US3689794A - Punctiform cathode, in particular suitable for detachable electric discharge tubes - Google Patents

Punctiform cathode, in particular suitable for detachable electric discharge tubes Download PDF

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Publication number
US3689794A
US3689794A US117501A US3689794DA US3689794A US 3689794 A US3689794 A US 3689794A US 117501 A US117501 A US 117501A US 3689794D A US3689794D A US 3689794DA US 3689794 A US3689794 A US 3689794A
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US
United States
Prior art keywords
cathode
filament
punctiform
plate
electric discharge
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
US117501A
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English (en)
Inventor
Johannes Van Esdonk
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US Philips Corp
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US Philips Corp
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Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3689794A publication Critical patent/US3689794A/en
Anticipated expiration legal-status Critical
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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/02—Details
    • H01J37/04—Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical arrangement
    • H01J37/06—Electron sources; Electron guns
    • H01J37/065—Construction of guns or parts thereof
    • 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
    • H01J1/15—Cathodes heated directly by an electric current
    • H01J1/16—Cathodes heated directly by an electric current characterised by the shape
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/04—Cathodes
    • 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

Definitions

  • the invention relates to. a punctiform cathode, particularly suitable for use in detachable electric discharge tubes, for example, electron diffraction tubes, electron microscopes and similar tubes, which have to be dismantled several times after use and in which the cathode, after having been in operation, is again contacted with air, or in tubes in which heat-sensitive parts are present and which therefore have to be evacuated without strong heating and can hence contain gas particles, for example, camera tubes, and the like.
  • detachable electric discharge tubes for example, electron diffraction tubes, electron microscopes and similar tubes, which have to be dismantled several times after use and in which the cathode, after having been in operation, is again contacted with air, or in tubes in which heat-sensitive parts are present and which therefore have to be evacuated without strong heating and can hence contain gas particles, for example, camera tubes, and the like.
  • punctiform cathodes are used in the said tubes which consist of a hairpin-like or V-shaped bent filament in which the strongly bent part or the top serves as a cathode and is usually arranged close to or in a small aperture of a plate-shaped electrode.
  • a cathode for electric discharge tubes consisting of a metal plate which is secured to the bent part of the V-shaped filament if, according to the invention, the filament consists of tungsten and the plate consists of tantalum.
  • the emission temperature of tantalum is lower than that of tungsten, namely l700 to 1800 C, the
  • the plate can be heated to the emission temperature by a tungsten filament without the filament having to be When a low heating energy is used, the filament must be very thin, however. It has been found that in many cases the temperature gradient along the filament strongly increases from the plate as a result of the comparatively poor heat conductivitythrough the tungsten filament to the plate, as a result of which the temperature of the filament at some distance from the plate can increase too high and the filament at thatregion fuses prematurily. It is found possible to strongly reduce this drawback by using several V-shaped filaments and connecting them with their tops to the tantalum plate.
  • heating energy can remain the same. If desirable, the
  • V-shaped bent heat conductor may be in the form of a ban T e invention
  • FIGS. 1, 2, 3 and 4 show various embodiments of cathodes according to the invention.
  • reference numeral 1 denotes a V-shaped tungsten filament which is secured to current supply pins 2.
  • the pins 2 are sealed in a glass head 3.
  • a tantalum plate 4 is welded or soldered.
  • the plate 4 may be circularor rectangular and have a diameter or diagonal of, for example, 1 mm.
  • the thickness of the plate 4 is, for example, 10p.
  • the diameter of the filament 1 is, for example, 250m.
  • the filaments 1 and 5 may also be secured to the plate 4 separately as is shown in FIG. 3. Furthermore, more than two filaments may be .used. a
  • one or more bandshaped filaments 7 may also be used as is shown in FIG.
  • the supporting rods may be sealed in a glass or ceramic disc 6.
  • two supply pins may be used, for ex-- 4 ample, and the filaments may be secured thereto, for

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  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Electron Sources, Ion Sources (AREA)
  • Discharge Lamp (AREA)
  • Solid Thermionic Cathode (AREA)
US117501A 1970-03-07 1971-02-22 Punctiform cathode, in particular suitable for detachable electric discharge tubes Expired - Lifetime US3689794A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7003279A NL7003279A (enrdf_load_stackoverflow) 1970-03-07 1970-03-07

Publications (1)

Publication Number Publication Date
US3689794A true US3689794A (en) 1972-09-05

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ID=19809525

Family Applications (1)

Application Number Title Priority Date Filing Date
US117501A Expired - Lifetime US3689794A (en) 1970-03-07 1971-02-22 Punctiform cathode, in particular suitable for detachable electric discharge tubes

Country Status (8)

Country Link
US (1) US3689794A (enrdf_load_stackoverflow)
AU (1) AU2610071A (enrdf_load_stackoverflow)
BE (1) BE763897A (enrdf_load_stackoverflow)
CA (1) CA934432A (enrdf_load_stackoverflow)
DE (1) DE2106497A1 (enrdf_load_stackoverflow)
FR (1) FR2081764A1 (enrdf_load_stackoverflow)
GB (1) GB1284047A (enrdf_load_stackoverflow)
NL (1) NL7003279A (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3937996A (en) * 1974-10-07 1976-02-10 General Electric Company Metal halide lamp using loop electrodes
WO1991003831A1 (en) * 1989-08-29 1991-03-21 Olgerd Ivanovich Babich Cathode-heating device for electron-ray tube
EP0641007A3 (en) * 1993-08-31 1995-06-21 Samsung Display Devices Co Ltd Directly heated supply cathode structure.
US5831379A (en) * 1994-01-28 1998-11-03 Samsung Display Devices Co., Ltd. Directly heated cathode structure
EP1063670A3 (en) * 1999-06-22 2006-05-10 Lucent Technologies Inc. Bonded article with improved work function uniformity and method for making the same
CN106191786A (zh) * 2016-08-10 2016-12-07 武汉博莱瑞汽车饰件有限公司 钨丝加热子
CN115656311A (zh) * 2022-11-09 2023-01-31 中国人民解放军战略支援部队航天工程大学 一种惰性气体亚稳态原子束流制备装置及方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2835489A1 (de) * 1978-08-12 1980-02-21 Standard Elektrik Lorenz Ag Kathodenaufbau fuer strahlungsgeheizte kathode
GB2583359A (en) * 2019-04-25 2020-10-28 Aquasium Tech Limited Electron beam emitting assembly

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2126894A (en) * 1933-05-04 1938-08-16 Telefunken Gmbh Indirectly heated cathode
US2151803A (en) * 1935-11-07 1939-03-28 Rca Corp Cathode for electron discharge devices
US3209197A (en) * 1959-08-14 1965-09-28 Philips Corp Gaseous glow-discharge tube with monocrystalline metal cathode
US3374386A (en) * 1964-11-02 1968-03-19 Field Emission Corp Field emission cathode having tungsten miller indices 100 plane coated with zirconium, hafnium or magnesium on oxygen binder
US3461338A (en) * 1967-01-16 1969-08-12 Ibm Non-inductive filament configuration

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2126894A (en) * 1933-05-04 1938-08-16 Telefunken Gmbh Indirectly heated cathode
US2151803A (en) * 1935-11-07 1939-03-28 Rca Corp Cathode for electron discharge devices
US3209197A (en) * 1959-08-14 1965-09-28 Philips Corp Gaseous glow-discharge tube with monocrystalline metal cathode
US3374386A (en) * 1964-11-02 1968-03-19 Field Emission Corp Field emission cathode having tungsten miller indices 100 plane coated with zirconium, hafnium or magnesium on oxygen binder
US3461338A (en) * 1967-01-16 1969-08-12 Ibm Non-inductive filament configuration

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3937996A (en) * 1974-10-07 1976-02-10 General Electric Company Metal halide lamp using loop electrodes
WO1991003831A1 (en) * 1989-08-29 1991-03-21 Olgerd Ivanovich Babich Cathode-heating device for electron-ray tube
EP0641007A3 (en) * 1993-08-31 1995-06-21 Samsung Display Devices Co Ltd Directly heated supply cathode structure.
US5831379A (en) * 1994-01-28 1998-11-03 Samsung Display Devices Co., Ltd. Directly heated cathode structure
EP1063670A3 (en) * 1999-06-22 2006-05-10 Lucent Technologies Inc. Bonded article with improved work function uniformity and method for making the same
CN106191786A (zh) * 2016-08-10 2016-12-07 武汉博莱瑞汽车饰件有限公司 钨丝加热子
CN115656311A (zh) * 2022-11-09 2023-01-31 中国人民解放军战略支援部队航天工程大学 一种惰性气体亚稳态原子束流制备装置及方法

Also Published As

Publication number Publication date
DE2106497A1 (de) 1971-09-23
FR2081764A1 (enrdf_load_stackoverflow) 1971-12-10
BE763897A (fr) 1971-09-06
CA934432A (en) 1973-09-25
NL7003279A (enrdf_load_stackoverflow) 1971-09-09
GB1284047A (en) 1972-08-02
AU2610071A (en) 1972-09-07

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