US2233276A - Secondary electron emissive electrode - Google Patents

Secondary electron emissive electrode Download PDF

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Publication number
US2233276A
US2233276A US197994A US19799438A US2233276A US 2233276 A US2233276 A US 2233276A US 197994 A US197994 A US 197994A US 19799438 A US19799438 A US 19799438A US 2233276 A US2233276 A US 2233276A
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US
United States
Prior art keywords
magnesium
electrode
emissive
secondary electron
alloy
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
US197994A
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English (en)
Inventor
Vladimir K Zworykin
Humboldt W Leverenz
John E Ruedy
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
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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
Priority to BE433432D priority Critical patent/BE433432A/xx
Application filed by RCA Corp filed Critical RCA Corp
Priority to US197994A priority patent/US2233276A/en
Priority to FR851749D priority patent/FR851749A/fr
Priority to GB9469/39A priority patent/GB526731A/en
Application granted granted Critical
Publication of US2233276A publication Critical patent/US2233276A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • H01J9/12—Manufacture of electrodes or electrode systems of photo-emissive cathodes; of secondary-emission electrodes
    • H01J9/125—Manufacture of electrodes or electrode systems of photo-emissive cathodes; of secondary-emission electrodes of secondary emission electrodes
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2201/00—Electrodes common to discharge tubes
    • H01J2201/32—Secondary emission electrodes

Definitions

  • Our invention relates to secondary electron dled as an ordinary metal for the preparation of emission devices, and more specifically to a secelectrodes, and from which high secondary enlisondary electron emission device in which the secsion may be obtained without any special activaondarily emissive electrode may be formed by a tion -Within a vacuum.
  • the invention is to form compounds or alloys of elealloy is further characterized bythe fact that nov ments which in themselves do not show a high activation is required to increase the secondarysecondary emissive property but which, in comelectron emissibility of the electrode surface.
  • FIG. 2 is a chart indicating the method of silver-plated electrode. After cleaning, the elecforming a secon-darily emissive electrode in actrode is mounted within a suitable envelope. cordance with our invention; The envelope is evacuated to 1 10-2 mm. of mer- Figure 3 is a graph showing the emissive propcury and then heated and evacuated to a preserties of elements and their compounds made in sure of the order of 1 1C
  • the silver surface cf Figure 5 is a temperature-composition curve 0f 'M the electrode is oxidized by applying a potential the elements gold and magnesium- 30 of the order of 500 volts which effects a glow dis- Referring te Fig- 1,y if' Will be Observed that charge. After the oxidation has been completed, eleven successive steps are required to form a any residual oxygen is exhausted and thereafter caesium-silver oxide secondary electron emissive caesium is distilled into the envelope. The Surface. In comparison, yreference is made to a. suitable surface whichy is fixed by baking the formed of the elements Copper and magnesium. envelope at approximately 210 C.
  • caesium combines with the silver cxide tc fcrm Fig. 2 in which,'by Way of example, an alloy is 35 or broughtl together in an alloy, thecompound or the alloy does not follow the ordinary rule of chemical mixtures.
  • the characteristics of the alloy depend not only on the proportions but also on the treatment which may result in many.
  • thermo-dynamicallystable stability of the electrode under baking and operating conditions term compound of elements in which the elements are represented in true atomic proportions; e. g., gold -Au and magnesium Mg form the following compounds; AuMg, AuMga and AuMga, as indicated by the maximum point or points in the temperature-composition diagram of Fig. 5.
  • a fraction of one percent to the order ot sixteen percent, by weight, of magnesium may be combined with copper to form a suitable alloy.
  • the following proportions may be used: of the order of 84 parts copper to 16 parts magnesium; of the order 80 parts silver to 20 parts magnesium; of the order of 70 parts gold to 30 parts magnesium; or 70 to 99.9
  • Y will give from 4 to 6 and higher secondary electron ratios at 200 volts and upwards at higher potentials,v in accordance with the curve of Fig. 3.
  • Such electrodes have surfaces which, when first subjected to electron bombardment, show a decrease in secondary emission. 'I'he surface eventually stabilizes with a comparatively high gain and thereafter remains stable at temperaturesup to 600 C.
  • a secondary electron emissive electrode including in combination a base metal element and magnesium united in a ratio of at/least two parts base metal to one part magnesium by weight and forming an alloy thermodynamically stable at operating temperatures approaching 600 C. during electron bombardment, and having a ratio of secondary electron emission to primary electron applied during bombardment oi' at least four.
  • a secondary electron emissive electrode formed by a compound of the elements copper and ma nesium in the ratio of the order of 84 parts cper and 16 parts magnesium by weight
  • a secondary electron emissive electrode formed by a compound of the elements gold and magnesium in the ratio of the order of 70 parts gold and 30 parts magnesium by weight.
  • the method oi makinga secondary emissive electrode from a base metal and magnesium which comprises alloying said base metal and said magnesium, forming an electrode of said alloy, cleaning said electrode, placing said electrode within an envelope, heating said envelope to approximately 450"v C., and evacuating said envelope.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Photovoltaic Devices (AREA)
  • Cold Cathode And The Manufacture (AREA)
US197994A 1938-03-25 1938-03-25 Secondary electron emissive electrode Expired - Lifetime US2233276A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
BE433432D BE433432A (en:Method) 1938-03-25
US197994A US2233276A (en) 1938-03-25 1938-03-25 Secondary electron emissive electrode
FR851749D FR851749A (fr) 1938-03-25 1939-03-17 Perfectionnements aux électrodes émettrices d'électrons secondaires
GB9469/39A GB526731A (en) 1938-03-25 1939-03-27 Improvements in secondary emissive electrodes

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US197994A US2233276A (en) 1938-03-25 1938-03-25 Secondary electron emissive electrode

Publications (1)

Publication Number Publication Date
US2233276A true US2233276A (en) 1941-02-25

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ID=22731572

Family Applications (1)

Application Number Title Priority Date Filing Date
US197994A Expired - Lifetime US2233276A (en) 1938-03-25 1938-03-25 Secondary electron emissive electrode

Country Status (4)

Country Link
US (1) US2233276A (en:Method)
BE (1) BE433432A (en:Method)
FR (1) FR851749A (en:Method)
GB (1) GB526731A (en:Method)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2784123A (en) * 1952-05-01 1957-03-05 Rca Corp Secondary electron emitter and process of preparing same
US3072816A (en) * 1959-08-05 1963-01-08 Landis & Gry A G Electrode device and method of producing the same
US3756682A (en) * 1967-02-13 1973-09-04 Schlumberger Technology Corp Method for outgassing permanent magnets

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2784123A (en) * 1952-05-01 1957-03-05 Rca Corp Secondary electron emitter and process of preparing same
US3072816A (en) * 1959-08-05 1963-01-08 Landis & Gry A G Electrode device and method of producing the same
US3756682A (en) * 1967-02-13 1973-09-04 Schlumberger Technology Corp Method for outgassing permanent magnets

Also Published As

Publication number Publication date
BE433432A (en:Method)
GB526731A (en) 1940-09-24
FR851749A (fr) 1940-01-13

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