EP0459567A2 - Source quasi-monochromatique de rayons X - Google Patents

Source quasi-monochromatique de rayons X Download PDF

Info

Publication number
EP0459567A2
EP0459567A2 EP91201225A EP91201225A EP0459567A2 EP 0459567 A2 EP0459567 A2 EP 0459567A2 EP 91201225 A EP91201225 A EP 91201225A EP 91201225 A EP91201225 A EP 91201225A EP 0459567 A2 EP0459567 A2 EP 0459567A2
Authority
EP
European Patent Office
Prior art keywords
target
screen
radiation
anode
radiation source
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
EP91201225A
Other languages
German (de)
English (en)
Other versions
EP0459567A3 (en
EP0459567B1 (fr
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
Publication of EP0459567A2 publication Critical patent/EP0459567A2/fr
Publication of EP0459567A3 publication Critical patent/EP0459567A3/de
Application granted granted Critical
Publication of EP0459567B1 publication Critical patent/EP0459567B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details

Definitions

  • the invention relates to a radiation source for generating essentially monochromatic X-rays, with an anode for generating X-rays, a target enclosed by the anode for converting X-rays into fluorescent radiation, and with a screen located between the target and the anode for shielding the target against electrons .
  • Such a radiation source is known from DE-OS 37 16 618.
  • the metal screen has the task of keeping (scattering) electrons away from the target, which would lead to the fact that polychromatic brake radiation is generated in the target in addition to the practically monochromatic fluorescent radiation.
  • This screen is penetrated by the X-ray radiation emitted from the anode, which is converted into fluorescence radiation in the target.
  • the screen is as thin-walled as possible and consists of a low-atom material (e.g. titanium (for a target made of tantalum)).
  • the object of the invention is to design a radiation source of the type mentioned at the outset in such a way that even more fluorescent radiation or monochromatic X-radiation can be generated.
  • This object is achieved in that the screen contains an element with a high atomic number.
  • the invention is based on the knowledge that a screen that has an element with a high atomic number ("high” in the sense of the invention is an atomic number whose deviation from the atomic number of the target material is small compared to the atomic number in question) in the periodic table of the elements contains more X-ray radiation from the anode than an equally strong screen made of a low-atom element, but that the radiation comprising an element with a high atomic number generates braking radiation which is converted in the target mainly into fluorescent radiation. In this way, the overall yield of fluorescent radiation can be increased.
  • a preferred development of the invention provides that the screen and the target each contain the same element with a high atomic number. It is provided in a still further embodiment of the invention that the screen and the target consist of tantalum.
  • the advantage of the further development is, on the one hand, that the thermal expansion of the target and screen is the same in both cases, so that mechanical stresses cannot occur when heated, and, on the other hand, that the spectral purity of the spectrum generated is deteriorated as little as possible, because the characteristic radiation generated in the screen has the same wavelength as the fluorescence radiation generated in the target.
  • tantalum as the material for the target and the screen, the high melting point of this material is added, so that the radiation source can be subjected to a much greater electrical power than is possible with the known radiation source with a titanium screen.
  • the radiation source comprises a piston which encloses an evacuated room in which the anode, the screen and the target are located. While in the known radiation source the screen hermetically seals the radiation source from the outside, so that the target and the surface facing it come into contact with the atmospheric oxygen, the target or this screen surface is in this development within the vacuum space of the radiation source. The screen and the target can therefore withstand high temperatures better.
  • a collimator arrangement is provided which is designed such that only the radiation emanating from the target can pass through the collimator arrangement. As a result, the braking radiation generated in the screen is largely suppressed.
  • the radiation source which is designed to be rotationally symmetrical with respect to an axis 1, comprises a cathode part 2 and an anode part 3, which are connected to one another in a vacuum-tight manner via a piston 4.
  • the cathode part 2 is connected to the piston 4, which is made of metal, via an insulator, not shown, and carries a voltage of, for example, 160 kV or more. It comprises a filament 21 which surrounds the axis of symmetry 1 in a ring and a cathode die 22 which forms the paths of the electrons emitted from the filament 21 in the desired manner.
  • the anode part 3 comprises a hollow body consisting of two parts 32 and 33, the cavity of which is flowed through in the operating state by a liquid coolant supplied from the outside in a manner not shown in detail.
  • a partition 34 prevents the coolant in the shortest possible way from the coolant inlet to the coolant outlet (neither shown) flows.
  • the parts 32 and 33 of the anode body can for example consist of copper.
  • the part 32 of the anode body 32, 33 has an inner surface open towards the cathode part 2 in the form of a truncated cone surface 31.
  • This lateral surface 31 is coated with a material that has a high atomic number, preferably with gold. The electrons emitted from the filament in the operating state hit this inner surface.
  • the electrons impinging on the anode 31 generate X-rays with a spectrum which is continuous up to a quantum energy determined by the voltage between the anode part and the cathode part and on which the line spectrum of gold is superimposed with a K line at approximately 68.8 keV.
  • the X-ray radiation strikes a target 36 made of tantalum through a thin cylindrical screen 35, which has the shape of a cone, the tip of which points away from the cathode part 2.
  • the target essentially converts X-ray quanta with an energy above the K absorption edge of the target (for tantalum approx. 67.4 keV) into monochromatic fluorescence radiation, the quantum energy of which is the characteristic energy of the target material (for tantalum: 57.5 keV) corresponds.
  • the screen 35 which carries the target 36, is fastened in a central bore in the disk-shaped part 33 of the anode body 32, 33, which is closed in a vacuum-tight manner by a window 37.
  • the invention uses the impact of the electrons on the screen 35 to generate additional X-rays.
  • the screen must consist of an element with a high atomic number or contain such an element to a sufficient extent.
  • the atomic number of this element should at most be slightly lower than that of the target, but if possible greater than 50.
  • the electron bombardment of the screen generates not only characteristic radiation but also polychromatic (braking) radiation. A much larger portion of this hits the target than of the radiation from the anode because the screen closely surrounds the target.
  • a suitable element - because of its high atomic number (74) and its high thermal resilience - would be tungsten, for example.
  • a screen made of tantalum is even cheaper than a screen made of tungsten.
  • the quantum energy of the characteristic radiation from tungsten is about 2 keV higher than that from tantalum. Even if the X-rays emitted by the screen were prevented from directly reaching the outside, this radiation could not be prevented from causing elastic or Compton scattering processes at the target, and in this way reaching the outside and impairing the spectral purity of the radiation.
  • the screen must be thick enough to keep the scattering electrons away from the target 36, but on the other hand it must be sufficiently thin so that the radiation emitted by the anode 31 is not weakened too much.
  • a suitable value for the wall thickness of the screen is 0.1 mm. Although this screen absorbs more X-rays than a titanium screen of the same strength, because of the additionally generated X-rays there is a higher emission of quasi-monochromatic radiation from the target 36 than with a titanium screen with the same wall thickness.
  • the screen becomes in operation due to its smaller area and wall thickness, and because of the lack of cooling, much hotter than the anode body.
  • the electrical power that can be supplied to the radiation source is therefore limited by the temperature resistance of the screen 35.
  • a tantalum umbrella is also superior to a titanium umbrella because of its much higher melting point. In connection with the significantly improved conversion of the electrical power into fluorescence radiation, this means that the intensity of the quasi-monochromatic radiation can be several times greater than in the case of a radiation source with a titanium screen.
  • the screen In order to take advantage of the high thermal load capacity of the tantalum components, it must be avoided that the tantalum parts come into contact with atmospheric oxygen. Therefore, the screen must not hermetically seal the radiation source from the outside - as in DE-OS 37 16 618, but must be provided with one or more small openings, not shown, so that the vacuum inside the bulb also the interior of the screen Fulfills.
  • the central hole in which the screen 35 is inserted is closed to the outside by the radiation exit window 37.
  • the radiation exit window is formed by a plate, which can also consist of tantalum. Because of the material used between the target and the radiation exit window, the absorption coefficient of the radiation exit window for the fluorescence radiation generated in the target is relatively low.
  • diaphragm arrangement In front of the radiation exit window there is e.g. from two perforated diaphragms 5, 6 provided diaphragm arrangement which is connected to the radiation source in a manner not shown.
  • the openings in this diaphragm arrangement are dimensioned such that the directly emerging X-ray radiation generated in the screen is largely suppressed by the diaphragm arrangement. This prevents the continuous spectrum of the radiation generated in the screen from affecting the spectral purity of the fluorescent radiation which passes through the diaphragm arrangement.
  • This diaphragm arrangement preferably consists of the same material as the target 36 and the window 37 — in the example, therefore, of tantalum.

Landscapes

  • X-Ray Techniques (AREA)
  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
EP91201225A 1990-05-26 1991-05-22 Source quasi-monochromatique de rayons X Expired - Lifetime EP0459567B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4017002 1990-05-26
DE4017002A DE4017002A1 (de) 1990-05-26 1990-05-26 Strahlenquelle fuer quasimonochromatische roentgenstrahlung

Publications (3)

Publication Number Publication Date
EP0459567A2 true EP0459567A2 (fr) 1991-12-04
EP0459567A3 EP0459567A3 (en) 1992-01-02
EP0459567B1 EP0459567B1 (fr) 1996-01-31

Family

ID=6407256

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91201225A Expired - Lifetime EP0459567B1 (fr) 1990-05-26 1991-05-22 Source quasi-monochromatique de rayons X

Country Status (4)

Country Link
US (1) US5157704A (fr)
EP (1) EP0459567B1 (fr)
JP (1) JP3105292B2 (fr)
DE (2) DE4017002A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6141400A (en) * 1998-02-10 2000-10-31 Siemens Aktiengesellschaft X-ray source which emits fluorescent X-rays

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19639241C2 (de) * 1996-09-24 1998-07-23 Siemens Ag Monochromatische Röntgenstrahlenquelle
DE19805290C2 (de) * 1998-02-10 1999-12-09 Siemens Ag Monochromatische Röntgenstrahlenquelle
DE19905802A1 (de) * 1999-02-12 2000-08-17 Philips Corp Intellectual Pty Röntgenröhre
US7180981B2 (en) 2002-04-08 2007-02-20 Nanodynamics-88, Inc. High quantum energy efficiency X-ray tube and targets
US7158612B2 (en) * 2003-02-21 2007-01-02 Xoft, Inc. Anode assembly for an x-ray tube
CN1302510C (zh) * 2003-05-15 2007-02-28 谭大刚 基于透射阳极x线机的可变换准单能或双能荧光x线源
US7567650B2 (en) * 2003-05-19 2009-07-28 Koninklijke Philips Electronics N.V. Fluorescent x-ray source
US7200203B2 (en) * 2004-04-06 2007-04-03 Duke University Devices and methods for targeting interior cancers with ionizing radiation
KR101063106B1 (ko) * 2004-11-08 2011-09-07 에스아이아이 나노 테크놀로지 가부시키가이샤 형광 ｘ선 분석 장치
US20070089227A1 (en) * 2005-10-26 2007-04-26 Joseph Battiston Transfer seat with rotatable wing
EP1988564A4 (fr) * 2006-02-01 2011-04-20 Toshiba Electron Tubes & Devic Source de rayons x et dispositif d'analyse de rayons x fluorescents
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
US7876883B2 (en) * 2008-04-10 2011-01-25 O'hara David Mammography X-ray homogenizing optic
WO2010120377A2 (fr) * 2009-04-16 2010-10-21 Silver Eric H Procédés et appareil à rayons x monochromatiques
WO2014175762A1 (fr) 2013-04-25 2014-10-30 Siemens Aktiengesellschaft Dispositif et procédé de génération de rayons x
US20150369758A1 (en) 2014-06-24 2015-12-24 Eric H. Silver Methods and apparatus for determining information regarding chemical composition using x-ray radiation
KR102658750B1 (ko) 2017-05-19 2024-04-22 이매진 싸이언티픽, 인크. 단색 엑스선 영상 시스템 및 방법
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
US10818467B2 (en) * 2018-02-09 2020-10-27 Imagine Scientific, Inc. Monochromatic x-ray imaging systems and methods
WO2020056281A1 (fr) 2018-09-14 2020-03-19 Imagine Scientific, Inc. Systèmes de composant de rayons x monochromatiques et procédés

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL55461C (fr) * 1938-07-23
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
US3963922A (en) * 1975-06-09 1976-06-15 Nuclear Semiconductor X-ray fluorescence device
DE3716618A1 (de) * 1987-05-18 1988-12-08 Philips Patentverwaltung Strahlenquelle zur erzeugung einer im wesentlichen monochromatischen roentgenstrahlung

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6141400A (en) * 1998-02-10 2000-10-31 Siemens Aktiengesellschaft X-ray source which emits fluorescent X-rays

Also Published As

Publication number Publication date
US5157704A (en) 1992-10-20
JPH04229539A (ja) 1992-08-19
JP3105292B2 (ja) 2000-10-30
EP0459567A3 (en) 1992-01-02
DE4017002A1 (de) 1991-11-28
EP0459567B1 (fr) 1996-01-31
DE59107329D1 (de) 1996-03-14

Similar Documents

Publication Publication Date Title
EP0459567B1 (fr) Source quasi-monochromatique de rayons X
EP0292055B1 (fr) Source de rayonnement pour la génération de rayons X essentiellement monochromatiques
EP0584871B1 (fr) Tube à rayons X ayant une anode en mode de transmission
DE10120335C2 (de) Ionenmobilitätsspektrometer mit nicht-radioaktiver Ionenquelle
DE2154888A1 (de) Roentgenroehre
DE10147473C2 (de) Drehanodenröntgenröhre
DE3107949A1 (de) Roentgenroehre
DE927584C (de) Zylindrische Vorratskathode, insbesondere fuer eine Magnetronroehre
DE19544203A1 (de) Röntgenröhre, insbesondere Mikrofokusröntgenröhre
DE3827511A1 (de) Roentgenstrahlquelle mit selektiver erzeugung punktfokussierter und linienfokussierter roentgenstrahlen
DE2441968B2 (de) Röntgenröhre zur Erzeugung monochromatischer Röntgenstrahlung
EP0021441B1 (fr) Accélérateur d'électrons pour radiothérapie aux rayons X
DE2719609A1 (de) Roentgenroehre
DE3490036T1 (de) Strahlungsquelle
DE102015210681B4 (de) Vorrichtung zur Erzeugung von Bremsstrahlung
DE3514700A1 (de) Roentgenroehre
DE10056623B4 (de) Röntgenröhre mit einer Seltenerdanode
DE202022104696U1 (de) Targetaufbau zur Erzeugung von Röntgenstrahlung
DE483337C (de) Gluehkathodenroehre, insbesondere Roentgenroehre
DE102010030713A1 (de) Röntgenquelle zur Erzeugung von Röntgenstrahlen mit einem Hohlkörpertarget und ein Verfahren zur Erzeugung von Röntgenstrahlung in einem Hohlkörpertarget
DE4209226A1 (de) Strahlenquelle zur erzeugung einer im wesentlichen monochromatischen roentgenstrahlung
DE2523360A1 (de) Gasentladungselektronenstrahlerzeugungssystem zum erzeugen eines elektronenstrahls mit hilfe einer glimmentladung
DE896533C (de) Einrichtung zur Erzeugung eines Strahles von positiven Ionen oder von Elektronen
DE2749856A1 (de) Roentgenroehre
DE2441986B2 (de) Röntgenröhre hoher Leistung

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): CH DE FR GB LI

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): CH DE FR GB LI

17P Request for examination filed

Effective date: 19920702

17Q First examination report despatched

Effective date: 19940929

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): CH DE FR GB LI

REF Corresponds to:

Ref document number: 59107329

Country of ref document: DE

Date of ref document: 19960314

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19960417

ET Fr: translation filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CH

Effective date: 19960531

Ref country code: LI

Effective date: 19960531

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

26N No opposition filed
REG Reference to a national code

Ref country code: FR

Ref legal event code: CD

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

REG Reference to a national code

Ref country code: GB

Ref legal event code: 746

Effective date: 20050609

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

REG Reference to a national code

Ref country code: FR

Ref legal event code: TP

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20100602

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20100528

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20100519

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 59107329

Country of ref document: DE

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20110521

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20110521

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20110523