EP0352152B1 - Method of manufacturing a scintillator, and scintillator so obtained - Google Patents

Method of manufacturing a scintillator, and scintillator so obtained Download PDF

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Publication number
EP0352152B1
EP0352152B1 EP89401788A EP89401788A EP0352152B1 EP 0352152 B1 EP0352152 B1 EP 0352152B1 EP 89401788 A EP89401788 A EP 89401788A EP 89401788 A EP89401788 A EP 89401788A EP 0352152 B1 EP0352152 B1 EP 0352152B1
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EP
European Patent Office
Prior art keywords
scintillator
metal
oxide
substrate
honeycomb structure
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EP89401788A
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German (de)
French (fr)
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EP0352152A1 (en
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Gérard Vieux
Paul De Groot
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Thales SA
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Thomson CSF SA
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/10—Screens on or from which an image or pattern is formed, picked up, converted or stored
    • H01J29/36—Photoelectric screens; Charge-storage screens
    • H01J29/38—Photoelectric screens; Charge-storage screens not using charge storage, e.g. photo-emissive screen, extended cathode
    • H01J29/385—Photocathodes comprising a layer which modified the wave length of impinging radiation
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K4/00—Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/12—Manufacture of electrodes or electrode systems of photo-emissive cathodes; of secondary-emission electrodes

Definitions

  • the invention relates to a method of manufacturing a scintillator more particularly intended for the input screen of an X-ray image intensifier tube. It also relates to a scintillator obtained by the implementation of such a method.
  • Radiological image intensifier tubes are well known in the art, they make it possible to transform a radiological image representative of the absorption of X-rays by the structure to be represented, into a visible image. Such devices are widely used for medical observation.
  • An image intensifier tube consists of an input screen, an electronic optical system and an observation screen.
  • the input screen has a scintillator which converts X photons into visible photons. These visible photons then strike a photocathode, generally constituted by an alkaline antimonide. The latter, thus excited, generates a flow of electrons.
  • This flux is then transmitted by the electronic optical system which focuses the electrons and directs them on an observation screen made up of a luminograph which then emits visible light reconstituting the radiological image.
  • This light can then be processed, for example by a television, cinema, or photography system.
  • the scintillator of the entry screen generally consists of cesium iodide deposited by evaporation under vacuum on a substrate.
  • the substrate generally consists of an aluminum cap with a spherical or hyperbolic profile.
  • a thickness of cesium iodide is deposited which is generally between 150 and 500 ⁇ m (microns).
  • Cesium iodide is deposited in the form of needles of 5 to 10 ⁇ m (microns) in diameter. Its refractive index being 1.8, there is a certain optical fiber effect which minimizes the lateral diffusion of light within the material scintillator.
  • a scintillator of this kind is for example described in EP-A-0215699.
  • the resolution of the tube depends on the ability of the cesium iodide needles to properly channel the light; it is therefore beneficial to reduce their diameter. It also depends on the thickness of the cesium iodide layer; an increase in thickness leads to a deterioration in resolution. On the other hand, the greater the thickness of cesium iodide, the more the X-rays are absorbed. A compromise must therefore be found between the absorption of X-rays and the resolution.
  • a French patent application published with the number FR-A-2 515 423 proposes to produce a scintillator by growing columns of cesium iodide on impurities contained in a metal substrate, after having released these impurities by a process pickling. With this method, the resolution is improved, since crystals in the form of needles having diameters of between 0.5 ⁇ m and 10 ⁇ m are obtained.
  • the invention proposes an improvement making it possible to further reduce the average diameter of the cesium iodide needles.
  • the invention therefore relates to a method of manufacturing a scintillator consisting in creating in the surface of a metal (11), a honeycomb structure (15), produced in the oxide of the metal, then in growing needles (13) of scintillator material (12) on said surface, characterized in that said honeycomb structure (15) is created by subjecting said surface of the metal to electrochemical anodization in a chemical medium having the property of dissolving said oxide.
  • This dimpled surface state or this dimpled structure consists in producing the oxidation of the surface of the substrate under conditions such that the oxide layer formed has such a dimpled structure.
  • This procedure is particularly indicated with an aluminum substrate which is most commonly used as a support for a scintillating layer.
  • the alumina produced can have a honeycomb structure if the oxidation treatment takes place in a chemical medium having the property of dissolving said oxide at the same time. This is particularly the case if one side of the substrate is subjected to electrochemical anodization, the anodization bath containing an acid or any other product having the property of chemically dissolving the oxide.
  • honeycomb structure is the result of two actions, that is to say on the one hand the electrochemical formation of the oxide layer and on the other hand its own dissolution, purely chemical, in the anodization bath.
  • an anodization bath containing phosphoric acid or sulfuric acid may be provided.
  • the invention relates to any process which results in the production of a cellular layer on the surface of the substrate.
  • evaporation under vacuum with redeposition on the substrate of any element can give rise to a honeycomb deposit if this operation is carried out voluntarily with a limited vacuum, in particular between 1 and 0.01 torr.
  • the invention also relates to any scintillator comprising a metal substrate (11), the surface of which has a honeycomb structure, made of metal oxide, on which is deposited a scintillator material (12) in the form of needles ( 13) substantially parallel, characterized in that the scintillator is manufactured according to the method as described in claim 1.
  • the known scintillator consists essentially of a substrate 11 made of aluminum on which is grown a layer of scintillator material 12 composed of the juxtaposition of needles 13 a arranged side-by-side, substantially parallel to each other, and standing approximately perpendicular to the surface of the substrate.
  • the scintillator material here is cesium iodide.
  • these needles are the result of a vacuum evaporation process of cesium iodide followed by its redeposition on the substrate.
  • the aluminum substrate has undergone a simple pickling in an acid or alkaline medium. With the surface condition resulting from this pickling, the needles develop with an average diameter of 5 to 10 ⁇ m (microns).
  • the substrate 11 and the layer 12 of scintillator material are composed of needles 13 b substantially thinner than in the prior art.
  • This advantageous result is attributed to the fact that these needles formed in the same way as above (evaporation and redeposition under vacuum of cesium iodide) developed on a layer of a honeycomb structure 15.
  • this layer is made of alumina resulting oxidation at the surface of the substrate itself. This oxidation is carried out according to a particular process which will be described later.
  • FIG. 3 shows that this honeycomb structure 15 is characterized, in the example described, by the presence of small columns 18 in the form of matches, the diameter of which is between 0.05 and 0.50 ⁇ m (500 and 5000 ⁇ ngstroms ).
  • this is obtained by forming the oxide layer (here alumina) in a medium having the property of chemically dissolving the oxide.
  • the alumina layer is therefore partially destroyed as it is formed, which results in the structure of FIG. 3. It is on this honeycomb structure which is subsequently made to grow the layer of scintillator material, which results in the formation of finer needles.
  • the treatment making it possible to obtain the honeycomb structure is illustrated in FIG. 4.
  • the substrate 11 (one face of which is temporarily protected by a varnish) is connected to the positive pole of a current source 20 and thus forms an electrode of a electrochemical anodizing system.
  • this substrate forming an electrode, is immersed in an electrochemical solution 21 capable of causing the formation of an alumina layer.
  • the negative pole of the current source 20 is connected to another electrode 22 immersed in this same solution.
  • the latter contains a chemical attacking the oxide as it is formed.
  • this product can be phosphoric acid or sulfuric acid.
  • the substrate is placed in an enclosure in which a vacuum is created.
  • the cesium iodide is then evaporated in said enclosure, according to a known process, which results in the formation of the needles 13b shown in FIG. 2.
  • the invention covers many variants.
  • it is the dimpled surface state on which the scintillator material is grown which is important for the implementation of the invention and not the chemical composition of the dimpled layer.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Manufacturing & Machinery (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
  • Measurement Of Radiation (AREA)
  • Formation Of Various Coating Films On Cathode Ray Tubes And Lamps (AREA)

Description

L'invention concerne un procédé de fabrication d'un scintillateur plus particulièrement destiné à l'écran d'entrée d'un tube intensificateur d'image radiologique. Elle concerne également un scintillateur obtenu par la mise en oeuvre d'un tel procédé.The invention relates to a method of manufacturing a scintillator more particularly intended for the input screen of an X-ray image intensifier tube. It also relates to a scintillator obtained by the implementation of such a method.

Les tubes intensificateurs d'image radiologique sont bien connus dans la technique, ils permettent de transformer une image radiologique représentative de l'absorption des rayons X par la structure à représenter, en une image visible. De tels dispositifs sont très utilisés pour l'observation médicale. Un tube intensificateur d'image est constitué par un écran d'entrée, un système d'optique électronique et un écran d'observation. L'écran d'entrée comporte un scintillateur qui convertit les photons X en photons visibles. Ces photons visibles viennent ensuite frapper une photocathode, généralement constituée par un antimoniure alcalin. Ce dernier, ainsi excité, engendre un flux d'électrons. Ce flux est ensuite transmis par le système d'optique électronique qui focalise les électrons et les dirige sur un écran d'observation constitué d'un luminographe qui émet alors une lumière visible reconstituant l'image radiologique. Cette lumière peut ensuite être traitée, par exemple par un système de télévision, de cinéma, ou de photographie.Radiological image intensifier tubes are well known in the art, they make it possible to transform a radiological image representative of the absorption of X-rays by the structure to be represented, into a visible image. Such devices are widely used for medical observation. An image intensifier tube consists of an input screen, an electronic optical system and an observation screen. The input screen has a scintillator which converts X photons into visible photons. These visible photons then strike a photocathode, generally constituted by an alkaline antimonide. The latter, thus excited, generates a flow of electrons. This flux is then transmitted by the electronic optical system which focuses the electrons and directs them on an observation screen made up of a luminograph which then emits visible light reconstituting the radiological image. This light can then be processed, for example by a television, cinema, or photography system.

Le scintillateur de l'écran d'entrée est généralement constitué d'iodure de césium déposé par évaporation sous vide sur un substrat. Le substrat est généralement constitué par une calotte d'aluminium à profil sphérique ou hyperbolique. On dépose une épaisseur d'iodure de césium qui est généralement comprise entre 150 et 500 µm (microns). L'iodure de césium se dépose sous forme d'aiguilles de 5 à 10 µm (microns) de diamètre. Son indice de réfraction étant de 1,8, on bénéficie d'un certain effet de fibre optique qui minimise la diffusion latérale de la lumière au sein du matériau scintillateur. Un scintillateur de ce genre est par exemple décrit dans EP-A-0215699.The scintillator of the entry screen generally consists of cesium iodide deposited by evaporation under vacuum on a substrate. The substrate generally consists of an aluminum cap with a spherical or hyperbolic profile. A thickness of cesium iodide is deposited which is generally between 150 and 500 μm (microns). Cesium iodide is deposited in the form of needles of 5 to 10 µm (microns) in diameter. Its refractive index being 1.8, there is a certain optical fiber effect which minimizes the lateral diffusion of light within the material scintillator. A scintillator of this kind is for example described in EP-A-0215699.

La résolution du tube dépend de la capacité des aiguilles d'iodure de césium à bien canaliser la lumière ; on a donc intérêt à réduire leur diamètre. Elle dépend aussi de l'épaisseur de la couche d'iodure de césium ; une augmentation d'épaisseur entraîne une détérioration de la résolution. En revanche, plus d'épaisseur d'iodure de césium est importante, plus les rayons X sont absorbés. Il faut donc trouver un compromis entre l'absorption des rayons X et la résolution.The resolution of the tube depends on the ability of the cesium iodide needles to properly channel the light; it is therefore beneficial to reduce their diameter. It also depends on the thickness of the cesium iodide layer; an increase in thickness leads to a deterioration in resolution. On the other hand, the greater the thickness of cesium iodide, the more the X-rays are absorbed. A compromise must therefore be found between the absorption of X-rays and the resolution.

Une demande de brevet français publiée avec le n° FR-A-2 515 423, propose de réaliser un scintillateur en faisant croître des colonnes d'iodure de césium sur des impuretés contenues dans un substrat métallique, après avoir dégagé ces impuretés par un procédé de décapage. Avec cette méthode on améliore la résolution, car on obtient des cristaux en forme d'aiguilles ayant des diamètres compris entre 0,5 µm et 10 µm.A French patent application published with the number FR-A-2 515 423, proposes to produce a scintillator by growing columns of cesium iodide on impurities contained in a metal substrate, after having released these impurities by a process pickling. With this method, the resolution is improved, since crystals in the form of needles having diameters of between 0.5 μm and 10 μm are obtained.

L'invention propose un perfectionnement permettant de réduire encore le diamètre moyen des aiguilles d'iodure de césium.The invention proposes an improvement making it possible to further reduce the average diameter of the cesium iodide needles.

Dans ce but l'invention concerne donc un procédé de fabrication d'un scintillateur consistant à créer dans la surface d'un métal (11), une structure alvéolée (15), réalisée dans l'oxyde du métal, puis à faire croître des aiguilles (13) de matériau scintillateur (12) sur ladite surface, caractérisé en ce que ladite structure alvéolée (15) est créée en soumettant ladite surface du métal à une anodisation électrochimique dans un milieu chimique ayant la propriété de dissoudre ledit oxyde.To this end, the invention therefore relates to a method of manufacturing a scintillator consisting in creating in the surface of a metal (11), a honeycomb structure (15), produced in the oxide of the metal, then in growing needles (13) of scintillator material (12) on said surface, characterized in that said honeycomb structure (15) is created by subjecting said surface of the metal to electrochemical anodization in a chemical medium having the property of dissolving said oxide.

On peut penser que le dépôt ultérieur de l'iodure de césium, par évaporation sous vide s'amorce sur les multiples aspérités qui sont créées par l'état de surface obtenu et qu'ainsi, des aiguilles plus fines peuvent croître en plus grand nombre sur une même surface du substrat.It may be thought that the subsequent deposition of cesium iodide, by vacuum evaporation, begins on the multiple asperities which are created by the surface state obtained and that, as a result, finer needles can grow in greater numbers. on the same surface of the substrate.

Une solution pour obtenir cet état de surface alvéolé ou cette structure alvéolée, consiste à produire l'oxydation de la surface du substrat dans des conditions telles que la couche d'oxyde formée ait une telle structure alvéolée. Cette façon de procéder est particulièrement indiquée avec un substrat en aluminium qui est le plus couramment utilisé en tant que support d'une couche scintillatrice. L'alumine produit peut avoir une structure alvéolée si le traitement d'oxydation a lieu dans un milieu chimique ayant la propriété de dissoudre en même temps ledit oxyde. C'est notamment le cas si on soumet une face du substrat à une anodisation électrochimique, le bain d'anodisation contenant un acide ou tout autre produit ayant la propriété de dissoudre chimiquement l'oxyde. La structure alvéolée est le résultat des deux actions, c'est-à-dire d'une part la formation électrochimique de la couche d'oxyde et d'autre part sa propre dissolution, purement chimique, dans le bain d'anodisation. Pour l'alumine, on pourra prévoir un bain d'anodisation renfermant de l'acide phosphorique ou de l'acide sulfurique.One solution for obtaining this dimpled surface state or this dimpled structure consists in producing the oxidation of the surface of the substrate under conditions such that the oxide layer formed has such a dimpled structure. This procedure is particularly indicated with an aluminum substrate which is most commonly used as a support for a scintillating layer. The alumina produced can have a honeycomb structure if the oxidation treatment takes place in a chemical medium having the property of dissolving said oxide at the same time. This is particularly the case if one side of the substrate is subjected to electrochemical anodization, the anodization bath containing an acid or any other product having the property of chemically dissolving the oxide. The honeycomb structure is the result of two actions, that is to say on the one hand the electrochemical formation of the oxide layer and on the other hand its own dissolution, purely chemical, in the anodization bath. For alumina, an anodization bath containing phosphoric acid or sulfuric acid may be provided.

Cependant, l'invention vise tout processus ayant pour conséquence la production d'une couche alvéolée à la surface du substrat. Ainsi, une évaporation sous vide avec redéposition sur le substrat d'un élément quelconque peut donner lieu à un dépôt alvéolé si on pratique volontairement cette opération avec un vide limité, notamment compris entre 1 et 0,01 torr.However, the invention relates to any process which results in the production of a cellular layer on the surface of the substrate. Thus, evaporation under vacuum with redeposition on the substrate of any element can give rise to a honeycomb deposit if this operation is carried out voluntarily with a limited vacuum, in particular between 1 and 0.01 torr.

L'invention se rapporte également à tout scintillateur comportant un substrat en métal (11), dont la surface présente une structure alvéolée, réalisée dans l'oxyde du métal, sur laquelle est déposé un matériau scintillateur (12) sous forme d'aiguilles (13) sensiblement parallèles, caractérisé en ce que le scintillateur est fabriqué selon le procédé tel que décrit à la revendication 1.The invention also relates to any scintillator comprising a metal substrate (11), the surface of which has a honeycomb structure, made of metal oxide, on which is deposited a scintillator material (12) in the form of needles ( 13) substantially parallel, characterized in that the scintillator is manufactured according to the method as described in claim 1.

L'invention sera mieux comprise et d'autres avantages de celle-ci apparaîtront plus clairement à la lumière de la description qui va suivre, donnée uniquement à titre d'exemple et faite en référence aux dessins annexés dans lesquels:

  • la figure 1 représente schématiquement en coupe une partie d'un scintillateur selon l'art antérieur;
  • la figure 2 représente schématiquement en coupe, à la même échelle que la figure 1, une partie d'un scintillateur selon l'invention;
  • la figure 3 est une représentation très agrandie de la structure alvéolée du scintillateur conforme à l'invention; et
  • la figure 4 illustre schématiquement un équipement permettant la mise en oeuvre de la phase essentiellement nouvelle d'un procédé de fabrication d'un tel scintillateur.
The invention will be better understood and other advantages thereof will appear more clearly in the light of the description which follows, given solely by way of example and made with reference to the appended drawings in which:
  • Figure 1 shows schematically in section a portion of a scintillator according to the prior art;
  • Figure 2 shows schematically in section, on the same scale as Figure 1, part of a scintillator according to the invention;
  • Figure 3 is a greatly enlarged representation of the honeycomb structure of the scintillator according to the invention; and
  • FIG. 4 schematically illustrates an item of equipment allowing the implementation of the essentially new phase of a process for manufacturing such a scintillator.

En se reportant à la figure 1, le scintillateur connu se compose essentiellement d'un substrat 11 en aluminium sur lequel on a fait croître une couche de matériau scintillateur 12 composé de la juxtaposition d'aiguilles 13a disposées côte-à-côte, sensiblement parallèles entre elles, et se dressant approximativement perpendiculaires à la surface du substrat. Le matériau scintillateur est ici de l'iodure de césium. Classiquement, ces aiguilles sont le résultat d'un processus d'évaporation sous vide de l'iodure de césium suivi de sa redéposition sur le substrat. Selon l'art antérieur représenté, le substrat en aluminium a subi un simple décapage en milieu acide ou alcalin. Avec l'état de surface résultant de ce décapage, les aiguilles se développent avec un diamètre moyen de 5 à 10 µm (microns).Referring to Figure 1, the known scintillator consists essentially of a substrate 11 made of aluminum on which is grown a layer of scintillator material 12 composed of the juxtaposition of needles 13 a arranged side-by-side, substantially parallel to each other, and standing approximately perpendicular to the surface of the substrate. The scintillator material here is cesium iodide. Conventionally, these needles are the result of a vacuum evaporation process of cesium iodide followed by its redeposition on the substrate. According to the prior art shown, the aluminum substrate has undergone a simple pickling in an acid or alkaline medium. With the surface condition resulting from this pickling, the needles develop with an average diameter of 5 to 10 µm (microns).

Selon l'invention, schématisée à la figure 2, on retrouve le substrat 11 et la couche 12 de matériau scintillateur mais celle-ci est composée d'aiguilles 13b sensiblement plus fines que dans l'art antérieur. On attribue ce résultat avantageux au fait que ces aiguilles formées de la même façon que précédemment (évaporation et redéposition sous vide de l'iodure de césium) se sont développées sur une couche d'une structure alvéolée 15. Ici cette couche est en alumine résultant d'une oxydation en surface du substrat lui-même. Cette oxydation est réalisée suivant un processus particulier qui sera décrit plus loin.According to the invention, shown diagrammatically in FIG. 2, we find the substrate 11 and the layer 12 of scintillator material but the latter is composed of needles 13 b substantially thinner than in the prior art. This advantageous result is attributed to the fact that these needles formed in the same way as above (evaporation and redeposition under vacuum of cesium iodide) developed on a layer of a honeycomb structure 15. Here this layer is made of alumina resulting oxidation at the surface of the substrate itself. This oxidation is carried out according to a particular process which will be described later.

La figure 3 montre que cette structure alvéolée 15 se caractérise, dans l'exemple décrit, par la présence de petites colonnes 18 en forme d'allumettes, dont le diamètre est compris entre 0,05 et 0,50 µm (500 et 5000 Ångstroms). Comme mentionné précédemment, on obtient ce résultat en formant la couche d'oxyde (ici l'alumine) dans un milieu ayant la propriété de dissoudre chimiquement l'oxyde. La couche d'alumine est donc partiellement détruite au fur et à mesure de sa formation, ce qui aboutit à la structure de la figure 3. C'est sur cette structure alvéolée que l'on fait croître ultérieurement la couche de matériau scintillateur, ce qui a pour conséquence la formation d'aiguilles plus fines.FIG. 3 shows that this honeycomb structure 15 is characterized, in the example described, by the presence of small columns 18 in the form of matches, the diameter of which is between 0.05 and 0.50 μm (500 and 5000 Ångstroms ). As mentioned above, this is obtained by forming the oxide layer (here alumina) in a medium having the property of chemically dissolving the oxide. The alumina layer is therefore partially destroyed as it is formed, which results in the structure of FIG. 3. It is on this honeycomb structure which is subsequently made to grow the layer of scintillator material, which results in the formation of finer needles.

Le traitement permettant d'obtenir la structure alvéolée est illustré à la figure 4. Le substrat 11 (dont une face est protégée provisoirement par un vernis) est connecté au pôle positif d'une source de courant 20 et forme ainsi une électrode d'un système d'anodisation électrochimique. Autrement dit, ce substrat, formant électrode, est plongé dans une solution électrochimique 21 propre à engendrer la formation d'une couche d'alumine. Le pôle négatif de la source de courant 20 est relié à une autre électrode 22 plongeant dans cette même solution. Cette dernière renferme un produit chimique attaquant l'oxyde au fur et à mesure de sa formation. Dans le cas de l'alumine, ce produit peut être de l'acide phosphorique ou de l'acide sulfurique.The treatment making it possible to obtain the honeycomb structure is illustrated in FIG. 4. The substrate 11 (one face of which is temporarily protected by a varnish) is connected to the positive pole of a current source 20 and thus forms an electrode of a electrochemical anodizing system. In other words, this substrate, forming an electrode, is immersed in an electrochemical solution 21 capable of causing the formation of an alumina layer. The negative pole of the current source 20 is connected to another electrode 22 immersed in this same solution. The latter contains a chemical attacking the oxide as it is formed. In the case of alumina, this product can be phosphoric acid or sulfuric acid.

A l'issue du processus d'anodisation, le substrat est placé dans une enceinte dans laquelle on fait le vide. On procède alors à l'évaporation de l'iodure de césium dans ladite enceinte, selon un processus connu, ce qui aboutit à la formation des aiguilles 13b représentées à la figure 2.At the end of the anodization process, the substrate is placed in an enclosure in which a vacuum is created. The cesium iodide is then evaporated in said enclosure, according to a known process, which results in the formation of the needles 13b shown in FIG. 2.

Il est clair que l'invention couvre de nombreuses variantes. En particulier, il est à noter que c'est l'état de surface alvéolé sur lequel on fait croître le matériau scintillateur qui est important pour la mise en oeuvre de l'invention et non pas la composition chimique de la couche alvéolée.It is clear that the invention covers many variants. In particular, it should be noted that it is the dimpled surface state on which the scintillator material is grown which is important for the implementation of the invention and not the chemical composition of the dimpled layer.

Claims (6)

  1. A method for manufacturing a scintillator consisting in creating on a metal surface (11) a honeycomb structure (15) made from the oxide of said metal, and then in making pins (13) of scintillator material (12) to grow on said surface, characterized in that said honeycomb structure (15) is obtained by electrochemically anodizing said metal surface in a chemical medium, which is capable of dissolving said oxide.
  2. A manufacturing method according to claim 1, characterized in that said metal (11) is aluminum and that a honeycomb layer (15) of alumina is created on said metal surface.
  3. A manufacturing method according to one of the preceding claims, characterized in that said metal surface (11) is connected to an electric generator (20) and is immersed in an anodizing bath containing an acid or other product capable of chemically dissolving said oxide.
  4. A scintillator comprising a metal substrate (11) whose surface presents a honeycomb structure and is realised from the oxide of said metal, a scintillator material (12) made of substantially parallel pins (13) being deposited thereon, characterized in that said scintillator is made according to the method as described in one of claims 1 to 3.
  5. A scintillator according to claim 1, characterized in that said substrate is made of aluminum and that its surface supporting said pins of scintillator material comprises a honeycomb layer (15) of alumina.
  6. A scintillator according to one of claims 4 or 5, characterized in that said scintillator material is caesium iodide.
EP89401788A 1988-07-22 1989-06-23 Method of manufacturing a scintillator, and scintillator so obtained Expired - Lifetime EP0352152B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8809938A FR2634562B1 (en) 1988-07-22 1988-07-22 METHOD FOR MANUFACTURING A SCINTILLATOR AND SCINTILLATOR THUS OBTAINED
FR8809938 1988-07-22

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EP0352152A1 EP0352152A1 (en) 1990-01-24
EP0352152B1 true EP0352152B1 (en) 1993-05-12

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EP (1) EP0352152B1 (en)
JP (1) JP3084713B2 (en)
DE (1) DE68906478T2 (en)
FR (1) FR2634562B1 (en)

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FR2698482B1 (en) * 1992-11-20 1994-12-23 Thomson Tubes Electroniques Device for generating images by luminescence effect.
DE4433132C2 (en) * 1994-09-16 1999-02-11 Siemens Ag Scintillator of a radiation converter that has a needle structure
FR2777112B1 (en) 1998-04-07 2000-06-16 Thomson Tubes Electroniques IMAGE CONVERSION DEVICE
FR2782388B1 (en) 1998-08-11 2000-11-03 Trixell Sas SOLID STATE RADIATION DETECTOR WITH INCREASED LIFE
EP1113458B1 (en) * 1999-12-27 2005-02-02 Agfa-Gevaert A binderless storage phosphor screen with needle shaped crystals and methods for producing the same
EP1158540A1 (en) * 2000-05-24 2001-11-28 Agfa-Gevaert N.V. A binderless storage phosphor screen with needle shaped crystals
DE10119783A1 (en) * 2001-04-23 2002-10-31 Siemens Ag radiation converter
JP4789372B2 (en) * 2001-08-27 2011-10-12 キヤノン株式会社 Radiation detection apparatus, system, and scintillator panel provided in them
US6967339B2 (en) 2002-03-26 2005-11-22 Agfa-Gevaert Needle-shaped cylindrical storage phosphor crystals
DE10242006B4 (en) * 2002-09-11 2006-04-27 Siemens Ag Phosphor plate
US7573035B2 (en) * 2004-10-29 2009-08-11 Koninklijke Philips Electronics N.V. GOS ceramic scintillating fiber optics x-ray imaging plate for use in medical DF and RF imaging and in CT
KR100693105B1 (en) 2005-04-26 2007-03-12 라드텍주식회사 A manufacturing method of structured pick cell type scintillator make detector module for obtain permeation image of radioactive rays
FR2888045B1 (en) * 2005-07-01 2007-10-19 Thales Sa IMAGE SENSOR WITH IMPROVED SPATIAL RESOLUTION AND SENSOR PRODUCTION METHOD
JP5456013B2 (en) * 2010-12-17 2014-03-26 富士フイルム株式会社 Radiation imaging device
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JP5657614B2 (en) 2011-08-26 2015-01-21 富士フイルム株式会社 Radiation detector and radiographic imaging apparatus
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Also Published As

Publication number Publication date
US5449449A (en) 1995-09-12
JPH02223129A (en) 1990-09-05
US4985633A (en) 1991-01-15
FR2634562B1 (en) 1990-09-07
DE68906478D1 (en) 1993-06-17
DE68906478T2 (en) 1993-09-09
JP3084713B2 (en) 2000-09-04
EP0352152A1 (en) 1990-01-24
FR2634562A1 (en) 1990-01-26

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