EP0168777A2 - X-ray tube - Google Patents

X-ray tube Download PDF

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Publication number
EP0168777A2
EP0168777A2 EP85108638A EP85108638A EP0168777A2 EP 0168777 A2 EP0168777 A2 EP 0168777A2 EP 85108638 A EP85108638 A EP 85108638A EP 85108638 A EP85108638 A EP 85108638A EP 0168777 A2 EP0168777 A2 EP 0168777A2
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EP
European Patent Office
Prior art keywords
cathode
ray tube
hole
concave mirror
anode
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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.)
Granted
Application number
EP85108638A
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German (de)
French (fr)
Other versions
EP0168777A3 (en
EP0168777B1 (en
Inventor
Hans-Erik Hjelmrodt
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Scanray AS
Original Assignee
Scanray AS
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Publication of EP0168777A2 publication Critical patent/EP0168777A2/en
Publication of EP0168777A3 publication Critical patent/EP0168777A3/en
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Publication of EP0168777B1 publication Critical patent/EP0168777B1/en
Expired 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
    • 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

Definitions

  • the invention relates to an X-ray tube of the type mentioned in the preamble of claim 1.
  • an X-ray tube of the type in question is known, in the evacuated piston of which a hot cathode surrounded by a grid, a hole anode and a target are arranged.
  • the hot cathode consists of a wire whose dimensions are large compared to the dimensions of the electron exit surface.
  • a device for achieving an increased surface temperature is provided at the point at which the electric field between the anode and cathode reaches its highest value. In this way, the smallest possible expansion of the electron exit area on the cathode is to be achieved.
  • external radiation is also provided, for example by exposure to light, infrared radiation or by means of a laser.
  • This radiation effect is stated to be complicated, while it is described as much simpler and just as effective to surround the hot cathode with a body which absorbs heat radiation in such a way that more radiation is absorbed from all sides of the surface of the filament than from the desired electron exit area.
  • the grid surrounding the cathode is provided as the heat-absorbing body.
  • the absorption of heat radiation from the hot cathode is done fairly evenly by everyone Surface areas of the hot cathode, also from the electron exit surface.
  • the invention has for its object to provide an X-ray tube of the type in question, in which the disadvantages of the known X-ray tube are not present, so that such a temperature difference on the surface of the glow-predominantly cathode is achieved without external radiation and without cooling measures Electrons / emerge from an extremely small area of the cathode, so as to facilitate the focusing of the electron beam.
  • the radiation emanating from the hot cathode itself is focused by optical means onto a small spot on the surface of the hot cathode, so that there is an increase in temperature in relation to the surrounding area.
  • the concave mirror can be arranged in a simple and expedient manner coaxial to the electron beam going from the cathode through the hole of the hole anode to the target, in which case a hole is provided in the concave mirror through which the electron beam can pass.
  • Special purpose It is moderate if the concave mirror is formed according to a development of the invention by the surface of the hole anode facing the cathode and preferably mirrored. This means that apart from a corresponding design of the hole anode and the mirroring, no additional measures are required in order to achieve the desired temperature increase in a narrowly limited focal point.
  • the development of the invention specified in claim 4 has the effect that the cathode, which is generally a V-shaped filament, is kept at such a temperature by electric heating that few electrons can escape from the surface.
  • the heat radiation is then sufficient, however, to achieve such an increase in temperature after focusing through the concave mirror on a fine point on the surface of the cathode that sufficient electrons can escape at this fine point.
  • the drawing shows, partially in section, an X-ray tube with a housing 1, which is connected to a line 2, which is connected to a pump, not shown, for lowering the pressure in the interior 3 of the X-ray tube.
  • a cathode 4 in the form of a small filament, which is bent in a V-shape and with its tip facing an anode 5 and a target 6.
  • a grid cap 7 is arranged in the region of the cathode 4, which projects into an opening 8 in the grid cap 7 and whose tip is approximately aligned with the front boundary of the opening 8. From this front boundary, the grille cap 7 widens in a conical surface 9.
  • a focusing coil 13 is arranged in the area of the metallic tube 10.
  • deflection coils 14 and 15 provided with which the electron beam can be deflected and which are of no further importance for the understanding of the invention.
  • the target 6 has an inclination to the axis 6 of the X-ray tube, indicated by a dash-dotted line, and is held in a holder 17 which is connected via pipes 18 and 19 to a cooling source (not shown) for the purpose of cooling the target.
  • a window 20 in the housing Radially next to the surface of the target 6 there is a window 20 in the housing through which X-rays emanating from the target 6 can emerge in the area between two dashed lines 21 and 22.
  • the angle between a central axis of the emerging x-rays, indicated by a broken line 23, and the surface of the target 6 is approximately + 45 degrees.
  • the usual supply voltages are applied to the cathode 4, the grid cap 7 and the hole anode 5, which require no explanation here.
  • the hole anode 5 has on its side facing the cathode 4 a hollow surface 24 which is designed to be specular and shaped so that heat radiation is reflected by the cathode 4 and is focused on a fine point on the tip of the V-shaped cathode 4. At this focal point, the temperature rises such that electrons essentially only emerge at this fine point. This results in a very fine electron beam and consequently also a very small spot of impact of the electron beam on the target 6, so that an X-ray tube with a very fine focus is created. The fine electron beam also makes focusing easier.

Abstract

1. X-ray tube, with a cathode, wich an apertured anode, with a target and with a means for directing electromagnetic radiation on to a spot on that surface of the cathode which is facing the apertured anode, characterised in that the arrangement consists of a concave mirror (24), which is arranged in the heat radiation range of the cathode (4) and the focal point of which lies on the surface of the cathode (4).

Description

Die Erfindung betrifft eine Röntgenröhre der im Oberbegriff des Anspruchs 1 genannten Art.The invention relates to an X-ray tube of the type mentioned in the preamble of claim 1.

Durch die DE-OS 32 22 511 ist eine Röntgenröhre der betreffenden Art bekannt, in deren evakuiertem Kolben eine von einem Gitter umgebene Glühkathode, eine Lochanode und ein Target angeordnet sind. Die Glühkathode besteht aus einem Draht, dessen Dimensionen groß gegenüber den Dimensionen der Elektronenaustrittsfläche sind. Außerdem ist eine Vorrichtung zur Erzielung einer erhöhten Oberflächentemperatur an derjenigen Stelle vorgesehen, an der das elektrische Feld zwischen Anode und Kathode seinen höchsten Wert erreicht. Auf diese Weise soll eine möglichst geringe Ausdehnung der Elektronenaustrittsfläche auf der Kathode erzielt werden. Zur Erzeugung des winzigen Flecks erhöhter Temperatur auf der Kathode ist u.a. auch eine äußere Strahlungseinwirkung z.B. durch Lichteinstrahlung, Infraroteinstrahlung oder mittels eines Lasers vorgesehen. Die Schaffung dieser Strahlungseinwirkung ist als kompliziert angegeben, während es als viel einfacher und ebenso wirkungsvoll bezeichnet ist, die Glühkathode mit einem Wärmestrahlung absorbierenden Körper so zu umgeben, daß von allen Seiten der Oberfläche des Glühdrahtes mehr Strahlung absorbiert wird als von der gewünschten Elektronenaustrittsfläche. Als wärmeabsorbierender Körper ist das die Kathode umgebende Gitter vorgesehen. Die Aufnahme von Wärmestrahlung von der Glühkathode erfolgt jedoch ziemlich gleichmäßig von allen Oberflächenbereichen der Glühkathode, auch von der Elektronenaustrittsfläche her. Zwar ist die Wärmestrahlungsaufnahme von der Elektronenaustrittsfläche geringer als von anderen Oberflächenbereichen der Glühkathode, jedoch ist dieser Kühlungsunterschied so gering, daß sich der gewünschte Unterschied in der Oberflächentemperatur nicht erreichen läßt, zumal auch eine Kühlung der Elektronenaustrittsfläche von der Lochanode her erfolgt, die eine niedrige Temperatur hat. Weder die Temperaturerhöhung im Bereich der Elektronenaustrittsfläche durch äußere Strahlungseinwirkung noch durch Kühlung umgebender Bereiche führt daher zu einer brauchbaren Lösung.From DE-OS 32 22 511 an X-ray tube of the type in question is known, in the evacuated piston of which a hot cathode surrounded by a grid, a hole anode and a target are arranged. The hot cathode consists of a wire whose dimensions are large compared to the dimensions of the electron exit surface. In addition, a device for achieving an increased surface temperature is provided at the point at which the electric field between the anode and cathode reaches its highest value. In this way, the smallest possible expansion of the electron exit area on the cathode is to be achieved. To generate the tiny spot of elevated temperature on the cathode, external radiation is also provided, for example by exposure to light, infrared radiation or by means of a laser. The creation of this radiation effect is stated to be complicated, while it is described as much simpler and just as effective to surround the hot cathode with a body which absorbs heat radiation in such a way that more radiation is absorbed from all sides of the surface of the filament than from the desired electron exit area. The grid surrounding the cathode is provided as the heat-absorbing body. However, the absorption of heat radiation from the hot cathode is done fairly evenly by everyone Surface areas of the hot cathode, also from the electron exit surface. Although the heat radiation absorption from the electron exit surface is lower than from other surface areas of the hot cathode, this cooling difference is so small that the desired difference in the surface temperature cannot be achieved, especially since the electron exit surface is also cooled from the hole anode, which is at a low temperature Has. Neither the temperature increase in the area of the electron exit surface due to external radiation nor through cooling of surrounding areas therefore leads to a usable solution.

Der Erfindung liegt die Aufgabe zugrunde, eine Röntgenröhre der betreffenden Art zu schaffen, bei der die Nachteile der bekannten Röntgenröhre nicht vorhanden sind, bei der also ohne äußere Strahlungseinwirkung und ohne Kühlungsmaßnahmen ein solcher Temperaturunterschied auf der Oberfläche der Glüh- überwiegend kathode erzielt wird, daß Elektronen / von einer äußerst geringen Fläche der Kathode austreten, um so die Fokussierung des Elektronenstrahls zu erleichtern.The invention has for its object to provide an X-ray tube of the type in question, in which the disadvantages of the known X-ray tube are not present, so that such a temperature difference on the surface of the glow-predominantly cathode is achieved without external radiation and without cooling measures Electrons / emerge from an extremely small area of the cathode, so as to facilitate the focusing of the electron beam.

Die der Erfindung zugrundeliegende Aufgabe wird durch die im Kennzeichen des Anspruchs 1 angegebene Lehre gelöst.The object on which the invention is based is achieved by the teaching specified in the characterizing part of claim 1.

Nach dem Grundgedanken der Erfindung wird die von der Glühkathode selbst ausgehende Strahlung durch optische Mittel auf einen kleinen Fleck auf der Oberfläche der Glühkathode fokussiert, so daß dort eine Temperaturerhöhung in bezug zu dem Umgebungsbereich stattfindet. Durch entsprechende Bemessung der strahlenden Oberfläche der Glühkathode und den die Strahlung zurückwerfenden Hohlspiegel läßt sich erreichen, daß Elektronen nur in diesem Fokussionspunkt aus der Oberfläche der Kahtode austreten können, während die Temperatur in den umgebenden Bereichen so gering ist, daß dort keine oder nur wenige Elektronen austreten.According to the basic idea of the invention, the radiation emanating from the hot cathode itself is focused by optical means onto a small spot on the surface of the hot cathode, so that there is an increase in temperature in relation to the surrounding area. By appropriate dimensioning of the radiating surface of the hot cathode and the concave mirror reflecting the radiation, it can be achieved that electrons can only emerge from the surface of the cathode at this focal point, while the temperature in the surrounding areas is so low that no or only a few electrons there emerge.

Der Hohlspiegel läßt sich in einfacher und zweckmäßiger Weise koaxial zu dem von der Kathode durch das Loch der Lochanode zu dem Target gehenden Elektronenstrahl anordnen, wobei dann in dem Hohlspiegel ein Loch vorgesehen ist, durch das der Elektronenstrahl hindurchtreten kann. Besonders zweckmäßig ist es dabei, wenn der Hohlspiegel gemäß einer Weiterbildung der Erfindung durch die der Kathode zugewandte und vorzugsweise verspiegelte Oberfläche der Lochanode gebildet ist. Das bedeutet, daß außer einer entsprechenden Gestaltung der Lochanode und der Verspiegelung keine zusätzlichen Maßnahmen erforderlich sind, um die gewünschte Temperaturerhöhung in einem eng begrenzten Fokuspunkt zu erzielen.The concave mirror can be arranged in a simple and expedient manner coaxial to the electron beam going from the cathode through the hole of the hole anode to the target, in which case a hole is provided in the concave mirror through which the electron beam can pass. Special purpose It is moderate if the concave mirror is formed according to a development of the invention by the surface of the hole anode facing the cathode and preferably mirrored. This means that apart from a corresponding design of the hole anode and the mirroring, no additional measures are required in order to achieve the desired temperature increase in a narrowly limited focal point.

Die in Anspruch 4 angegebene Weiterbildung der Erfindung bewirkt, daß durch elektrische Heizung die Kathode, die in der Regel ein V-förmig-gebogener Glühdraht ist, auf einer solchen Temperatur gehalten wird, daß wenige Elektronen aus der Oberfläche austreten können. Die Wärmestrahlung reicht dann aber aus, um nach Fokussierung durch den Hohlspiegel auf einen feinen Punkt auf der Oberfläche der Kathode dort eine solche Temperaturerhöhung zu erzielen, daß an diesem feinen Punkt genügend Elektronen austreten können.The development of the invention specified in claim 4 has the effect that the cathode, which is generally a V-shaped filament, is kept at such a temperature by electric heating that few electrons can escape from the surface. The heat radiation is then sufficient, however, to achieve such an increase in temperature after focusing through the concave mirror on a fine point on the surface of the cathode that sufficient electrons can escape at this fine point.

Anhand der Zeichnung soll die Erfindung an einem Ausführungsbeispiel näher erläutert werden.The invention will be explained in more detail using an exemplary embodiment with reference to the drawing.

Die Zeichnung zeigt teilweise geschnitten eine Röntgenröhre mit einem Gehäuse 1, das an eine Leitung 2 angeschlossen ist, die mit einer nicht dargestellten Pumpe zur Absenkung des Druckes im Innenraum 3 der Röntgenröhre verbunden ist.The drawing shows, partially in section, an X-ray tube with a housing 1, which is connected to a line 2, which is connected to a pump, not shown, for lowering the pressure in the interior 3 of the X-ray tube.

Im Innenraum 3 befindet sich eine Kathode 4 in Form eines kleinen Glühdrahtes, der V-förmig gebogen ist und mit seiner Spitze einer Anode 5 und einem Target 6 zugewandt ist. Eine Gitterkappe 7 ist im Bereich der Kathode 4 angeordnet, die in einen Durchbruch 8 der Gitterkappe 7 ragt und mit ihrer Spitze etwa mit der vorderen Begrenzung des Durchbruchs 8 fluchtet. Von dieser vorderen Begrenzung aus erweitert sich die Gitterkappe 7 in einer Kegelfläche 9.In the interior 3 there is a cathode 4 in the form of a small filament, which is bent in a V-shape and with its tip facing an anode 5 and a target 6. A grid cap 7 is arranged in the region of the cathode 4, which projects into an opening 8 in the grid cap 7 and whose tip is approximately aligned with the front boundary of the opening 8. From this front boundary, the grille cap 7 widens in a conical surface 9.

Auf der Rückseite der Lochanode 5 befindet sich eine Röhre 10 mit variablem Durchmesser, die mit der Lochanode 5 leitend verbunden ist. Durch die Lochanode 5 verläuft ein Loch 11, das sich in einen Innenraum 12 der metallischen Röhre 10 fortsetzt.On the back of the hole anode 5 there is a tube 10 with a variable diameter, which is conductively connected to the hole anode 5. A hole 11 runs through the hole anode 5 and continues into an interior 12 of the metallic tube 10.

Im Bereich der metallischen Röhre 10 ist eine Fokussierspule 13 angeordnet. Außerdem sind Ablenkspulen 14 und 15 vorgesehen, mit denen der Elektronenstrahl ablenkbar ist und die für das Verständnis der Erfindung nicht weiter von Bedeutung sind.A focusing coil 13 is arranged in the area of the metallic tube 10. There are also deflection coils 14 and 15 provided with which the electron beam can be deflected and which are of no further importance for the understanding of the invention.

Das Target 6 weist zu der durch eine strichpunktierte Linie angedeuteten Achse 6 der Röntgenröhre eine Neigung auf und ist in einer Halterung 17 gehalten, die zum Zwecke der Kühlung des Targets über Rohrleitungen 18 und 19 an eine nicht gezeigte Kühlquelle angeschlossen ist.The target 6 has an inclination to the axis 6 of the X-ray tube, indicated by a dash-dotted line, and is held in a holder 17 which is connected via pipes 18 and 19 to a cooling source (not shown) for the purpose of cooling the target.

Radial neben der Oberfläche des Targets 6 befindet sich in dem Gehäuse ein Fenster 20, durch das von dem Target 6 ausgehende Röntgenstrahlung im Bereich zwischen zwei gestrichelten Linien 21 und 22 austreten kann. Der Winkel zwischen einer durch eine gestrichelte Linie 23 angedeuteten Mittelachse der austretenden Röntgenstrahlung und der Oberfläche des Targets 6 beträgt circa +45 Grad. Bei Betrieb sind an die Kathode 4, die Gitterkappe 7 und die Lochanode 5 die üblichen Speisespannungen gelegt, die hier keiner Erläuterung bedürfen.Radially next to the surface of the target 6 there is a window 20 in the housing through which X-rays emanating from the target 6 can emerge in the area between two dashed lines 21 and 22. The angle between a central axis of the emerging x-rays, indicated by a broken line 23, and the surface of the target 6 is approximately + 45 degrees. In operation, the usual supply voltages are applied to the cathode 4, the grid cap 7 and the hole anode 5, which require no explanation here.

Die Lochanode 5 weist auf ihrer der Kathode 4 zugewandten Seite eine Hohlfläche 24 auf, die spiegelnd ausgebildet und so geformt ist, daß Wärmestrahlung von der Kathode 4 reflektiert und auf einen feinen Punkt auf der Spitze der V-förmigen Kathode 4 fokussiert wird. In diesem Brennpunkt erfolgt eine solche Temperaturerhöhung, daß Elektronen im wesentlichen nur in diesem feinen Punkt austreten. Daraus ergibt sich ein sehr feiner Elektronenstrahl und folglich auch ein sehr kleiner Auftrefffleck des Elektronenstrahls auf dem Target 6, so daß eine Röntgenröhre mit sehr feinem Fokus geschaffen ist. Der feine Elektronenstrahl erleichtert auch die Fokussierung.The hole anode 5 has on its side facing the cathode 4 a hollow surface 24 which is designed to be specular and shaped so that heat radiation is reflected by the cathode 4 and is focused on a fine point on the tip of the V-shaped cathode 4. At this focal point, the temperature rises such that electrons essentially only emerge at this fine point. This results in a very fine electron beam and consequently also a very small spot of impact of the electron beam on the target 6, so that an X-ray tube with a very fine focus is created. The fine electron beam also makes focusing easier.

Claims (4)

1. Röntgenröhre, mit einer Kathode, mit einer Lochanode, mit einem Target und mit einer Einrichtung zum Richten elektromagnetischer Strahlung auf einen Punkt auf der der Lochanode zugewandten Oberfläche der Kathode, dadurch ge- kennzeichnet, daß die Einrichtung aus einem Hohlspiegel (14) besteht, der im Wärmestrahlungsbereich der Kathode (4) angeordnet ist und dessen Brennpunkt auf der Oberfläche der Kathode (4) liegt.1. X-ray tube, with a cathode, with a hole anode, with a target and with a device for directing electromagnetic radiation to a point on the surface of the cathode facing the hole anode, characterized in that the device consists of a concave mirror (14) , which is arranged in the heat radiation region of the cathode (4) and whose focal point lies on the surface of the cathode (4). 2. Röntgenröhre nach Anspruch 1, dadurch gekenn- zeichnet, daß der Hohlspiegel (24) koaxial zu dem von der Kathode (4) durch das Loch (11) der Lochanode (5) zu dem Target (6) gehenden Elektronenstrahl angeordnet ist und im Bereich des Elektronenstrahls ebenso wie die Lochanode (5) ein Loch aufweist.2. X-ray tube according to claim 1, characterized in that the concave mirror (24) is arranged coaxially to the electron beam going from the cathode (4) through the hole (11) of the hole anode (5) to the target (6) and in Area of the electron beam as well as the hole anode (5) has a hole. 3. Röntgenröhre nach Anspruch 2, dadurch gekenn- zeichnet, daß der Hohlspiegel (24) durch die der Kathode (4) zugewandte und verspiegelte Oberfläche der Lochanode (5) gebildet ist.3. X-ray tube according to claim 2, characterized in that the concave mirror (24) by the cathode (4) facing and mirrored surface of the hole anode (5) is formed. 4. Röntgenröhre nach Anspruch 1, dadurch gekennzeichnet, daß die Kathode (4) eine elektrisch vorgeheizte Glühkathode ist, wobei die durch die Vorheizung erzeugte Temperatur im wesentlichen dicht bei der für den Austritt von Elektronen erforderlichen Temperatur liegt, während die Zufuhr elektromagnetischer Strahlung durch den Hohlspiegel (24) auf die Oberfläche der Kathode (4) so bemessen ist, daß überwiegend an diesem Punkt Elektronen austreten.4. X-ray tube according to claim 1, characterized in that the cathode (4) is an electrically preheated hot cathode, the he by the preheating witnessed temperature is substantially close to the temperature required for the exit of electrons, while the supply of electromagnetic radiation through the concave mirror (24) to the surface of the cathode (4) is dimensioned such that predominantly electrons emerge at this point.
EP19850108638 1984-07-19 1985-07-11 X-ray tube Expired EP0168777B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3426624 1984-07-19
DE19843426624 DE3426624A1 (en) 1984-07-19 1984-07-19 X-RAY TUBES

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EP0168777A2 true EP0168777A2 (en) 1986-01-22
EP0168777A3 EP0168777A3 (en) 1987-08-19
EP0168777B1 EP0168777B1 (en) 1989-02-01

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DE (1) DE3426624A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0473228A2 (en) * 1990-08-28 1992-03-04 Koninklijke Philips Electronics N.V. Improved anode for arc discharge devices
US5202910A (en) * 1990-08-28 1993-04-13 North American Philips Corporation Anode for arc discharge devices
WO2007043390A1 (en) 2005-10-07 2007-04-19 Hamamatsu Photonics K.K. X-ray tube and nondestructive inspection equipment

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3388280A (en) * 1966-04-19 1968-06-11 Victor E. De Lucia Laser energized hot cathode type of electron discharge device
US3564317A (en) * 1967-05-13 1971-02-16 Philips Corp Cathode for an x-ray tube cooled by heat-conductive coaxial cylinders
EP0096824A1 (en) * 1982-06-16 1983-12-28 feinfocus Verwaltungs GmbH & Co. KG Fine focus X-ray tube and method for the production of a finely focused electron emission from an X-ray filament cathode
EP0147009A2 (en) * 1983-12-28 1985-07-03 Kabushiki Kaisha Toshiba X-ray scanner

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE619621C (en) * 1933-09-06 1935-10-04 C H F Mueller Akt Ges X-ray tube with perforated hollow anode
DE2855905A1 (en) * 1978-12-23 1980-06-26 Licentia Gmbh DEVICE WITH A X-RAY TUBE

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3388280A (en) * 1966-04-19 1968-06-11 Victor E. De Lucia Laser energized hot cathode type of electron discharge device
US3564317A (en) * 1967-05-13 1971-02-16 Philips Corp Cathode for an x-ray tube cooled by heat-conductive coaxial cylinders
EP0096824A1 (en) * 1982-06-16 1983-12-28 feinfocus Verwaltungs GmbH & Co. KG Fine focus X-ray tube and method for the production of a finely focused electron emission from an X-ray filament cathode
EP0147009A2 (en) * 1983-12-28 1985-07-03 Kabushiki Kaisha Toshiba X-ray scanner

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0473228A2 (en) * 1990-08-28 1992-03-04 Koninklijke Philips Electronics N.V. Improved anode for arc discharge devices
EP0473228A3 (en) * 1990-08-28 1992-04-08 N.V. Philips' Gloeilampenfabrieken Improved anode for arc discharge devices
US5202910A (en) * 1990-08-28 1993-04-13 North American Philips Corporation Anode for arc discharge devices
WO2007043390A1 (en) 2005-10-07 2007-04-19 Hamamatsu Photonics K.K. X-ray tube and nondestructive inspection equipment
EP1933360A1 (en) * 2005-10-07 2008-06-18 Hamamatsu Photonics Kabushiki Kaisha X-ray tube and nondestructive inspection equipment
EP1933360A4 (en) * 2005-10-07 2010-10-20 Hamamatsu Photonics Kk X-ray tube and nondestructive inspection equipment

Also Published As

Publication number Publication date
EP0168777A3 (en) 1987-08-19
DE3426624A1 (en) 1986-01-30
DE3426624C2 (en) 1987-04-23
EP0168777B1 (en) 1989-02-01

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