EP0046244A2 - Dispositif de représentation sous forme d'image de la répartition d'intensité d'un rayonnement - Google Patents

Dispositif de représentation sous forme d'image de la répartition d'intensité d'un rayonnement Download PDF

Info

Publication number
EP0046244A2
EP0046244A2 EP81106169A EP81106169A EP0046244A2 EP 0046244 A2 EP0046244 A2 EP 0046244A2 EP 81106169 A EP81106169 A EP 81106169A EP 81106169 A EP81106169 A EP 81106169A EP 0046244 A2 EP0046244 A2 EP 0046244A2
Authority
EP
European Patent Office
Prior art keywords
wires
chamber
wire
radiation
gas
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.)
Withdrawn
Application number
EP81106169A
Other languages
German (de)
English (en)
Other versions
EP0046244A3 (fr
Inventor
Horst Dr. Brüning
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.)
Siemens AG
Siemens Corp
Original Assignee
Siemens AG
Siemens Corp
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 Siemens AG, Siemens Corp filed Critical Siemens AG
Publication of EP0046244A2 publication Critical patent/EP0046244A2/fr
Publication of EP0046244A3 publication Critical patent/EP0046244A3/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J47/00—Tubes for determining the presence, intensity, density or energy of radiation or particles
    • H01J47/06—Proportional counter tubes
    • H01J47/062—Multiwire proportional counter tubes

Definitions

  • the invention relates to a device for multi-dimensional, pictorial representation of the intensity distribution in cross section of a bundle of penetrating radiation, in particular an X-ray beam, with a detector chamber, the interior of which is under pressure of a predetermined gas, in which two electrodes extending on at least approximately parallel surfaces are arranged, one of which is highly transparent for the electrically charged particles produced by ionization in the gas space in accordance with the intensity distribution of the incident radiation and between which an at least approximately homogeneous electric field is formed by means of annular auxiliary electrodes, and on the side of the highly transparent which is remote from the auxiliary electrodes Electrode is designed as a multi-wire chamber, which contains wires tensioned without crossing in one plane and with one another, and with means for registration and further processing of the wires on the de r multi-wire chamber signals generated by the electrically charged particles, an assignment of these signals to the respective origin of an electrically charged particle in the gas space on the one hand by the position coordinate of the wire of the multi-wire chamber registering the
  • Particle between the place of its creation in the gas space and the registering wire is made by the at least approximately homogeneous electric field.
  • a corresponding device is e.g. in the reference "Nuclear Instruments and Methods", Vol. 158, 1979, pages 81 to 88.
  • the electrons striking these wires in turn call out secondary ions in a so-called avalanche process, which ions are registered at detector element planes running parallel to the plane of the wires.
  • Wires are generally also used as detector elements, the wires of one level being crossed with respect to the wires of the other level.
  • the detector elements facing the drift volume can at the same time. be an electrode. With these detector elements, it is thus possible to determine the origin of the respective electron projected into the plane of the multi-wire chamber. For a three-dimensional determination of the place of origin, the "Nucl. Instr. And Meth.” known device also uses the drift time of the electron through the homogeneous field between the electrodes of the drift volume.
  • the known multi-wire chamber can also be operated in a corresponding manner as a one-dimensional detector in which the incident X-rays are collimated by a slit diaphragm that is movable transversely to its extension.
  • a similar operating mode can be found in the ionization detectors that are generally used in computer tomography. Due to the . necessary mechanical guidance of the slit diaphragm over the object to be examined requires a relatively complex mechanism. In addition, the small solid angle, which can be used for quantum absorption, requires a very powerful and expensive X-ray source.
  • this device should have a high resolution and require short exposure times.
  • This object is achieved in that the direction of incidence for a two-dimensional representation device of the radiation entering the interior of the detector chamber runs at least approximately parallel to the plane of the wires of the multi-wire chamber serving as collector wires, that the wires of the multi-wire chamber are aligned at least approximately parallel with respect to the direction of incidence of the radiation and that the electrically charged particles to be registered have positive ions of Gases are.
  • this device can be seen in particular in its simplicity. This is because only a single plane of detector wires is required for a two-dimensional representation, which have a predetermined orientation with respect to the incident radiation and thus enable a unique assignment of a coordinate to the radiation quanta incident in the interior. The use of only one level of wires also ensures very little dead time. In addition, positive, relatively slow gas ions diffuse as little information carriers in the homogeneous electric field, so that for this reason too the assignment of the detector wires to the radiation particles incident in the gas space is very precise. The second coordinate results from the drift time of the gas ions.
  • FIGS. 1 and 2 schematically illustrate an exemplary embodiment of a detector chamber of a device according to the invention.
  • 3 and 4 show electronic circuits for image reconstruction with a
  • a detector chamber adapted to a punctiform radiation source is partially indicated in FIG.
  • FIG. 1 and 2 each show a longitudinal section through a detector chamber of a device according to the invention, the sectional planes according to the two figures being placed such that they form a right angle with one another.
  • a drift chamber with an assigned multi-wire chamber is assumed, as described, for example, in the cited references "Nuclear Instruments and Methods", vol. 158, 1979, page 81 and “IEEE Transactions on Nuclear Science", vol. NS -22 February 1975, page 269 are indicated.
  • the detector chamber, generally designated 2 contains a pressure housing 3, which is provided on one side with an opening 4, which is sealed gas-tight by a window 5.
  • the interior 6 of the chamber is under a predetermined excess pressure of, for example, 2 to 15, preferably 5 to 10 bar of a gas which has a high absorption cross section for the radiation provided.
  • Corresponding gases are e.g. Noble gases such as krypton or xenon, to which small amounts of other gases may be added.
  • the window consists for example of a carbon or glass fiber reinforced plastic, while the housing 3 is partially made of a metal such as e.g. Aluminum or stainless steel is made.
  • a bundle of radiation in particular an X-ray beam, which is indicated by individual arrowed lines 7, enters through the window 5 from the side into the interior 6 of the chamber 2, which beam comes from a radiation source not shown in the figure was caused and has penetrated an object to be examined.
  • absorption volume 8 of the interior 6 which is expanded in accordance with the dimensions of the window 5, absorption then takes place on the atoms of the gas, for example the krypton.
  • the absorption volume 8 is limited by two planar electrodes 9 and 10 which are parallel to one another and to the direction of incidence of the radiation. At least the lower electrode 10, which is at a negative potential, is designed to be highly transparent for positive ions of the gas.
  • the upper, opposite electrode 9 can also be designed or also consist of a metallic foil or plate.
  • E d there is a strong electric field E d between the two electrodes, which is illustrated in FIG. 2 by individual arrowed lines 11 and whose field strength is between 1.0 and 2.5 kV / cm, preferably around 1.5 kV / cm.
  • the absorption volume 8 penetrated by this field is also enclosed by a plurality of auxiliary electrodes 12 lying in parallel planes.
  • a detection zone 14 also adjoins the absorption volume 8 penetrated by the electric field E d on the side of the lower electrode 10 facing away from the auxiliary electrodes 12.
  • This detection zone is designed in accordance with a one-dimensional multi-wire chamber, in that between the electrode 10 and a parallel counter-electrode provided for reasons of field symmetry trode 15 a plurality of wires 16 which are free of crossings, for example at least approximately parallel, are tensioned.
  • these wires are provided as collector wires. Their mutual distance is expediently between 0.2 and 1 mm and is, for example, 0.5 mm.
  • Suitable collector wires that are at negative potential are in particular 20 to 100 ⁇ m thick, preferably approximately 50 ⁇ m thick copper beryllium wires or corresponding wires made of tungsten or steel. According to the invention, they are all arranged in a plane parallel to the direction of incidence of the radiation and, moreover, are also aligned at least approximately parallel to this direction.
  • the image reconstruction of the intensity distribution of the incident radiation can be carried out analog or digital in individual image elements.
  • the y i coordinate of a pixel of finite extent, also referred to as a pixel, is determined by projection onto the time axis t, while the x i coordinate is determined by the respective collector wire number.
  • this value can be tapped periodically as the output voltage of an integrator circuit with which each collector wire 16 is equipped, and can be given to the Z axis of a CRT screen.
  • An embodiment of such an integrator circuit is indicated in FIG. 3. Resistance and capacitor values are entered directly in the figure, while the other parts provided with reference numerals are the following components:
  • Digital data acquisition can e.g. 4 via a multiplexer 28, fast logarithmic AD converter 29 and a computer-controlled storage 30 with reset r and sample / hold switching s / h on a removable plate 31, a printer 32 or a color television playback device 23 .
  • Such data acquisition is generally known, for example, in the field of computer tomography.
  • a major advantage of the design of the device according to the invention lies in its great dynamics and fine gray gradation, which can be achieved, for example, with digital signal processing.
  • the current strength with an unattenuated beam is typically 1 / uA.
  • a dynamic range of a few 10 5 can thus be achieved, the dynamic range being understood to mean the quantity generally used in the field of medical technology under this term.
  • the display on a television monitor can take place, for example, in the window technology generally known from computer tomography, the achievable pixel size being approximately 1 mm 2 . As is known, this size is limited downwards by the diffusion of the ions influenced by the product kT and the space charge, the range of the photoelectrons in the absorption volume, the inhomogeneity of the drift field and the parallax errors due to finite thickness of the absorption volume.
  • the most important point namely the diffusion of an initially localized ion concentration, can be achieved by applying a sufficiently strong drift field E d of, for example, 1.5 kV / cm, by a pressure that is not too high of 5 to 10 bar and by expanding the absorption volume in y - Limit the direction of at most 25 to 30 cm to a value ⁇ 1 mm.
  • the range of the photoelectrons is much smaller. Inhomogeneities in the drift field E d can be kept sufficiently small by a corresponding geometry of the auxiliary electrodes in order to exclude distortions.
  • the parallax error can be completely eliminated, for example, by radially aligning the collector wires to a fixed focus position of, for example, approximately 800 mm in one plane.
  • a corresponding exemplary embodiment of this recording technique is indicated in FIG. 5 as a top view of a section parallel to the plane of the collector wires.
  • a beam generator with 35 which is a radiance emanating from him beams delimiting bundles, illustrated by arrowed lines with 36 and 37, a detector chamber with 38 and their collector wires lying in one plane, radially aligned with respect to the beam generator 35, designated 39.
  • a 70 kV X-ray tube with high pulse power is provided as the beam generator, for example, the pulse duration being approximately 0.5 msec.
  • the device according to the invention can advantageously also be used as an X-ray television set for recording dynamic processes in medical technology.

Landscapes

  • Measurement Of Radiation (AREA)
EP81106169A 1980-08-18 1981-08-06 Dispositif de représentation sous forme d'image de la répartition d'intensité d'un rayonnement Withdrawn EP0046244A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19803031136 DE3031136C2 (de) 1980-08-18 1980-08-18 Vorrichtung zur bildmäßigen Darstellung einer Röntgenstrahlung
DE3031136 1980-08-18

Publications (2)

Publication Number Publication Date
EP0046244A2 true EP0046244A2 (fr) 1982-02-24
EP0046244A3 EP0046244A3 (fr) 1983-03-30

Family

ID=6109846

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81106169A Withdrawn EP0046244A3 (fr) 1980-08-18 1981-08-06 Dispositif de représentation sous forme d'image de la répartition d'intensité d'un rayonnement

Country Status (2)

Country Link
EP (1) EP0046244A3 (fr)
DE (1) DE3031136C2 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2538906A1 (fr) * 1983-01-04 1984-07-06 Commissariat Energie Atomique Procede d'examen de l'image radiographique d'un objet irradie a l'aide d'une source de rayonnements ionisants et chambre d'ionisation pour la mise en oeuvre du procede
WO2006103403A1 (fr) * 2005-03-29 2006-10-05 The Science And Technology Facilities Council Detecteur de rayonnement

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3901837A1 (de) * 1989-01-23 1990-07-26 H J Dr Besch Bildgebender strahlendetektor mit pulsintegration

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
NUCLEAR INSTRUMENTS & METHODS, Band 161, Nr. 3, Mai 1979, Seiten 383-390, Amsterdam, NL. D. FANCHER et al.: "Performance of a time-projection chamber" *
NUCLEAR INSTRUMENTS AND METHODS 158, 1979, Seiten 81-88, North-Holland Publishing Co. D. FRIEDRICH et al.: "Positive ion effects in large-volume drift-chambers" *
NUCLEAR INSTRUMENTS AND METHODS, Band 111, Nr. 1, 1. August 1973, Seiten 77-81, Amsterdam, NL. J. SAUDINOS et al.: "Localisation de particules par compteur à migration" *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2538906A1 (fr) * 1983-01-04 1984-07-06 Commissariat Energie Atomique Procede d'examen de l'image radiographique d'un objet irradie a l'aide d'une source de rayonnements ionisants et chambre d'ionisation pour la mise en oeuvre du procede
EP0115734A1 (fr) * 1983-01-04 1984-08-15 Commissariat A L'energie Atomique Procédé d'examen de l'image radiographique d'un objet irradié à l'aide d'une source de rayonnements ionisants et chambre d'ionisation pour la mise en oeuvre du procédé
US4645934A (en) * 1983-01-04 1987-02-24 Commissariat A L'energie Atomique Process for examining a flat radiograph of an object and ionization chamber for performing the process
WO2006103403A1 (fr) * 2005-03-29 2006-10-05 The Science And Technology Facilities Council Detecteur de rayonnement

Also Published As

Publication number Publication date
EP0046244A3 (fr) 1983-03-30
DE3031136A1 (de) 1982-03-18
DE3031136C2 (de) 1986-12-11

Similar Documents

Publication Publication Date Title
DE69715092T2 (de) Hochauflösende radiografische Bilderzeugungsvorrichtung
DE69414879T2 (de) Gas-ionisations-netzdetektoren für die radiographie
DE3689492T2 (de) Kinestatische Ladungsnachweisung durch synchrone Bewegung der Detektorvorrichtung.
DE2627448C2 (fr)
DE2025136C3 (de) Einrichtung zum Messen der räumlichen Intensitätsverteilung von Beta-, Röntgen- oder Gammastrahlung, mit einem im Proportionalbereich arbeitenden, eine Vielzahl von parallelen Anodendrähten aufweisenden Gasentladungs-Detektor
DE2323610A1 (de) Verfahren und einrichtung zur untersuchung mittels roentgenstrahlen
DE3688932T2 (de) Vorrichtung zur Wahrnehmung und Lokalisierung von neutralen Partikeln und deren Anwendung.
DE2460686C2 (de) Proportionalzählrohr zur Messung der räumlichen Intensitätsverteilung ionisierender Strahlung
DE2738918A1 (de) Ionisationskammer
DE2719856A1 (de) Hochgeschwindigkeits-system zum erzeugen tomographischer roentgenbilder
EP2820448A1 (fr) Procédé de détection d'un rayonnement et dispositif d'analyse permettant d'analyser un échantillon en mettant en uvre un rayonnement.
DE2108359A1 (de) Vorrichtung zur Erzeugung eines gebündelten Strahlen geladener Teilchen, insbesondere für Elektronenspektrometer
EP0944108B1 (fr) Dispositif de mesure de rayonnement avec une chambre à ionisation
DE3031136C2 (de) Vorrichtung zur bildmäßigen Darstellung einer Röntgenstrahlung
DE69810785T2 (de) Analyse geladener teilchen
DE2105805A1 (de) Gerat zur Elektronenspektroskopie
DE2363581A1 (de) Verfahren zur zerstoerungsfreien chemischen analyse
EP0858674B1 (fr) Spectrometre de masse a temps de vol avec detecteur sensible a la position
EP1648019A1 (fr) Dispositif de radiographie de type a fonctionnement a balayage et variantes
DE68918871T2 (de) Verfahren und vorrichtung zur bidimensionalen lokalisierung nichtgeladener partikel, insbesondere bei geringer zählrate.
DE68924266T2 (de) Verfahren für quantitative autoradiographie-analyse.
DE2642741C2 (fr)
DE2715965A1 (de) Ionenkammeranordnung mit reduziertem totraum
DE2022132A1 (de) Spektrometer
DE3913043C2 (de) Energieanalysator

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

17P Request for examination filed

Effective date: 19811028

AK Designated contracting states

Designated state(s): FR GB NL

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): FR GB NL

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19840116

RIN1 Information on inventor provided before grant (corrected)

Inventor name: BRUENING, HORST, DR.