GB523982A - Improvements in secondary electron emission layers for use in electron discharge devices - Google Patents

Improvements in secondary electron emission layers for use in electron discharge devices

Info

Publication number
GB523982A
GB523982A GB1765/39A GB176539A GB523982A GB 523982 A GB523982 A GB 523982A GB 1765/39 A GB1765/39 A GB 1765/39A GB 176539 A GB176539 A GB 176539A GB 523982 A GB523982 A GB 523982A
Authority
GB
United Kingdom
Prior art keywords
vacuo
electron
beryllium
oxygen
foundation
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
GB1765/39A
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.)
British Thomson Houston Co Ltd
Original Assignee
British Thomson Houston Co Ltd
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 British Thomson Houston Co Ltd filed Critical British Thomson Houston Co Ltd
Publication of GB523982A publication Critical patent/GB523982A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00Apparatus 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
    • H01J9/02Manufacture of electrodes or electrode systems
    • H01J9/12Manufacture of electrodes or electrode systems of photo-emissive cathodes; of secondary-emission electrodes
    • H01J9/125Manufacture of electrodes or electrode systems of photo-emissive cathodes; of secondary-emission electrodes of secondary emission electrodes
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2201/00Electrodes common to discharge tubes
    • H01J2201/32Secondary emission electrodes

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Cold Cathode And The Manufacture (AREA)

Abstract

523,982. Electrode materials. BRITISH THOMSON-HOUSTON CO., Ltd. Jan. 18, 1939, No. 1765. Convention date, Jan. 18, 1938. [Class 39 (i)] A secondary emitting layer for the electrodes of an electron multiplier is formed of a film of beryllium vaporized in vacuo on to a foundation metal such as molybdenum or nickel, and the film and foundation metal are then subjected to a heat treatment. This heat treatment may be carried out in the presence of oxygen, the greater the oxygen pressure the lower the temperature required. In one method, the beryllium vaporized layer having been formed in vacuo on the foundation metal, the whole is exposed to air and heated to 350‹C. Alternatively, after formation and exposure to air the foundation and layer may be heated, e.g. by high frequency current, in vacuo to a temperature between 600‹C. and 800‹C. for a few minutes. The resulting multiplication ratio is about 4 to 5. A further increase of emissivity may be obtained by a subsequent heating to about 1,000‹C. in vacuo. These beryllium films are not impaired by the presence of oxygen or by heavy electron bombardment, and are useful for electron multipliers where the electrodes are raised to temperatures above 150‹C. by electron bombardment. The first stages of a multiplier in which the heating effect results in temperatures of less than 150‹C. may be caesium on oxidized silver films of high emissivity.
GB1765/39A 1938-01-18 1939-01-18 Improvements in secondary electron emission layers for use in electron discharge devices Expired GB523982A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE523982X 1938-01-18

Publications (1)

Publication Number Publication Date
GB523982A true GB523982A (en) 1940-07-26

Family

ID=6552133

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1765/39A Expired GB523982A (en) 1938-01-18 1939-01-18 Improvements in secondary electron emission layers for use in electron discharge devices

Country Status (2)

Country Link
FR (1) FR849026A (en)
GB (1) GB523982A (en)

Also Published As

Publication number Publication date
FR849026A (en) 1939-11-13

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