JP2019049437A - Radiation detection device, and radiation detection system - Google Patents

Abstract

To suppress sharpness from falling, as suppressing a falling of an image quality due to a protrusion part of a scintillator layer.SOLUTION: A radiation detection device has: a sensor substrate 11 that has a photoelectric conversion element 112; a scintillator layer 12 that has a plurality of columnar crystals 121, and is arranged on one surface of the sensor substrate; and a coating member 3 that coats a surface of the scintillator layer 12. The scintillator layer 12 has: a film thickness distribution; and a protrusion part 123 that is smaller than a difference between a maximum value of a film thickness of the scintillator layer 12 and a minimum layer thereof. The coating member 3, in which a surface on a scintillator layer 12 side has a shape along the film thickness distribution, is in contact with a flatness part 124 having the protrusion part 123 flattened, and at least one part of other columnar crystals 121 excluding the protrusion part 123.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radiation detection apparatus and a radiation detection system.

  The radiation detection apparatus includes a scintillator layer that emits light according to incident radiation, and a sensor substrate on which a photoelectric conversion element that converts light emitted from the scintillator layer into an electrical signal is provided. The scintillator layer is made of, for example, a columnar crystal of a material that emits light upon incidence of radiation, and is formed by an evaporation method. In the radiation detection apparatus, a reflection layer can be provided on the scintillator layer to improve the amount of light taken into the sensor substrate. During the formation of the scintillator layer, columnar crystals may grow abnormally with foreign substances such as impurities as growth nuclei. In this case, the abnormally grown portion of the columnar crystal becomes a local protrusion on the surface of the formed scintillator layer. The size of the abnormally grown portion is proportional to the maximum film thickness of the scintillator layer, and a step of about 5% of the maximum film thickness can occur on the surface of the scintillator layer due to local protrusions. Since the amount of light emitted from the local protrusion is different from that of other portions, if there is a local protrusion on the surface of the scintillator layer, artifacts due to the protrusion occur, and the image quality of the generated image is degraded. For this reason, in Patent Document 1, as a method of manufacturing the scintillator layer, a glass plate having good flatness is arranged on the surface of the formed scintillator layer, and the scintillator layer is pressed by pressing the glass plate and pushing the protruding portion. A method of performing a flattening process for flattening the surface is disclosed.

JP 2006-335887 A

  However, in the method described in Patent Document 1, there is a concern that the image quality is deteriorated when a film thickness distribution exists in the scintillator layer. The film thickness distribution of the scintillator layer may occur with a size of about 10 to 20% of the maximum film thickness of the scintillator layer. In such a case, in the method described in Patent Document 1, sufficient flattening processing cannot be performed in a region where the film thickness of the scintillator layer is small, and there is a concern about image quality degradation due to artifacts caused by the protruding portions.

  In view of the above situation, the problem to be solved by the present invention is to provide a radiation detection apparatus that suppresses a decrease in sharpness while suppressing a decrease in image quality due to a protrusion.

  In order to solve the above problems, a radiation detection apparatus of the present invention includes a sensor substrate having a photoelectric photoelectric conversion element, a scintillator layer having a plurality of columnar crystals and disposed on one surface of the sensor substrate, and the scintillator. The scintillator layer has a thickness distribution, and has a protrusion smaller than the difference between the maximum value and the minimum value of the scintillator layer. The covering member has a shape on the scintillator layer side of the thickness distribution along the film thickness distribution, and at least a part of the columnar crystal excluding the protruding portion and the flattened portion where the protruding portion is flattened. It is in contact with and.

  ADVANTAGE OF THE INVENTION According to this invention, the radiation detection apparatus which suppresses a sharpness fall can be provided, suppressing the fall of the image quality by a protrusion part.

It is a cross-sectional schematic diagram of the radiation detection apparatus of this invention. It is a cross-sectional schematic diagram of the radiation detection apparatus of this invention. It is a schematic diagram for demonstrating the film thickness distribution of a scintillator layer. It is a cross-sectional schematic diagram of the radiation detection apparatus of this invention. It is a cross-sectional schematic diagram of the radiation detection apparatus of a comparative example. It is a schematic diagram for demonstrating the manufacturing method of the radiation detection apparatus of this invention. It is a figure which shows the structural example of a radiation detection system.

  Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the drawings. In the present invention, radiation includes not only X-rays but also electromagnetic waves other than X-rays such as α-rays, β-rays, and γ-rays.

  FIG. 1 is a cross-sectional view schematically showing a configuration example of the radiation detection apparatus 1a. As shown in FIG. 1, the radiation detection apparatus 1 a according to the first embodiment includes a sensor substrate 11, a scintillator layer 12, an adhesive layer 13, a member 14, a reflective layer 16, and a reflective layer protective layer 16. Have

  The sensor substrate 11 is a substrate having a photoelectric conversion element 112. For example, the sensor substrate 11 includes a glass substrate 111, a plurality of photoelectric conversion elements 112 arranged in a two-dimensional matrix on the surface of the glass substrate 111, and a protective film 113 that covers the plurality of photoelectric conversion elements 112. . In addition, the sensor substrate 11 takes out a switching element for switching charge accumulation and emission of the photoelectric conversion element 112, a wiring for transmitting a signal for driving the switching element, and a charge (electric signal) accumulated in the photoelectric conversion element 112. Wiring. In addition, a plurality of drive electrodes 114 for inputting a signal for driving the switching element and a plurality of readout electrodes 115 for reading out charges from the photoelectric conversion element 112 are provided on the periphery of the sensor substrate 11.

  A flexible wiring 101 is connected to each of the drive electrode 114 and the readout electrode 115 arranged at the peripheral edge of the sensor substrate 11. The sensor circuit board 11 is connected to the driving circuit board 102 and the reading circuit board 103 via the flexible wiring 101. In addition, since these flexible wirings 101 are connected to the peripheral portion of the sensor substrate 11, a scintillator layer 12, a member 14, a reflective layer 16, a reflective layer protective layer 16, and a sealing member 17 described later are disposed. Not.

  The scintillator layer 12 is disposed on one surface of the sensor substrate 11. The scintillator layer 12 emits light when excited by radiation. For convenience of explanation, the light emitted from the scintillator layer 12 upon incidence of radiation is referred to as scintillation light. The scintillator layer 12 is composed of a plurality of columnar crystals 121. For example, the scintillator layer 12 is composed of a plurality of columnar crystals 121 of cesium iodide (CsI). Cesium iodide has thallium-activated cesium iodide added with a small amount of thallium (Tl) as an activator or sodium-activated cesium iodide added with a small amount of sodium to improve characteristics (improve luminous efficiency). Etc. apply. In addition, a gap 122 exists between the columnar crystals 121. Note that the scintillator layer 12 is not limited to a configuration including columnar crystals of cesium iodide, as long as the scintillator layer 12 includes a plurality of columnar crystals 121 and a gap 122 exists between them. For example, the scintillator layer 12 can be made of a material mainly composed of an alkali halide.

  A vapor deposition method is applied to form the scintillator layer 12. In the embodiment of the present invention, the scintillator layer 12 is not formed separately from the sensor substrate 11 and bonded to the sensor substrate 11 but directly formed on the surface of the sensor substrate 11 by vapor deposition. The columnar crystals 121 can be formed on the surface of the sensor substrate 11 by appropriately setting the deposition conditions, for example, the temperature of the sensor substrate 11, the arrangement position of the vapor deposition material, the arrangement position of the sensor substrate 11, and the like. A gap 122 can be formed between the two. The surface shape of the scintillator layer 12 has a film thickness distribution as shown, for example, in FIGS. The film thickness distribution of the scintillator layer 12 may be generated with a size of about 10 to 20% of the maximum value of the film thickness of the scintillator layer 12. In other words, the maximum difference in the film thickness distribution of the scintillator layer 12 (difference between the maximum value and the minimum value of the film thickness) can occur at a magnitude of about 10 to 20% of the maximum value of the film thickness of the scintillator layer 12.

  If the columnar crystal 121 grows abnormally during vapor deposition, the tip of the abnormally grown columnar crystal 121 may be higher than the other columnar crystals 121 around it. As a result, a locally protruding protrusion 123 appears on the surface of the scintillator layer 12. For example, during the vapor deposition, the protrusion 123 has a columnar shape due to a growth nucleus formed by foreign matters such as impurities, dust, and scratches present on the surface of the sensor substrate 11 and foreign matters caused by material bumping when the vapor deposition material is heated. It appears when the crystal 121 grows abnormally. Such a protrusion 123 protrudes at a height of about 5% of the film thickness of the scintillator layer 12 with respect to the surface of the scintillator layer 12. That is, the scintillator layer 12 has a protrusion 123 that has a film thickness distribution and is smaller than the difference between the maximum value and the minimum value of the film thickness. Such a protrusion 123 causes a reduction in the image quality of the generated radiographic image, and is thus crushed and flattened using the covering member 3 described below.

  The covering member 3 that covers the surface of the scintillator layer 12 includes a member 14 and a reflective layer 16, and preferably further includes a base 13 and an adhesive layer 15. The surface of the covering member 3 on the scintillator layer 12 side has a shape that follows the film thickness distribution of the scintillator layer 12, and the surface of the flattened portion 124 in which the protruding portion 123 is flattened and the other portions except for the protruding portion 123. It is in contact with at least a part of the columnar crystal 123. Further, an insulating surface that satisfies at least one of a Mohs hardness of 3 or more and a Shore hardness of D24 or more is applied to the surface of the covering member 3 on the scintillator layer 12 side. Below, the covering member 3 includes a base 13, a reflective layer 16 disposed on the scintillator layer 12 side of the base 13, and a member 14 disposed between the base 13 and the reflective layer 16. The configuration will be described.

  The base 13 is installed for the purpose of supporting a member 14 described later. For example, the base 13 is made of a resin material such as polyether ether ketone (PEEK) or polyimide (PI), or a material having high radiation transmittance and low moisture permeability such as carbon or carbon fiber reinforced plastic (CFRP). Applicable. A member 14 is disposed on the surface of the base 13 on the scintillator layer side.

  Next, the member 14 will be described with reference to FIG. The member 14 is a plate-shaped member, and the surface on the base 13 side has a flat shape and is fixed to the base 13. The surface opposite to the surface on the base 13 side (surface on the scintillator layer 12 side) has a surface shape along the film thickness distribution of the scintillator layer 12 described above. The surface shape of the member 14 may be formed according to the measured thickness distribution of the scintillator layer 12 by measuring the thickness distribution of the scintillator layer 12 in advance.

  As shown in FIG. 2, the thickness D of the member 14 is the difference between the maximum difference d2 in the film thickness distribution of the scintillator layer 12 and the maximum and minimum values of the surface shape of the member 14 formed corresponding thereto. It is larger than d1. Although depending on the layer thickness of the scintillator layer 12, the thickness D of the member 14 can achieve the object if the average film thickness of the scintillator layer 12 is, for example, 1 mm or more. That is, the member 14 has a film thickness distribution corresponding to the film thickness distribution of the scintillator layer 12. In addition, the member 14 may be configured with the same material as the base 13.

  The material of the member 14 is (1) highly transparent to the extent that radiation images are not affected (2) can form a surface shape that follows the surface shape of the scintillator layer 12 (3) What is necessary is just to satisfy the conditions of providing sufficient strength and hardness to support the reflective layer protective layer. As a material that satisfies these conditions, for example, a thermosetting plastic such as a silicone resin, or a thermoplastic plastic such as polyethylene (PE), polystyrene (PE), or polypropylene (PP) is preferably used. Further, engineering plastic materials such as polycarbonate (PC), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyether ether ketone (PEEK) are preferably used. Further, carbon fiber reinforced plastic (CFRP) or a carbon plate can be processed and used.

  The member 14 may be made of a material that can be deformed by applying pressure as long as the above (3) is satisfied. In that case, a material such as silicone rubber having excellent radiation performance can be suitably applied. When a deformable material such as silicone rubber is applied, the member 14 is arranged along the surface shape of the scintillator layer 12 without forming the surface shape in advance according to the surface shape of the scintillator layer 12. Can do. Therefore, the processing cost of the member 14 can be reduced.

  An example of the manufacturing process of the radiation detection apparatus will be described with reference to FIGS. In the state of FIG. 6A, the surface of the covering member 3 on the scintillator layer 12 side is prepared reflecting the film thickness distribution shape of the scintillator layer 12. Next, as shown in FIG. 6B, the protruding portion 123 of the scintillator layer 12 and the covering member 3 are brought into contact with each other. Then, as shown in FIG. 6C, the covering member 3 and the scintillator layer 12 are pressed to flatten the protruding portion 123 of the scintillator layer 12 to obtain a flattened portion 124. Then, the covering member 3 and the scintillator layer are arranged such that the surface of the covering member 3 on the scintillator layer 12 side is in contact with the flattened portion 124 of the scintillator layer 12 and a part of the surface of the scintillator layer 12 excluding the flattened portion 124. 12 is pressed. Thereafter, the covering member 3 is fixed by the sealing member 17. The target structure can be obtained through the above steps.

  The reflective layer 16 (see FIG. 4A) is disposed at a position facing the scintillator layer 12. The reflective layer 16 increases the amount of scintillation light incident on the photoelectric conversion element 112 of the sensor substrate 11 by reflecting the scintillation light. For this reason, a material having a higher scintillation light reflectance than the other components of the covering member 3 is applied to the reflective layer 16. Further, the reflective layer 16 may also have a function of a moisture-proof layer that suppresses intrusion of moisture into the scintillator layer 12. Furthermore, since the reflection layer 16 causes the radiation to enter the scintillator layer 12, a material having a high radiation transmittance is applied to the extent that radiation imaging is not affected. Because of such a function, for example, a sheet or plate using a metal material, more specifically, aluminum (Al), magnesium (Mg), or the like can be applied to the reflective layer 16. In addition, an insulating film, an insulating sheet, or the like on which a paint containing a white pigment with high reflectance such as titanium oxide (TiO 2) is applied can be used. However, the reflective layer 16 should just satisfy the above-mentioned conditions, and is not limited to these materials.

The reflective layer 21 using a metal material (see FIG. 4B) is formed, for example, by vapor-depositing aluminum or silver on the surface of the member 14 on the scintillator layer 12 side by vapor deposition. When a metal material is used as the reflective layer, the metal surface may react due to contact with the scintillator layer 12 and the reflectance may be reduced. In particular, the protrusion 123 formed on the surface of the scintillator layer 12 has a high possibility. Therefore, when a metal material is used as the reflective layer, it is preferable to form the reflective layer protective layer 22 on the surface thereof. In that case, the reflective layer protective layer 22 has a function for flattening the surface of the scintillator layer 12 by crushing the protrusion 123. The reflective layer protective layer 22 prevents the scintillator layer 12 and the reflective layer 21 from directly contacting each other. The reflective layer protective layer 22 satisfies the following conditions. (1) Harder than columnar crystals. Specifically, when the reflective layer protective layer 22 is pressed against the protruding portion 123 of the scintillator layer 12, the protruding portion 123 can be crushed without the reflective layer protective layer 22 being broken or having a hole. . (2) The scintillation light transmittance is high to the extent that radiation imaging is not affected. (3) Good adhesion to the reflective layer 16. (4) The surface on the scintillator layer 12 side has electrical insulation. Examples of materials that satisfy the conditions (1) to (4) include films of resin materials such as polyethylene (PE) and polyethylene terephthalate (PET), silicon dioxide (SiO ₂ ), and silicon nitride (SiN). An inorganic material film is preferable. More specifically, when cesium iodide is applied as the material of the scintillator layer 12, the reflective layer protective layer 22 satisfies at least one of a Mohs hardness of 3 or more and a Shore hardness of D24 or more. A material having electrical insulation is applied. In this case, polyethylene (PE) or polyethylene terephthalate (PET) can be applied as a material that satisfies these conditions. However, the reflective layer protective layer 22 only needs to satisfy the conditions (1) to (4), and the specific material is not limited to the material.

  In the configuration of FIG. 4B, the tip of at least some of the columnar crystals 121 among the plurality of columnar crystals 121 of the scintillator layer 12 that is the protruding portion 123 of the scintillator layer 12 is the outermost surface of the covering member 3. It is in contact with the reflective layer protective layer 22. Specifically, the tip portion of the abnormally grown columnar crystal 121 that is the protruding portion 123 is crushed by the reflective layer protective layer 22 to become a flattened portion 124, and the surface of the flattened portion 124 becomes the reflective layer protective layer 22. In contact. The reflective layer protective layer 22 has an insulating surface on the scintillator layer 12 side that satisfies at least one of a Mohs hardness of 3 or more and a Shore hardness of D24 or more.

  According to such a configuration, the protruding portion 123 of the scintillator layer 12 is flattened by the reflective layer protective layer 22. For this reason, the nonuniformity of the emitted light amount resulting from the local protrusion part 123 can be suppressed, and the fall of an image quality can be suppressed.

  Further, in the configuration of FIG. 4B, the reflective layer protection layer 22 crushes the protruding portion 123 of the scintillator layer 12, so that the reflective layer 21 and the scintillator layer are not brought into contact with the scintillator layer 12. 12 can be approached. That is, when the reflective layer 21 is an electrical conductor such as a metal, the scintillator layer 12 and the reflective layer 21 are prevented from contacting each other in order to suppress electrochemical corrosion of the scintillator layer 12. In the case where the protruding portion 123 exists on the surface of the scintillator layer 12, the distance between the reflecting layer 21 and the scintillator layer 12 is set higher than the height of the protruding portion 123 in order to prevent the reflecting layer 21 and the protruding portion 123 from contacting each other. Must also be larger. On the other hand, in the present embodiment, the protruding portion 123 is crushed by the reflective layer protective layer 22 and the reflective layer protective layer 22 is interposed between the reflective layer 21 and the scintillator layer 12. With such a configuration, the reflective layer 16 can be brought close to the scintillator layer 12 without bringing the reflective layer 21 into direct contact with the scintillator layer 12. In particular, when the reflective layer 16 is disposed immediately above the reflective layer protective layer 22, these distances can be further reduced without bringing the scintillator layer 12 and the reflective layer 16 into contact with each other.

  Therefore, according to such a configuration, it is possible to improve the sharpness (MTF) and detection quantum efficiency (DQE) of the generated radiation image. Further, the unevenness of the light emission amount and the sharpness can be reduced over the entire range to be photographed. Moreover, even when a conductor such as a metal is applied to the reflective layer 21, electrochemical corrosion of the scintillator layer 12 is suppressed.

  Furthermore, according to such a configuration, since the exposure of the scintillator layer 12 to the atmosphere can be suppressed after the step of crushing the protruding portion 123 of the scintillator layer 12, deterioration of the characteristics of the scintillator layer 12 can be suppressed. As described above, it is possible to suppress deterioration of characteristics due to exposure of the scintillator layer 12 to the atmosphere while suppressing deterioration in image quality due to the protruding portion 123 of the scintillator layer 12. Furthermore, the step of crushing the protruding portion 123 of the scintillator layer 12 and the formation of each protective layer that protects the scintillator layer 12 can be performed in the same step. For this reason, the manufacturing process of the radiation detection apparatus 1a can be reduced, and the manufacturing cost can be reduced.

  In the configuration of FIG. 4B, the reflective layer protective layer 22 is harder than the scintillator layer 12. Therefore, even if the protrusion 123 of the scintillator layer 12 contacts the reflective layer protective layer 22, the reflective layer protective layer 22 is damaged. Is prevented. Therefore, the protrusion 123 of the scintillator layer 12 is prevented from penetrating the reflective layer protective layer 22 and directly contacting the reflective layer 16. For this reason, when the reflective layer 16 is an electrical conductor, electrochemical corrosion due to the protrusion 123 of the scintillator layer 12 coming into contact with the reflective layer is suppressed. In addition, in this embodiment, although the whole reflection layer protective layer 22 shows the structure formed from the resin material which has electrical insulation, it is not limited to such a structure. The reflective layer protective layer 22 only needs to have an electrically insulating surface on the scintillator layer 12 side. At that time, if the thickness of the reflective layer protective layer 22 is large, the distance between the scintillator layer 12 and the reflective layer 21 is increased, and the sharpness is lowered. The thickness of the reflective layer protective layer 22 is preferably 30 μm or less, and more preferably 15 μm or less.

Further, if the reflective layer 16 is not a metal or the like and is a material whose surface state does not change by contact with the scintillator layer 12, the reflective layer 16 and the scintillator layer 12 may be in direct contact. As shown in FIG. 4C, the reflective layer 23 made of an insulating material whose surface state does not change by contact with the scintillator layer 12 is harder than the columnar crystal 121 and has a high reflectance of scintillation light. Applies. For example, the reflective layer 23 is made of a white material having high light reflectance such as titanium dioxide (TiO ₂ ), alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), yttrium oxide (Y ₂ O ₃ ), or the like. A sheet containing powder is applied. And the sheet | seat of resin materials, such as polyethylene (PE) and polyethylene terephthalate (PET), can be applied to this sheet. When cesium iodide is used as the material of the scintillator layer 12, a material that satisfies at least one of a Mohs hardness of 3 or more and a Shore hardness of D24 or more is applied to the reflective layer. In this case, polyethylene (PE) or polyethylene terephthalate (PET) can be applied as a material that satisfies these conditions. However, the reflective layer 23 is not limited to the above configuration. As described above, the reflective layer 23 may be any material as long as it is harder than the columnar crystal 121 and has a high radiation transmittance and high scintillation light reflectance, and the specific material is not limited.

  In addition, the member 14 may have the function of the reflective layer 16. As shown in FIG. 4D, the member 24 having a reflection function may be a resin material containing powder of white material with high light reflectance such as TiO 2. That is, the member 14 and the reflective layer 16 can be made of the same material. In the case where cesium iodide is applied as the material of the scintillator layer 12, a material that satisfies the same conditions as the reflective layer 23 is applied to the member 24. That is, a material that satisfies at least one of a Mohs hardness of 3 or more and a Shore hardness of D24 or more is applied to the member 24. In this case, polyethylene (PE), polyethylene terephthalate (PET), or the like can be applied as a material that satisfies these conditions. However, the member 24 is not limited to the above configuration. As described above, the member 24 may be any material as long as it is harder than the columnar crystal 121 and has high radiation transmittance and high scintillation light reflectance, and the specific material is not limited.

  Further, the member 14 may have the function of the base 13 and the function of the reflective layer 16. As shown in FIG. 4E, the member 25 having a support function and a reflection function can be a resin material containing a powder of a white material having a high light reflectance such as TiO 2. That is, the base 13, the member 14, and the reflective layer 16 can be made of the same material. When cesium iodide is applied as the material of the scintillator layer 12, a material that satisfies the same conditions as the reflective layer 23 is applied to the member 25. That is, a material that satisfies at least one of a Mohs hardness of 3 or more and a Shore hardness of D24 or more is applied to the member 25. In this case, polyethylene (PE), polyethylene terephthalate (PET), or the like can be applied as a material that satisfies these conditions. However, the member 24 is not limited to the above configuration. As described above, the member 25 may be any material as long as it is harder than the columnar crystal 121 and has high radiation transmittance and high scintillation light reflectance, and the specific material is not limited.

<First embodiment>
Next, a first embodiment of the present invention will be described. First, the scintillator layer 12 was formed on one surface of the sensor substrate 11 by vapor deposition. As a result of measuring the film thickness of the central portion of the scintillator layer 12 formed on another substrate by the vapor deposition method, it was confirmed that the film thickness distribution was the distribution shape of FIG. At that time, the center film thickness was 600 μm. Moreover, the film thickness of the edge part of the scintillator layer 12 was 570 micrometers. Further, when the surface of the scintillator layer 12 of the sample after the film thickness measurement was observed with a scanning electron microscope (SEM), it was confirmed that a gap 122 was formed between the columnar crystals 121. Further, the presence of the protrusion 123 due to the abnormally grown columnar crystal 121 was also confirmed.

  In the first example, the covering member 3 having the base 13, the member 14, and the reflective layer 16 was created. The base 13 of the covering member 3 was made of carbon fiber reinforced plastic (CFRP) having a thickness of 1 mm. The member 14 was made of an acrylic resin having a thickness of 200 μm. For the member 14, the film thickness distribution of the scintillator layer formed under the same manufacturing conditions as the scintillator layer 12 was measured in advance, and the distribution was reflected on the surface shape of the member 14 as shown in FIG. The reflective layer 16 is formed along the surface shape of the member 14. The reflective layer 16 was obtained by bonding a titanium oxide (TiO 2) -containing resin film having a thickness of 50 μm to the surface of the member 14 via the adhesive layer 16. Affixing of the reflective layer 16 was performed by a vacuum laminating process.

  Thereafter, the covering member 3 was placed on the scintillator layer 12 in the direction in which the film thickness distribution of the scintillator layer 12 and the surface shape of the member 14 matched. At that time, the scintillator layer 12 and the covering member 3 are in close contact with each other without an adhesive layer. Further, the protruding portion 123 present in the scintillator layer 12 was crushed through the reflective layer 16 to obtain a flattened portion 124 that was flattened. By performing these processes, the gap between the scintillator layer 12 and the reflective layer 16 due to the height of the protrusion 123 is eliminated. Then, the edge part of the coating | coated member 3 and the sealing member 17 were connected, and it adhered and fixed. The sealing structure of the scintillator layer 12 is formed by this connection process.

  A radiation detection apparatus is produced through the above steps. The produced radiation detection apparatus can provide an image with excellent sharpness in both the central portion and the peripheral portion of the panel.

<Comparative example>
Next, a comparative example (see FIG. 5) will be described. This comparative example is an example in which the radiation detection apparatus 1b is manufactured by forming the covering member 3 without using the member 14 in the first embodiment.

  A reflective layer 16 using a titanium oxide-containing resin film is bonded to a base 13 made of CFRP via an adhesive layer 15. Since the surface of the base 13 is flat, the surface of the reflective layer 16 is also a flat surface. Thereafter, the covering member 3 is installed on the surface of the scintillator layer 12 having the same film thickness distribution as that of Example 1 in such a direction that the surface of the reflective layer 16 contacts the surface of the scintillator layer 12. At that time, since the film thickness of the scintillator layer 12 is maximum at the central portion and decreases toward the peripheral portion, the contact point is only near the center of the scintillator layer 12 and the peripheral portion has a gap of about 30 μm at maximum. A contact portion 26 is present.

  In the non-contact part 26, the distance between the reflective layer 16 and the scintillator layer 12 is larger than the contact part. Therefore, the sharpness of the peripheral portion is lowered as compared with the first embodiment in which the scintillator layer 12 and the reflective layer 16 are in contact with each other.

<Second embodiment>
Next, a second embodiment will be described. The second embodiment is an embodiment in which the member 14 in the first embodiment is made of silicone rubber having a thickness of 200 μm instead of acrylic resin.

  As the silicone rubber used in this embodiment, a thermosetting silicone rubber (for example, a thermosetting millable silicone rubber manufactured by Asahi Kasei Wacker) is used. The member 14 made of silicone rubber is deformed following the film thickness distribution of the scintillator layer 12. (That is, the amount of deformation is large in the central portion of the scintillator layer 12 and small in the peripheral portion.) Further, the locally existing protruding portion 123 does not deform following the fine surface shape. Therefore, the protrusion 123 can be flattened via the reflective layer 16 as in the first embodiment.

  In the second embodiment, the sharpness is excellent as compared with the apparatus of Comparative Example 1, and in particular, the scintillator layer 12 and the reflective layer 16 are in close contact with the peripheral portion of the panel, so that the sharpness of the peripheral portion of the panel is excellent. ing.

<Third embodiment>
Next, a third embodiment will be described. In the third embodiment, the thickness of the member 14 used in the first embodiment is 1 mm, and the member 14 is not connected to the base 13. That is, in the third embodiment, the covering member 3 is configured without using the base 13. A shape reflecting the film thickness distribution of the scintillator layer 12 is formed in advance on one surface of the member 14 in the same manner as in the first embodiment, and a reflective layer is formed by the same method as in the first embodiment. Thereafter, a radiation detection apparatus is manufactured by the same method as in the first embodiment. The produced radiation detection apparatus exhibits the same sharpness characteristics as those produced in the first embodiment. Further, compared with the radiation detection apparatus of the first embodiment, since the number of members and manufacturing can be reduced, it is advantageous in terms of cost.

<Radiation detection system>
Next, an embodiment of the radiation detection system 6000 will be described with reference to FIG. FIG. 7 is a diagram schematically illustrating a configuration example of the radiation detection system 6000 according to the embodiment of the present invention. The radiation detection apparatus according to each embodiment of the present invention is applied to the radiation detection system 6000 according to the embodiment of the present invention.

  As shown in FIG. 7, the X-ray 6060 (radiation) generated in the X-ray tube 6050 passes through the imaging target region 6062 of the subject 6061 and enters the radiation detection apparatuses 1a to 1d. This incident X-ray includes information inside the body of the subject 6061. The scintillator layer 12 emits light corresponding to the incidence of X-rays, and this is photoelectrically converted by the photoelectric conversion element 112 of the sensor substrate 11 to obtain electrical information. This information can be digitally converted and image-processed by an image processor 6070 serving as a signal processing means and observed on a display 6080 serving as a display means in a control room.

  Further, this information can be transferred to a remote place by a transmission processing means such as a network 6090 such as a telephone, a LAN, and the Internet, and can be displayed on a display 6081 serving as a display means such as a doctor room in another place. Alternatively, it can be stored in recording means such as an optical disk. Therefore, it is possible for a remote doctor to make a diagnosis. Moreover, it can also record on the film 6110 by the film processor 6100 used as a recording means.

  As mentioned above, although embodiment and the Example of this invention were described in detail with reference to drawings, the said embodiment and Example only showed the specific example in implementation of this invention. The technical scope of the present invention is not limited to the above-described embodiments and examples. The present invention can be variously modified without departing from the spirit thereof, and these are also included in the technical scope of the present invention.

  The radiation detection apparatus according to the present invention can be applied to a medical radiation detection apparatus or a non-medical analysis / inspection apparatus using radiation, such as a nondestructive inspection apparatus.

DESCRIPTION OF SYMBOLS 1a, 1b Radiation detection apparatus 3 Cover member 11 Sensor substrate 111 Glass substrate 112 Photoelectric conversion element 113 Protective film 12 Scintillator layer 121 Columnar crystal 122 Gap 123 Projection part 13 Base 14 Member 15 Adhesive layer 16, 21, 23 Reflective layer 17 Sealing Stop member 22, 24, 25 Reflective layer protective layer

Claims (11)

A sensor substrate having a photoelectric conversion element;
A scintillator layer having a plurality of columnar crystals and disposed on one surface of the sensor substrate;
A covering member that covers the surface of the scintillator layer;
Have
The scintillator layer has a film thickness distribution, and has a protrusion smaller than the difference between the maximum value and the minimum value of the film thickness of the scintillator layer,
The covering member has a shape in which the surface on the scintillator layer side conforms to the film thickness distribution, and a flattened portion in which the protruding portion is flattened, and at least a part of other columnar crystals excluding the protruding portion, A radiation detection apparatus that is in contact with   The radiation detecting apparatus according to claim 1, wherein the covering member has an insulating surface on the scintillator layer side that satisfies at least one of a Mohs hardness of 3 or more and a Shore hardness of D24 or more.   The said covering member contains the base, the reflection layer which reflects the light light-emitted by the said scintillator layer, and the member arrange | positioned between the said base and the said reflection layer, It is characterized by the above-mentioned. The radiation detection apparatus according to 1 or 2.   The radiation detection apparatus according to claim 3, wherein the member has a film thickness distribution corresponding to a film thickness distribution of the scintillator layer.   The radiation detection apparatus according to claim 3 or 4, wherein the reflection layer is made of an insulating material whose surface state does not change by contact with the scintillator layer.   The radiation detection apparatus according to claim 5, wherein the member is made of the same material as the reflective layer.   The radiation detection apparatus according to claim 3, wherein the base is made of the same material as the member. The reflective layer is made of a metal material,
The covering member further includes a reflective layer protective layer between the reflective layer and the scintillator layer,
The radiation according to claim 3 or 4, wherein the reflective layer protective layer has an insulating surface on the scintillator layer side that satisfies at least one of a Mohs hardness of 3 or more and a Shore hardness of D24 or more. Detection device.   The radiation detection apparatus according to claim 1, wherein the columnar crystal is a columnar crystal of cesium iodide.   The radiation detection apparatus according to claim 4, wherein the member is made of a material that can be deformed by applying pressure. The radiation detection apparatus according to any one of claims 1 to 9,
Signal processing means for processing signals obtained by the radiation detection device;
A radiation detection system comprising:

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