EP0292055B1 - Source de rayonnement pour la génération de rayons X essentiellement monochromatiques - Google Patents

Source de rayonnement pour la génération de rayons X essentiellement monochromatiques Download PDF

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Publication number
EP0292055B1
EP0292055B1 EP88200941A EP88200941A EP0292055B1 EP 0292055 B1 EP0292055 B1 EP 0292055B1 EP 88200941 A EP88200941 A EP 88200941A EP 88200941 A EP88200941 A EP 88200941A EP 0292055 B1 EP0292055 B1 EP 0292055B1
Authority
EP
European Patent Office
Prior art keywords
anode
radiation source
radiation
rays
cathode
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
EP88200941A
Other languages
German (de)
English (en)
Other versions
EP0292055A2 (fr
EP0292055A3 (en
Inventor
Geoffrey Dr. Harding
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.)
Philips Intellectual Property and Standards GmbH
Koninklijke Philips NV
Original Assignee
Philips Patentverwaltung GmbH
Philips Gloeilampenfabrieken NV
Koninklijke Philips Electronics NV
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 Philips Patentverwaltung GmbH, Philips Gloeilampenfabrieken NV, Koninklijke Philips Electronics NV filed Critical Philips Patentverwaltung GmbH
Priority to AT88200941T priority Critical patent/ATE74690T1/de
Publication of EP0292055A2 publication Critical patent/EP0292055A2/fr
Publication of EP0292055A3 publication Critical patent/EP0292055A3/de
Application granted granted Critical
Publication of EP0292055B1 publication Critical patent/EP0292055B1/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
    • 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
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2235/00—X-ray tubes
    • H01J2235/16—Vessels
    • H01J2235/165—Shielding arrangements
    • H01J2235/168—Shielding arrangements against charged particles
    • 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
    • H01J35/112—Non-rotating anodes
    • H01J35/116—Transmissive anodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/16—Vessels; Containers; Shields associated therewith
    • H01J35/18—Windows
    • H01J35/186—Windows used as targets or X-ray converters

Definitions

  • the invention relates to a radiation source for generating an essentially monochromatic X-ray radiation with a cathode for generating electrons accelerated to an anode and with a conical body enclosed by the anode, which converts the X-rays impinging on it into fluorescent radiation and with its tapering end onto one Radiation leakage points.
  • Such a radiation source is known from DE-OS 22 59 382.
  • the monochromatic radiation is formed by the fluorescent radiation which emanates from the body when it is struck by primary X-ray radiation.
  • the primary X-ray radiation is suppressed by a collimator located at a suitable location.
  • the anode In the known radiation source, the anode is designed as a so-called transmission anode, ie it is struck by electrons on its outer surface and the X-ray radiation that strikes the conical body emerges from the inner surface of the anode.
  • the thickness of the anode must be a compromise between the contradictory demands to absorb as many electrons as possible on the one hand and to weaken the generated X-rays as little as possible on the other. This results in relatively small thicknesses, which results in poor heat dissipation and thus a limited tube load capacity.
  • the object of the present invention is to design a radiation source of the type mentioned at the outset in such a way that there is an increased thermal load capacity.
  • This object is achieved in that the anode is hit on its inner surface facing the body by the electrons emitted from the cathode.
  • the heat can be dissipated much better from the anode, for example by liquid cooling and / or by using a relatively thick-walled anode.
  • DE-A-2 029 141 discloses an analysis arrangement in which a sample holder is partially surrounded by a cylindrical, water-cooled anode with a radiation outlet and a conical inner surface, while a cathode filament is coaxial with the radiation outlet and the sample holder lies.
  • the electrons of the cathode hit the inner surface of the anode and generate primary X-rays.
  • the sample attached to the sample holder is exposed to primary X-rays and emits fluorescent X-rays and secondary electrons that are measured together.
  • a further development of the invention provides that the inner surface of the anode facing the body has the shape of a truncated cone jacket tapering towards the radiation exit.
  • the anode consists of a solid metal block which is provided on its inner surface with a heavy-duty metal layer.
  • the material of the metal block of the anode can consist of a thermally highly conductive material, for example copper, while the metal on the inner surface can be chosen with a view to the highest possible fluorescence radiation yield.
  • the material for the inner surface of the anode and the outer surface of the body is selected so that the characteristic X-ray radiation emitted from the anode has an energy that is slightly greater than the K-absorption edge of the body. Since X-rays, the energy of which is slightly above the absorption edge of a material, are converted into fluorescence radiation to a particularly high percentage, this results in an increased intensity of the fluorescence radiation.
  • a cylindrical metal screen which surrounds the body and which only weakens the X-ray radiation only slightly.
  • the screen absorbs the secondary electrons and prevents them from generating X-rays with an energy different from the energy of the fluorescent radiation.
  • the rotationally symmetrical radiation source has a cylindrical housing 1 to which a cathode arrangement 3 with a ring-shaped or spiral-shaped cathode 4 is attached via a ceramic insulator 2.
  • a cathode arrangement 3 with a ring-shaped or spiral-shaped cathode 4 is attached via a ceramic insulator 2.
  • an electron beam indicated by the dashed lines 4a, is emitted, which strikes the inner surface of an anode, which is shaped like the shell of a truncated cone. This results in a relatively uniform distribution of the electrons on the inner surface of the anode.
  • the anode consists of a metal block 5a made of a thermally highly conductive material, preferably copper, which is coated on its inner surface with a heavy-duty metal layer, in which X-rays are generated by the electron bombardment.
  • the X-ray radiation strikes a target 7 through a thin cylindrical screen 6, which is conical on its side facing away from the cathode and converts the primary radiation striking it into essentially monochromatic fluorescent radiation.
  • the screen 6, which carries the target 7, has the task of keeping scattered electrons away from the target 7. These stray electrons would generate an undesirable bremsradiation spectrum when they hit the target 7.
  • the screen 6 absorbs too much primary X-ray radiation and on the other hand even emits X-radiation due to stray or secondary electrons, the screen 6 is as thin-walled as is just permitted for mechanical reasons and consists of a low-atom material, e.g. Titanium.
  • the primary X-ray radiation emanating from the anode 5a, 5b is suppressed by a collimator arrangement 8, in the center of which the screen 6 is attached in a vacuum-tight manner.
  • the collimator consists of a radiation-absorbing material or a plurality of plates of such a material which are offset with respect to one another in the direction of the axis of symmetry, the thickness of the collimator or the distance between the outer plates of this collimator being selected such that the anode starts primary X-ray radiation must hit the collimator before it reaches the radiation exit 9.
  • the energy of the fluorescence radiation depends on the material of the target. If tantalum is chosen as the material, the energy of the fluorescent radiation is 57.5 keV (K ⁇ 1 line). If a fluorescence radiation with higher or lower energy is to be generated, the tantalum target must be replaced by a target which consists of an element or an alloy with a higher or lower atomic number.
  • the tube voltage (expressed in kV) must be about twice as high as the energy of the fluorescent radiation (expressed in keV).
  • it is expedient to detachably e.g. by a screw connection to connect to the screen.
  • the screen must be designed so that it hermetically seals the inside of the evacuated housing of the radiation source to the outside
  • the layer 5b in which the primary X-ray radiation is generated, has a high atomic number and is expediently chosen such that the energy of the characteristic radiation generated in this layer lies slightly above the K absorption edge of the target 7, because this results in a particularly good implementation in fluorescence radiation. If the target consists of tantalum (K absorption edge at 67.4 keV), this condition is met by a layer 5b of gold (K ⁇ line at 68.8 keV).
  • the layer 5b is preferably applied to a solid metal block 5a made of copper.
  • the back of this copper block is cooled by a cooling liquid which flows into a cavity 10, which is hermetically sealed from the inside of the tube, around the copper block from the outside in a manner not shown in detail.
  • a cooling liquid which flows into a cavity 10, which is hermetically sealed from the inside of the tube, around the copper block from the outside in a manner not shown in detail.
  • water is preferably used as the cooling liquid.
  • a metal block enclosed by a cavity for cooling it is also possible to use a metal block in which cooling channels, for example in spiral form, have already been incorporated. With a suitable design, this allows the cooling surface and thus also the maximum electrical power that can be supplied to be increased.
  • the fluorescence radiation generated on the target 7 is not completely monochromatic. This is because other lines besides the desired K ⁇ lines are excited, e.g. the higher energy Kß line or L lines with much lower energy.
  • the Kß line can be suppressed by a radiation filter arranged in the radiation outlet, which consists of a material whose absorption edge lies between the K ⁇ and the Kß line.
  • filters made of ytterbium or thulium are suitable as radiation filters.
  • the soft lines can optionally be suppressed by the same filter or by a filter made of a material with a lower atomic number, which is dimensioned such that the desired K ⁇ line is only slightly weakened, while the L lines are largely suppressed.

Landscapes

  • X-Ray Techniques (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)

Claims (12)

  1. Source de rayonnement pour la production d'un rayonnement X en substance monochromatique, comportant une cathode (3,4) pour la production d'électrons accélérés sur une anode (5a, 5b) et un corps conique (7) entouré par l'anode qui convertit le rayonnement X qui le touche en rayonnement de fluorescence et est orienté par son extrémité allant en s'amincissant vers une sortie de rayonnement, caractérisée en ce que l'anode est touchée, sur sa face interne (5b) orientée vers le corps (7), par les électrons émis par la cathode (4).
  2. Source de rayonnement suivant la revendication 1, caractérisée en ce que la cathode (4) est disposée du côté éloigné de la sortie de rayonnement et a une forme annulaire ou hélicoïdale.
  3. Source de rayonnement suivant l'une quelconque des revendications précédentes, caractérisée en ce que la face interne (5b) de l'anode qui est orientée vers le corps a la forme d'une enveloppe tronconique allant en diminuant vers la sortie de rayonnement.
  4. Source de rayonnement suivant l'une quelconque des revendications 1 à 3, caractérisée en ce que la face externe de l'anode peut être refroidie à l'aide d'un liquide de refroidissement.
  5. Source de rayonnement suivant l'une quelconque des revendications précédentes, caractérisée en ce que la cathode est connectée à un potentiel de haute tension négatifet l'anode, au potentiel de la terre, et que de l'eau est utilisée comme agent de refroidissement.
  6. Source de rayonnement suivant l'une quelconque des revendications précédentes, caractérisée en ce que l'anode est constituée d'un bloc métallique massif (5a) qui est pourvu, sur sa face interne, d'une couche à métal de haut poids atomique (5b).
  7. Source de rayonnement suivant l'une quelconque des revendications précédentes, caractérisée en ce que le matériau constitutif de la face interne de l'anode et de la face externe du corps est choisi tel que le rayonnement X caractéristique émis par l'anode possède une énergie qui est légèrement supérieure à la discontinuité d'absorption (K) de la face externe du corps.
  8. Source de rayonnement suivant la revendication 7, caractérisée en ce que l'anode est constituée d'or, au moins dans la une de sa face interne, et que le corps est constitué de tantale.
  9. Source de rayonnement suivant l'une quelconque des revendications 1 à 8, caractérisée en ce qu'entre l'anode et le corps est prévu un écran métallique cylindrique (6) entourant le corps, qui n'affaiblit que légèrement le rayonnement X.
  10. Source de rayonnement suivant la revendication 9, caractérisée en ce que l'écran (6) porte le corps (7) et ferme, de manière étanche au vide, le boîtier de la source de rayonnement.
  11. Source de rayonnement suivant la revendication 9, caractérisée en ce que l'écran (6) est ouvert vers l'extérieur et que le corps (7) est fixé de manière amovible à l'écran.
  12. Source de rayonnement suivant l'une quelconque des revendications précédentes, caractérisée en ce que, dans la sortie de rayonnement est monté un filtre (9) constitué d'un matériau dont la discontinuité d'absorption est située entre la raie Kα et la raie Kβ du corps.
EP88200941A 1987-05-18 1988-05-11 Source de rayonnement pour la génération de rayons X essentiellement monochromatiques Expired - Lifetime EP0292055B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88200941T ATE74690T1 (de) 1987-05-18 1988-05-11 Strahlenquelle zur erzeugung einer im wesentlichen monochromatischen roentgenstrahlung.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3716618 1987-05-18
DE19873716618 DE3716618A1 (de) 1987-05-18 1987-05-18 Strahlenquelle zur erzeugung einer im wesentlichen monochromatischen roentgenstrahlung

Publications (3)

Publication Number Publication Date
EP0292055A2 EP0292055A2 (fr) 1988-11-23
EP0292055A3 EP0292055A3 (en) 1989-04-19
EP0292055B1 true EP0292055B1 (fr) 1992-04-08

Family

ID=6327798

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88200941A Expired - Lifetime EP0292055B1 (fr) 1987-05-18 1988-05-11 Source de rayonnement pour la génération de rayons X essentiellement monochromatiques

Country Status (5)

Country Link
US (1) US4903287A (fr)
EP (1) EP0292055B1 (fr)
JP (1) JP2747295B2 (fr)
AT (1) ATE74690T1 (fr)
DE (2) DE3716618A1 (fr)

Families Citing this family (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0432568A3 (en) * 1989-12-11 1991-08-28 General Electric Company X ray tube anode and tube having same
DE4017002A1 (de) * 1990-05-26 1991-11-28 Philips Patentverwaltung Strahlenquelle fuer quasimonochromatische roentgenstrahlung
DE4215343A1 (de) * 1992-05-09 1993-11-11 Philips Patentverwaltung Filterverfahren für ein Röntgensystem und Anordnung zur Durchführung eines solchen Filterverfahrens
US5433771A (en) * 1994-04-25 1995-07-18 Westinghouse Electric Corporation Hot gas filtration system fail-safe and thermal regeneration device
DE19509006C2 (de) * 1995-03-13 1998-11-05 Siemens Ag Röntgenröhre
DE19544203A1 (de) * 1995-11-28 1997-06-05 Philips Patentverwaltung Röntgenröhre, insbesondere Mikrofokusröntgenröhre
DE19808342C1 (de) * 1998-02-27 1999-08-19 Siemens Ag Abschaltbare Fluoreszenz-Röntgenstrahlenquelle
JPH11288678A (ja) * 1998-02-10 1999-10-19 Siemens Ag 蛍光ｘ線源
RU2161843C2 (ru) * 1999-02-17 2001-01-10 Кванта Вижн, Инк. Точечный высокоинтенсивный источник рентгеновского излучения
DE10251635A1 (de) * 2002-11-06 2004-05-27 Feinfocus Röntgen-Systeme GmbH Röntgenröhre, insbesondere Mikrofokus-Röntgenröhre
CN1791960A (zh) * 2003-05-19 2006-06-21 皇家飞利浦电子股份有限公司 荧光x射线源
US7200203B2 (en) * 2004-04-06 2007-04-03 Duke University Devices and methods for targeting interior cancers with ionizing radiation
JP4738189B2 (ja) * 2006-02-01 2011-08-03 東芝電子管デバイス株式会社 Ｘ線源および蛍光ｘ線分析装置
KR100974119B1 (ko) * 2006-02-01 2010-08-04 도시바 덴시칸 디바이스 가부시키가이샤 Ｘ선원 및 형광 ｘ선 분석 장치
JP2007207539A (ja) * 2006-02-01 2007-08-16 Toshiba Corp Ｘ線源および蛍光ｘ線分析装置
EP2420112B1 (fr) 2009-04-16 2017-03-01 Eric H. Silver Appareil à rayons x monochromatiques
TWI555511B (zh) 2010-12-07 2016-11-01 和鑫生技開發股份有限公司 一種穿透式ｘ光管及一種反射式ｘ光管
DE102012011309B4 (de) 2011-10-28 2022-08-25 Gamc Biotech Development Co., Ltd. Röntgenstrahlröhre vom Transmissionstyp und Röntgenstrahlröhre vom Reflektionstyp
US9368316B2 (en) * 2013-09-03 2016-06-14 Electronics And Telecommunications Research Institute X-ray tube having anode electrode
CA3098114A1 (fr) 2017-05-19 2018-11-22 Imagine Scientific, Inc. Systemes et procedes d'imagerie par rayons x monochromatiques
US10818467B2 (en) 2018-02-09 2020-10-27 Imagine Scientific, Inc. Monochromatic x-ray imaging systems and methods
JP7299226B2 (ja) * 2018-02-09 2023-06-27 イマジン サイエンティフィック，インコーポレイテッド 単色ｘ線撮像システム及び方法
WO2020056281A1 (fr) 2018-09-14 2020-03-19 Imagine Scientific, Inc. Systèmes de composant de rayons x monochromatiques et procédés

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US1655455A (en) * 1923-09-29 1928-01-10 Gen Electric X-ray apparatus
US2309566A (en) * 1940-09-09 1943-01-26 Gen Electric X Ray Corp Window for X-ray tubes
US2343730A (en) * 1942-11-30 1944-03-07 Gen Electric X Ray Corp X-ray tube
US3567928A (en) * 1969-06-12 1971-03-02 Du Pont Fluorescent analytical radiation source for producing soft x-rays and secondary electrons
GB1443048A (en) * 1972-12-05 1976-07-21 Strahlen Umweltforsch Gmbh X-ray source
JPS542084A (en) * 1977-06-02 1979-01-09 Philips Corp Rotary anode xxray tube

Also Published As

Publication number Publication date
US4903287A (en) 1990-02-20
DE3716618A1 (de) 1988-12-08
EP0292055A2 (fr) 1988-11-23
ATE74690T1 (de) 1992-04-15
JPS63304557A (ja) 1988-12-12
EP0292055A3 (en) 1989-04-19
JP2747295B2 (ja) 1998-05-06
DE3869829D1 (de) 1992-05-14

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