DE813573C - Cathode whose emission properties are caused by thorium oxide - Google Patents

Cathode whose emission properties are caused by thorium oxide

Info

Publication number
DE813573C
DE813573C DEP54597A DEP0054597A DE813573C DE 813573 C DE813573 C DE 813573C DE P54597 A DEP54597 A DE P54597A DE P0054597 A DEP0054597 A DE P0054597A DE 813573 C DE813573 C DE 813573C
Authority
DE
Germany
Prior art keywords
thorium oxide
cathode
caused
emission properties
whose emission
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
DEP54597A
Other languages
German (de)
Inventor
Antonius Josephus Va Genuchten
Robert Loosjes
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.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
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 Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
Application granted granted Critical
Publication of DE813573C publication Critical patent/DE813573C/en
Expired legal-status Critical Current

Links

Classifications

    • 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
    • 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
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—Electrodes; Screens; Shields
    • H01J61/06—Main electrodes
    • H01J61/073—Main electrodes for high-pressure discharge lamps
    • H01J61/0735—Main electrodes for high-pressure discharge lamps characterised by the material of the electrode
    • 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]
    • Y10T428/2958—Metal or metal compound in coating
    • 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
    • Y10T428/298—Physical dimension

Description

(WiGBl. S. 175)(WiGBl. P. 175)

AUSGEGEBEN AM 13. SEPTEMBER 1951ISSUED SEPTEMBER 13, 1951

P 54597 VIII c12ig DP 54597 VIII c12ig D

Die vorliegende Erfindung bezieht sich auf eine. Kathode, deren Emissionseigenschaften durch Thoriumoxyd bedingt werden und deren Kathodenkörper aus einem gesinterten Gemisch von Thoriumoxyd und einem hochschmelzenden Metall, wie Wolfram, besteht.The present invention relates to a. Cathode, the emission properties of which are caused by thorium oxide and their cathode body from a sintered mixture of thorium oxide and a refractory metal such as Tungsten.

Die obenerwähnten Kathoden wurden bereits in Gasentladungslampen verwendet, in denen sie durch die Entladung erhitzt werden. Wenn das Gemisch unter hinreichend hohem Druck gepreßt und bei hinreichend hoher Temperatur gesintert ist, hat der Kathodenkörper eine hohe mechanische Festigkeit. Ein Nachteil ist, daß das Oxyd-Metall-Gemisch schwarz ist, so daß die Strahlung einen höheren Wert aufweist. Auch die spezifische Emission ist verhältnismäßig niedrig.The above-mentioned cathodes have already been used in gas discharge lamps in which they be heated by the discharge. When the mixture is pressed and under sufficiently high pressure is sintered at a sufficiently high temperature, the cathode body has a high mechanical Strength. One disadvantage is that the oxide-metal mixture is black, so that the radiation makes one has a higher value. The specific emission is also relatively low.

Die Erfindung bezweckt, eine Verbesserung der obenerwähnten Kathode zu schaffen.The invention aims to provide an improvement on the cathode mentioned above.

Eine Kathode, deren Emissionseigenschaften durch Thoriumoxyd bedingt werden und wobei der Kathodenkörper aus einem unter hohem Druck gepreßten und darauf gesinterten Gemisch von Thoriumoxyd und einem hochschmelzenden Metall, wie Wolfram, besteht, ist nach der Erfindung mit einer dünnen Thoriumoxydschicht überzogen, die am Kathodenkörper festgesintert ist. Da das Thoriumoxyd weiß ist, ist die Wärmestrahlung verhältnismäßig gering, und die spezifische Elektronenemission des Thoriumoxyds ist wesentlich höher als diejenige des Thoriumoxyd-Metall-Gemisches. Eine Formierbehandlung der Kathode ist nicht erforderlich, da die Kathode nach dem Einbau in einerA cathode whose emission properties are caused by thorium oxide and where the Cathode body made from a mixture of thorium oxide pressed under high pressure and then sintered and a refractory metal such as tungsten, is according to the invention with a thin layer of thorium oxide, which is sintered to the cathode body. Since the thorium oxide is white, the thermal radiation is relatively low, and the specific electron emission the thorium oxide is considerably higher than that of the thorium oxide-metal mixture. One Forming treatment of the cathode is not necessary because the cathode after installation in a

Röhre gleich emissionsfähig ist. Die Zusammensetzung der Kathode wird an Hand des nachfolgenden Beispiels näher erläutert.Tube is equally emissive. The composition of the cathode is based on the following Example explained in more detail.

Ein aus 8o Volumprozent Thoriumoxyd und 20 Volumprozent Wolfram bestehendes Gemisch wird unter hohem Druck zu einem Zylinderröhrchen mit einem Außendurchmesser von 2,5 mm und einem Innendurchmesser von 1,5 mm gepreßt und bei 19000 C in Wasserstoff gesintert. Darauf wird eine Thoriumoxydschicht mit einer Stärke von 50 Mikron aufgebracht, welche gleichfalls auf 19000 C festgesintert wird. An den Enden des Röhrchens können unter Zuhilfenahme eines aus Molybdänpulver und Ammoniummolybdat bestehenden Gemisches Molybdänkappen angefertigt und auf Molybdänpolen festgesintert werden. Die erhaltene Kathode hat eine hohe mechanische Festigkeit und deformiert bei Temperaturen bis 23000 C nicht. Infolge der innigen Vermischung des Wolframs und des Thoriumoxyds ist die Erhitzung der Kathode gleichmäßig. Wird die Kathode mit Impulsen betrieben, so kann die spezifische Emission bis Amp./cm2 bei einer Temperatur von 2200° K. betragen. Die Lebensdauer ist besonders hoch.A mixture consisting of 80 percent by volume of thorium oxide and 20 percent by volume of tungsten is pressed under high pressure into a cylinder tube with an outside diameter of 2.5 mm and an inside diameter of 1.5 mm and sintered at 1900 ° C. in hydrogen. Then, a Thoriumoxydschicht is applied with a thickness of 50 microns, which is likewise festgesintert at 1900 0 C. At the ends of the tube, with the aid of a mixture of molybdenum powder and ammonium molybdate, molybdenum caps can be made and sintered onto molybdenum poles. The cathode obtained has a high mechanical strength and does not deform at temperatures up to 2300 ° C. As a result of the intimate mixing of the tungsten and thorium oxide, the heating of the cathode is uniform. If the cathode is operated with pulses, the specific emission can be up to Amp./cm 2 at a temperature of 2200 ° K. The service life is particularly long.

Claims (2)

PATENTANSPRUCH!-::PATENT CLAIM! - :: 1. Kathode, deren Emissionseigenschaften durch Thoriumoxyd bedingt werden und deren Kathodenkörper aus einem gesinterten Gemisch von Thoriumoxyd und einem hochschmelzenden Metall, wie Wolfram, besteht, dadurch gekennzeichnet, daß auf dem Kathodenkörper eine1. Cathode whose emission properties are caused by thorium oxide and whose Cathode body made from a sintered mixture of thorium oxide and a high-melting point Metal, such as tungsten, is characterized in that on the cathode body a • dünne Thoriumoxydschicht festgesintert ist.• a thin layer of thorium oxide is firmly sintered. 2. Kathodenach Anspruch 1, dadurch gekennzeichnet, daß der Kathodenkörper aus gleichen Mengen Gewichtsprozent Wolfram und Thoriumoxyd besteht und die Thoriumoxydschicht eine Stärke von etwa 50 Mikron hat.2. Cathode according to claim 1, characterized in that that the cathode body consists of equal amounts of weight percent tungsten and thorium oxide and the thorium oxide layer is about 50 microns thick. Q 1477 9. Q 1477 9.
DEP54597A 1948-09-14 1949-09-11 Cathode whose emission properties are caused by thorium oxide Expired DE813573C (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL278121X 1948-09-14

Publications (1)

Publication Number Publication Date
DE813573C true DE813573C (en) 1951-09-13

Family

ID=19782192

Family Applications (1)

Application Number Title Priority Date Filing Date
DEP54597A Expired DE813573C (en) 1948-09-14 1949-09-11 Cathode whose emission properties are caused by thorium oxide

Country Status (7)

Country Link
US (1) US2614942A (en)
BE (1) BE491070A (en)
CH (1) CH278121A (en)
DE (1) DE813573C (en)
FR (1) FR995225A (en)
GB (1) GB666053A (en)
NL (1) NL70864C (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1009727B (en) * 1953-01-10 1957-06-06 Deutsche Elektronik Gmbh Process for producing solid, well-adhering emission layers made of thorium oxide on a carrier metal made of tungsten or molybdenum
DE1063282B (en) * 1954-06-16 1959-08-13 Csf Pressed body for use as an emitting part of a sintered barium cathode and process for its manufacture
DE1080700B (en) * 1958-05-17 1960-04-28 Deutsche Elektronik Gmbh Process for the production of an indirectly heated cathode, in particular for magnetrons with high oscillating power, and cathode produced according to this process

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2717975A (en) * 1951-03-30 1955-09-13 Wihtol Weltis Cathodes for electron tubes
US2845515A (en) * 1953-03-12 1958-07-29 Raytheon Mfg Co Semimetallic resistive filaments
US2847328A (en) * 1957-03-04 1958-08-12 James E Cline Method of making thorium oxide cathodes
US3558966A (en) * 1967-03-01 1971-01-26 Semicon Associates Inc Directly heated dispenser cathode
US3973155A (en) * 1975-01-31 1976-08-03 Westinghouse Electric Corporation Incandescent source of visible radiations
US4333035A (en) * 1979-05-01 1982-06-01 Woodland International Corporation Areal array of tubular electron sources
US4438557A (en) * 1979-05-01 1984-03-27 Woodland International Corporation Method of using an areal array of tubular electron sources
US20090085463A1 (en) * 2007-09-28 2009-04-02 General Electric Company Thermo-optically functional compositions, systems and methods of making

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2339392A (en) * 1942-10-06 1944-01-18 Rca Corp Cathode
US2477601A (en) * 1947-06-11 1949-08-02 Raytheon Mfg Co Directly heated cathode

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1009727B (en) * 1953-01-10 1957-06-06 Deutsche Elektronik Gmbh Process for producing solid, well-adhering emission layers made of thorium oxide on a carrier metal made of tungsten or molybdenum
DE1063282B (en) * 1954-06-16 1959-08-13 Csf Pressed body for use as an emitting part of a sintered barium cathode and process for its manufacture
DE1080700B (en) * 1958-05-17 1960-04-28 Deutsche Elektronik Gmbh Process for the production of an indirectly heated cathode, in particular for magnetrons with high oscillating power, and cathode produced according to this process

Also Published As

Publication number Publication date
US2614942A (en) 1952-10-21
BE491070A (en)
GB666053A (en) 1952-02-06
NL70864C (en)
FR995225A (en) 1951-11-29
CH278121A (en) 1951-09-30

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