US2808531A - Cathode for electrical discharge tubes - Google Patents

Cathode for electrical discharge tubes Download PDF

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Publication number
US2808531A
US2808531A US341514A US34151453A US2808531A US 2808531 A US2808531 A US 2808531A US 341514 A US341514 A US 341514A US 34151453 A US34151453 A US 34151453A US 2808531 A US2808531 A US 2808531A
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US
United States
Prior art keywords
cathode
sheet
electrical discharge
discharge tubes
retaining wall
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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
US341514A
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English (en)
Inventor
Katz Helmut
Costa Siegfried
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 and Halske AG
Siemens Corp
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Siemens Corp
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Publication date
Application filed by Siemens Corp filed Critical Siemens Corp
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Publication of US2808531A publication Critical patent/US2808531A/en
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    • 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
    • H01J1/20—Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment
    • H01J1/28—Dispenser-type cathodes, e.g. L-cathode

Definitions

  • Jaw gm 1 a United States Patent CATHODE FOR ELECTRICAL DISCHARGE TUBES Helmut Katz and Siegfried Costa, Kunststoff, Germany, assignors to Siemens & Halske Aktiengesellschaft, Kunststoff and Berlin, Germany, a German corporation Application March 10, 1953, Serial No. 341,514
  • the emissive material migrates in operation through a retaining wall forming the emitting surface.
  • a retaining wall has in known cathodes of this kind a porous structure or is otherwise provided with fine passages.
  • Sintered tungsten or molybdenum bodies are oftentimes used. Barium or thorium compositions or alloys made of such substances dilfuse through the pores or fine passages of the corresponding wall and migrate thus to the emitting surface formed thereby for distribution thereon.
  • a cathode of the dispenser type comprising a receptacle containing thorium as an emissive material, and having a retaining wall made of a relatively dense sheet of molybdenum or similar high melting metal.
  • the emissive thorium material diffuses through the dense sheet of the retaining wall to the emitting surface formed thereby.
  • the sheet may be up to several tenths of a millimeter thick, even more, if correspondingly long times for forming and high forming temperatures can be provided for or tolerated.
  • the cathode diagrammatically shown therein is a flat indirectly heated cathode.
  • the emissive material 1 which may be thorium or a known thorium" composition or alloy, is disposed inside of a pot-shaped receptacle having a retaining wall 2 and closed on top by a thin metallic sheet 3 of dense structure, such sheet forming the emitting surface.
  • the thickness of the sheet will depend on the size and geometric form thereof, which may of course vary, and amounts at the most to several tenths of a millimeter, that is, in any case less than one millimeter.
  • the sheet 3 may be made of molybdenum or a similar metal of high ice melting point.
  • the emissive thorium-containing substance 1 difluses in the operation of the cathode through the dense sheet 3, thus migrating to the emitting surface formed thereby.
  • the retaining wall 2 of the pot-shaped receptacle is thicker than the sheet 3 so as to inhibit as much as possible diffusion of the emissive substance therethrough.
  • the cathode is mounted on a tubular member 4 which also serves as a heat radiation shield.
  • the cathode is heated by a heater coil 5 which is in usual manner provided with an insulating layer 6.
  • An indirectly heated dispenser type cathode for electrical discharge tubes having a receptacle for holding a normally migratory emissive material of the class of thorium, said receptacle comprising a metallic retaining wall and a cover sheet made of high melting metallic material of relatively dense structure substantially free of pores and fissures, said cover sheet being less than one millimeter thick and forming with said retaining wall which is thicker than said sheet an interiorly unobstructed cavity containing said emissive material, the outside of said cover sheet forming the emitting surface of said cathode, diffusion of said emissive material through said retaining wall being substantially inhibited by the thickness thereof to confine migration of such material during the operation of said cathode substantially through said cover sheet to the emitting surface formed thereby.
  • a cathode according to claim 3 comprising a tubular holder extending from said retaining wall, and a heater disposed within said holder for heating said receptacle to heat said emissive material so as to cause migration thereof through said cover sheet to the emitting surface formed thereby.

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  • Solid Thermionic Cathode (AREA)
US341514A 1952-03-24 1953-03-10 Cathode for electrical discharge tubes Expired - Lifetime US2808531A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE315203X 1952-03-24

Publications (1)

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US2808531A true US2808531A (en) 1957-10-01

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US341514A Expired - Lifetime US2808531A (en) 1952-03-24 1953-03-10 Cathode for electrical discharge tubes

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US (1) US2808531A (de)
CH (1) CH315203A (de)
FR (1) FR1073208A (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2869017A (en) * 1956-10-24 1959-01-13 Philips Corp Thermionic dispenser cathode
US2945295A (en) * 1957-12-20 1960-07-19 Westinghouse Electric Corp High temperature metallic joint
US3018404A (en) * 1958-03-27 1962-01-23 Raytheon Co Electron tube cathodes
US3155864A (en) * 1960-03-21 1964-11-03 Gen Electric Dispenser cathode
US3176180A (en) * 1961-09-01 1965-03-30 Gen Electric Dispenser cathode
US3243637A (en) * 1962-10-31 1966-03-29 Gen Electric Dispenser cathode
US3290543A (en) * 1963-06-03 1966-12-06 Varian Associates Grain oriented dispenser thermionic emitter for electron discharge device
US3376461A (en) * 1964-12-28 1968-04-02 Varian Associates Thermionic cathodes and high frequency electron discharge devices
US3437865A (en) * 1964-12-23 1969-04-08 Nat Res Dev Thermionic electron emitter having a porous refractory metal matrix and an alloy of active metal and mobilizer metal therein
US3848153A (en) * 1972-05-25 1974-11-12 Energy Sciences Inc Elongated electron-emission cathode assembly and method
US20030025435A1 (en) * 1999-11-24 2003-02-06 Vancil Bernard K. Reservoir dispenser cathode and method of manufacture

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2175345A (en) * 1935-07-12 1939-10-10 Gen Electric Electric gaseous discharge device
US2452075A (en) * 1941-12-18 1948-10-26 Raytheon Mfg Co Velocity modulation electron discharge tube
US2460739A (en) * 1946-04-17 1949-02-01 Gen Electric Electrode construction
US2640950A (en) * 1951-06-06 1953-06-02 Atomic Energy Commission Point electron source
US2640949A (en) * 1951-02-07 1953-06-02 Atomic Energy Commission Electron source
US2647216A (en) * 1950-04-01 1953-07-28 Rca Corp Dispenser cathode
US2673277A (en) * 1949-10-25 1954-03-23 Hartford Nat Bank & Trust Co Incandescible cathode and method of making the same
US2687489A (en) * 1952-06-26 1954-08-24 Hanovia Chemical & Mfg Co Electrode

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2175345A (en) * 1935-07-12 1939-10-10 Gen Electric Electric gaseous discharge device
US2452075A (en) * 1941-12-18 1948-10-26 Raytheon Mfg Co Velocity modulation electron discharge tube
US2460739A (en) * 1946-04-17 1949-02-01 Gen Electric Electrode construction
US2673277A (en) * 1949-10-25 1954-03-23 Hartford Nat Bank & Trust Co Incandescible cathode and method of making the same
US2647216A (en) * 1950-04-01 1953-07-28 Rca Corp Dispenser cathode
US2640949A (en) * 1951-02-07 1953-06-02 Atomic Energy Commission Electron source
US2640950A (en) * 1951-06-06 1953-06-02 Atomic Energy Commission Point electron source
US2687489A (en) * 1952-06-26 1954-08-24 Hanovia Chemical & Mfg Co Electrode

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2869017A (en) * 1956-10-24 1959-01-13 Philips Corp Thermionic dispenser cathode
US2945295A (en) * 1957-12-20 1960-07-19 Westinghouse Electric Corp High temperature metallic joint
US3018404A (en) * 1958-03-27 1962-01-23 Raytheon Co Electron tube cathodes
US3155864A (en) * 1960-03-21 1964-11-03 Gen Electric Dispenser cathode
US3176180A (en) * 1961-09-01 1965-03-30 Gen Electric Dispenser cathode
US3243637A (en) * 1962-10-31 1966-03-29 Gen Electric Dispenser cathode
US3243638A (en) * 1962-10-31 1966-03-29 Gen Electric Dispenser cathode
US3290543A (en) * 1963-06-03 1966-12-06 Varian Associates Grain oriented dispenser thermionic emitter for electron discharge device
US3437865A (en) * 1964-12-23 1969-04-08 Nat Res Dev Thermionic electron emitter having a porous refractory metal matrix and an alloy of active metal and mobilizer metal therein
US3376461A (en) * 1964-12-28 1968-04-02 Varian Associates Thermionic cathodes and high frequency electron discharge devices
US3848153A (en) * 1972-05-25 1974-11-12 Energy Sciences Inc Elongated electron-emission cathode assembly and method
US20030025435A1 (en) * 1999-11-24 2003-02-06 Vancil Bernard K. Reservoir dispenser cathode and method of manufacture

Also Published As

Publication number Publication date
FR1073208A (fr) 1954-09-21
CH315203A (de) 1956-07-31

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