EP0317402B1 - Tube à rayons X ayant une cible en molybdène - Google Patents

Tube à rayons X ayant une cible en molybdène Download PDF

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Publication number
EP0317402B1
EP0317402B1 EP88402830A EP88402830A EP0317402B1 EP 0317402 B1 EP0317402 B1 EP 0317402B1 EP 88402830 A EP88402830 A EP 88402830A EP 88402830 A EP88402830 A EP 88402830A EP 0317402 B1 EP0317402 B1 EP 0317402B1
Authority
EP
European Patent Office
Prior art keywords
anode
target
molybdenum
vanadium
ray
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.)
Expired - Lifetime
Application number
EP88402830A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0317402A1 (fr
Inventor
Jacques Delair
Olivier Peyret
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric CGR SA
Original Assignee
General Electric CGR SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Electric CGR SA filed Critical General Electric CGR SA
Priority to AT88402830T priority Critical patent/ATE77176T1/de
Publication of EP0317402A1 publication Critical patent/EP0317402A1/fr
Application granted granted Critical
Publication of EP0317402B1 publication Critical patent/EP0317402B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime 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

Definitions

  • the invention relates to an x-ray tube according to the first part of claim 1, in particular for mammography, and particularly relates to a molybdenum anode target.
  • X-radiation is obtained under the effect of an electronic bombardment of a target carried by the anode, or formed from the anode itself.
  • a small surface is subjected to electronic bombardment and constitutes the source of X-ray radiation.
  • the characteristics of X-ray radiation depend on the characteristics of the incident electron beam, and on the nature of the material of which the target is made.
  • Molybdenum targets are commonly used in X-ray tube anodes for mammography.
  • Molybdenum targets are commonly obtained by sintering molybdenum powder. Most often it is the anode itself which is produced, in a massive manner, by a sintering of molybdenum powder, the target being constituted by a part of the anode; the anode may be of the fixed anode type or of the rotating anode type. Other conventional methods, such as for example chemical vapor deposition, or else electrolytic deposition make it possible to deposit a layer of molybdenum on the anode in order to constitute a target on all or part of the surface of the anode, according to a focal track for example, in the case of a rotating anode.
  • this intensity is reduced by approximately 20% after three months of normal operation of the X-ray tube, and it is reduced by approximately 40% in a plane near the anode plane.
  • the present invention relates to an X-ray tube with fixed or rotating anode in which the problems of cracking of the molybdenum target mentioned above have been resolved in whole or in part by the use of a target comprising vanadium alloyed with molybdenum in predetermined proportions.
  • United States Patent No. US-A-4,641,334 shows a rotating anode structure which includes a layer 21 ( Figure 3 of the patent) composed of molybdenum or tungsten and vanadium.
  • this layer is not emissive and serves, with other layers, as a connection between the body 16 of the graphite anode and the disc 12, the latter supporting the target 14.
  • an X-ray tube comprising an anode and a cathode, the cathode delivering an electron beam, the anode comprising a target bombarded by said electron beam on a surface constituting the X-ray source, the target being made of molybdenum, is characterized in that the molybdenum of the target is alloyed with vanadium in a proportion, by weight, of between 0.5% and 7%.
  • the proportion is between 2.5% and 3.5%.
  • the figure shows by way of nonlimiting example, an X-ray tube 1 according to the invention, particularly intended for application to mammography.
  • the X-ray tube 1 is conventionally contained in a sheath 2.
  • the X-ray tube 1 comprises an envelope 3 made of glass for example, containing in particular a cathode 4 and an anode 5.
  • the anode 5 is a rotating anode having the general shape of a disc, and which is carried in the center of the disc by a support shaft 7 secured to a rotor 8.
  • the rotor 8 is arranged along an axis of symmetry 9 of the anode disc 5; the rotor 8 itself being carried in a conventional manner by a support 10 fixed to the casing 3.
  • a stator 11 is arranged outside the casing 3 and causes the rotation of the rotor 8, and consequently the rotation of the anode 5 around its axis of symmetry 9.
  • the cathode 4 is also carried in a conventional manner by the envelope 3 facing the periphery or edge 12 of the anode disc 5.
  • the cathode 4 delivers an electron beam 13 which bombards a target 30 which, in the nonlimiting example described, is formed on the wafer 12.
  • the anode 5 being a rotating anode, the target 30 constitutes a focal track along of the wafer 12 and around the axis of symmetry 9.
  • the electron beam 13 bombards the target 30 on a limited surface 15 of the latter, called focal point and which constitutes the source of X-radiation.
  • the target 30, bombarded by the electron beam 13 is made of molybdenum alloyed with vanadium or doped with vanadium in a proportion of at least 0.5% by weight. This makes it possible to delay and significantly reduce the aging of the target 30 and the cracking of the latter, under the effect of the bombardment of the electron beam 13, as it was previously mentioned.
  • vanadium is mixed with molybdenum in a proportion, by weight, of between 2.5 and 3.5%; an excess of vanadium (from 7% for example) which can lead to a non-negligible reduction in the intensity of the X-ray after filtration, if a filtration of the X-ray leaving the tube 1 is carried out to obtain that the energy spectrum of the X-ray covers a relatively narrow band containing the characteristic lines of molybdenum.
  • this filtration is carried out at an outlet window 33, by which the X-ray radiation leaves the sheath 2 after having left the tube 1 through a first outlet window 32 which is not very absorbent of the X-ray radiation.
  • the first outlet window 32 being, for example, conventionally, in beryllium, and the second window 33 in molybdenum.
  • the X-rays leaving the sheath 2 pass conventionally through a collimator 41, and then constitutes a useful X-rays 43 having limits 45, 46.
  • the first limit 45 which is situated on the side of the cathode 4 represents the limit of the X-ray beam 43 which, in mammography, is generally situated towards the costal grill of the patient (not shown); while on the side of anode 5, the second limit 46 represents the beam limit located towards the end or mammal of a breast to be examined.
  • the second limit 46 forms with the anode plane constituted by the edge 12, a relatively small angle ⁇ of the order for example of 2 °, and the drop in efficiency previously mentioned is a characteristic of the X-ray radiation 43 between the two limits 45, 46; that is, the intensity of the X-ray increases from the second limit 46 to the first limit 45, in a way which tends to compensate for the variations in absorption of the X-ray by the breast (not shown ) due to variations in thickness of the latter between the mammal and the costal grill.
  • a curve 50 illustrates by way of nonlimiting example, the variation in intensity of the radiation between the two limits 45,46; the curve 50 expresses its variations in percentage of a maximum intensity which the X-ray has along the first limit 45: it is observed by following the curve 50, that the intensity of the X-ray which is 100% at the level of the first limit 45, decreases with an increasingly steep slope, up to approximately 65% at the level of the second limit 46.
  • this target is practically not cracked, either that this target consists of molybdenum doped with vanadium in accordance with the invention, or that this target is pure molybdenum having been subjected very little to electron bombardment.
  • a second curve 51 in dotted lines, illustrates the modifications exhibited by the intensity of the X-radiation, under the same conditions as in the example above, but for a molybdenum target according to the prior art and whose aging under the effect of the electronic bombardments led to its cracking: we observe that the intensity of the X-radiation at the level of the first limit 45 is approximately 80%, that is to say that it is reduced by approximately 20 %, and the second curve 51 shows that the intensity of the X-ray decreases with a much steeper slope than in the first case for reach 25% at the second limit 46.
  • a target 30 made of mobybdenum alloyed with or doped with vanadium, in accordance with the invention makes it possible, by avoiding cracking of the target due to repeated electronic bombardment, to avoid a significant reduction in the intensity of the radiation.
  • X and its evolution in the field these two drawbacks being particularly serious for an X-ray tube for mammography.

Landscapes

  • X-Ray Techniques (AREA)
  • Apparatus For Radiation Diagnosis (AREA)
  • External Artificial Organs (AREA)
  • Solid Thermionic Cathode (AREA)
EP88402830A 1987-11-13 1988-11-10 Tube à rayons X ayant une cible en molybdène Expired - Lifetime EP0317402B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88402830T ATE77176T1 (de) 1987-11-13 1988-11-10 Roentgenroehre mit einer treffplatte aus molybdaen.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8715671A FR2623331A1 (fr) 1987-11-13 1987-11-13 Tube a rayons x ayant une cible en molybdene
FR8715671 1987-11-13

Publications (2)

Publication Number Publication Date
EP0317402A1 EP0317402A1 (fr) 1989-05-24
EP0317402B1 true EP0317402B1 (fr) 1992-06-10

Family

ID=9356737

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88402830A Expired - Lifetime EP0317402B1 (fr) 1987-11-13 1988-11-10 Tube à rayons X ayant une cible en molybdène

Country Status (6)

Country Link
US (1) US4876705A (ja)
EP (1) EP0317402B1 (ja)
JP (1) JP2731803B2 (ja)
AT (1) ATE77176T1 (ja)
DE (1) DE3871913T2 (ja)
FR (1) FR2623331A1 (ja)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04118841A (ja) * 1990-05-16 1992-04-20 Toshiba Corp 回転陽極ｘ線管およびその製造方法
US5592525A (en) * 1994-11-30 1997-01-07 General Electric Company Method for making a rotating anode with an integral shaft
US5647775A (en) * 1995-12-07 1997-07-15 Molex Incorporated Electrical connector with terminal locking means
US7180981B2 (en) 2002-04-08 2007-02-20 Nanodynamics-88, Inc. High quantum energy efficiency X-ray tube and targets
US6798865B2 (en) * 2002-11-14 2004-09-28 Ge Medical Systems Global Technology HV system for a mono-polar CT tube
US6925152B2 (en) * 2003-05-13 2005-08-02 Ge Medical Systems Global Technology Co., Llc Target attachment assembly
JP5238259B2 (ja) * 2005-10-27 2013-07-17 株式会社東芝 モリブデン合金およびそれを用いたｘ線管回転陽極ターゲット、ｘ線管並びに溶融るつぼ
US8284899B2 (en) * 2007-11-21 2012-10-09 Varian Medical Systems, Inc. X-ray tube having a focal spot proximate the tube end
WO2023043340A1 (ru) 2021-09-17 2023-03-23 Общество С Ограниченной Ответственностью "Пробиодукты" Пробиотическая композиция на растительном сырье и способ её получения

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2231686A1 (de) * 1972-06-28 1974-01-17 Siemens Ag Roentgenroehren-drehanode
DE2618235C3 (de) * 1976-04-26 1983-01-13 Siemens AG, 1000 Berlin und 8000 München Röntgenröhren-Drehanode
FR2386132A1 (fr) * 1977-03-29 1978-10-27 Eurotungstene Anode tournante pour tube radiogene
DE3107924A1 (de) * 1981-03-02 1982-09-16 Siemens AG, 1000 Berlin und 8000 München Roentgenroehren-drehanode
JPS60250546A (ja) * 1984-05-28 1985-12-11 Hitachi Ltd Ｘ線管用ロ−タ
US4641334A (en) * 1985-02-15 1987-02-03 General Electric Company Composite rotary anode for X-ray tube and process for preparing the composite

Also Published As

Publication number Publication date
FR2623331A1 (fr) 1989-05-19
EP0317402A1 (fr) 1989-05-24
US4876705A (en) 1989-10-24
DE3871913T2 (de) 1993-01-14
DE3871913D1 (de) 1992-07-16
FR2623331B1 (ja) 1995-02-10
ATE77176T1 (de) 1992-06-15
JPH01281644A (ja) 1989-11-13
JP2731803B2 (ja) 1998-03-25

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