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EP0412868A1 - X-ray tube cathode and tube provided with such a cathode - Google Patents

X-ray tube cathode and tube provided with such a cathode 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
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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
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German (de)
French (fr)
Inventor
André Plessis
Catherine Thomas
Paul Hery
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General Electric CGR SA
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General Electric CGR SA
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Publication date
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Publication of EP0412868A1 publication Critical patent/EP0412868A1/en
Ceased legal-status Critical Current

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    • 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.

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  • Electron Sources, Ion Sources (AREA)
  • Solid Thermionic Cathode (AREA)

Abstract

The invention relates to X-ray tubes and, more particularly, the cathodes for such tubes. The invention lies in the fact that the cathode, comprising an emitter filament 26, is produced with the aid of a main body 10 in insulating material on which are arranged metal electrodes 16 to 19 which are isolated from one another by the main body. The filament 26 and the electrodes 16 to 19 are connected to conductors 27, 21 to 23 which traverse the main body. <IMAGE>

Description

L'invention concerne les tubes à rayons X et, plus particulièrement, une cathode pour tube à rayons X.The invention relates to X-ray tubes and, more particularly, to a cathode for an X-ray tube.

Un tube à rayons X comporte, dans une enceinte sous vide, une cathode constituée d'un filament chauffé qui émet des électrons et d'un dispositif de concentration adossé au filament qui focalise les électrons émis sur une anode portée à un potentiel positif par rapport à la cathode. Le point d'impact du faisceau d'électrons sur l'anode constitue la source de rayonnement X sous la forme d'un faisceau.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.

L'évolution des systèmes d'imagerie à rayons X conduit à l'utilisation de tubes à rayons X de plus en plus complexes de manière à obtenir les fonctions souhaitées. C'est ainsi que l'on cherche à contrôler la géométrie du faisceau d'électrons qui frappe l'anode pour obtenir un point d'impact de dimensions précises et présentant une répartition énergétique aussi uniforme que possible.The evolution of X-ray imaging systems has led to the use of increasingly complex X-ray tubes in order to obtain the desired functions. Thus it is sought to control the geometry of the electron beam which strikes the anode to obtain an impact point of precise dimensions and having an energy distribution as uniform as possible.

Dans certaines applications, il est nécessaire d'obtenir des faisceaux de rayons X qui ont des énergies différentes et/ou des incidences différentes; à cet effet, la cathode peut présenter plusieurs filaments émetteurs dont il faut controler le flux d'électrons en dimensions mais aussi en direction pour obtenir des points d'impact précis du faisceau d'électrons sur l'anode.In some applications, it is necessary to obtain X-ray beams which have different energies and / or different incidences; for this purpose, 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.

Dans d'autres applications, il est nécessaire de modifier le débit du flux d'électrons et éventuellement le bloquer par une électrode appelée grille.In other applications, it is necessary to modify the flow rate of the electron flow and possibly block it by an electrode called a grid.

Pour réaliser les fonctions qui viennent d'être énumérées, les cathodes ont des formes géométriques compliquées et peuvent comporter plusieurs électrodes métalliques séparées mécaniquement et isolées électriquement les unes des autres.To carry out the functions which have just been enumerated, the cathodes have geometric shapes complicated and may include several metal electrodes separated mechanically and electrically isolated from each other.

Dans le brevet français no 2538948 déposé le 3 décembre 1982 et intitulé : "TUBE A RAYONS X A BALAYAGE" ainsi que dans la demande de brevet français no 89 03888 déposée le 24 mars 1989 et intitulée : "TUBE A RAYONS X A BALAYAGE AVEC PLAQUES DE DEFLEXION", la demanderesse a décrit des cathodes de tubes à rayons X qui sont réalisées à l'aide d'électrodes multiples dont la fabrication et l'assemblage sont difficiles et d'un prix de revient élevé.In French Patent No. 2538948 filed December 3, 1982 and entitled "TUBE X-RAY SCAN" and in the French patent application No. 89 03888 filed on 24 March 1989 and entitled "RAY TUBE XA SWEEP WITH PLATE DE DEFLEXION ", the Applicant has described cathodes of X-ray tubes which are produced using multiple electrodes whose fabrication and assembly are difficult and of a high cost price.

Un but de la présente invention est donc de réaliser une cathode pour tube à rayons X à électrodes multiples ou non dont la fabrication soit simple et d'un prix de revient réduit.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.

L'invention se rapporte à une cathode pour tube à rayons X comportant au moins un filament émetteur d'électrons, caractérisée en ce qu'elle comprend un corps principal qui est réalisé en un matériau isolant, des électrodes métalliques qui sont disposées en des endroits déterminés dudit corps principal et isolées les unes des autres grâce au matériau isolant du corps principal et des conducteurs électriques traversant ledit corps principal pour alimenter ledit filament et appliquer des tensions de polarisation auxdites électrodes métalliques.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.

Le corps principal est réalisé en une céramique telle que l'alumine et les électrodes sont en molybdène, manganèse ou tungstène ou un alliage de ces métaux.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.

D'autres caractéristiques et avantages de la présente invention apparaîtront à la lecture de la description suivante d'un exemple particulier de réalisation, ladite description étant faite en relation avec les dessins joints dans lesquels :

  • - la figure 1 est une vue en perspective cavalière d'un exemple, de réalisation selon l'invention d'une cathode de tube à rayons X, et
  • - la figure 2 est une vue en coupe suivant la ligne II-II de la figure 1.
Other characteristics and advantages of the present invention will appear on reading the following description of a particular embodiment, said description being given in relation to the drawings joints in which:
  • FIG. 1 is a perspective view of an example of an embodiment according to the invention of an X-ray tube cathode, and
  • - Figure 2 is a sectional view along line II-II of Figure 1.

Les cathodes de l'art antérieur, notamment celles décrites dans les demandes de brevets français précitées, comportent toujours une partie métallique qui sert d'électrode portée à un potentiel négatif pour éloigner les électrons émis par un filament chauffé et de support audit filament et à d'autres électrodes. Ces autres électrodes sont également métalliques et doivent être isolées électriquement de cette partie métallique de support et l'une par rapport à l'autre.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.

L'invention propose une cathode dont le corps principal est en un matériau isolant sur lequel sont réalisées les différentes électrodes, l'isolation entre les différentes électrodes étant obtenue par le matériau isolant du corps principal.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.

Plus précisément, le corps principal 10 est, par exemple, un bloc d'alumine qui est convenablement usiné pour obtenir la forme représentée sur les figures 1 et 2, c'est-à-dire un cylindre de révolution dont la partie diamétrale 9 est creusée en forme de marches d'escalier référencées 12 et 13 d'un côté et 14,15 de l'autre. Les électrodes sont obtenues par des dépôts métalliques qui sont disposés à des endroits précis de la surface du corps principal, notamment sur le faces verticales et horizontales des marches d'escalier 12,13,14 et 15. Par exemple, toute la superficie de la face horizontale des marches d'escalier 12 et 14 est recouverte d'un dépôt métallique référencé respectivement 16 et 18. Par ailleurs, pour les marches d'escalier 13 et 15, c'est toute la surface de la face verticale qui est recouverte d'un dépôt métallique référencé 17 et 19 selon la marche concernée.More specifically, 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. For example, 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. Furthermore, for 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.

Ces dépôts métalliques 16 à 19, formant électrodes, sont polarisés à des potentiels appropriés par l'intermédiaire de conducteurs électriques 20 à 23 qui traversent le corps principal 10 et émergent sur les faces horizontales des marches d'escalier. Dans le cas des marches 12 et 14 les conducteurs 20 et 22 viennent directement abuter sur les dépôts métalliques 16 et 18 auxquels ils sont connectés. Dans le cas des marches 13 et 15, les conducteurs 21 et 23 sont connectés aux dépôts métalliques 17 et 19 par l'intermédiaire de languettes métalliques 24 et 25 qui sont disposées sur les faces horizontales des marches 13 et 15 et sont connectées électriquement aux dépôts métalliques 17 et 19.These 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. In the case of steps 12 and 14 the conductors 20 and 22 come directly abutant on the metal deposits 16 and 18 to which they are connected. In the case of steps 13 and 15, 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.

Le ou les filaments de cathode (référence 26) sont disposés de manière classique dans le puits diamétral de manière à dépasser le niveau des dépôts métalliques 16 et 18. Leur alimentation électrique est obtenue par l'intermédiaire de conducteurs (référence 27) qui traversent le corps principal 10.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.

Les dépôts métalliques 16 à 19 ainsi que les languettes métalliques 24 et 25 peuvent être obtenus de différentes manières, notamment, par dépôt en couches minces sur le substrat d'alumine du corps principal, ledit substrat étant convenablement dopé pour permettre l'accrochage des couches minces. Les dopants peuvent être des métaux, tels que le molybdène et le manganèse, qui sont déposés en couches liquides aux endroits des électrodes puis l'ensemble est chauffé pour obtenir le dopage de la couche superficielle du corps 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.

Le matériau des dépôts métalliques doit s'accrocher à l'alumine du corps principal 10 et résister aux hautes températures. Les matériaux appropriés seront, par exemple, le molybdène, le manganèse, le tungstène, ou un alliage de deux de ces matériaux entre eux ou avec d'autres métaux. Le dépôt peut être obtenu par évaporation sous vide, par sublimation des métaux, par bombardement ionique, par torche à plasma.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.

On a indiqué que le corps principal 10 était en alumine. La pureté de l'alumine est de l'ordre de 95% à 97%, ce qui est une qualité courante. L'alumine peut être remplacé par une autre céramique.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.

Avec une cathode pour tube à rayons X réalisée selon la présente invention, la précision géométrique de la position des électrodes est détérminée par celle de l'usinage du corps principal qui peut être très grande et reproductible. Par rapport aux cathodes de l'art antérieur, on élimine ainsi les opérations de montage dont la précision dépend de la dextérité des opérateurs et dont la reproductibilité n'est pas constante au cours du temps et d'un opérateur à l'autre. Il en résulte, en outre, un coût de fabrication plus faible que celui des cathodes de l'art antérieur.With an cathode for an X-ray tube produced according to the present invention, 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.

Par l'utilisation d'un corps principal 10 d'une seule pièce, on évite les effets des différentiels de dilatation entre les différents éléments, notamment, les électrodes séparées des cathodes de l'art antérieur. Il en résulte que les déformations sont très faibles.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.

Enfin, comme le corps principal 10 est isolant, les conducteurs électriques (27) d'alimentation du filament 26 et de polarisation (21 à 23) des électrodes 16 à 19, traversent ledit corps sans gaine autour des conducteurs 21 à 23 et 27 simplifie la fabrication des cathodes et abaisse leur prix de revient.Finally, as the main body 10 is insulating, the electrical conductors (27) for supplying the filament 26 and for biasing (21 to 23) of the electrodes 16 to 19, pass through the said sheathless body around the conductors 21 to 23 and 27 simplifies manufacturing cathodes and lowering their cost price.

Claims (6)

1. Cathode de tube à rayons X comportant au moins un filament (26) émetteur d'électrons, caractérisée en ce qu'elle comprend un corps principal (10) qui est réalisé en un matériau isolant, des électrodes métalliques (16 à 19) qui sont disposées en des endroits déterminés dudit corps principal et isolées les unes des autres grâce au matériau isolant du corps principal et des conducteurs électriques (21 à 23) traversant ledit corps principal (10) pour alimenter ledit filament (26) et appliquer des tensions de polarisation auxdites électrodes métalliques (16 à 19).1. X-ray tube cathode comprising at least one electron-emitting filament (26), characterized in that it comprises a main body (10) which is made of an insulating material, metal electrodes (16 to 19) which are arranged in specific locations of said main body and isolated from each other by means of the insulating material of the main body and of the electrical conductors (21 to 23) passing through said main body (10) to supply said filament (26) and apply voltages of polarization to said metal electrodes (16 to 19). 2. Cathode selon la revendication 1, caractérisée en ce que le matériau isolant est une céramique.2. Cathode according to claim 1, characterized in that the insulating material is a ceramic. 3. Cathode selon la revendication 1, caractérisée en ce que le matériau isolant est de l'alumine.3. Cathode according to claim 1, characterized in that the insulating material is alumina. 4. Cathode selon la revendication 1, 2 ou 3, caractérisée en ce que le matériau isolant du corps principal est dopé en éléments métalliques, au moins aux endroits des électrodes métalliques, de manière à permettre l'accrochage desdites électrodes;4. Cathode according to claim 1, 2 or 3, characterized in that the insulating material of the main body is doped with metallic elements, at least at the locations of the metallic electrodes, so as to allow the attachment of said electrodes; 5. Cathode selon l'une quelconque des revendications précédentes, caractérisée en ce que le métal des électrodes métalliques (16 à 19) est choisi dans le groupe comportant le molybdène, le manganèse, le tungstène.5. Cathode according to any one of the preceding claims, characterized in that the metal of the metal electrodes (16 to 19) is chosen from the group comprising molybdenum, manganese, tungsten. 6. Tube à rayons X caractérisé en ce qu'il comporte une cathode selon l'une quelconque des revendications précédentes 1 à 5.6. X-ray tube characterized in that it comprises a cathode according to any one of the preceding claims 1 to 5.
EP90402122A 1989-08-07 1990-07-24 X-ray tube cathode and tube provided with such a cathode Ceased EP0412868A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8910611A FR2650703B1 (en) 1989-08-07 1989-08-07 X-RAY TUBE CATHODE AND TUBE THUS OBTAINED
FR8910611 1989-08-07

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EP0412868A1 true EP0412868A1 (en) 1991-02-13

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EP (1) EP0412868A1 (en)
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US20160217965A1 (en) * 2015-01-28 2016-07-28 Varian Medical Systems, Inc. X-ray tube having a dual grid and dual filament cathode

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US6785359B2 (en) * 2002-07-30 2004-08-31 Ge Medical Systems Global Technology Company, Llc Cathode for high emission x-ray tube
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JP4516565B2 (en) * 2003-03-03 2010-08-04 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ X-ray tube cathode assembly and interfacial reaction bonding 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
CN108352282B (en) 2015-11-13 2020-05-22 皇家飞利浦有限公司 Method for assembling a cathode for an X-ray tube
EP3496127A1 (en) 2017-12-07 2019-06-12 Koninklijke Philips N.V. Cathode assembly component for x-ray imaging
EP4177927A1 (en) * 2021-11-09 2023-05-10 Koninklijke Philips N.V. X-ray tube

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Publication number Priority date Publication date Assignee Title
FR2675629A1 (en) * 1991-04-17 1992-10-23 Gen Electric Cgr Cathode for X-ray tube and tube thus obtained
NL1003389C2 (en) * 1996-06-21 1997-12-23 Optische Ind Oede Oude Delftoe X-ray tube.
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 (en) * 2015-01-28 2017-11-28 万睿视影像有限公司 With for turning to and focusing on the double grid lattice of electron beam and the X-ray tube of double filament cathodes

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US5031200A (en) 1991-07-09
FR2650703B1 (en) 1991-10-11

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