from the spirit of my invenion.
Having thus described one form which my invention may take, what I claim as new and desire to secure by Letters Patent is:
1. A metallic cathode coated with an emitter and having an outer thin surface layer of finely divided carbon.
2. A metallic cathode having a thin layer of finely divided carbon, a surrounding thin layer of an emitter and a coating of finely divided carbon. 7
3. The process of forming a cathode which consists in coating a metallic base with a finely divided carbon and with an emitter oxide 7 and then heating the combination to a temperature sufliciently large to change the oxide to a carbide.
4. A metallic cathode coated with an alkaline earth emitter and having an outer thin surface layer of finely divided carbon.
5. A metallic cathode having a thin layer of finely divided carbon, a surrounding thin layer of an alkaline earth emitter and a coating of finely divided carbon.
6. An electrode for gaseous conduction devices consisting of a base metal having barium carbide thereon.
7. An electrode for gaseous conduction devices consisting of a base metal having a coating thereon including a carbide of an alkaline earth metal.
8. A method of making an electrode for gaseousronduction devices which consists in coating a base metal with an oxide of an alkaline earth metal and heating said electrode in the presence of carbon whereby to at Least partially convert the coating to a car:
9. A cathode for positive column gaseous conduction tubes having a surface including a carbide of an alkaline earth metal.
10. An electrode for positive column gaseous conduction tubes consisting of a nickel base having'a discharge surface provided with a compound coating including a carbide of an alkaline earth metal.
In witness whereof, I hereunto subscribe my name this 3rd day of August, A. D. 1928.
RICHARD E. MIESSE.
US305122A 1928-09-10 1928-09-10 High electron emissive cathode Expired - Lifetime US1822359A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US305122A US1822359A (en) 1928-09-10 1928-09-10 High electron emissive cathode

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US305122A US1822359A (en) 1928-09-10 1928-09-10 High electron emissive cathode

Publications (1)

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US1822359A true US1822359A (en) 1931-09-08

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