EP0234967A1 - Drehanode aus Graphit für Röntgenröhre - Google Patents

Drehanode aus Graphit für Röntgenröhre Download PDF

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Publication number
EP0234967A1
EP0234967A1 EP87400061A EP87400061A EP0234967A1 EP 0234967 A1 EP0234967 A1 EP 0234967A1 EP 87400061 A EP87400061 A EP 87400061A EP 87400061 A EP87400061 A EP 87400061A EP 0234967 A1 EP0234967 A1 EP 0234967A1
Authority
EP
European Patent Office
Prior art keywords
graphite
beryllium
rotating anode
tungsten
target material
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.)
Granted
Application number
EP87400061A
Other languages
English (en)
French (fr)
Other versions
EP0234967B1 (de
Inventor
Emile Gabbay
Jean-Marie Penato
Yves Debrouwer
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
Thomson CGR
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, Thomson CGR filed Critical General Electric CGR SA
Priority to AT87400061T priority Critical patent/ATE47936T1/de
Publication of EP0234967A1 publication Critical patent/EP0234967A1/de
Application granted granted Critical
Publication of EP0234967B1 publication Critical patent/EP0234967B1/de
Expired 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
    • H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/08—Anodes; Anti cathodes
    • H01J35/10—Rotary anodes; Arrangements for rotating anodes; Cooling rotary anodes
    • H01J35/108—Substrates for and bonding of emissive target, e.g. composite structures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2235/00—X-ray tubes
    • H01J2235/08—Targets (anodes) and X-ray converters
    • H01J2235/083—Bonding or fixing with the support or substrate
    • H01J2235/084—Target-substrate interlayers or structures, e.g. to control or prevent diffusion or improve adhesion

Definitions

  • the present invention relates to a rotating anode of the composite type with graphite, for an X-ray tube.
  • X-rays are produced by the bombardment of a refractory material with a high atomic number, carried by the anode, by an electron beam generated by a cathode.
  • a refractory material with a high atomic number consist for example of tungsten, tantalum or even molybdenum, and are called in the following description "target materials”.
  • the emission of X photons is accompanied by a strong emission of heat. Indeed, the energy yield of the X-rays produced, that is to say the energy ratio of the X photons to the energy of the incident electrons, is of the order of 1%, the rest is transformed into heat.
  • the anodes and in particular the rotating anodes are most often formed so as to promote thermal radiation, and for this purpose comprise one or more graphite parts.
  • the main function of graphite is to increase thermal radiation.
  • the increase in radiated energy ⁇ W can be written: where W is the energy and ⁇ the radiation coefficient or emissivity coefficient.
  • the gain in dissipated energy varies linearly with the emissivity coefficient, all conditions being equal elsewhere.
  • the anode disc is a composite disc, formed of a basic body of which one face is covered at least partially by a target material.
  • the basic body can be made directly from graphite.
  • the target material for example tungsten can be applied to graphite either by brazing methods, or for example according to a layer deposited on graphite by a gas phase deposition process, or even for example by igneous electrolysis.
  • the quality of the bond between tungsten and graphite is essential for, on the one hand, obtaining sufficient adhesion of tungsten to graphite and, on the other hand, constituting a minimum thermal resistance between, the tungsten or target material considered. as the heat source, and the spelling which is intended to dissipate the heat by radiation.
  • This connection between the tungsten or target material and the graphite is produced by a layer of a connecting element: in the case of brazing it is the brazing element which constitutes this connecting element and in the case of deposition by gas phase or by igneous electrolysis, this connecting element consists of an element called an intermediate element, deposited in a thin layer between the target material and the graphite; this intermediate element generally consisting of rhenium, which is itself a refractory material.
  • the basic body is constituted for example by molybdenum, on which the target material, such as tungsten, is applied according to a mechanical process for example; a piece of graphite being brazed on the basic molybdenum body, on a opposite side of the target material.
  • the bonding element being constituted by the brazing element, itself made of relatively refractory material such as, for example, zirconium, Titanium, palladium, rhodium etc ...
  • brazing element has a too low melting point, or a too high vapor pressure, this can lead to lowering the temperature of use of the entire anode disc. , and thus lead to a decrease in the amount of energy radiated.
  • the present invention relates to a rotating anode of the composite type, comprising graphite intended in particular to increase the quantity of radiated energy, and in which the quality of the connection between the graphite and the elements to which it is secured is considerably improved compared to the prior art, so as to increase the operating temperature limits of the anode disc.
  • a rotary anode of the composite type comprising, around an axis of symmetry, a first part secured to a second part made of graphite, the first part comprising a target material intended to produce a ray ment X, is characterized in that the first and second parts are joined by a connecting element comprising beryllium.
  • FIG. 1 shows a rotary anode 1 according to the invention, comprising, in the nonlimiting example described, a base body 2 constituted by a graphite mass, having an axis of symmetry 3.
  • the base body 2 comprises a hole 4 arranged along the axis of symmetry 3, intended to allow the fixing of the rotating anode 1 on its support (not shown).
  • a layer 6 of a target material in tungsten for example or in a composite of the latter, is deposited on a first face 7 of the base body 2.
  • the layer 6 of target material is deposited on a sloping part 30 of the face 7, in the form of a crown centered on the axis of symmetry 3 and intended in the operation of the anode to constitute a focal crown.
  • the layer 6 of target material was deposited according to a conventional method, such as chemical deposition in the gas phase for example, on a second layer 8 of a connecting element.
  • the connecting element partly consists of an intermediate element, conventional in this configuration, intended in particular to achieve sufficient adhesion of the target material or tungsten to the graphite of the base body 2 and to avoid the carburetion of tungsten; this intermediate element being for example rhenium.
  • the second layer 8 formed by the connecting element is formed by the intermediate element described above to which beryllium has been added.
  • Beryllium constitutes a wetting agent which improves the tungsten-graphite bond, even in small quantities and whose proportion relative to the intermediate element is not critical, as will appear in a following description;
  • the second layer 8 of connecting element which may be constituted by the intermediate element to which the beryllium has been added in a proportion, for example of the order of 10% by weight.
  • the first layer 6 of tungsten constitutes a first part, secured to a second part formed by the graphite constituting the base body 2, by means of the second layer 8 constituted by the element of liaison.
  • the layer 6 of target material constitutes the heat source, and the quality of the tungsten-graphite bond which is ensured by the layer 8 of connecting element according to the invention, makes it possible to '' dissipate this heat by the radiation of graphite optimally.
  • the deposition of the second layer 8 as a connecting element can be carried out according to one of the conventional methods, used to effect the prior deposition of an intermediate layer of Rhenium, such as electrolysis for example.
  • FIG. 2 illustrates another possibility of depositing the second layer 8, by showing part of the anode 1 represented in a box 34 in FIG. 1.
  • the second layer 8 in connection element comprises a layer called intermediate layer 32 and formed of rhenium, either pure, or mixed with pure beryllium, in contact either with the first layer 6 of target material, or with the basic body graphite 2.
  • the second layer 8 as a connecting element comprises an upper layer 31 and a lower layer 33 of pure beryllium, with between these upper and lower layers 31, 33, the intermediate layer 32; these upper, lower, intermediate layers 31, 33, 32 can be deposited for example by an electrolysis process.
  • FIG. 3 illustrates a preferred version of the invention, in which the rotating anode 1 also comprises a base body 2 of graphite, but where the target material consists of a crown 5 secured to the base body 2 by a method of solder.
  • the crown 5 can be made in a conventional manner, of pure pure or alloyed target material such as, for example, solid tungsten or an alloy of the latter, or else a tungsten-molybdenum composite such as comprising tungsten (possibly alloyed) at the surface. and a support (not shown) in molybdenum as an under layer.
  • the face 7 of the base body 2 has a groove 12 in the form of a crown centered around the axis of symmetry 3.
  • the crown 5 of target material is applied to the base body 2 of graphite , in the groove 12 in which a third layer 13 of a connecting element has previously been deposited in a conventional manner.
  • the connecting element and consisting of a brazing element as mentioned above such as for example, titanium or zirconium to which is added a relatively small amount of beryllium; the soldering being carried out by means in themselves known (not shown), in particular allowing the rotary anode 1 to be heated while a force is conventionally exerted on the crown 5 of target material in order to press it against the basic body 2.
  • the proportion of beryllium is not critical, both in the case where it is added to the rhenium according to the preceding examples, and in the case where it is added to a brazing element. Tests have shown that the quality of the bonding of tungsten to graphite is improved even with a proportion of beryllium of 1% by weight, and it has not been considered useful, in practice, to go beyond 15% , the excess beryllium being removed by evaporation under vacuum.
  • solders used such as zirconium, titanium, do not wet graphite and the target material well, tungsten or molybdenum for example.
  • Beryllium constitutes a wetting agent which diffuses widely in tungsten or molybdenum and in graphite, creating alloys which can, by heating under vacuum at high temperature, displace the equilibria and vaporize the excess material.
  • beryllium although having a low melting point and a high vapor pressure, can be explained as follows: after having alloyed with, for example titanium or zirconium, the alloyed beryllium, d on the one hand fills in particular the porosities of graphite, and on the other hand the beryllium diffuses in the mesh of tungsten or molybdenum and allies with tungsten in any proportion, thus ensuring good quality of the tungstenberyllium bond.
  • the excess beryllium goes away by evaporation under vacuum; the rest, being trapped in tungsten or molybdenum and graphite, can no longer evaporate during a rise in high temperature of the anode during its operation, and thus adversely affect this operation.
  • the operating temperature is not limited by the temperature of the brazing. It is further noted that under these conditions the amount of beryllium is not critical.
  • FIG. 4 shows a version of the anode according to the invention in which the latter comprises a body 20 formed by a mass of molybdenum.
  • the target material consists of a thick layer 26, made of tungsten for example, entirely covering the first face 7.
  • tungsten 6 has a relatively large thickness e, and has been secured, by a conventional mechanical and thermal process, to the body 20 in molybdenum with which it forms a first part.
  • the rotating anode 1 also comprises a second part formed by a graphite ring 16 disposed on a second face 17 of the body 20 in molybdenum.
  • the graphite ring 16 is centered around the axis of symmetry 3, in a second groove 18 machined in a second face 17 of the body 20.
  • the graphite ring 16 is brazed on the molybdenum of the body 2 thanks to a fourth layer 25 of a connecting element.
  • the connecting element is constituted, as in the example relating to FIG. 3, by a brazing element of a conventional type to which beryllium has been added, so as to perfect, as previously described , the quality of the bond between graphite and molybdenum.
  • the present invention is applicable to any type of anode in which a graphite element has been incorporated.

Landscapes

  • X-Ray Techniques (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Lubricants (AREA)
  • Discharge Heating (AREA)
  • Ceramic Products (AREA)
EP87400061A 1986-01-17 1987-01-13 Drehanode aus Graphit für Röntgenröhre Expired EP0234967B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT87400061T ATE47936T1 (de) 1986-01-17 1987-01-13 Drehanode aus graphit fuer roentgenroehre.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8600654A FR2593324B1 (fr) 1986-01-17 1986-01-17 Anode tournante avec graphite pour tube radiogene
FR8600654 1986-01-17

Publications (2)

Publication Number Publication Date
EP0234967A1 true EP0234967A1 (de) 1987-09-02
EP0234967B1 EP0234967B1 (de) 1989-11-08

Family

ID=9331229

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87400061A Expired EP0234967B1 (de) 1986-01-17 1987-01-13 Drehanode aus Graphit für Röntgenröhre

Country Status (5)

Country Link
US (1) US4799250A (de)
EP (1) EP0234967B1 (de)
AT (1) ATE47936T1 (de)
DE (1) DE3760979D1 (de)
FR (1) FR2593324B1 (de)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0787082B2 (ja) * 1987-07-24 1995-09-20 株式会社日立製作所 Ｘ線管用回転陽極ターゲット
FR2625035B1 (fr) * 1987-12-22 1993-02-12 Thomson Cgr Anode tournante en materiau composite pour tube a rayons x
FR2655191A1 (fr) * 1989-11-28 1991-05-31 Genral Electric Cgr Sa Anode pour tube a rayons x.
FR2655192A1 (fr) * 1989-11-28 1991-05-31 Gen Electric Cgr Anode pour tube a rayons x a corps de base composite.
US5204891A (en) * 1991-10-30 1993-04-20 General Electric Company Focal track structures for X-ray anodes and method of preparation thereof
FI102697B1 (fi) * 1997-06-26 1999-01-29 Metorex Int Oy Polarisoitua herätesäteilyä hyödyntävä röntgenfluoresenssimittausjärjestely ja röntgenputki
US6256376B1 (en) * 1999-12-17 2001-07-03 General Electric Company Composite x-ray target
US7253717B2 (en) * 2000-11-29 2007-08-07 Mobile Technics Llc Method and system for communicating with and tracking RFID transponders
US20080101541A1 (en) * 2006-11-01 2008-05-01 General Electric Company, A New York Corporation X-ray system, x-ray apparatus, x-ray target, and methods for manufacturing same
US8428222B2 (en) * 2007-04-20 2013-04-23 General Electric Company X-ray tube target and method of repairing a damaged x-ray tube target
US8116432B2 (en) 2007-04-20 2012-02-14 General Electric Company X-ray tube target brazed emission layer
JP2015180859A (ja) * 2014-03-05 2015-10-15 株式会社東芝 フォトンカウンティングｃｔ装置
EP3496128A1 (de) * 2017-12-11 2019-06-12 Koninklijke Philips N.V. Drehanode für eine röntgenquelle

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3329847A (en) * 1964-07-22 1967-07-04 Friedman Herbert Stroboscopic x-ray tube
FR1575111A (de) * 1966-01-03 1969-07-25
US3890521A (en) * 1971-12-31 1975-06-17 Thomson Csf X-ray tube target and X-ray tubes utilising such a target
DE2719609A1 (de) * 1977-05-02 1978-11-09 Richard Dr Bauer Roentgenroehre
EP0023065A1 (de) * 1979-07-19 1981-01-28 Philips Patentverwaltung GmbH Drehanode für Röntgenröhren
EP0037956A1 (de) * 1980-04-11 1981-10-21 Kabushiki Kaisha Toshiba Eine Drehanode für eine Röntgenstrahlröhre und Verfahren zu ihrer Herstellung

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3998632A (en) * 1972-04-27 1976-12-21 Valentin Petrovich Kosteruk Metal alloy
US4637042A (en) * 1980-04-18 1987-01-13 The Machlett Laboratories, Incorporated X-ray tube target having electron pervious coating of heat absorbent material on X-ray emissive surface

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3329847A (en) * 1964-07-22 1967-07-04 Friedman Herbert Stroboscopic x-ray tube
FR1575111A (de) * 1966-01-03 1969-07-25
US3890521A (en) * 1971-12-31 1975-06-17 Thomson Csf X-ray tube target and X-ray tubes utilising such a target
DE2719609A1 (de) * 1977-05-02 1978-11-09 Richard Dr Bauer Roentgenroehre
EP0023065A1 (de) * 1979-07-19 1981-01-28 Philips Patentverwaltung GmbH Drehanode für Röntgenröhren
EP0037956A1 (de) * 1980-04-11 1981-10-21 Kabushiki Kaisha Toshiba Eine Drehanode für eine Röntgenstrahlröhre und Verfahren zu ihrer Herstellung

Also Published As

Publication number Publication date
DE3760979D1 (en) 1989-12-14
FR2593324B1 (fr) 1988-03-25
FR2593324A1 (fr) 1987-07-24
US4799250A (en) 1989-01-17
ATE47936T1 (de) 1989-11-15
EP0234967B1 (de) 1989-11-08

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