EP0412868A1 - Röntgenröhrenkathode und Röhre mit einer solchen Kathode - Google Patents

Röntgenröhrenkathode und Röhre mit einer solchen Kathode Download PDF

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Publication number
EP0412868A1
EP0412868A1 EP90402122A EP90402122A EP0412868A1 EP 0412868 A1 EP0412868 A1 EP 0412868A1 EP 90402122 A EP90402122 A EP 90402122A EP 90402122 A EP90402122 A EP 90402122A EP 0412868 A1 EP0412868 A1 EP 0412868A1
Authority
EP
European Patent Office
Prior art keywords
main body
cathode
electrodes
insulating material
ray tube
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.)
Ceased
Application number
EP90402122A
Other languages
English (en)
French (fr)
Inventor
André Plessis
Catherine Thomas
Paul Hery
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.)
General Electric CGR SA
Original Assignee
General Electric CGR SA
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 General Electric CGR SA filed Critical General Electric CGR SA
Publication of EP0412868A1 publication Critical patent/EP0412868A1/de
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/14—Arrangements for concentrating, focusing, or directing the cathode ray
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/06—Cathodes
    • H01J35/064—Details of the emitter, e.g. material or structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/06—Cathodes
    • H01J35/066—Details of electron optical components, e.g. cathode cups

Definitions

  • the invention relates to X-ray tubes and, more particularly, to a cathode for an X-ray tube.
  • An X-ray tube comprises, in a vacuum enclosure, a cathode made up of a heated filament which emits electrons and of a concentration device backed by the filament which focuses the electrons emitted on an anode brought to a positive potential compared to at the cathode.
  • the point of impact of the electron beam on the anode constitutes the source of X-radiation in the form of a beam.
  • the cathode may have several emitting filaments for which it is necessary to control the flow of electrons in dimensions but also in direction in order to obtain precise points of impact of the electron beam on the anode.
  • the cathodes have geometric shapes complicated and may include several metal electrodes separated mechanically and electrically isolated from each other.
  • An object of the present invention is therefore to produce a cathode for an X-ray tube with or without multiple electrodes, the manufacture of which is simple and of reduced cost price.
  • the invention relates to a cathode for an X-ray tube comprising at least one electron-emitting filament, characterized in that it comprises a main body which is made of an insulating material, metal electrodes which are arranged in places determined from said main body and isolated from each other by means of the insulating material of the main body and electrical conductors passing through said main body to supply said filament and apply bias voltages to said metal electrodes.
  • the main body is made of a ceramic such as alumina and the electrodes are made of molybdenum, manganese or tungsten or an alloy of these metals.
  • the cathodes of the prior art in particular those described in the aforementioned French patent applications, always include a metal part which serves as an electrode brought to a negative potential to repel the electrons emitted by a heated filament and to support said filament and to other electrodes.
  • These other electrodes are also metallic and must be electrically isolated from this metallic support part and with respect to one another.
  • the invention provides a cathode whose main body is made of an insulating material on which the different electrodes are made, the insulation between the different electrodes being obtained by the insulating material of the main body.
  • the main body 10 is, for example, an alumina block which is suitably machined to obtain the shape shown in FIGS. 1 and 2, that is to say a cylinder of revolution whose diametrical part 9 is dug in the form of stair treads referenced 12 and 13 on one side and 14.15 on the other.
  • the electrodes are obtained by metallic deposits which are placed at precise locations on the surface of the main body, in particular on the vertical and horizontal faces of the stair treads 12, 13, 14 and 15.
  • the entire surface of the horizontal face of the stair treads 12 and 14 is covered with a metallic deposit referenced respectively 16 and 18.
  • the stair treads 13 and 15 it is the entire surface of the vertical face which is covered with a metal deposit referenced 17 and 19 depending on the step concerned.
  • metal deposits 16 to 19, forming electrodes are polarized at suitable potentials by means of electrical conductors 20 to 23 which pass through the main body 10 and emerge on the horizontal faces of the stair treads.
  • the conductors 20 and 22 come directly abutant on the metal deposits 16 and 18 to which they are connected.
  • the conductors 21 and 23 are connected to the metal deposits 17 and 19 by means of metal tabs 24 and 25 which are arranged on the horizontal faces of the steps 13 and 15 and are electrically connected to the deposits 17 and 19.
  • the cathode filament (s) (reference 26) are conventionally arranged in the diametral well so as to exceed the level of the metallic deposits 16 and 18. Their electrical supply is obtained by means of conductors (reference 27) which pass through the main body 10.
  • the metal deposits 16 to 19 as well as the metal tabs 24 and 25 can be obtained in different ways, in particular, by depositing in thin layers on the alumina substrate of the main body, said substrate being suitably doped to allow the attachment of the layers. thin.
  • the dopants can be metals, such as molybdenum and manganese, which are deposited in liquid layers at the locations of the electrodes and then the assembly is heated to obtain doping of the surface layer of the body 10.
  • the material of the metallic deposits must cling to alumina from main body 10 and resist high temperatures. Suitable materials will be, for example, molybdenum, manganese, tungsten, or an alloy of two of these materials together or with other metals.
  • the deposit can be obtained by vacuum evaporation, by sublimation of metals, by ion bombardment, by plasma torch.
  • Main body 10 has been reported to be of alumina.
  • the purity of the alumina is of the order of 95% to 97%, which is a common quality.
  • the alumina can be replaced by another ceramic.
  • the geometrical precision of the position of the electrodes is determined by that of the machining of the main body which can be very large and reproducible. Compared to the cathodes of the prior art, this eliminates the mounting operations whose precision depends on the dexterity of the operators and whose reproducibility is not constant over time and from one operator to another. This also results in a lower manufacturing cost than that of the cathodes of the prior art.
  • main body 10 By using a main body 10 in one piece, the effects of expansion differentials between the different elements, in particular the electrodes separated from the cathodes of the prior art, are avoided. As a result, the deformations are very small.

Landscapes

  • Electron Sources, Ion Sources (AREA)
  • Solid Thermionic Cathode (AREA)
EP90402122A 1989-08-07 1990-07-24 Röntgenröhrenkathode und Röhre mit einer solchen Kathode Ceased EP0412868A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8910611 1989-08-07
FR8910611A FR2650703B1 (fr) 1989-08-07 1989-08-07 Cathode de tube a rayons x et tube ainsi obtenu

Publications (1)

Publication Number Publication Date
EP0412868A1 true EP0412868A1 (de) 1991-02-13

Family

ID=9384535

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90402122A Ceased EP0412868A1 (de) 1989-08-07 1990-07-24 Röntgenröhrenkathode und Röhre mit einer solchen Kathode

Country Status (3)

Country Link
US (1) US5031200A (de)
EP (1) EP0412868A1 (de)
FR (1) FR2650703B1 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2675629A1 (fr) * 1991-04-17 1992-10-23 Gen Electric Cgr Cathode pour tube a rayons x et tube ainsi obtenu.
NL1003389C2 (nl) * 1996-06-21 1997-12-23 Optische Ind Oede Oude Delftoe Röntgenbuis.
US20160217965A1 (en) * 2015-01-28 2016-07-28 Varian Medical Systems, Inc. X-ray tube having a dual grid and dual filament cathode

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5303281A (en) * 1992-07-09 1994-04-12 Varian Associates, Inc. Mammography method and improved mammography X-ray tube
DE19510048C2 (de) * 1995-03-20 1998-05-14 Siemens Ag Röntgenröhre
US6785359B2 (en) * 2002-07-30 2004-08-31 Ge Medical Systems Global Technology Company, Llc Cathode for high emission x-ray tube
US7012989B2 (en) * 2002-09-03 2006-03-14 Parker Medical, Inc. Multiple grooved x-ray generator
WO2004079762A2 (en) * 2003-03-03 2004-09-16 Koninklijke Philips Electronics N.V. X-ray tube cathode assembly and interface reaction joining process
US7466799B2 (en) * 2003-04-09 2008-12-16 Varian Medical Systems, Inc. X-ray tube having an internal radiation shield
US7657002B2 (en) * 2006-01-31 2010-02-02 Varian Medical Systems, Inc. Cathode head having filament protection features
US11232926B2 (en) 2015-11-13 2022-01-25 Koninklijke Philips N.V. Cathode for an X-ray tube
EP3496127A1 (de) 2017-12-07 2019-06-12 Koninklijke Philips N.V. Kathodenbaugruppenkomponente zur röntgenbildgebung
EP4177927A1 (de) * 2021-11-09 2023-05-10 Koninklijke Philips N.V. Röntgenröhre

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3753022A (en) * 1971-04-26 1973-08-14 Us Army Miniature, directed, electron-beam source
FR2267637A1 (de) * 1974-04-11 1975-11-07 Philips Nv

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3001141A1 (de) * 1980-01-14 1981-07-16 Siemens AG, 1000 Berlin und 8000 München Kathodenanordnung fuer eine roentgenroehre
JPS59165353A (ja) * 1983-03-11 1984-09-18 Toshiba Corp 回転陽極型ｘ線管

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3753022A (en) * 1971-04-26 1973-08-14 Us Army Miniature, directed, electron-beam source
FR2267637A1 (de) * 1974-04-11 1975-11-07 Philips Nv

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2675629A1 (fr) * 1991-04-17 1992-10-23 Gen Electric Cgr Cathode pour tube a rayons x et tube ainsi obtenu.
NL1003389C2 (nl) * 1996-06-21 1997-12-23 Optische Ind Oede Oude Delftoe Röntgenbuis.
WO1997049115A1 (en) * 1996-06-21 1997-12-24 B.V. Optische Industrie 'de Oude Delft' X-ray tube
US20160217965A1 (en) * 2015-01-28 2016-07-28 Varian Medical Systems, Inc. X-ray tube having a dual grid and dual filament cathode
WO2016123405A1 (en) * 2015-01-28 2016-08-04 Varian Medical Systems, Inc. X-ray tube having a dual grid for steering and focusing the electron beam and dual filament cathode
US9779907B2 (en) 2015-01-28 2017-10-03 Varex Imaging Corporation X-ray tube having a dual grid and dual filament cathode
CN107408482A (zh) * 2015-01-28 2017-11-28 万睿视影像有限公司 具有用于转向和聚焦电子束的双栅格和双灯丝阴极的x射线管

Also Published As

Publication number Publication date
US5031200A (en) 1991-07-09
FR2650703B1 (fr) 1991-10-11
FR2650703A1 (fr) 1991-02-08

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