US1717309A - X-ray tube - Google Patents

X-ray tube Download PDF

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Publication number
US1717309A
US1717309A US35930A US3593025A US1717309A US 1717309 A US1717309 A US 1717309A US 35930 A US35930 A US 35930A US 3593025 A US3593025 A US 3593025A US 1717309 A US1717309 A US 1717309A
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US
United States
Prior art keywords
anticathode
ray tube
ray
ray tubes
tungsten
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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.)
Expired - Lifetime
Application number
US35930A
Inventor
Bouwers Albert
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.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
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Filing date
Publication date
Application filed by Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
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Publication of US1717309A publication Critical patent/US1717309A/en
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Expired - Lifetime legal-status Critical Current

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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00X-ray tubes
    • H01J35/02Details
    • H01J35/04Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/08Anodes; Anti cathodes
    • H01J35/12Cooling non-rotary anodes

Definitions

  • This invention relates to X-ray tubes, more particularly to X-ray tubes in which the active portion of the anticathode is made of tungsten.
  • WVhen using X-ray tubes for radiographic purposes great energy is as a rule concentrated for a very short time on a small portion of the anticathode, but also in X-ray tubes for therapeutic purposes great energy is frequently supplied to the anticathode.
  • Many means for carrying off this energy have been proposed which may be based on heat conduction or on heat radiation. In spite of these means it occurs, however, that the energy supplied to the anticathode cannot be carried off so quickly that the anticathode is prevented from disintegrating.
  • An object of the invention is to provide a' construction of an Xray tube in which much energy can be carried off from a very small focal spot. Another object of the invention is to diminish the risk of disintegration of the anticathode. A further object of the invention is to provide an X-ray tube showing a very effective cooling of the active surface of the anticathode.
  • the tungsten anticathode of an X-ray tube of the incandescent cathode type is hollowed at the place of the focal spot.
  • the focal spot in such an X-ray tube being consequently located in a cavity of the anticathode, the cooling is much more effective than in X-ray tubes having a plane anticathode, for in X-ray tubes according to the invention the ratio of the surface of the anticathode portion struck by the cathode-rays and the section of the beam of X-rays leaving the anticathode will be greater than it is in X-ray tubes having a plane anticathode. In X-ray tubes having a.
  • plan-e anticathode the surface of which forms an angle of with the direction of the X-ray beam, the ratio of the surface of the focal spot and the section of the leaving beam of X-rays is about 2 whereas r in X-ray tubes according to the invention comprising an anticathode with a cavity having the form of a cone the solid angle of which is for example 30, the ratio of the surface of the focal spot and the section of the beam of X-rays leaving the anticathode in the direction of the axis of the cone, will be about 4.2. For that. reason, too, the cooling of the anticathode at a given sharpness of image will be more intensive than an X-ray tube in Which-the active portion of the anticathode forms a plane. d
  • An additional advantage of X-ray tubes according to the invention exists in that in the cavity of the anticathode there is a space nearly free from any electric field.
  • X-ray tubes as hitherto known it often occurs that the strong field between the cathode and the anticathode draws tungsten particles off'the incandescent anticathode, which,on the contrary in X-ray tubes according to the invention owing to the presence of said space nearly free from any electric field, occurs to a less extent so that also on that account the possibility of the anticathode being damaged is diminished.
  • An incandescent cathode 2 is fiXed in a metal vessel 1 to the wall of which is secured a metal cover 3 having an aperture in front of which stretches part of the surface of an anticathode 4.
  • the anticathode of an X-raytube is provided with a tungsten target mounted in a copper body.
  • the anticathodeof the tube illustrated which on the outsidemay consist for example, of chrome-iron, comode X-ray tubes hitherto known in that the tungsten body 5 has a hollow conical face.
  • a window for the passage of the X-rays generated is generated in the metal vessel opposite the anticathode.
  • This window consists of a glass hood 7 which is hermetically sealed to the metal wall, an annular metal plate 8, for example, of iron being provided for screening the X-rays and for preventing the Weld 9 from being struck by cathode rays.
  • One leading-in wire 10 for the incandescent cathode passes insulatingly through the metal ring 8 and is sealed into the glass hood 7 the other leading-in wire is formed by the conductive connection of the pole 11 with the metal ring 8 and the metal :nvelope 1.
  • the X-ray tube is either highly evacuted or has a gaseous filling of hydrogen or helium hav-' ing a pressure above 0.0006 millimetre of mercury which is such that any gas ionization can be obtained.
  • An X-ray tube comprising an incandes- 15 cent filament cathode and an anticathode consisting partly of tungsten, the anticathode being hollowed at the place of the focal spot.
  • An X-ray tube comprising an incandescent filament cathode and ananticathode pro- Vided With a hollow cone-shaped insert of tungsten at the place of the focal spot.
  • An X-ray tube comprising an incandescent cathode and an anticathode provided With a cone-shaped insert of tungsten of approximately uniform thickness at the place of the focal spot.

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  • X-Ray Techniques (AREA)
  • Electron Sources, Ion Sources (AREA)

Description

X-RAY TUBE Filed June 9, 1925 Inventor Patented June 11, 1929.
UNITED STATES PATENT OFFICE.
ALBERT nouwnns, or EINDHOVEN, NETHERLANDS, AssIG'N'oR TO, N. v. PHILIPS GLOEILAMBENEABRIEKEN, or nmnnovnn, NETHERLANDS. I
X-RAY T BE.
Application filed June 9, 1925, Serial No. 35,930, ,and in the Netherlands July 23, 1924.
This invention relates to X-ray tubes, more particularly to X-ray tubes in which the active portion of the anticathode is made of tungsten. WVhen using X-ray tubes for radiographic purposes, great energy is as a rule concentrated for a very short time on a small portion of the anticathode, but also in X-ray tubes for therapeutic purposes great energy is frequently supplied to the anticathode. Many means for carrying off this energy have been proposed which may be based on heat conduction or on heat radiation. In spite of these means it occurs, however, that the energy supplied to the anticathode cannot be carried off so quickly that the anticathode is prevented from disintegrating.
An object of the invention is to provide a' construction of an Xray tube in which much energy can be carried off from a very small focal spot. Another object of the invention is to diminish the risk of disintegration of the anticathode. A further object of the invention is to provide an X-ray tube showing a very effective cooling of the active surface of the anticathode.
According to this invention the tungsten anticathode of an X-ray tube of the incandescent cathode type is hollowed at the place of the focal spot. The focal spot in such an X-ray tube being consequently located in a cavity of the anticathode, the cooling is much more effective than in X-ray tubes having a plane anticathode, for in X-ray tubes according to the invention the ratio of the surface of the anticathode portion struck by the cathode-rays and the section of the beam of X-rays leaving the anticathode will be greater than it is in X-ray tubes having a plane anticathode. In X-ray tubes having a. plan-e anticathode the surface of which forms an angle of with the direction of the X-ray beam, the ratio of the surface of the focal spot and the section of the leaving beam of X-rays is about 2 whereas r in X-ray tubes according to the invention comprising an anticathode with a cavity having the form of a cone the solid angle of which is for example 30, the ratio of the surface of the focal spot and the section of the beam of X-rays leaving the anticathode in the direction of the axis of the cone, will be about 4.2. For that. reason, too, the cooling of the anticathode at a given sharpness of image will be more intensive than an X-ray tube in Which-the active portion of the anticathode forms a plane. d
An additional advantage of X-ray tubes according to the invention exists in that in the cavity of the anticathode there is a space nearly free from any electric field. In X-ray tubes as hitherto known it often occurs that the strong field between the cathode and the anticathode draws tungsten particles off'the incandescent anticathode, which,on the contrary in X-ray tubes according to the invention owing to the presence of said space nearly free from any electric field, occurs to a less extent so that also on that account the possibility of the anticathode being damaged is diminished.
The invention will be more clearly understood with reference to the accompanying drawing, representing an embodiment of the invention. An incandescent cathode 2 is fiXed in a metal vessel 1 to the wall of which is secured a metal cover 3 having an aperture in front of which stretches part of the surface of an anticathode 4. In known arrangements the anticathode of an X-raytube is provided with a tungsten target mounted in a copper body. The anticathodeof the tube illustrated which on the outsidemay consist for example, of chrome-iron, comode X-ray tubes hitherto known in that the tungsten body 5 has a hollow conical face. In the metal vessel opposite the anticathode is a window for the passage of the X-rays generated. This window consists of a glass hood 7 which is hermetically sealed to the metal wall, an annular metal plate 8, for example, of iron being provided for screening the X-rays and for preventing the Weld 9 from being struck by cathode rays. One leading-in wire 10 for the incandescent cathode passes insulatingly through the metal ring 8 and is sealed into the glass hood 7 the other leading-in wire is formed by the conductive connection of the pole 11 with the metal ring 8 and the metal :nvelope 1. The X-ray tube is either highly evacuted or has a gaseous filling of hydrogen or helium hav-' ing a pressure above 0.0006 millimetre of mercury which is such that any gas ionization can be obtained.
That I claim is: 1. An X-ray tube comprising an incandes- 15 cent filament cathode and an anticathode consisting partly of tungsten, the anticathode being hollowed at the place of the focal spot.
2. An X-ray tube comprising an incandescent filament cathode and ananticathode pro- Vided With a hollow cone-shaped insert of tungsten at the place of the focal spot.
3. An X-ray tube comprising an incandescent cathode and an anticathode provided With a cone-shaped insert of tungsten of approximately uniform thickness at the place of the focal spot.
In testimony whereof I affix my signature, at the city of Eindhoven, this 20th day of May, A. D. 1925. I v
ALBERT BOUWERS.
US35930A 1924-07-23 1925-06-09 X-ray tube Expired - Lifetime US1717309A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL27648A NL16507C (en) 1924-07-23 1924-07-23

Publications (1)

Publication Number Publication Date
US1717309A true US1717309A (en) 1929-06-11

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Family Applications (1)

Application Number Title Priority Date Filing Date
US35930A Expired - Lifetime US1717309A (en) 1924-07-23 1925-06-09 X-ray tube

Country Status (5)

Country Link
US (1) US1717309A (en)
DE (1) DE526003C (en)
FR (1) FR599512A (en)
GB (1) GB237580A (en)
NL (1) NL16507C (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2426198A (en) * 1941-10-24 1947-08-26 Standard Telephones Cables Ltd Electron discharge tube for ultra high frequencies
US2767341A (en) * 1952-08-12 1956-10-16 Dunlee Corp Anode structure for double filament x-ray tube
US3892989A (en) * 1971-03-08 1975-07-01 Watkins Johnson Co Convergent flow hollow beam X-ray gun construction
WO1986001938A1 (en) * 1984-09-07 1986-03-27 American Telephone & Telegraph Company X-ray source
FR2591386A1 (en) * 1985-12-10 1987-06-12 Thomson Cgr X-ray tube for imaging by scanning
US4811375A (en) * 1981-12-02 1989-03-07 Medical Electronic Imaging Corporation X-ray tubes
EP0777255A1 (en) * 1995-11-28 1997-06-04 Philips Patentverwaltung GmbH X-ray tube, in particular microfocus X-ray tube
EP1418610A1 (en) * 2002-11-06 2004-05-12 feinfocus Röntgen-Systeme GmbH Microfocus X-ray tube
EP1599883A2 (en) * 2003-02-21 2005-11-30 Xoft Microtube, Inc. Anode assembly for an x-ray tube

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2426198A (en) * 1941-10-24 1947-08-26 Standard Telephones Cables Ltd Electron discharge tube for ultra high frequencies
US2767341A (en) * 1952-08-12 1956-10-16 Dunlee Corp Anode structure for double filament x-ray tube
US3892989A (en) * 1971-03-08 1975-07-01 Watkins Johnson Co Convergent flow hollow beam X-ray gun construction
US4811375A (en) * 1981-12-02 1989-03-07 Medical Electronic Imaging Corporation X-ray tubes
WO1986001938A1 (en) * 1984-09-07 1986-03-27 American Telephone & Telegraph Company X-ray source
FR2591386A1 (en) * 1985-12-10 1987-06-12 Thomson Cgr X-ray tube for imaging by scanning
EP0777255A1 (en) * 1995-11-28 1997-06-04 Philips Patentverwaltung GmbH X-ray tube, in particular microfocus X-ray tube
EP1418610A1 (en) * 2002-11-06 2004-05-12 feinfocus Röntgen-Systeme GmbH Microfocus X-ray tube
US7050543B2 (en) 2002-11-06 2006-05-23 Feinfocus Röntgen-Systeme GmbH Microfocus X-ray tube
EP1599883A2 (en) * 2003-02-21 2005-11-30 Xoft Microtube, Inc. Anode assembly for an x-ray tube
EP1599883A4 (en) * 2003-02-21 2010-03-24 Xoft Microtube Inc Anode assembly for an x-ray tube

Also Published As

Publication number Publication date
DE526003C (en) 1931-06-02
NL16507C (en) 1927-07-15
GB237580A (en) 1926-05-06
FR599512A (en) 1926-01-14

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