GB750339A - Improvements in or relating to thermionic cathodes - Google Patents

Improvements in or relating to thermionic cathodes

Info

Publication number
GB750339A
GB750339A GB22495/53A GB2249553A GB750339A GB 750339 A GB750339 A GB 750339A GB 22495/53 A GB22495/53 A GB 22495/53A GB 2249553 A GB2249553 A GB 2249553A GB 750339 A GB750339 A GB 750339A
Authority
GB
United Kingdom
Prior art keywords
cathode
per cent
layer
mixture
nickel
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
GB22495/53A
Inventor
Arnold Hugh William Beck
Alan Butler Cutting
Alan Douglas Brisbane
George King
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.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
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 Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Publication of GB750339A publication Critical patent/GB750339A/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
    • 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
    • H01J3/027—Construction of the gun or parts thereof
    • 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

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Solid Thermionic Cathode (AREA)
  • Powder Metallurgy (AREA)
  • Microwave Tubes (AREA)

Abstract

750,339. Cathode materials and processing. STANDARD TELEPHONES & CABLES, Ltd. Aug. 6, 1954 [Aug. 14, 1953], No. 22495/53. Class 39 (1). An indirectly-heated cathode in which emission is confined to a restricted solid angle comprises a compacted mass of mixed powders of nickel (or cobalt) and alkaline earth material, together with a reducing agent, the mass being sintered and firmly united to a metal support. A suitable mixture is 69 per cent nickel, 30 per cent barium-strontium carbonates, and 1 per cent zirconium hydride as a reducing agent, ballmilled as described. In the construction of Fig. 1, the mixture is applied as a layer 5 to the end surface of a cup 1; the adhesion is improved by an intermediate nickel layer 4. The nickel is sintered by stoving in vacuo or hydrogen, to form a roughened surface on to which is brushed or sprayed the emissive mixture suspended in amyl acetate. It is then dried and compressed. The cathode may be temporarily stored in this state by coating with a suitable plastic. In the alternative form of Fig. 2, a plug 7 of the compressed emissive mixture is contained in the cupshaped end of the cathode sleeve 6. A backing- plate 8 gives additional support, and prevents rearward emission. The cathode may be activated after assembly in the finished tube, or by mounting in a temporary tube with an anode. The cathode is first outgassed, during which the sintering also takes place, and then current is drawn from it in the usual manner. Such cathodes can then be removed, since they are temporarily stable in air. Fig. 3 (not shown) is a modification of Fig. 2 in which the plug 7 has a composite structure providing a greater porosity in the interior than at the surface. This is obtained by varying the amount of alkaline earth carbonate in the original powder mixture, reduction of the carbonate proportion giving reduced porosity. The powder is introduced in several layers, the central layer having 40 per cent carbonate, the upper layer 20 per cent and the lower layer 10 per cent. The cathode surface may be covered with a closure of porous sintered tungsten, or other specified metal. Particulars are given regarding temperatures, pressures, grain sizes, dimensions, and layer thicknesses. Fig. 4 (not shown) is a set of curves comparing the performance of the cathode of the invention with other cathodes. Suitable applications are for cathode-ray tubes, high-voltage rectifiers, and high-frequency beam tubes.
GB22495/53A 1953-08-14 1953-08-14 Improvements in or relating to thermionic cathodes Expired GB750339A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB328590X 1953-08-14
GB3013171X 1955-06-23

Publications (1)

Publication Number Publication Date
GB750339A true GB750339A (en) 1956-06-13

Family

ID=32396015

Family Applications (1)

Application Number Title Priority Date Filing Date
GB22495/53A Expired GB750339A (en) 1953-08-14 1953-08-14 Improvements in or relating to thermionic cathodes

Country Status (7)

Country Link
US (2) US2912611A (en)
BE (3) BE544065A (en)
CH (3) CH328590A (en)
DE (1) DE1015941B (en)
FR (3) FR1113771A (en)
GB (1) GB750339A (en)
NL (1) NL97850C (en)

Families Citing this family (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3076915A (en) * 1954-12-24 1963-02-05 Egyesuelt Izzolampa Cathode assembly and method of making same
US3159461A (en) * 1958-10-20 1964-12-01 Bell Telephone Labor Inc Thermionic cathode
GB904505A (en) * 1958-11-25 1962-08-29 Harries Electronics Corp Ltd Improvements in or relating to electron discharge tubes for television, radar and the like
NL101694C (en) * 1959-03-06
US3113236A (en) * 1959-06-23 1963-12-03 Philips Corp Oxide dispenser type cathode
US3170772A (en) * 1961-01-05 1965-02-23 Tokyo Shibaura Electric Co Oxide coated cathodes for electron tubes
US3160780A (en) * 1961-01-17 1964-12-08 Philips Corp Indirectly heated cathode
NL278653A (en) * 1961-06-01
US3263115A (en) * 1962-05-23 1966-07-26 Gen Electric Dispenser cathode and method of manufacture
US3374385A (en) * 1963-07-10 1968-03-19 Rca Corp Electron tube cathode with nickel-tungsten alloy base and thin nickel coating
DE1255207B (en) * 1963-09-19 1967-11-30 Western Electric Co Matrix or layer cathode for glow cathode tubes
US3307241A (en) * 1963-10-14 1967-03-07 Litton Prec Products Inc Process for making cathodes
US3303378A (en) * 1964-06-17 1967-02-07 Chorney Paul Monolithic cathode structure
US3436583A (en) * 1966-03-15 1969-04-01 Gen Electric Electron gun
US3436584A (en) * 1966-03-15 1969-04-01 Gen Electric Electron emission source with sharply defined emitting area
NL6608782A (en) * 1966-06-24 1967-12-27
US3465400A (en) * 1967-02-01 1969-09-09 Varian Associates Method of making cylindrical mesh electrode for electron tubes
BE759247A (en) * 1969-11-22 1971-05-21 Philips Nv DEVICE EQUIPPED WITH AN ELECTRONIC TUBE, AND ELECTRONIC TUBE INTENDED FOR SUCH A DEVICE
US3803677A (en) * 1972-04-28 1974-04-16 Air Liquide Method for making cathodes for electron guns
US3835327A (en) * 1972-05-08 1974-09-10 United Aircraft Corp Triode electron gun for electron beam machines
US3974414A (en) * 1975-07-09 1976-08-10 Gte Sylvania Incorporated Cathode ray tube cathode
DE2808134A1 (en) * 1978-02-25 1979-08-30 Licentia Gmbh Long-life cathode with porous two layer emitter - has emitting layer thinner and of lower porosity than supporting layer
FR2525808A1 (en) * 1982-04-23 1983-10-28 Thomson Csf Thermo-electronic cathode with impregnated porous matrix - brazed to support via interposed compact layer
DE3485897T2 (en) * 1983-12-20 1993-01-07 Eev Ltd ELECTRONIC RADIATOR.
JPS63224127A (en) * 1987-03-11 1988-09-19 Hitachi Ltd Impregnated cathode
JPH0298921A (en) * 1988-10-05 1990-04-11 Fujitsu Ltd Electron gun and manufacture thereof aligner equipped with same electron gun and manufacture of semiconductor device using same aligner
FR2647257B1 (en) * 1989-05-19 1991-07-05 Thomson Tubes Electroniques IMPREGNATED CATHODE WITH REDUCED CAPACITY WITH APPLICATION TO BEAM INDEXING VISUALIZATION TUBES, AND ELECTRONIC TUBES COMPRISING SUCH A DEVICE
KR920008300B1 (en) * 1990-09-22 1992-09-26 삼성전관 주식회사 The method of manufacturing dispenser-type cathode
KR930007461B1 (en) * 1991-04-23 1993-08-11 주식회사 금성사 Method of making a dispenser type cathode
JPH0850849A (en) * 1994-05-31 1996-02-20 Nec Kansai Ltd Cathode member and electronic tube using it
JPH09147735A (en) * 1995-09-21 1997-06-06 Matsushita Electron Corp Cathode-ray tube emitter material and manufacture thereof
JPH11339633A (en) * 1997-11-04 1999-12-10 Sony Corp Impregnated cathode and manufacture therefor and electron gun and electronic tube

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2733378A (en) * 1956-01-31 Thermionic cathodes for electronic discharge devices
US1552310A (en) * 1923-07-24 1925-09-01 Gen Electric Electrode for discharge tubes
US1931254A (en) * 1928-02-28 1933-10-17 Electrons Inc Electronic tube
US2147447A (en) * 1936-09-21 1939-02-14 Siemens Ag Glow cathode
US2275886A (en) * 1941-04-30 1942-03-10 Gen Electric Process of activating cathodes
US2543439A (en) * 1945-05-02 1951-02-27 Edward A Coomes Method of manufacturing coated elements for electron tubes
US2492142A (en) * 1945-10-17 1949-12-27 Kenneth J Germeshausen Electric system embodying coldcathode gaseous discharge device
GB629126A (en) * 1947-04-14 1949-09-13 British Thomson Houston Co Ltd Improvements in and relating to cathodes for electric discharge devices
BE498869A (en) * 1949-10-25
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
US2741717A (en) * 1951-06-14 1956-04-10 Siemens Ag Dispenser type cathode having gettercoated parts
NL91132C (en) * 1951-11-29
NL96177C (en) * 1952-02-27
BE526506A (en) * 1953-02-16
NL94233C (en) * 1954-12-06

Also Published As

Publication number Publication date
FR68247E (en) 1958-04-09
US2912611A (en) 1959-11-10
NL97850C (en)
CH338908A (en) 1959-06-15
CH328590A (en) 1958-03-15
DE1015941B (en) 1957-09-19
CH337954A (en) 1959-04-30
FR1113771A (en) 1956-04-04
BE531122A (en)
US3013171A (en) 1961-12-12
BE548876A (en)
BE544065A (en)
FR71337E (en) 1959-12-22

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