Scintillator unit and radiation detector

Abstract

Provided is a scintillator unit (11) comprising: a holding member having two element-row-accommodating frame parts (44), and frame connection parts (41, 42) for connecting the two element-row-accommodating frame parts so that an element array arrangement space is formed therebetween, the frame parts and the frame connection parts being configured from a material that blocks scintillating light; a plurality of first scintillator elements (3) that are accommodated in each of the two element-row-accommodating frame parts in a state of being arrayed one-dimensionally; and a plurality of second scintillator elements (3) that are arranged in the element array arrangement space in a state of being arrayed two-dimensionally. Also provided is a radiation detector (1) comprising: a scintillator unit (11); and a photodetector (7) having a plurality of detection elements (71) for detecting the intensity at each incidence position of light emitted from the scintillator element.

Description

Scintillator unit and radiation detector

[0001] The present invention relates to a scintillator unit and a radiation detector.

[0002] In the medical field, devices that use positron emission tomography (PET) (PET devices) are used to visualize information about internal body functions such as metabolic disorders and to diagnose cancer. PET devices create images that show the density distribution of radioactive drugs within the body by detecting radiation emitted from patients who have been administered drugs containing radioactive substances (radiopharmaceuticals). PET devices detect radiation emitted from the patient by arranging multiple radiation detectors in a cylindrical shape that surrounds the patient.

[0003] Each radiation detector has a stacked structure of a scintillator unit and a photodetector. The scintillator unit is a two-dimensional array of cylindrical scintillator elements, each measuring several millimeters square and emitting light when exposed to radiation. The photodetector is a two-dimensional array of photodetectors that receive the light (scintillation light) emitted from each scintillator element. Furthermore, to ensure that the photodetectors of a given radiation detector detect all scintillation light emitted from the scintillator elements, the periphery of the radiation detector is treated to prevent light leakage. In a radiation detector, the scintillation light generated by radiation incident on a scintillator element passes through the interior of the scintillator element and enters one or more photodetectors. The photodetector measures the intensity of the scintillation light incident on each photodetector, determines the position of the center of gravity of the scintillation light from the intensity distribution of the light incident on the photodetector, and thereby identifies the scintillator element on which radiation is incident.

[0004] In the above-described scintillator unit, when radiation is incident on a scintillator element other than the outermost one, the scintillation light is detected as spreading in all directions. On the other hand, when radiation is incident on the outermost scintillator element, the scintillation light does not spread outward, but spreads only in other directions. As a result, the position of the center of gravity of the light intensity distribution shifts inward from the position of the scintillator element on which the radiation is incident, and the position of the center of gravity obtained when radiation is incident on the outermost scintillator element and the position of the center of gravity obtained when radiation is incident on the scintillator element adjacent to it on the inside are close to each other. This makes it difficult to determine which scintillator element the radiation is incident on.

[0005] To solve the above problem, Patent Document 1 proposes inserting a sheet-like light-blocking member between the outermost scintillator element and the scintillator element located inside it. Patent Document 1 shows an example in which the position of the center of gravity determined when radiation is incident on the outermost scintillator element is separated from the position of the center of gravity determined when radiation is incident on the adjacent scintillator element located inside it.

[0006] Japanese Patent Application Laid-Open No. 2022-148952

[0007] Although Patent Document 1 does not disclose a method for manufacturing a scintillator unit, it is conceivable to manufacture it, for example, as follows. First, scintillator elements other than those on the outermost periphery are arranged two-dimensionally to create a scintillator array. Next, a sheet-like light-blocking member is placed on the side of the scintillator array, and scintillator elements are arranged one-dimensionally outside of that. Then, the entire scintillator unit is fixed in place by, for example, wrapping tape around the scintillator elements arranged on the outermost periphery.

[0008] In this manufacturing method, when wrapping tape around the outermost scintillator elements, it is necessary to hold down the outermost scintillator elements arranged in a one-dimensional pattern with a jig or the like from the outside to prevent them from falling over. However, if such a jig is placed around the entire outer periphery of the outermost scintillator elements, it gets in the way when wrapping the tape, resulting in poor work efficiency. In particular, when a large number of radiation detectors are used, such as in a PET device, a scintillator unit must be manufactured for each of these many radiation detectors, and therefore there is a demand for improving the manufacturing efficiency of scintillator units.

[0009] An object of the present invention is to provide a scintillator unit and a radiation detector that can be manufactured more efficiently than ever before.

[0010] The scintillator unit of the present invention, which has been made to solve the above-mentioned problems, is characterized by comprising: a holding member made of a material that blocks scintillation light, and having two element array housing frame portions and a frame connecting portion that connects the two element array housing frame portions so that an element array arrangement space is formed between them; a plurality of first scintillator elements housed in each of the two element array housing frame portions in a one-dimensional array arrangement; and a plurality of second scintillator elements arranged in a two-dimensional array arrangement in the element array arrangement space.

[0011] "Blocking light" as mentioned above means not allowing light to leak to the outside, and includes reflecting light, etc. The shape of the element array arrangement space (the outer shape of the plurality of second scintillator elements (scintillator array) arranged two-dimensionally in the space) is typically rectangular, but may be other shapes (polygonal, circular, etc.). The planar shapes of the first scintillator elements and the second scintillator elements are also typically rectangular, but may be other shapes. Furthermore, the one-dimensional arrangement may be a linear arrangement, an arc-shaped arrangement, etc.

[0012] The scintillator unit according to the present invention includes a holding member having two element array housing frames and a frame connecting portion that connects the two element array housing frames across an element array arrangement space. Some of the scintillator elements (first scintillator elements) located at the outermost periphery of the scintillator unit are housed in each of the two element array housing frames in a one-dimensional array arrangement. Therefore, when fixing the scintillator unit, it is only necessary to hold down some of the scintillator elements located at the outermost periphery of the scintillator unit with a jig or the like, thereby improving the manufacturing efficiency of the scintillator unit.

[0013] Furthermore, in the above scintillator unit, the element array arrangement space can be rectangular, the holding member can further include two element array accommodating frame portions, the frame connecting portion can connect the four element array accommodating frame portions so that the four element array accommodating frame portions surround the element array arrangement space, and each of the four element array accommodating frame portions can accommodate a plurality of first scintillator elements arranged in a one-dimensional manner.

[0014] In the scintillator unit of the above aspect, the four element array housing frames are arranged to surround the rectangular element array arrangement space, and more of the scintillator elements arranged at the outermost periphery of the scintillator unit are housed in the element array housing frames, thereby further improving the manufacturing efficiency of the scintillator unit.

[0015] The radiation detector according to the present invention comprises: the scintillator unit; and a photodetector having a plurality of detection elements that detect light emitted from the first scintillator element and the second scintillator element.

[0016] By using the present invention, it is possible to improve the manufacturing efficiency of scintillator units and radiation detectors.

[0017] FIG. 1 is a diagram illustrating the configuration of a main part of an embodiment of a radiation detector according to the present invention. FIG. 2 is a diagram illustrating a first light reflecting member and a second light reflecting member used in the scintillator units of the first to third embodiments. FIG. 3 is a top view of the first light reflecting member and the second light reflecting member combined together according to the first embodiment. FIG. 4 is a top view of the first scintillator element fixing auxiliary member and the second scintillator element fixing auxiliary member according to the first embodiment. FIG. 5 is a diagram illustrating the state before assembly of the first scintillator element fixing auxiliary member and the second scintillator element fixing auxiliary member according to the first embodiment. FIG. 6 is a perspective view illustrating how a scintillator element partition member and a scintillator element are accommodated in the first scintillator element fixing auxiliary member and the second scintillator element fixing auxiliary member according to the first embodiment. FIG. 7 is a diagram illustrating the state before assembly of the scintillator element partition member according to the first embodiment. FIG. 8 is a diagram illustrating the state after assembly of the scintillator element partition member according to the first embodiment. FIG. 9 is a side view of the state in which a scintillator element partition member is inserted into the first scintillator element fixing auxiliary member and the second scintillator element fixing auxiliary member according to the first embodiment. FIG. 10 is a perspective view of the scintillator element fixing auxiliary member according to the second embodiment. a scintillator element partition member and a scintillator element being accommodated in a scintillator element fixing auxiliary member of a second embodiment; a perspective view illustrating a scintillator element fixing auxiliary member of a third embodiment; a perspective view illustrating a scintillator element partition member and a scintillator element being accommodated in a scintillator element fixing auxiliary member and a scintillator element array housing frame member of the third embodiment; a view illustrating a state before assembly of a scintillator element array housing frame member of the third embodiment; a perspective view of a first light reflecting member of a related embodiment that applies a partition piece connecting portion of a scintillator element partition member of the present invention; a top view of a state in which the first light reflecting member and the second light reflecting member of the first embodiment are combined; a view illustrating the shape of a fixing member of a related embodiment; a view illustrating the shape of a side surface of a scintillator unit of a related embodiment.

[0018] Hereinafter, embodiments of the scintillator unit and radiation detector according to the present invention will be described with reference to the drawings. Note that the scale of the drawings used in the following description has been appropriately changed from the actual scale in order to clearly show the features of each part.

[0019] 1 shows the configuration of the main parts of a radiation detector 1 according to the first embodiment. The radiation detector 1 is broadly divided into a scintillator unit 11, a photodetector 7, and a control and processing unit 8. The scintillator unit 11 and the photodetector 7 are bonded together with an adhesive 6 that transmits (is optically transparent to) light emitted from scintillator elements 3 (scintillation light) and that is made of a highly transparent silicone rubber or the like that has a refractive index similar to that of the material that constitutes the scintillator elements 3.

[0020] The scintillator unit 11 has a plurality of first light-reflecting members 21 and a plurality of second light-reflecting members 22, as shown in the perspective view of Fig. 2. The first light-reflecting member 21 is an elongated rectangular plate-shaped (strip-shaped) light-reflecting member having a short side with a length corresponding to the height of the scintillator elements 3 (described later), with a plurality of slits 211, each having a length approximately half the length of the short side, provided at a predetermined interval corresponding to the width of the scintillator elements 3 (described later). The second light-reflecting member 22 is an elongated rectangular plate-shaped (strip-shaped) light-reflecting member having a short side with a length corresponding to the height of the scintillator elements 3 (described later), with a plurality of slits 221, each having a length approximately half the length of the short side, provided at a predetermined interval corresponding to the width of the scintillator elements 3 (described later). The slits 211 of the first light-reflecting member 21 are inserted from above into the slits 221 of the second light-reflecting member 22, so that the first light-reflecting member 21 and the second light-reflecting member 22 are arranged orthogonally. Here, the lengths of the slits 211 of the first light reflecting member 21 and the slits 221 of the second light reflecting member 22 are the same, but the sum of the lengths of these slits 211, 221 need only be equal to or greater than the length of the short sides of the first light reflecting member 21 and the second light reflecting member 22, and the lengths of the slits 211, 221 can be changed as appropriate.

[0021] The first light reflecting member 21 and the second light reflecting member 22 are made of a material that reflects scintillation light emitted from the scintillator element 3, which will be described later. The first light reflecting member 21 and the second light reflecting member 22 may be made of, for example, a multilayer optical film such as an ESR (Enhanced Specular Reflector) film, or a polyester film such as Lumirror (a registered trademark of Toray Industries, Inc.).

[0022] The scintillator unit 11 further includes a plurality of scintillator elements 3. As shown in the top view of FIG. 3, a first light-reflecting member 21 and a second light-reflecting member 22 are combined to form a lattice-like pattern of numerous spaces (including spaces that are open to the outside). The scintillator elements 3 in this embodiment and in the second and third embodiments described below are columnar bodies having a planar shape of several millimeters square and a height of 20 to 30 mm, and a scintillator element 3 is housed in each of the lattice-like spaces formed by the first light-reflecting member 21 and the second light-reflecting member 22. Note that the shape and size of the scintillator elements 3 are merely examples, and scintillator elements of an appropriate shape and size can be used depending on the purpose of use and the object to be measured.

[0023] The scintillator element 3 is made of a material that emits scintillation light when exposed to radiation. 12 (BGO), Ce-doped Lu2SiO5 (LSO), Ce-doped Lu 2(1－X) Y 2X SiO5 (LYSO), Ce-doped Gd3(AlGa)5O 12 (GAGG), Ce- and Zr-doped Gd2SiO5 (GSO), Ce-doped Lu 2(1－X) Gd 2X SiO5 (LGSO), Pr-doped Lu3Al5O 12 (LuAG), Ce-doped LaBr3, Ce-doped LaCl3, Ce-doped Lu 0.7 Y 0.3 Crystals of AlO3 (LuYAP) and Lutetium Fine Silicate (LFS) can be molded into columnar bodies with a planar shape of several mm square.

[0024] Hereinafter, the scintillator elements 3 arranged in each of the spaces formed in a grid pattern by the first light reflecting member 21 and the second light reflecting member 22 will be referred to as a scintillator array 31. The scintillator array 31 corresponds to the central portion of the scintillator unit 11 excluding the scintillator elements 3 arranged on the outermost periphery, etc. The scintillator elements 3 included in the scintillator array 31 correspond to the second scintillator elements in the present invention.

[0025] A scintillator element fixing auxiliary member 4 is disposed outside the scintillator array 31. Fig. 4 shows a top view of the scintillator element fixing auxiliary member 4. As indicated by the dashed line and the alternate long and short dash line in Fig. 4, the scintillator element fixing auxiliary member 4 is formed by combining a rectangular frame-shaped first scintillator element fixing auxiliary member 41 (shown by the dashed line) and a similarly rectangular frame-shaped second scintillator element fixing auxiliary member 42 (shown by the alternate long and short dash line) such that one short side and the other long side are parallel to each other.

[0026] 5 , in the first scintillator element fixing auxiliary member 41, a slender rectangular plate-like (strip-like) member is divided into four regions in the longitudinal direction, and two non-adjacent regions are formed near both ends of the bottom side of each of the two remaining regions, and a plurality of rectangular cutouts 412 are formed at the top of each of the remaining two regions, at intervals corresponding to the width of the scintillator elements 3. In the second scintillator element fixing auxiliary member 42, a slit 421 is formed near both ends of the top side of each of two non-adjacent regions in the longitudinal direction, and a plurality of cutouts 422 are formed at the top of each of the two remaining regions, at intervals corresponding to the width of the scintillator elements 3.

[0027] A material that reflects scintillation light is used for the first scintillator element fixing auxiliary member 41 and the second scintillator element fixing auxiliary member 42. For example, a multilayer optical film such as an ESR (Enhanced Specular Reflector) film, or a polyester film such as Lumirror (a registered trademark of Toray Industries, Inc.) can be used for the first scintillator element fixing auxiliary member 41 and the second scintillator element fixing auxiliary member 42.

[0028] By inserting the slits 411 of the first scintillator element fixing auxiliary member 41 and the slits 421 of the second scintillator element fixing auxiliary member 42 into each other, a scintillator element fixing auxiliary member 4 is formed as shown in the perspective view of Fig. 6. A space (corresponding to the element array arrangement space of the present invention) having the same size and shape (a flat rectangular parallelepiped in the example shown in Fig. 6) as the outer shape of the scintillator array 31 is formed in the center of the scintillator element fixing auxiliary member 4. For example, the scintillator element fixing auxiliary member 4 is placed on the outer periphery of the scintillator array 31 by covering it from above. Frame-shaped scintillator element array accommodation frames 44 are formed on the outside of the four sides of the scintillator array 31, each consisting of a part of the first scintillator element fixing auxiliary member 41 and a part of the second scintillator element fixing auxiliary member 42. In this embodiment, the first scintillator element fixing auxiliary members 41 and the second scintillator element fixing auxiliary members 42 constitute four scintillator element array housing frames 44 and also function as frame connecting portions.

[0029] In this embodiment, by using a combination of the first scintillator element fixing auxiliary member 41 and the second scintillator element fixing auxiliary member 42 in this manner, the scintillator element array housing frame 44, which has an internal space for housing the scintillator elements 3 arranged on the outermost periphery, is fixed and positioned on the outside of each side of the scintillator array 31. Here, for convenience of explanation, the scintillator element fixing auxiliary member 4 is arranged after the scintillator array 31 is constructed, but it is also possible to arrange the first light reflecting member 21 and the second light reflecting member 22 orthogonally inside the scintillator element fixing auxiliary member 4, and then arrange the scintillator elements 3.

[0030] The width of the scintillator element array housing frame 44 is extremely small, being approximately the same as one side of the planar shape of the scintillator element 3, i.e., a few millimeters. Therefore, if a scintillator element 3 falls over while being placed one by one in the scintillator element array housing frame 44, it is extremely difficult to right the fallen scintillator element 3 or to pick it up and place it again. Furthermore, even if scintillator elements 3 can be placed in the internal space of the scintillator element array housing frame 44, it is difficult to insert tiny light-reflecting materials having the same shape as the side surfaces of the scintillator element 3 between adjacent scintillator elements 3. Therefore, in this embodiment, before the scintillator elements 3 are placed inside the scintillator element array housing frame 44, scintillator element partition members 46 are placed to define the position of each scintillator element 3.

[0031] The scintillator element partition member 46 is formed by bending a long, narrow rectangular plate-shaped (strip-shaped) member, as shown in Fig. 7, into multiple regions partitioned in the longitudinal direction, with plate-shaped portions 461 (corresponding to partition pieces of the present invention) and connecting portions provided alternately. The connecting portions include first connecting portions 462 (corresponding to first partition piece connecting portions of the present invention) provided between the upper ends of the plate-shaped portions 461 and second connecting portions 463 (corresponding to second partition piece connecting portions of the present invention) provided in the center of the side edges of the plate-shaped portions 461, and the first connecting portions 462 and second connecting portions 463 are provided alternately. The plate-shaped portions 461, the first connecting portions 462, and the second connecting portions 463 all have a width corresponding to one side of the planar shape of the scintillator elements 3.

[0032] Of the boundaries of each compartment of the scintillator element compartment member 46, both side edges of the first connecting portion 462 are mountain-folded and both side edges of the second connecting portion 463 are valley-folded to form a shape as shown in Fig. 8. In the state formed into the shape as shown in Fig. 8, the scintillator element compartment member 46 has a configuration in which two adjacent plate-like portions 461 are connected by the first connecting portion 462 between the upper end portions of the respective sides on one side (the front side in Fig. 8), and the two plate-like portions 461 connected by the first connecting portion 462 are connected by the second connecting portion 463 between the centers of the respective sides on the other side (the back side in Fig. 8).

[0033] Slits are made in advance at the mountain folds and valley folds. Because mountain folds widen slits, the fold lines are less likely to shift than valley folds. Therefore, mountain folds are made between the plate-like portion 461 and the first connecting portion 462, which are formed at the same height, and valley folds are made between the plate-like portion 461 and the second connecting portion 463, which are formed at different heights. This prevents misalignment at the boundary between the plate-like portion 461 and the first connecting portion 462 and the boundary between the plate-like portion 461 and the second connecting portion 463.

[0034] Next, as shown in Fig. 6 , the molded scintillator element partition members 46 are inserted into the four frame-shaped scintillator element array housing frames 44. As a result, as shown in the side view of Fig. 9 , the first connecting portions 462 of the scintillator element partition members 46 are inserted into the notches 412 of the first scintillator element fixing auxiliary members 41 or the notches 422 of the second scintillator element fixing auxiliary members 42, and the scintillator element partition members 46 are positioned inside the scintillator element array housing frames 44.

[0035] A material that reflects scintillation light is also used for the scintillator element partitioning member 46. For the scintillator element partitioning member 46, for example, a multilayer optical film such as an ESR (Enhanced Specular Reflector) film or a polyester film such as Lumirror (a registered trademark of Toray Industries, Inc.) can be used.

[0036] One scintillator element 3 is placed in each space partitioned by the scintillator element partitioning members 46 positioned in this manner. In the present embodiment, because the internal space of the scintillator element array housing frame 44 is partitioned by the scintillator element partitioning members 46, the scintillator elements 3 are less likely to fall over inside the scintillator element array housing frame 44, and the scintillator elements 3 can be efficiently arranged. Furthermore, by arranging the scintillator element partitioning members 46, the plate-like portions 461 are disposed between adjacent scintillator elements 3, eliminating the need to insert minute light-reflecting material.

[0037] In the above example, the second connecting portion 463 is disposed in the center of the side edge of the plate-like portion 461. However, the position of the second connecting portion 463 may be offset from the upper end of the side edge of the plate-like portion 461 and does not have to be in the center. If the first connecting portion 462 or the second connecting portion 463 is positioned lower, the scintillator element 3 may get caught on the first connecting portion 462 or the second connecting portion 463 inside the scintillator element array housing frame 44 when being inserted. It is easier to insert the scintillator element 3 if the first connecting portion 462 and the second connecting portion 463 are provided on the side where the scintillator element 3 is inserted (the side closer to the upper end of the scintillator element partition member 46). In consideration of this point, the second connecting portion 463 is preferably provided in the range between the upper end and the center of the side edge of the plate-like portion 461.

[0038] When the scintillator elements 3 are inserted into the space defined by the scintillator element partitioning members 46, all of the scintillator elements 3 constituting the scintillator unit 11 except for the four located at the four corners are fixed and positioned. The scintillator elements 3 inserted into the space defined by the scintillator element partitioning members 46 in the scintillator element fixing auxiliary member 4 correspond to the first scintillator elements in the present invention. One scintillator element 3 with its side surfaces covered with a light-reflecting material is placed at each of the four corners, and a sheet-like fixing member 5 is wrapped around the entire periphery. In this way, all of the scintillator elements 3 are fixed, and the scintillator unit 11 is completed.

[0039] The scintillator unit 11 completed here is turned upside down and used in the radiation detector 1 shown in Fig. 1 . That is, when used in the radiation detector 1, the scintillator unit 11 is arranged so that the portions where the first connecting portions 462 of the scintillator element partitioning member 46 are inserted into the notches 412 of the first scintillator element fixing auxiliary member 41 and the notches 422 of the second scintillator element fixing auxiliary member 42 are located on the photodetector 7 side. The portions where the first connecting portions 462 of the scintillator element partitioning member 46 are inserted into the notches 412 of the first scintillator element fixing auxiliary member 41 and the notches 422 of the second scintillator element fixing auxiliary member 42 (upper side in Fig. 9 ) are less likely to bulge outward than the portions where these portions are not present (lower side in Fig. 9 ), so the scintillator elements 3 are more reliably fixed and positioned. The aspect of arrangement of the scintillator unit so that the portions where the connecting portions are inserted into the notches are located on the photodetector 7 side is the same in second and third embodiments and related forms described below. Furthermore, a light reflecting material that transmits radiation and reflects scintillation light is arranged on the upper surface of the scintillator unit 11 (the side opposite to the photodetector 7) so as to cover the scintillator unit 11. This also prevents the scintillation light from leaking above the scintillator unit 11.

[0040] In this embodiment, of the scintillator elements 3 located on the outermost periphery, those other than those located at the four corners are fixed inside the scintillator element array housing frame 44 and are positioned with respect to the scintillator array 31. Furthermore, two side surfaces of the scintillator elements 3 located at the four corners are fixed by the wall surfaces of the adjacent first scintillator element fixing auxiliary members 41 and second scintillator element fixing auxiliary members 42. Therefore, even if force is applied to the scintillator elements 3 located at the four corners when the sheet-like fixing member 5 is wrapped around the periphery, this will not cause displacement of the scintillator elements 3, and the shape of the scintillator unit 11 will not be distorted.

[0041] The fixing member 5 also uses a material that reflects scintillation light. For example, a multilayer optical film such as an ESR (Enhanced Specular Reflector) film or a polyester film such as Lumirror (a registered trademark of Toray Industries, Inc.) can be used for the fixing member 5. Note that, because the fixing member 5 is not disposed between the scintillator elements 3, it does not have to be a thin member such as a film. For example, a sheet-like substrate surface coated with a light-reflecting material such as polytetrafluoroethylene, barium sulfate, aluminum oxide, or titanium oxide and then solidified can also be used.

[0042] The photodetector 7 is provided on the bottom surface of the scintillator unit 11, and has a plurality of photoreceptor elements 71 arranged two-dimensionally. Each photoreceptor element 71 detects light emitted from the scintillator element 3 located above it and outputs a signal corresponding to the intensity of the light. For example, a silicon photomultiplier or a photomultiplier tube is used as the photoreceptor element 71. As shown in FIG. 1 , in this embodiment, the photoreceptor elements 71 are arranged in a grid pattern with spacing wider than that of the scintillator elements 3.

[0043] The control / processing unit 8 includes a memory unit 81 that stores positional information for the plurality of scintillator elements 3 and positional information for the plurality of light-receiving elements 71, and signals read out from the plurality of light-receiving elements 71 are stored in the memory unit 81 together with the positional information for the light-receiving elements 71. The control / processing unit 8 also includes an operation control unit 82 that controls the operation of the photodetector 7, and a radiation incident position identifying unit 83 that identifies the incident position of radiation by performing predetermined arithmetic processing based on the output signals and positional information from each light-receiving element 71. These processes are similar to those in conventional radiation detectors, and therefore detailed description thereof will be omitted. The control / processing unit 8 can be configured, for example, by a personal computer, and functional blocks such as the operation control unit 82 and the radiation incident position identifying unit 83 are realized by executing predetermined software (dedicated program) that has been installed in advance. In addition, an input unit 85 that allows a user to perform predetermined input operations, a display unit 86 that displays appropriate information, and the like are connected to the control / processing unit 8.

[0044] One possible method for inserting a light-reflecting material between the outermost scintillator element and scintillator elements located inside it in order to improve the positional resolution at the edge of the radiation detector is to two-dimensionally arrange the scintillator elements other than the outermost one to create a scintillator array, place a sheet-like light-blocking member on the side of the scintillator array, and then arrange the scintillator elements one-dimensionally outside it. After this, a scintillator unit is manufactured by fixing the entire scintillator array and the outermost scintillator elements together, for example by wrapping tape around the outermost scintillator element, and a radiation detector is manufactured by combining such a scintillator unit with a photodetector.

[0045] In this method, when wrapping tape around the outer periphery of the scintillator element arranged at the outermost periphery, it is necessary to hold down the entire periphery of the scintillator element with a jig or the like to prevent the outermost scintillator element from falling outward. However, using such a jig gets in the way when wrapping tape around the outermost scintillator element, resulting in poor work efficiency.

[0046] Alternatively, it is conceivable to place two sheets of light-reflecting material on the outside of the scintillator array, spaced apart by the same width as the scintillator elements, and place the outermost scintillator elements between them. However, there is no way to fix the two light-blocking members, especially the inner light-blocking member, and the light-blocking member would move while the outermost scintillator elements were being placed, again resulting in poor work efficiency.

[0047] Another option is to prepare four frame members to house the outermost scintillator elements, place the scintillator elements in them, and then place the frame members housing the scintillator elements around the periphery of the scintillator array. This method requires only supporting the four frame members housing the scintillator elements with a jig or similar. However, the width of the frame members is approximately the same as the width of the scintillator elements, i.e., a few millimeters, making it difficult to arrange the scintillator elements one by one upright in such a small space. Furthermore, once a scintillator element falls over, it is difficult to stand it up or reposition it.

[0048] Furthermore, when either of the above methods is adopted, the scintillator elements on the outermost periphery are not fixed to the scintillator array in the center, and therefore, when tape is wrapped around the outside to fix them, the scintillator elements are likely to be pulled by the tape and become misaligned, or localized force is applied to the corners, causing the scintillator elements to be pushed inward. In addition, when the corners of the outer periphery of the scintillator unit are pushed in with tape, a bulge is likely to occur in the center of the side, causing the scintillator elements located in that location to become misaligned, and the scintillation light spreads in the bulged space, reducing the accuracy in identifying the incident position of radiation.

[0049] Furthermore, in a radiation detector such as that described in Patent Document 1, when inserting light-reflecting materials between scintillator elements arranged at the outermost periphery, sheet-like light-reflecting materials several millimeters wide and shaped like the side surfaces of the scintillator elements must be inserted between the scintillator elements. The task of inserting such small sheet-like light-reflecting materials one by one is not easy and takes time. Furthermore, because light-reflecting materials are often thin films, it is difficult to determine from the outside after placement whether a light-reflecting material has been omitted or whether it has been placed twice.

[0050] In contrast, in the scintillator unit 11 of the first embodiment, the scintillator element fixing auxiliary members 4 are arranged so as to surround the scintillator array 31, and the scintillator element partition members 46 are arranged in the scintillator element array housing frames 44 of the scintillator element fixing auxiliary members 4. Then, scintillator elements 3 (first scintillator elements) are inserted into the spaces partitioned by the scintillator element partition members 46. As a result, of the scintillator elements 3 constituting the scintillator unit 11, all but four located at the four corners are fixed and positioned with respect to the scintillator array 31. Therefore, when wrapping the sheet-like fixing members 5, only the scintillator elements 3 located at the four corners need to be held with a jig or the like, which significantly improves workability and manufacturing efficiency.

[0051] Furthermore, in the scintillator unit 11 of the first embodiment, the two side surfaces of the scintillator element 3 located at the corner are positioned by the wall surfaces of the adjacent first scintillator element fixing auxiliary member 41 and the wall surfaces of the second scintillator element fixing auxiliary member 42, so that the scintillator element 3 at the corner is less likely to become misaligned when the fixing member 5 is wrapped around the outer circumference of the scintillator unit 11.

[0052] Furthermore, because the space in the scintillator element array housing frame 44 is partitioned by the scintillator element partitioning member 46, the scintillator elements 3 are less likely to tip over inside the scintillator element array housing frame 44, and there is no need to insert a tool into a space several millimeters wide to upright a toppled scintillator element 3. Furthermore, there is no need to worry about missing or double-placed light-reflecting material.

[0053] Furthermore, as explained in Figure 9, the first connecting portion 462 of the scintillator element partition member 46 is inserted into the notch 412 of the first scintillator element fixing auxiliary member 41 or the notch 422 of the second scintillator element fixing auxiliary member 42, so that bulging is less likely to occur in the center of the scintillator element array housing frame portion 44 when a sheet is wrapped around and fixed to the outer periphery of the scintillator unit 11.

[0054] Second Embodiment Next, a radiation detector and a scintillator unit according to a second embodiment will be described. In the second embodiment, the configuration of the scintillator array 31 is the same as in the above-described embodiment, and therefore other points, in particular the configuration of the scintillator element fixing auxiliary member 94, will be described.

[0055] As shown in Figure 10, the scintillator element fixing auxiliary member 94 in the second embodiment comprises a top surface portion 941 (corresponding to the frame connecting portion of the present invention) that is approximately the same size and shape as the top surface of the scintillator array 31, side surface portions 942 that are connected to the top surface portion 941 and are located on each side of the scintillator array 31, a first protrusion piece 943 provided at one end of each of the four side surface portions 942, and a second protrusion piece 944 provided at the other end of the side surface portion 942.

[0056] A material that transmits radiation and reflects scintillation light is used for the scintillator element fixing auxiliary member 94. For example, a multilayer optical film such as an ESR (Enhanced Specular Reflector) film, or a polyester film such as Lumirror (a registered trademark of Toray Industries, Inc.) can be used for the scintillator element fixing auxiliary member 94.

[0057] The first overhanging piece 943 has the same height and width as the scintillator elements 3. The second overhanging piece 944 has a connecting piece 9441 connected to the corner and having the same shape as the first overhanging piece 943, and an extending piece 9442 in the form of a long, narrow rectangular plate that extends from the connecting piece 9441 and has the same width as the side surface of the scintillator array 31. A plurality of notches 9443 are provided on the lower side of the extending piece 9442 at intervals equal to the width of the scintillator elements 3.

[0058] In the second embodiment, for example, a scintillator unit is manufactured as follows.

[0059] The scintillator array 31 is covered with a top surface portion 941, and the tip of an extension piece 9442 of a second overhang piece 944 provided on the same side surface portion 942 as the first overhang piece 943 is fixed to the tip of each first overhang piece 943. As a result, a scintillator element array housing frame portion 945 is formed on each side surface of the scintillator array 31, as shown in FIG.

[0060] Furthermore, a scintillator element partition member 96 having a shape obtained by turning the scintillator element partition member 46 of the first embodiment upside down is inserted into the interior of the scintillator element array housing frame 945. As a result, the first connecting portions of the scintillator element partition member 96 are inserted into the cutout portions 9443 of the extension pieces 9442, and the scintillator element partition member 96 is positioned inside the scintillator element array housing frame 945. Then, scintillator elements 3 (first scintillator elements) are housed in each space partitioned by the scintillator element partition member 46. Finally, as in the first embodiment, one scintillator element 3 having its side surfaces covered with a light-reflecting material is placed at each of the four corners, and a sheet-like fixing member 5 is wrapped around the entire periphery thereof to fix all of the scintillator elements 3, thereby completing the scintillator unit 11.

[0061] Alternatively, the scintillator unit can be manufactured as follows.

[0062] The scintillator element fixing auxiliary member 94 is inverted upside down from the state shown in FIG. 10 , and the scintillator array 31 is formed on the top surface portion 941. A scintillator element partitioning member 96 (inverted upside down from that shown in FIG. 11 ) is inserted into the scintillator element array housing frame 945, and scintillator elements 3 are placed in each partitioned space. A sheet-like fixing member 5 is then wrapped around the entire outer periphery to fix the entire assembly, and the assembly is then inverted upside down to complete the scintillator unit 11. By using this method, the scintillator array 31 can be formed in the space surrounded by the top surface portion 941 and the side surface portion 942. Furthermore, because the first connecting portion and the second connecting portion of the scintillator element partitioning member 96 are located near the end (top end) where the scintillator elements 3 are inserted, it is easy to insert the scintillator elements 3 into the space partitioned by the scintillator element partitioning member 96.

[0063] In the second embodiment, as in the first embodiment, of the scintillator elements 3 constituting the scintillator unit, all but four located at the four corners are fixed and positioned. Therefore, when wrapping the sheet-like fixing member 5, only the scintillator elements 3 located at the four corners need to be held by a jig or the like, which significantly improves workability and manufacturing efficiency.

[0064] 12 , a scintillator element fixing auxiliary member 95 in the third embodiment includes a top surface portion 951 (corresponding to a frame connecting portion of the present invention) that is the same size and shape as the top surface of the scintillator array 31, side surface portions 952 that are connected to the top surface portion 951 and that are located on two opposing side surfaces of the scintillator array 31, first protrusion pieces 953 that are provided on one end of each of the two side surface portions 952, and a second protrusion piece 954 that is provided on the other end of the side surface portion 952. The first protrusion piece 953 has the same height and width as the scintillator elements 3.

[0065] The second protrusion piece 954 has a connecting piece 9541 of the same shape as the first protrusion piece 953 connected to the corner, and an elongated rectangular plate-like extension piece 9542 extending from the connecting piece 9541 and having the same width as the side of the scintillator array 31, and the lower edge of the extension piece 9542 has multiple notches 9543 spaced at intervals the same as the width of the scintillator element 3.

[0066] A material that transmits radiation and reflects scintillation light is used for the top surface 951 of the scintillator element fixing auxiliary member 95. A material that reflects scintillation light is used for the portions of the scintillator element fixing auxiliary member 95 other than the top surface 951. Both may be made of the same material. For example, a multilayer optical film such as an ESR (Enhanced Specular Reflector) film or a polyester film such as Lumirror (a registered trademark of Toray Industries, Inc.) may be used for the scintillator element fixing auxiliary member 95.

[0067] 13, a frame-shaped scintillator element array housing frame member 97 is disposed on each of the two side surfaces of the scintillator array 31 that are not provided with side surface portions 952. Each of these scintillator element array housing frame members 97 is formed by dividing a single elongated rectangular plate-like (strip-like) member into four sections, and providing a plurality of notches 9543 at the bottom edge of one of the sections at intervals equal to the width of the scintillator elements 3, as shown in FIG. 14. The scintillator element array housing frame member 97 is formed by folding the boundary between each section and connecting both ends.

[0068] A material that reflects scintillation light is used for the scintillator element array housing frame member 97. For example, a multilayer optical film such as an ESR (Enhanced Specular Reflector) film, or a polyester film such as Lumirror (a registered trademark of Toray Industries, Inc.) can be used for the scintillator element array housing frame member 97.

[0069] In the third embodiment, for example, the scintillator unit can be manufactured as follows.

[0070] A top surface 951 is placed over the top of the scintillator array 31, and the tip of an extension piece 9542 of a second protruding piece 954 provided at the opposite corner of the same side surface is fixed to the tip of the first protruding piece 953, thereby forming a scintillator element array housing frame portion 955 as shown in FIG. 13 . Furthermore, a scintillator element array housing frame member 97 is placed on each of the two open side surfaces. A scintillator element array housing frame portion 955 is also formed inside the scintillator element array housing frame member 97. Then, scintillator element partition members 96, each having a shape obtained by inverting the scintillator element partition member 46 in the first embodiment, are inserted into the scintillator element array housing frame portions 955 located on each side surface of the scintillator array 31. As a result, the entire side surface is covered with a light-reflecting material, as in the first embodiment. Then, scintillator elements 3 are housed in each space partitioned by the scintillator element partition members 46. Finally, as in the first and second embodiments, one scintillator element 3 with its side surfaces covered with a light-reflecting material is placed at each of the four corners, and the entire periphery is wrapped with a sheet-like fixing member 5. In this way, all of the scintillator elements 3 are fixed in place, and the scintillator unit 11 is completed.

[0071] In the third embodiment, as in the second embodiment, the scintillator array 31 is constructed by inverting the scintillator element fixing auxiliary member 95 and the scintillator element array housing frame member 97 upside down, and the scintillator element partition member 96 is also inserted into the scintillator element array housing frame portion 955 in an inverted state from the state shown in Figure 13, allowing the scintillator elements 3 to be arranged individually.

[0072] In the third embodiment, as in the first embodiment, of the scintillator elements 3 constituting the scintillator unit, all but four located at the four corners are fixed or housed. Therefore, when wrapping the sheet-like fixing member 5, it is only necessary to hold only the scintillator elements 3 located at the four corners while the two scintillator element array housing frame members 97 are in contact with the side surfaces of the scintillator array 31, which significantly improves workability and manufacturing efficiency.

[0073] <Related Forms> In each of the above-described embodiments, a light-reflecting material is disposed between the outermost scintillator elements 3 and the scintillator array 31, as in Patent Document 1, in order to increase the positional resolution of the scintillation light emitted from the outermost scintillator elements 3. However, many of the scintillator units and radiation detectors that have been widely used in the past have a configuration in which all of the scintillator elements are arranged in an array (two-dimensional arrangement) without being separated into the scintillator array 31 and the outermost scintillator elements 3. In scintillator units and radiation detectors with such a configuration, the configuration of the scintillator element partitioning member 96 used in each of the above-described embodiments can be applied to the first light-reflecting member 21 and the second light-reflecting member 22 that partition the scintillator elements 3 within the scintillator unit.

[0074] Fig. 15 is a perspective view of a first light reflecting member 23 provided with connecting portions 232, which is used in such a scintillator unit. Fig. 16 is a top view of a state in which the first light reflecting member 23 provided with connecting portions 232 and the second light reflecting member 24 provided with connecting portions 242 are combined together to form a lattice-like space in which the scintillator elements 3 are arranged.

[0075] In the above embodiment, the first light reflecting member 21 and the second light reflecting member 22 are individually formed by forming slits 211, 221 in a plurality of plate-like members. On the other hand, in the first light reflecting member 23 of a related embodiment, two adjacent plate-like members are connected by a connecting portion 232, and in the second light reflecting member 24, two adjacent plate-like members are connected by a connecting portion 242. This allows each member to have a U-shape in plan view, allowing each to stand on its own. Here, an example is shown in which two plate-like members are connected by the connecting portions 232, 242, but three or more plate-like members may be connected.

[0076] The connecting portions 232, 242 are provided at the upper ends of the first light reflecting member 23 and the second light reflecting member 24. In a related embodiment, the scintillator elements 3 are arranged in a lattice-like space formed by combining the first light reflecting member 23 and the second light reflecting member 24, and a sheet-like fixing member 51 is wrapped around the periphery to complete the scintillator unit 11. In a related embodiment, the fixing member 51 has notches 511 formed at locations corresponding to the connecting portions 232, 242, as shown in FIG. 17 . When constructing a conventional scintillator unit, a problem exists in that when a sheet-like fixing member is wrapped around the periphery, bulging tends to occur on the side surface, particularly in the central portion of the side surface. In contrast, in a related embodiment, as shown in the side view of the scintillator unit in FIG. 18 , inserting the connecting portions 232, 242 into the notches 511 of the fixing member 51 can prevent bulging from occurring in the central portion of the side surface of the scintillator unit.

[0077] The above-described embodiments are merely examples and can be modified as appropriate in accordance with the spirit of the present invention.

[0078] In the above embodiment, the scintillator elements 3 are arranged in a grid pattern in the scintillator unit 11 and the scintillator array 31, and the same number of scintillator elements 3 are arranged on both sides, but the scintillator elements 3 may be arranged two-dimensionally, and the arrangement may be honeycomb-shaped, or the outer shape of the scintillator unit 11 may be polygonal or circular.

[0079] In the second and third embodiments, the tips of the extension pieces 9442, 9532 of the second extension piece 944, which is provided at the opposite corner of the same side, are fixed to the tips of the first extension pieces 943, 953, but the first extension pieces 943, 953 and the extension pieces 9442, 9542 of the second extension pieces 944, 954 may be made longer than those in the second and third embodiments and provided with slits, and the slits of the first extension pieces 943, 953 and the slits of the extension pieces 9442, 9542 of the second extension pieces 944, 954 may be inserted into each other to fix the two together and form the scintillator element array housing frame portions 945, 955.

[0080] In the above embodiment, the first light reflecting member 21 and the second light reflecting member 22 are used to prevent the light emitted from the scintillator elements 3 from spreading excessively, but the scintillator unit or the radiation detector may be configured without using the first light reflecting member 21 and the second light reflecting member 22. In addition, the scintillator element partitioning members 46, 96 are also preferred components but are not essential to the present invention. Furthermore, in the above embodiment, the scintillator element partitioning members 46, 96 are configured as a single member, but the scintillator element partitioning members 46, 96 may be configured by combining a plurality of members.

[0081] In the above embodiment, the fixing member 5 is made of a material that reflects scintillation light, but it is not essential to use such a material for the fixing member. However, by using a material that reflects scintillation light for the fixing member 5, the scintillation light generated in the scintillator elements 3 in the scintillator unit 11 can be more reliably detected by the photodetector 7. It can also be prevented that the scintillation light leaks, reducing the signals of each light receiving element and increasing statistical fluctuations, causing blurring of each point when the center of gravity position of the light is mapped.

[0082] In the above embodiment, the radiation detector 1 is constructed by combining one scintillator unit 11 and a photodetector 7, but the radiation detector may also be constructed by combining a stack of multiple scintillator units 11 with a photodetector 7. Furthermore, a light guide may be disposed between the scintillator unit 11 and the photodetector 7, and the spread of the scintillation light may be adjusted by its thickness.

[0083] In the above embodiment, the outermost row of scintillation elements 3 is housed in the scintillator element row housing frame portion 44, 945, 955, but multiple rows of scintillation elements 3 from the outside may be separated from the scintillator array 31 and housed in the scintillator element housing frame portion. The number of scintillator elements 3 housed in the scintillator element housing frame portion can be changed by adjusting the lengths of the two sides of the first scintillator element fixing auxiliary member 41 and the second scintillator element fixing auxiliary member 42 in the first embodiment, or by adjusting the lengths of the first protruding piece 943 and the connecting piece 9441 in the second embodiment.

[0084] Aspects It will be apparent to those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0085] (Item 1) A scintillator unit according to one aspect of the present invention is characterized in that it comprises: a holding member made of a material that blocks scintillation light, the holding member having two element array housing frame portions and a frame connecting portion that connects the two element array housing frame portions so as to form an element array arrangement space therebetween; a plurality of first scintillator elements housed in each of the two element array housing frame portions in a one-dimensional array arrangement; and a plurality of second scintillator elements arranged in a two-dimensional array arrangement in the element array arrangement space.

[0086] "Blocking light" as mentioned above means preventing light from leaking to the outside, and includes reflecting light, etc. The shape of the element array arrangement space, i.e., the outer shape of the multiple scintillator elements arranged two-dimensionally, is typically rectangular, but may also be other polygonal or circular shapes. Furthermore, the one-dimensional arrangement may be a linear arrangement or an arc-shaped arrangement.

[0087] The scintillator unit according to paragraph 1 includes a holding member having two element array housing frame portions and a frame connecting portion that connects the two element array housing frame portions across an element array arrangement space. A portion of the plurality of scintillator elements (first scintillator elements) located at the outermost periphery of the scintillator unit are housed in each of the two element array housing frame portions in a one-dimensional array arrangement. Therefore, unlike conventional methods, it is not necessary to hold down all of the scintillator elements located at the outermost periphery of the scintillator unit with a jig or the like. This improves the manufacturing efficiency of the scintillator unit.

[0088] (Clause 2) The scintillator unit according to clause 2 is the scintillator unit according to clause 1, wherein the element array arrangement space is rectangular, the holding member further comprises two element array accommodating frame portions, the frame connecting portion connects the four element array accommodating frame portions so that the four element array accommodating frame portions surround the element array arrangement space, and each of the four element array accommodating frame portions accommodates a plurality of first scintillator elements arranged in a one-dimensional manner.

[0089] In the scintillator unit according to the second aspect, the four element array housing frames are arranged to surround the rectangular element array arrangement space, and more of the scintillator elements arranged at the outermost periphery of the scintillator unit are housed in the element array housing frames. Therefore, in the above aspect, the manufacturing efficiency of the scintillator unit is further improved.

[0090] (Clause 3) The scintillator unit according to clause 3 is the scintillator unit according to clause 1 or 2, further comprising a scintillator element array partition member that partitions the internal space of the element array accommodating frame portion into spaces in which each scintillator element is accommodated.

[0091] In the scintillator unit according to the third aspect, the inside of the element array accommodating frame is partitioned, so there is no need to worry about the scintillator elements falling over when they are accommodated, and the scintillator elements are more reliably fixed.

[0092] (4th paragraph) A scintillator unit according to the 4th paragraph is the scintillator unit according to the 3rd paragraph, wherein the scintillator element array partition member is made of a material that blocks the scintillation light.

[0093] In the scintillator unit according to the fourth aspect, it is possible to suppress the spread of scintillation light emitted from the scintillator elements housed in the scintillator element array housing frame.

[0094] (Clause 5) The scintillator unit according to clause 5 is the scintillator unit according to clause 3 or 4, wherein the scintillator elements are columnar with a rectangular planar shape, and the scintillator element array partition member is composed of a plurality of partition pieces that divide the internal space of the element array housing frame portion, first partition piece connecting portions that connect two of the plurality of partition pieces together at one side of each, and second partition piece connecting portions that connect two partition pieces connected by the first partition piece connecting portions together at the other side of each.

[0095] (Item 6) The scintillator unit according to item 6 is the scintillator unit according to item 5, wherein the first partition piece connecting portion and the second partition piece connecting portion each have a vertical length that is smaller than the vertical length of the partition piece, the first partition piece connecting portion is provided between the upper ends of one side of the partition piece, and the second partition piece connecting portion is provided between the upper end and center of the other side of the partition piece.

[0096] In the scintillator unit according to paragraph 5, adjacent scintillator elements are partitioned by partition pieces. Furthermore, the partition pieces are connected by first partition piece connecting portions and second partition piece connecting portions. As described in paragraph 6, it is preferable that the first partition piece connecting portion in paragraph 5 is provided between the upper ends of one side of the partition pieces, and the second partition piece connecting portion is provided between the upper end and the center of the other side of the partition pieces. This allows the scintillator elements to be easily inserted into the space partitioned by the scintillator element partitioning member.

[0097] (Item 7) The scintillator unit according to item 7 is the scintillator unit according to item 6, wherein a cutout portion having the same shape as the first partition piece connecting portion is provided in a portion of the element array housing frame portion that forms part of the outer peripheral surface of the scintillator unit.

[0098] In the scintillator unit according to paragraph 7, the scintillator element partition member is positioned inside the scintillator element array housing frame by inserting the first partition piece connecting portion into the notch provided in the element array housing frame, thereby making it possible to prevent bulging of the side surface of the scintillator unit when the entire scintillator unit is fixed by the fixing member.

[0099] (Item 8) The scintillator unit according to item 8 is the scintillator unit according to any one of items 1 to 7, wherein the frame connecting portion is made of a material that transmits radiation incident on the second scintillator element and is arranged to cover the element array arrangement space.

[0100] In the scintillator unit according to paragraph 8, the side and top surfaces of the scintillator array can be fixed by the element array accommodating frame portion and the frame connecting portion.

[0101] (Clause 9) A radiation detector according to clause 9 comprises: a scintillator unit according to any one of clauses 1 to 8; and a photodetector having a plurality of detection elements that detect light emitted from the first scintillator element and the second scintillator element.

[0102] The scintillator units described in items 1 to 8 can be suitably used as radiation detectors such as those described in item 9, for example.

[0103] DESCRIPTION OF SYMBOLS 1...Radiation detector 11...Scintillator unit 21, 23...First light reflecting member 211...Slit 232...Connecting portion 22, 24...Second light reflecting member 221...Slit 242...Connecting portion 3...Scintillator element 31...Scintillator array 4...Scintillator element fixing auxiliary member 41...First scintillator element fixing auxiliary member 411...Slit 412...Notch portion 42...Second scintillator element fixing auxiliary member 421...Slit 422...Notch portion 44...Scintillator element array accommodating frame portion 46...Scintillator element partition member 461...Plate-shaped portion 462...First connecting portion 463...Second connecting portion 5, 51...Fixing member 511...Notch portion 6...Adhesive 7...Photodetector 71...Light receiving element 8...Control / processing unit 81...Storage unit 82...Operation control unit 83...Radiation incidence position specifying section 85...Input section 86...Display section 94, 95...Scintillator element fixing auxiliary members 941, 951...Top surface section 942, 952...Side surface section 943, 953...First protruding piece 944, 954...Second protruding piece 9441, 9541...Connecting piece 9442, 9542...Extending piece 9443, 9543...Notched section 945, 955...Scintillator element array housing frame section 96...Scintillator element partition member 97...Scintillator element array housing frame member

Claims

1. A scintillator unit comprising: a holding member composed of a material that blocks scintillation light, the holding member having two element row accommodating frame portions and a frame connecting portion that connects the two element row accommodating frame portions such that an element array arrangement space is formed therebetween; a plurality of first scintillator elements accommodated in each of the two element row accommodating frame portions in a one-dimensional arrangement; and a plurality of second scintillator elements arranged in a two-dimensional arrangement in the element array arrangement space.

2. The scintillator unit according to claim 1, wherein the element array arrangement space is rectangular, the holding member further includes two element row accommodating frame portions, the frame connecting portion connects the four element row accommodating frame portions such that the four element row accommodating frame portions surround the element array arrangement space, and a plurality of first scintillator elements are accommodated in each of the four element row accommodating frame portions in a one-dimensional arrangement.

3. The scintillator unit according to claim 1 or 2, further comprising a scintillator element row partitioning member that partitions the internal space of the element row accommodating frame portion into spaces for accommodating the respective scintillator elements.

4. The scintillator unit according to claim 3, wherein the scintillator element row partitioning member is composed of a material that blocks scintillation light.

5. The scintillator element is columnar with a rectangular planar shape, and the scintillator element row partitioning member includes a plurality of partition pieces that partition the internal space of the element row accommodating frame portion, a first partition piece connecting portion that connects two of the plurality of partition pieces on one side of each of them, and a second partition piece connecting portion that connects the two partition pieces connected by the first partition piece connecting portion on the other side of each of them. The scintillator unit according to claim 3 or 4, characterized in that it is configured as such.

6. The scintillator unit according to claim 5, wherein the first partition piece connecting portion and the second partition piece connecting portion each have a vertical length smaller than the vertical length of the partition piece, the first partition piece connecting portion is provided between the upper end portions of one side of the partition piece, and the second partition piece connecting portion is provided between the upper end portion and the central portion of the other side of the partition piece.

7. The scintillator unit according to claim 6, wherein a notch having the same shape as the first partition connecting portion is provided in a portion of the element row accommodating frame portion that constitutes a part of the outer peripheral surface of the scintillator unit.

8. The scintillator unit according to any one of claims 1 to 7, wherein the frame connecting portion is made of a material that transmits radiation incident on the second scintillator element and is provided so as to cover the element array arrangement space.

9. A radiation detector comprising: the scintillator unit according to any one of claims 1 to 8; and a photodetector having a plurality of detection elements that detect light emitted from the first scintillator element and the second scintillator element.

Images