GB1070473A - Thermionic emitter for electron discharge devices and methods of fabricating same - Google Patents

Thermionic emitter for electron discharge devices and methods of fabricating same

Info

Publication number
GB1070473A
GB1070473A GB22601/64A GB2260164A GB1070473A GB 1070473 A GB1070473 A GB 1070473A GB 22601/64 A GB22601/64 A GB 22601/64A GB 2260164 A GB2260164 A GB 2260164A GB 1070473 A GB1070473 A GB 1070473A
Authority
GB
United Kingdom
Prior art keywords
tungsten
substrate
layer
deposited
hydrogen
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
GB22601/64A
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.)
Varian Medical Systems Inc
Original Assignee
Varian Associates Inc
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 claimed from US285150A external-priority patent/US3284657A/en
Application filed by Varian Associates Inc filed Critical Varian Associates Inc
Priority to FR18772A priority Critical patent/FR88266E/en
Publication of GB1070473A publication Critical patent/GB1070473A/en
Priority to FR125340A priority patent/FR94316E/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
    • H01J1/20—Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment
    • H01J1/28—Dispenser-type cathodes, e.g. L-cathode
    • 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
    • H01J3/00—Details of electron-optical or ion-optical arrangements or of ion traps common to two or more basic types of discharge tubes or lamps
    • H01J3/02—Electron guns
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J45/00—Discharge tubes functioning as thermionic generators

Landscapes

  • Solid Thermionic Cathode (AREA)
  • Chemical Vapour Deposition (AREA)

Abstract

An oriented polycrystalline tungsten layer is deposited on a tungsten substrate by heating the latter while directing on to it a stream of hydrogen and tungsten hexafluoride, the ratio of the two gases in the mixture determining the crystal orientation of the deposited polycrystals. A steady flow of hydrogen is passed into the deposition chamber (144) Fig. 20 (not shown) which is maintained at a pressure of 400 torr and the tungsten substrate (141) is raised to a temperature between 500 DEG C. and 800 DEG C. - preferably 600 DEG C. - by a heater (145), whereafter tungsten hexafluoride is added, in adjustable proportion, to the flowing hydrogen which is directed on to the substrate from a conduit (147). When the deposited layer (142) reaches the desired thickness - e.g. 0.0001" to 0.001" - deposition is terminated by disconnecting the heater (145) and directing cold water on to the rear surface of the specimen mount (143) while the flow of gas mixture is maintained. Surface irregularities are removed by electropolishing, and the layer may be held at 1,900 DEG C. for 30 minutes to improve its uniformity. Gas mixture ranges for producing either (100) or (210) orientation are specified. In an alternative deposition arrangement Fig. 21 (not shown) the substrate is a 0.006" diameter thoriated tungsten filament held under tension, and having a carbonized surface layer Fig. 11 (not shown); a porous, sintered tungsten substrate impregnated with barium and aluminium oxides is also referred to. Other materials referred to include: for the substrate - molybdenum, rhenium, niobium, and tantalum; and for the grain oriented polycrystalline layer - molybdenum, rhenium, niobium, tantalum, hafnium, iridium, osmium, platinum, rhodium, ruthenium, thorium, titanium, vanadium, ytterbium, and zirconium. The use of the grain oriented surface as a thermionic emitter in a variety of electric discharge apparatus is described (see Division H1).
GB22601/64A 1962-05-15 1964-06-01 Thermionic emitter for electron discharge devices and methods of fabricating same Expired GB1070473A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
FR18772A FR88266E (en) 1962-05-15 1965-05-28 Pigmentation process of organic matter
FR125340A FR94316E (en) 1962-05-15 1967-10-20 Pigmentation process for organic materials.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US285150A US3284657A (en) 1963-06-03 1963-06-03 Grain-oriented thermionic emitter for electron discharge devices
US367183A US3290543A (en) 1963-06-03 1964-05-13 Grain oriented dispenser thermionic emitter for electron discharge device

Publications (1)

Publication Number Publication Date
GB1070473A true GB1070473A (en) 1967-06-01

Family

ID=26963011

Family Applications (1)

Application Number Title Priority Date Filing Date
GB22601/64A Expired GB1070473A (en) 1962-05-15 1964-06-01 Thermionic emitter for electron discharge devices and methods of fabricating same

Country Status (3)

Country Link
US (1) US3290543A (en)
DE (1) DE1439890A1 (en)
GB (1) GB1070473A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1063669A2 (en) * 1999-06-23 2000-12-27 Lucent Technologies Inc. Cathode with improved work function and method for making the same
EP2847780B1 (en) * 2012-05-10 2023-04-19 Thermo Scientific Portable Analytical Instruments Inc. An electrically heated planar cathode

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3371240A (en) * 1965-06-29 1968-02-27 Westinghouse Electric Corp Frame type electrodes for electron discharge devices
DE1614642B2 (en) * 1967-02-22 1971-10-07 Siemens AG, 1000 Berlin u 8000 München SUPPLY CATHODE IN PARTICULAR MK CATHODE
CH582951A5 (en) * 1973-07-09 1976-12-15 Bbc Brown Boveri & Cie
US4165473A (en) * 1976-06-21 1979-08-21 Varian Associates, Inc. Electron tube with dispenser cathode
DE3148441A1 (en) * 1981-12-08 1983-07-21 Philips Patentverwaltung Gmbh, 2000 Hamburg METHOD FOR PRODUCING A THERMIONIC CATHODE
DE3205746A1 (en) * 1982-02-18 1983-08-25 Philips Patentverwaltung Gmbh, 2000 Hamburg THERMIONIC CATHODE AND METHOD FOR THE PRODUCTION THEREOF
US4587455A (en) * 1982-10-12 1986-05-06 Hughes Aircraft Company Controlled porosity dispenser cathode
US8183756B2 (en) * 2007-07-24 2012-05-22 Koninklijke Philips Electronics Nv Thermionic electron emitter, method for preparing same and X-ray source including same
DE102008020163A1 (en) * 2008-04-22 2009-10-29 Siemens Aktiengesellschaft Cathode has incandescent emitter made from material, which emits electrons thermally, where emission layer is applied partially or completely on incandescent emitter
DE102008020165A1 (en) * 2008-04-22 2009-10-29 Siemens Aktiengesellschaft Cathode, has emitter made of material and emitting electrons thermally, and emission layer made of material and partially applied on emitter, where material of emission layer exhibits electron work function less than material of emitter
US9443691B2 (en) 2013-12-30 2016-09-13 General Electric Company Electron emission surface for X-ray generation

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1826514A (en) * 1926-11-26 1931-10-06 Westinghouse Lamp Co Tungsten and method of manufacturing the same
CH305872A (en) * 1951-11-19 1955-03-15 Siemens Ag Cathode for electrical discharge vessels.
CH315203A (en) * 1952-03-24 1956-07-31 Siemens Ag Cathode for electrical discharge vessels
US3155864A (en) * 1960-03-21 1964-11-03 Gen Electric Dispenser cathode
US3134924A (en) * 1960-07-05 1964-05-26 Monsanto Co Emissive materials of a metal matrix with molecularly dispersed additives

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1063669A2 (en) * 1999-06-23 2000-12-27 Lucent Technologies Inc. Cathode with improved work function and method for making the same
EP1063669A3 (en) * 1999-06-23 2006-08-16 Lucent Technologies Inc. Cathode with improved work function and method for making the same
US7179148B2 (en) 1999-06-23 2007-02-20 Agere Systems Inc. Cathode with improved work function and method for making the same
EP2847780B1 (en) * 2012-05-10 2023-04-19 Thermo Scientific Portable Analytical Instruments Inc. An electrically heated planar cathode

Also Published As

Publication number Publication date
US3290543A (en) 1966-12-06
DE1439890A1 (en) 1969-04-17

Similar Documents

Publication Publication Date Title
GB1070473A (en) Thermionic emitter for electron discharge devices and methods of fabricating same
Buckingham Thermionic emission properties of a lanthanum hexaboride/rhenium cathode
GB682105A (en) Method of making surface-type and point-type rectifiers and crystal-amplifier layers from semiconductor material
Fort Jr et al. Adsorption of water on clean aluminum by measurement of work function changes
DE1187098B (en) Process for the production of bodies from highly purified semiconductor material
Goldwater et al. Certain refractory compounds as thermionic emitters
US2723363A (en) Cathode and method of producing same
Edinger et al. Development of a high brightness gas field ion source
US3130073A (en) Method of providing molybdenum wire with a carbon coating
US2487581A (en) Electrical resistor and method of making same
Collins et al. The adsorption and nucleation of zirconium on tungsten field emitters
US3284657A (en) Grain-oriented thermionic emitter for electron discharge devices
Morgan Temporal growth of ionization in gases
US2521315A (en) Geiger tube
US3372297A (en) High frequency electron discharge devices and thermionic cathodes having improved (cvd) refractory insulation coated heater wires
Rivière The work function of uranium
US2766397A (en) Hydrogen-filled electric discharge device
US2986326A (en) High vacuum
Hopkins et al. The work function of a (110) oriented tungsten single-crystal face
JPS6481216A (en) Vapor growth apparatus
US2237242A (en) Phototube
Madey et al. Thermal Desorption of Sr from W
US3476971A (en) Apparatus for plasma processing
US3936532A (en) Activation of thin wire emitters for field ionization/field desorption mass spectrometry
Center Source for Negative Ions of Refractory Metal Oxides