JP2013200188A - Radiation detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a thermal influence on a radiation detecting panel from a circuit board.SOLUTION: A radiation detecting device 30 includes a radiation detecting panel 21, a support plate 81, an analog circuit board 91, and a digital circuit board 92. The radiation detecting panel 21 detects radiation. The support plate 81 is formed into a form of a plate having a first plane for supporting the radiation detecting panel 21, and a second plane provided in an opposite side of the first plane. The inside of the support plate is partitioned by cell walls so as to be filled with a plurality of columnar spaces extending from the first plane toward the second plane. The analog circuit board 91 and the digital circuit board 92 are supported by the support plate 81 in the second plane side and drives the radiation detecting panel 21.

Description

  Embodiments generally relate to a radiation detection apparatus for detecting radiation.

  X-ray detectors that detect radiation, particularly X-rays, are used in a wide range of fields such as industrial non-destructive inspection, medical diagnosis, and scientific research such as structural analysis. In recent years, for example, in medical diagnosis apparatuses, portable X-ray detection apparatuses that can be carried are used as well as fixed ones.

  X-ray detection devices include fragile components that are extremely susceptible to damage from physical or collisional impacts. In addition, since the X-ray detection apparatus dislikes dust and moisture, it often has a completely sealed structure in which the inside and outside of the housing are completely isolated.

  Among X-ray detection apparatuses, there is one in which a plurality of photosensors and TFTs (Thin Film Transistors) are two-dimensionally arranged as high sensitivity and sharpness. In this X-ray detection apparatus, a phosphor layer that converts X-rays into light that can be detected by the photoelectric conversion element portion is directly formed on a photodetector having a photoelectric conversion element portion in which a photosensor and a TFT are two-dimensionally arranged. The formed X-ray detection panel is provided.

  This X-ray detection panel is supported on one surface of a plate-like support member. A circuit board for driving the X-ray detection panel is supported on the other surface of the support member. The X-ray detection panel and the circuit board are electrically connected by a flexible circuit board.

  When the X-ray detector is activated, heat is generated from the circuit board. Although some of the heat generated by the circuit board is dissipated into the air inside the housing of the X-ray detector, most of it moves to the lower temperature part due to heat conduction and is caused by thermal resistance. Make the temperature distribution inside and outside the housing non-uniform while creating a temperature difference.

  For example, heat generated from the circuit board flows into a support member that supports the circuit board. Further, the heat flowing into the support member flows into the X-ray detection panel having a lower temperature.

  Due to the heat transmitted to the X-ray detection panel, the temperature of the X-ray detection panel rises and the operating temperature becomes high. When the operating temperature becomes high, the dark current of the photoelectric conversion element of the X-ray detection panel and the leak current of the TFT increase, and the amount of fixed noise varies. As a result, the X-ray image captured by the X-ray detection panel may be uneven.

  As a means for cooling the circuit board, in addition to a natural cooling type cooler, there are those that have improved cooling efficiency by a Peltier element, a cold water circulation device, or the like. There is also a method of energizing 24 hours before use so that the leakage current does not change during use.

  On the other hand, a structure for releasing heat generated in the circuit board to the housing has been proposed. In a structure in which heat is released to the housing, metal parts are generally used in order to conduct heat sufficiently.

JP 2005-283262 A

  However, when a cooling device such as a Peltier element or a chilled water circulation device is used to cool the circuit board of the X-ray detection device, it is necessary to control the cooling device, so that an additional system is required. In addition, it is not practical to energize 24 hours before use so that the amount of change in the leakage current is constant, because it is not environmentally friendly and takes too much time to use. Furthermore, in a structure that conducts heat to a metal object, the apparatus becomes heavy and portability is impaired.

  Therefore, an object of the embodiment is to suppress the thermal influence from the circuit board on the radiation detection panel.

  In order to achieve the above-described object, according to one embodiment, a radiation detection apparatus detects a radiation incident from a surface and outputs a two-dimensional radiation intensity distribution as an electrical signal; A circuit board provided on the back side of the radiation detection panel for driving the radiation detection panel; a first surface for supporting the radiation detection panel facing the radiation detection panel; and the circuit board facing the circuit board. A cylindrical cell wall formed in a plate shape having a second surface to be supported and extending from the first surface toward the second surface is arranged without gaps between the first surface and the second surface And a board.

  According to one embodiment, the radiation detection apparatus includes a flat radiation detection panel that detects radiation incident from the surface and outputs a two-dimensional radiation intensity distribution as an electrical signal, and a rear side of the radiation detection panel. A circuit board for driving the radiation detection panel, a support plate formed in a plate shape having a first surface supporting the radiation detection panel and a second surface opposite to the first surface, and the radiation A support plate formed in a plate shape having a first surface facing the detection panel and supporting the radiation detection panel; and a second surface facing the circuit board and supporting the circuit board; and a peripheral portion of the honeycomb structure And a housing in which a housing space for housing the radiation detection panel, the support plate, and the circuit board is formed inside the periphery.

1 is a block diagram of a radiation detection apparatus according to a first embodiment. It is a typical perspective view of the radiation detection panel by 1st Embodiment. It is a circuit diagram of the image detection part by 1st Embodiment. It is a top view of the radiation detection panel in 1st Embodiment. It is a sectional side view of the radiation detection apparatus in 1st Embodiment. It is a perspective view of the support plate by 1st Embodiment. It is sectional drawing of the support plate by 1st Embodiment. It is a sectional side view of the housing | casing of the radiation detection apparatus by 2nd Embodiment. It is a cross-sectional view of the radiation detection apparatus according to the second embodiment.

  Hereinafter, radiation detection devices according to some embodiments will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or similar structure, and the overlapping description is abbreviate | omitted.

[First Embodiment]
FIG. 1 is a block diagram of the radiation detection apparatus according to the first embodiment. FIG. 2 is a schematic perspective view of the radiation detection panel according to the present embodiment. FIG. 3 is a circuit diagram of the image detection unit according to the present embodiment.

  The radiation detection apparatus 30 includes a radiation detection panel 21, a gate driver 32, an integration amplifier 33, an A / D converter 34, a row selection circuit 35, and an image synthesis circuit 36. The radiation detection panel is a flat device that detects incident X-rays and outputs a two-dimensional intensity distribution as an electrical signal.

  The radiation detection panel 21 includes a fluorescence conversion film 38 and an image detection unit 12. The fluorescence conversion film 38 generates fluorescence in the visible light region when the X-ray 37 enters. The generated fluorescence reaches the surface of the image detection unit 12.

  The image detection unit 12 receives the fluorescence generated by the fluorescence conversion film 38 and generates an electrical signal. As a result, the visible light image generated in the fluorescence conversion film 38 by the incident X-rays 37 is converted into image information expressed by an electrical signal in the image detection unit 12.

  The image detection unit 12 has a plurality of fine pixels 70 arranged in a square lattice pattern. Each pixel 70 is formed on the glass substrate 11. 2 and 3, the pixels are only described for 5 rows and 5 columns or 4 rows and 4 columns, but actually, more pixels are formed according to the resolution and the imaging area. In FIG. 2, the fluorescence conversion film 38 and the image detection unit 12 are illustrated separately, but in reality they are in close contact.

  Each pixel 70 includes a thin film transistor 14, a capacitor 15, and a photodiode 39. The photodiode 39 and the capacitor 15 are connected to the thin film transistor 14 in parallel. The gate lines 13 are provided in the same number as the number of rows in the grid in which the pixels 70 are arranged, and the gate terminals of the thin film transistors 14 in the pixels in the same row are connected to the same gate line 13. The signal lines 17 are provided in the same number as the number of columns in the grid in which the pixels 70 are arranged, and the capacitors 15 in the pixels in the same column are connected to the same signal line 17 through the thin film transistor 14.

  Each gate line 13 is connected to a gate driver 32. There are a plurality of gate drivers 32, for example. The gate driver 32 is connected to the row selection circuit 35. The gate driver 32 receives a signal from the row selection circuit 35 and sequentially changes the voltages of the many gate lines 13. The row selection circuit 35 sends a signal for selecting a predetermined row for scanning the X-ray image to the gate driver 32.

  Each signal line 17 is connected to an integrating amplifier 33. The integrating amplifier 33 amplifies and outputs a very small charge signal output from the radiation detection panel 21 through the signal line 17. The integrating amplifier 33 is connected to the A / D converter 34. The A / D converter 34 is connected to the image composition circuit 36.

  FIG. 4 is a plan view of the radiation detection panel in the present embodiment.

  The radiation detection panel 21 is formed with a terminal group 61 for drawing out the gate line 13 (see FIG. 3) and the signal line 17 (see FIG. 3). The terminal group 61 that pulls out the gate line 13 (see FIG. 3) and the terminal group 61 that pulls out the signal line 17 (see FIG. 3) are arranged in the vicinity of those sides along the adjacent sides of the radiation detection panel 21, respectively. Yes. A moisture barrier 65 that covers the fluorescence conversion film 38 (see FIG. 2) may be fixed to the radiation detection panel 21.

  FIG. 5 is a side sectional view of the radiation detection apparatus according to the present embodiment.

  The radiation detection device 30 has a housing 22. The housing 22 is a box in which an opening covered with the radiation incident window 19 is formed on the X-ray detection surface side.

  A radiation detection panel 21, a shielding plate 20, a support plate 81, a circuit board group, a flexible board 18, and the like are housed inside the housing 22. The circuit board group is composed of, for example, a plurality of circuit boards, electrically drives the radiation detection panel 21, performs predetermined processing on the electrical signals output from the radiation detection panel 21, and outputs them as image data to the outside. Output. The circuit board group includes an analog circuit board 91 and a digital circuit board 92. The circuit board group is provided on the back side of the radiation detection panel 21, that is, on the opposite side to the incident surface of the X-ray 37.

  The analog circuit board 91 receives the analog signal output from the radiation detection panel 21, performs a predetermined process, and converts it into a digital signal. The digital circuit board 92 receives the digital signal generated by the analog circuit board 91, performs a predetermined process, and outputs the digital signal to a display outside the radiation detection apparatus 30. The digital circuit board 92 may control other circuit boards. The circuit board group may include a control board (not shown) for controlling the radiation detection panel 21, a power supply circuit board 93 for supplying power to another circuit board or the radiation detection panel 21, and the like.

  The radiation detection panel 21 is disposed in contact with one surface of the shielding plate 20. The radiation detection panel 21 is pressed against the shielding plate 20 by an elastic member (not shown) disposed between, for example, the inner surface of the housing 22. The shielding plate 20 is, for example, a lead plate, shields the radiation transmitted through the radiation incident window 19 and the radiation detection panel 21, and suppresses the incidence of radiation to the circuit board group.

  The support plate 81 is formed in a plate shape having a first surface 84 that supports the radiation detection panel 21 via the shielding plate 20 and a second surface 85 on the opposite side. The support plate 81 is fixed to the housing 22 by a fixing member (not shown). The support plate 81 is in contact with the surface of the shielding plate 20 opposite to the surface in contact with the radiation detection panel 21 and supports the shielding plate 20 and the radiation detection panel 21. In the present embodiment, the shielding plate 20 is provided between the support plate 81 and the radiation detection panel 21, but the radiation detection panel 21 may be directly supported by the support plate 81.

  The circuit board is fixed to the support plate 81 via the spacer 25. The circuit board may be fixed to the support plate 81 using a heat insulating support member 94.

  The flexible substrate 18 electrically connects the terminal group 61 (see FIG. 4) of the radiation detection panel 21 and the analog circuit substrate 91. The flexible substrate 18 and the terminal group 61 (see FIG. 4) are electrically connected, for example, by bonding with an anisotropic conductive adhesive. The flexible substrate 18 may also be electrically connected between a plurality of circuit boards or between the radiation detection panel 21 and another control board (not shown).

  FIG. 6 is a perspective view of the support plate according to the present embodiment. FIG. 7 is a cross-sectional view of the support plate according to the present embodiment.

  A front plate 86 is disposed on each side of the support plate 81. The space between the front plate 86 provided on each of the first surface 84 (see FIG. 5) and the second surface 85 (see FIG. 5) of the support plate 81 is from the first surface 84 (see FIG. 5) to the second. Filled with a plurality of columnar spaces 88 extending toward the surface 85 (see FIG. 5). These columnar spaces 88 are partitioned by cell walls 87.

  Both the two front plates 86 and the cell walls 87 are made of CFRP (Carbon Fiber Reinforced Plastics). The front plate 86 and the cell wall 87 may be formed of GFRP (Glass Fiber Reinforced Plastics).

  Each of the columnar spaces 88 partitioned by the cell walls 87 is a regular hexagonal column. That is, the inside of the support plate 81 has a honeycomb structure in which regular hexagonal columnar spaces 88 are arranged without gaps. The two front plates 86 may be formed of a heat insulating material having a thermal conductivity smaller than that of CFRP. The front plate 86 and the cell wall 87 are bonded and fixed with, for example, an adhesive or a double-sided tape.

  The surface of the support plate 81 facing the radiation detection panel 21, that is, the surface in contact with the shielding plate 20 may be made conductive. Thereby, static electricity generated in the radiation detection panel 21 can be removed.

  Next, the operation of the radiation detection apparatus 30 will be described with reference to FIGS.

  In the initial state, a charge is stored in the capacitor 15 connected in parallel with the photodiode 39, and a reverse bias voltage is applied to the photodiode 39 connected in parallel. This voltage is the same as the voltage applied to the signal line 17. Since the photodiode 39 is a kind of diode, even if a reverse bias voltage is applied, almost no current flows. Therefore, the electric charge stored in the capacitor 15 is held without decreasing.

  In such a situation, when X-rays 37 are incident on the fluorescence conversion film 38, high-energy X-rays are converted into a large amount of low-energy visible light inside the fluorescence conversion film 38. Part of the fluorescence generated inside the fluorescence conversion film 38 reaches the photodiode 39 disposed on the surface of the image detection unit 12.

  Fluorescence incident on the photodiode 39 is converted into charges composed of electrons and holes inside the photodiode 39, and reaches both terminals of the photodiode 39 along the direction of the electric field applied by the capacitor 15. This charge movement is observed as a current flowing through the photodiode 39.

  The current flowing inside the photodiode 39 generated by the incidence of fluorescence flows into the capacitor 15 connected in parallel. Along with this, the electric charge stored in the capacitor 15 is canceled. As a result, the charge stored in the capacitor 15 decreases, and the potential difference generated between the terminals of the capacitor 15 also decreases compared to the initial state.

  The gate driver 32 has a function of changing the potentials of a large number of gate lines 13 in order. At a specific time, only one gate line 13 is changed in potential by the gate driver 32. Between the source terminal and the drain terminal of the thin film transistor 14 connected in parallel to the signal line 17 connected to the gate line 13 whose potential has changed, the state changes from an insulated state to a conductive state. A specific voltage is applied to each signal line 17. The voltage applied to the signal line is applied to the capacitor 15 connected through the source and drain terminals of the thin film transistor 14 connected to the gate line 13 whose potential has changed.

  Since the capacitor 15 is in the same potential state as that of the signal line 17 in the initial state, when the charge amount of the capacitor 15 is not changed from the initial state, no charge transfer from the signal line 17 occurs in the capacitor 15. However, in the capacitor 15 connected in parallel with the photodiode 39 into which the fluorescence generated inside the fluorescence conversion film 38 by the X-ray 37 incident from the outside is incident, the charge stored inside is reduced, and the initial value is reduced. The potential of the state has changed. For this reason, the movement of the charge is generated from the signal line 17 through the thin film transistor 14 in the conductive state, and the amount of charge stored in the capacitor 15 returns to the initial state. Further, the amount of the electric charge that has moved becomes a signal flowing through the signal line 17 and is transmitted to the outside.

  The current flowing through the signal line 17 is input to the corresponding integrating amplifier 33. The integrating amplifier 33 integrates the current that flows within a predetermined time, and outputs a voltage corresponding to the integrated value to the outside. By performing this operation, the amount of charge flowing through the signal line 17 within a certain time can be converted into a voltage value. As a result, the charge signal generated in the photodiode 39 corresponding to the fluorescence intensity distribution generated in the fluorescence conversion film 38 by the X-ray 37 is converted into potential information by the integrating amplifier 33.

  The potential generated in the integrating amplifier 33 is sequentially converted into a digital signal by the A / D converter 34. The signals that have become digital values are sequentially arranged in accordance with the rows and columns of pixels arranged inside the image detection unit 12 inside the image composition circuit 36, and are output to the outside as image signals.

  By continuously performing these operations, the X-ray image information incident from the outside is converted into image information by an electric signal and output to the outside. The image information by the electric signal output to the outside is imaged by, for example, a general display device, and the X-ray image can be observed as an image by visible light by the image.

  When the radiation detection device 30 is activated, heat is generated from each circuit board disposed on the back side of the radiation detection panel 21. Part of the heat generated from each circuit board is transferred to the air inside the housing 22. Most of the heat generated in the circuit board moves to a lower temperature portion due to heat conduction, and generates a temperature distribution inside the housing 22 while creating a temperature difference due to thermal resistance. Heat generated from each circuit board and transmitted to the housing 22 is radiated from the outer surface of the housing 22 to the outside air.

  The heat generated from each circuit board flows into the support plate 81 directly or through an air layer. The heat flowing into the support plate 81 flows into the lower temperature radiation detection panel 21 through the shielding plate 20. However, in the present embodiment, since the support plate 81 is a CFRP member, it is transmitted to the radiation detection panel 21 as compared with the case where a support plate made of a material having higher thermal conductivity than CFRP such as metal is used. Heat can be reduced. Moreover, since CFRP has anisotropy in thermal conductivity, heat transfer from the circuit board group to the radiation detection panel 21 can be reduced. Further, the support plate 81 has a honeycomb structure inside, and has a substantially narrow heat conduction path compared to a solid structure. For this reason, the heat transfer to the radiation detection panel 21 can be made extremely small.

  Furthermore, when a heat insulating material (not shown) is disposed between the radiation detection panel 21 and the shielding plate 20, the thermal resistance between the circuit board group and the radiation detection panel 21 is further increased. As a result, the radiation detection panel 21 is thermally isolated from the circuit board group, and the rate at which the heat generated in the power supply circuit of the circuit board group reaches the radiation detection panel 21 is reduced.

  Further, since the heat capacities of the CFRP support plates 81 are relatively large, the heat transferred to these is distributed and flattened in the respective parts, so that the temperature changes gradually. Therefore, it is possible to reduce the possibility that the operating temperature of the radiation detection panel 21 is increased by the heat generated in the circuit board group without using a cooling device. Further, by suppressing a sharp temperature change, it is possible to suppress the occurrence of image unevenness in the X-ray image.

  CFRP can be reduced in weight while maintaining strength as compared to metal or the like. Moreover, by using a honeycomb structure, the material used can be reduced and the weight can be reduced while maintaining the strength. As a result, the support plate 81 is reduced in weight, and the radiation detection apparatus 30 as a whole is also reduced in weight.

  Thus, according to the present embodiment, the thermal influence from the circuit board to the radiation detection panel 21 is suppressed while maintaining the strength of each part of the radiation detection device 30 and reducing the weight of the radiation detection device 30 as a whole. can do.

[Second Embodiment]
FIG. 8 is a plan sectional view of the housing of the radiation detection apparatus according to the second embodiment. FIG. 9 is a side sectional view of the radiation detection apparatus according to the present embodiment.

  In the present embodiment, the housing 40 is formed by hollowing out the inside of a rectangular parallelepiped having a honeycomb structure to form an accommodation space 41 for accommodating the radiation detection panel 21, the circuit board, the flexible board 18, and the like. The housing 40 is formed of CFRP.

  The accommodation space 41 is cut out so as to correspond to the size of each component accommodated, such as the radiation detection panel 21, the analog circuit board 91, the digital circuit board 92, and the flexible board 18. In the present embodiment, the storage space 41 is formed integrally with a space for storing each component. However, the space for storing each component may be formed separately.

  More specifically, the housing 40 has two front plates 42 provided in parallel. An opening is formed in one of the front plates 42, and a radiation incident window 19 is attached so as to cover the opening.

  The outer periphery of the space between the two front plates 42 is partitioned by a cell wall 44 into a regular hexagonal columnar space 45. An accommodation space 41 is formed inside the outer peripheral portion filled with the columnar space 45. A rib 89 is provided on the opposite side of the accommodation space 41 with respect to the radiation incident window 19. The rib 89 protrudes toward the inside of the housing 40 from the surface plate 42 on the side opposite to the side where the radiation incident window 19 is formed. The ribs 89 are provided so as to divide the inner surface of the front plate 42 into the same regular hexagon as the cross section of the columnar space 45.

  Further, a pair of grip portions 43 are provided in the vicinity of the outer periphery of the housing 40. These grip portions 43 are provided for the user of the radiation detection apparatus 30 to grip and hold the apparatus.

  In the present embodiment, the housing 40 is made of CFRP, and a part thereof has a honeycomb structure. For this reason, compared with the case where the housing | casing 40 with the same intensity | strength is formed with a metal box, it can be made lightweight.

  Further, the columnar space 43 exists between the analog circuit board 91 and the digital circuit board 92 which are heat generating parts and the grip part 43 which is touched by the user's hand. Furthermore, the periphery of the grip part 43 is made of CFRP, which has a smaller thermal conductivity than metal or the like. For this reason, heat generated in the analog circuit board 91 and the digital circuit board 92 is not easily conducted to the grip portion 43. Therefore, the possibility that the temperature of the gripping portion 43 rises excessively is reduced, and the possibility of a user burn or a low temperature burn is reduced.

[Other embodiments]
Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 11 ... Glass substrate, 12 ... Image detection part, 13 ... Gate line, 14 ... Thin-film transistor, 15 ... Condenser, 17 ... Signal line, 18 ... Flexible substrate, 19 ... Radiation entrance window, 20 ... Shielding plate, 21 ... Radiation detection panel , 22 ... casing, 25 ... spacer, 30 ... radiation detector, 32 ... gate driver, 33 ... integration amplifier, 34 ... A / D converter, 35 ... row selection circuit, 36 ... image composition circuit, 37 ... X-ray 38 ... Fluorescent conversion film, 39 ... Photodiode, 40 ... Housing, 41 ... Accommodating space, 42 ... Front plate, 43 ... Grip portion, 44 ... Cell wall, 45 ... Columnar space, 61 ... Terminal group, 65 ... Moisture proof Body, 70 ... Pixel, 81 ... Support plate, 86 ... Front plate, 87 ... Cell wall, 88 ... Columnar space, 89 ... Rib, 91 ... Analog circuit board, 92 ... Digital circuit board, 94 ... Support member

Claims (8)

A flat radiation detection panel that detects radiation incident from the surface and outputs a two-dimensional radiation intensity distribution as an electrical signal;
A circuit board provided on the back side of the radiation detection panel and driving the radiation detection panel;
The plate is formed in a plate shape having a first surface that faces the radiation detection panel and supports the radiation detection panel, and a second surface that faces the circuit board and supports the circuit board. A support plate in which cylindrical cell walls extending toward the surface are arranged without gaps between the first surface and the second surface;
A radiation detection apparatus comprising:   The radiation detection apparatus according to claim 1, wherein the support member is formed of one of carbon fiber reinforced plastic and glass fiber reinforced plastic.   The radiation detection apparatus according to claim 1, wherein the support member includes a front plate facing the circuit board.   The radiation detection apparatus according to claim 3, wherein the front plate has a thermal conductivity smaller than that of the cell wall.   The radiation detection apparatus according to claim 1, wherein a surface of the support member facing the radiation detection panel has conductivity.   2. A housing having a peripheral portion of a honeycomb structure, and a housing space in which the radiation detection panel, the support plate, and the circuit board are accommodated is formed inside the peripheral portion. The radiation detector according to claim 5.   The radiation detector according to claim 6, wherein a grip portion is provided at the peripheral portion. A flat radiation detection panel that detects radiation incident from the surface and outputs a two-dimensional radiation intensity distribution as an electrical signal;
A circuit board provided on the back side of the radiation detection panel and driving the radiation detection panel;
A support plate formed in a plate shape having a first surface that supports the radiation detection panel and a second surface opposite to the first surface;
A support plate formed in a plate shape having a first surface that faces the radiation detection panel and supports the radiation detection panel, and a second surface that faces the circuit board and supports the circuit board;
A housing having a peripheral portion of the honeycomb structure, and a housing space in which the radiation detection panel, the support plate, and the circuit board are accommodated inside the peripheral portion;
A radiation detection apparatus comprising:

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