GB1234905A - Improvements in or relating to thorium film cathodes - Google Patents

Improvements in or relating to thorium film cathodes

Info

Publication number
GB1234905A
GB1234905A GB4850369A GB4850369A GB1234905A GB 1234905 A GB1234905 A GB 1234905A GB 4850369 A GB4850369 A GB 4850369A GB 4850369 A GB4850369 A GB 4850369A GB 1234905 A GB1234905 A GB 1234905A
Authority
GB
United Kingdom
Prior art keywords
metals
thorium
carbide
weight
coating
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
Application number
GB4850369A
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.)
Siemens AG
Original Assignee
Siemens AG
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 Siemens AG filed Critical Siemens AG
Publication of GB1234905A publication Critical patent/GB1234905A/en
Expired legal-status Critical Current

Links

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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/04—Manufacture of electrodes or electrode systems of thermionic cathodes
    • H01J9/042—Manufacture, activation of the emissive part

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Solid Thermionic Cathode (AREA)

Abstract

1,234,905. Cathode materials and processing. SIEMENS AG. 2 Oct., 1969 [3 Oct., 1968], No. 48503/69. Heading H1D. A thorium film cathode is manufactured by mechanically forming a cathode blank from a starting material consisting of a core of one or more high-melting point metals, e.g. W, containing thorium oxide, at least one of the metals being capable of forming a stable carbide, an outer coating of a high-melting point metal or metals, e.g. Rh, Os, Ir, Pt and Re, having no tendency to form a stable carbide or carbides, and subsequently subjecting the blank to a conventional carburizing process to produce an inner reducing coating of, for example tungsten carbide. The material of the outer coating has a higher escape energy than the carbide(s) of the core material, has good migration properties for thorium, and is such that carbon can diffuse through it. The core material may comprise tungsten wire containing 1-2% by weight of thorium oxide, and an outer layer of rhenium at least 0À5Á thick (preferably 2-5Á) may be formed on the tungsten wire by plating or coating by electrolytic, chemical or vapour deposition; alternatively it may be formed by ease-forging and the combination is subjected to a common drawing or rolling process. The core material may be alloyed or mixed with up to 25% by weight of one or more of the metals Rh, Os, Ir, Pt and Re, e.g. 23% by weight of Be. The cathodes so formed may be annealed in a hydrocarbon atmosphere for the carburizing process.
GB4850369A 1968-10-03 1969-10-02 Improvements in or relating to thorium film cathodes Expired GB1234905A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19681800945 DE1800945B2 (en) 1968-10-03 1968-10-03 PROCESS AND ELECTRODE STARTING MATERIAL FOR THE MANUFACTURING OF A THORIUM FILM CATHOD FOR ELECTRIC DISCHARGE VESSELS

Publications (1)

Publication Number Publication Date
GB1234905A true GB1234905A (en) 1971-06-09

Family

ID=5709522

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4850369A Expired GB1234905A (en) 1968-10-03 1969-10-02 Improvements in or relating to thorium film cathodes

Country Status (3)

Country Link
DE (1) DE1800945B2 (en)
FR (1) FR2019800A1 (en)
GB (1) GB1234905A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111850524A (en) * 2020-07-17 2020-10-30 广东威特真空电子制造有限公司 Rare earth tungsten cathode and preparation method and application thereof

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2445605A1 (en) * 1978-12-27 1980-07-25 Thomson Csf DIRECT HEATING CATHODE AND HIGH FREQUENCY ELECTRONIC TUBE COMPRISING SUCH A CATHODE
DE4305558A1 (en) * 1993-02-24 1994-08-25 Asea Brown Boveri Process for the manufacture of wires which are especially suitable for cathodes of electron tubes

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111850524A (en) * 2020-07-17 2020-10-30 广东威特真空电子制造有限公司 Rare earth tungsten cathode and preparation method and application thereof
CN111850524B (en) * 2020-07-17 2022-08-30 广东威特真空电子制造有限公司 Rare earth tungsten cathode and preparation method and application thereof

Also Published As

Publication number Publication date
FR2019800A1 (en) 1970-07-10
DE1800945A1 (en) 1970-06-18
DE1800945B2 (en) 1972-03-30

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