Detection Equipment

Abstract

To provide a radiation detection device which correctly acquires information about Compton scattering generated between a drift electrode and an electron detector.SOLUTION: A detection device for detecting radiation includes: a container 20 including a first portion 21, a second portion 22 facing the first portion 21 in a first direction, and a side portion 23 extending from the first portion 21 toward the second portion 22, where a gas is contained; an electron detector 30 located inside the container 20, which detects an electron generated by Compton scattering; a drift electrode 40 located inside the container 20 closer to the second portion than the electron detector 30 and facing the electron detector 30; a radiation detector 50 located closer to the second portion 22 than the drift electrode 40, which detects scattered radiation; and an auxiliary drift electrode having a plurality of ring electrodes which are arrayed along the direction in which the electron detector 30 faces the drift electrode 40 and a spacer which is located between the adjacent two ring electrodes.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE An embodiment of the present disclosure relates to a detection device for detecting radiation. [Background technology]

[0002] Known radiation detection devices that detect Compton scattered radiation and electrons generated by Compton scattering are disclosed in, for example, Patent Documents 1 to 3. The detection device includes a container that contains a gas, a drift electrode and an electron detector that face each other inside the container, and a radiation detector located outside the container. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 057674 Brochure [Patent Document 2] JP 2016-217874 A [Patent Document 3] JP 2016-161522 A Summary of the Invention

[0004] It is preferable to accurately obtain information regarding the Compton scattering that occurs between the drift electrode and the electron detector. Such information includes, for example, the position where the Compton scattering occurs, the trajectory of the recoil electrons generated by the Compton scattering, the energy of the Compton-scattered radiation, etc. However, depending on the arrangement of the drift electrode, the electron detector, and the radiation detector, it may not be possible to obtain this information accurately.

[0005] For example, in the detection devices of Patent Documents 1 to 3, radiation Compton-scattered inside the container passes through the electron detector, the container, and the air outside the container before entering the radiation detector. In this case, there is a possibility that mutual reactions occur between the radiation and the electron detector, the container, and the air outside the container. For example, it is considered that the radiation is photoelectrically absorbed, or that radiation having a different energy is generated. It is also considered that Compton scattering occurs in the electron detector, the container, and the air outside the container. When these phenomena occur, there are cases where the energy, position, etc. of the radiation detected by the radiation detector do not correspond to the Compton scattering that occurred between the drift electrode and the electron detector. This makes it easy for the detection results to vary and cause errors.

[0006] An object of the embodiments of the present disclosure is to provide a detection device that can effectively solve such problems.

[0007] One embodiment of the present disclosure is a detection device for detecting radiation, comprising: a container including a first portion, a second portion facing the first portion in a first direction, and a side portion extending from the first portion toward the second portion, the container containing a gas; an electron detector located inside the vessel for detecting electrons generated by Compton scattering; a drift electrode located inside the container on the second portion side of the electron detector and facing the electron detector; a radiation detector located on the second portion side of the drift electrode and detecting scattered radiation; an auxiliary drift electrode including a plurality of ring electrodes arranged along a direction in which the electron detector and the drift electrode face each other, and a spacer positioned between two adjacent ring electrodes; the radiation detector is located outside the container; The container is a detection device that comprises plastic and has a thickness of 30 mm or less, or comprises metal and has a thickness of 20 mm or less.

[0008] In the detection device according to one embodiment of the present disclosure, a distance between an inner surface of the first portion and the electron detector may be 10 mm or less.

[0009] One embodiment of the present disclosure is a detection device for detecting radiation, comprising: a container including a first portion, a second portion facing the first portion in a first direction, and a side portion extending from the first portion toward the second portion, the container containing a gas; an electron detector located inside the vessel for detecting electrons generated by Compton scattering; a drift electrode located inside the container on the first portion side of the electron detector and facing the electron detector; a radiation detector located closer to the second section than the electron detector and detecting scattered radiation; an auxiliary drift electrode including a plurality of ring electrodes arranged along a direction in which the electron detector and the drift electrode face each other, and a spacer positioned between two adjacent ring electrodes; the radiation detector is located outside the container; The container is a detection device that comprises plastic and has a thickness of 30 mm or less, or comprises metal and has a thickness of 20 mm or less.

[0010] A detection device according to one embodiment of the present disclosure may include an auxiliary drift electrode including a plurality of ring electrodes arranged along the direction in which the electron detector and the drift electrode face each other and a spacer positioned between two adjacent ring electrodes, and an intermediate substrate supporting the auxiliary drift electrode and the electron detector, wherein the drift electrode may be attached to the auxiliary drift electrode so as to face the electron detector, and the intermediate substrate may be disposed on the second part.

[0011] In the detection device according to one embodiment of the present disclosure, a distance between the inner surface of the first portion and the drift electrode may be not less than 10 mm and not more than 100 mm.

[0012] In a detection device according to one embodiment of the present disclosure, the first part may include an outer surface that extends flat in an area that overlaps the electron detector when viewed along the direction in which the electron detector and the drift electrode face each other.

[0013] In the detection device according to one embodiment of the present disclosure, the radiation detector may include a plurality of detection elements, and the drift electrode may include a plurality of through holes overlapping the detection elements in the first direction.

[0014] One embodiment of the present disclosure is a detection device for detecting radiation, comprising: a container including a first portion, a second portion facing the first portion in a first direction, and a side portion extending from the first portion toward the second portion, the container containing a gas; an electron detector located inside the vessel for detecting electrons generated by Compton scattering; a drift electrode located inside the container and facing the electron detector in a direction intersecting the first direction; a radiation detector that is closer to the second portion than to the first portion and detects scattered radiation.

[0015] In the detection device according to one embodiment of the present disclosure, the radiation detector may be located inside the container.

[0016] In the detection device according to one embodiment of the present disclosure, the radiation detector may be located outside the container.

[0017] A detection apparatus according to an embodiment of the present disclosure may include an electron amplifier located between the electron detector and the drift electrode and facing the electron detector and the drift electrode.

[0018] In a detection device according to one embodiment of the present disclosure, the electron detector may include a plurality of collecting electrodes, and the electron amplifier may include a substrate having a front surface and a back surface, and having a through hole formed therein that overlaps with the collecting electrode in a direction opposite to the drift electrode, a first electrode located on the front surface, and a second electrode located on the back surface.

[0019] In the detection device according to one embodiment of the present disclosure, the radiation detector may include a scintillator that is excited by the scattered radiation to emit fluorescence, and a photodetector that detects the fluorescence.

[0020] In the detection apparatus according to an embodiment of the present disclosure, the radiation detector may include a semiconductor detection element that detects the scattered radiation.

[0021] In the detection device according to one embodiment of the present disclosure, the side of the container may have a cylindrical shape.

[0022] The detection device according to an embodiment of the present disclosure may include a circulation path connected to the container, and a pump and a filter inserted in the circulation path.

[0023] According to the embodiments of the present disclosure, it is possible to improve the detection accuracy of a radiation detector. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a perspective view illustrating an example of a detection device according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the detection device of FIG. [Diagram 3] FIG. 2 is a perspective view showing an example of an electron detector. [Figure 4] FIG. 1 is a perspective view showing an example of a radiation detector. [Diagram 5] 2 is a diagram for explaining the operation of the detection device of FIG. 1. [Figure 6] FIG. 4 is a cross-sectional view showing a first modified example of the detection device according to the first embodiment. [Figure 7] FIG. 4 is a cross-sectional view showing a second modified example of the detection device according to the first embodiment. [Figure 8] FIG. 11 is a cross-sectional view showing a third modified example of the detection device according to the first embodiment. [Figure 9] FIG. 11 is a cross-sectional view showing a fourth modified example of the detection device according to the first embodiment. [Figure 10] FIG. 11 is a cross-sectional view showing a fifth modified example of the detection device according to the first embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing a sixth modified example of the detection device according to the first embodiment. [Figure 12] FIG. 11 is a perspective view illustrating an example of a detection device according to a second embodiment. [Figure 13] FIG. 13 is a cross-sectional view of the detection device of FIG. [Figure 14] 13 is a diagram for explaining the operation of the detection device of FIG. 12. [Figure 15] FIG. 11 is a perspective view illustrating an example of a detection device according to a third embodiment. [Figure 16] FIG. 16 is a cross-sectional view of the detection device of FIG. [Figure 17] 16 is a diagram for explaining the operation of the detection device of FIG. 15. [Figure 18] FIG. 11 is a cross-sectional view showing a first modified example of the detection device according to the third embodiment. [Figure 19] FIG. 11 is a cross-sectional view showing a second modified example of the detection device according to the third embodiment. [Figure 20] FIG. 11 is a cross-sectional view showing a modified example of the detection device according to the second embodiment. [Figure 21] FIG. 11 is a perspective view showing a container according to a first common modification example. [Figure 22] FIG. 11 is a cross-sectional view showing an example in which a container according to a first common modification is applied to the first embodiment. [Figure 23] FIG. 11 is a cross-sectional view showing an example in which a container according to a first common modification is applied to the first embodiment. [Figure 24] FIG. 11 is a cross-sectional view showing an example in which a container according to the first common modification is applied to the second embodiment. [Diagram 25]FIG. 11 is a cross-sectional view showing an example in which a container according to the first common modification is applied to the second embodiment. [Figure 26] FIG. 13 is a cross-sectional view showing an example in which a container according to the first common modification is applied to the third embodiment. [Figure 27] FIG. 13 is a cross-sectional view showing an example in which a container according to the first common modification is applied to the third embodiment. [Figure 28] FIG. 13 is a perspective view showing an auxiliary drift electrode according to a second common modification example. [Figure 29] FIG. 11 is a cross-sectional view showing an auxiliary drift electrode according to a second common modification example. [Diagram 30] FIG. 2 is a plan view showing an example of a ring electrode. [Diagram 31] FIG. 13 is a cross-sectional view showing an example in which an auxiliary drift electrode according to a second common modification is applied to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The following embodiments are examples of the present disclosure, and the present disclosure is not to be construed as being limited to these embodiments. In this specification, terms such as "substrate", "base material", "sheet" and "film" are not distinguished from each other based only on the difference in name. For example, "substrate" and "base material" are concepts that include members that can be called sheets and films. Furthermore, terms such as "parallel" and "orthogonal" and values ​​of length and angle that specify shapes and geometric conditions and their degrees, as used in this specification, are interpreted to include the range in which similar functions can be expected without being bound by strict meanings.

[0026] In the drawings referred to in this specification, the same parts or parts having similar functions are denoted by the same or similar reference numerals, and repeated explanations of them may be omitted. In addition, the dimensional ratios of the drawings may differ from the actual ratios for the convenience of explanation, and some components may be omitted from the drawings.

[0027] In this specification, when multiple upper limit candidates and multiple lower limit candidates are given for a certain parameter, the numerical range of the parameter may be formed by combining any one of the upper limit candidates and any one of the lower limit candidates. For example, consider a case where "parameter B is, for example, A1 or more, may be A2 or more, or may be A3 or more. Parameter B is, for example, A4 or less, may be A5 or less, or may be A6 or less." In this case, the numerical range of parameter B may be A1 or more and A4 or less, A1 or more and A5 or less, A1 or more and A6 or less, A2 or more and A4 or less, A2 or more and A5 or less, A2 or more and A6 or less, A3 or more and A4 or less, A3 or more and A5 or less, or A3 or more and A6 or less.

[0028] First embodiment Hereinafter, a configuration of a detection device 10 according to a first embodiment of the present disclosure will be described in detail with reference to the drawings. First, an overview of the detection device 10 will be described. Fig. 1 is a perspective view showing an example of the detection device 10. Fig. 2 is a cross-sectional view of the detection device 10 of Fig. 1.

[0029] (Detection device) The detection device 10 includes a container 20, an electron detector 30, a drift electrode 40, and a radiation detector 50 located inside the container 20. The container 20 is, for example, a chamber. At least a rare gas such as argon or xenon is contained inside the container 20. In addition to the rare gas, a quenching gas having a quenching effect such as carbon dioxide or methane may be contained inside the container 20.

[0030] The container 20 includes a first surface 21, a second surface 22 facing the first surface 21 in the first direction D1, and a side surface 23 extending from the first surface 21 toward the second surface 22. The detection device 10 is assumed to detect radiation entering the inside of the container 20 through the first surface 21. The container 20 may be placed so that the second surface 22 faces or contacts a surface such as a floor or a table. As shown in FIG. 1, the container 20 may have a cylindrical shape. That is, the side surface 23 may have a circular cross section. Although not shown, the container 20 may have a shape other than a cylindrical shape, for example, a cube or a rectangular parallelepiped shape. Although not shown, the first surface 21 may be curved so as to be convex toward the outside of the container 20.

[0031] The radiation-emitting object is located outside the container 20. The first surface 21 is the surface of the container that is closest to the object. In the following description, the first surface 21 is also referred to as the first portion 21. The second surface 22 is also referred to as the second portion 22. The side surface 23 is also referred to as the side portion 23.

[0032] The material of the container 20 is preferably one that easily transmits radiation. This can prevent the radiation from being absorbed or scattered by the container 20 while passing through the container 20. The container 20 may contain, for example, plastic or metal. The plastic may be fiber-reinforced plastic. When a metal is used, the container 20 may be composed of a single metal element or an alloy. As the metal, for example, aluminum or an aluminum alloy may be used. To reduce the weight of the container 20, a metal with a specific gravity of less than 4 may be used.

[0033] When the container 20 includes plastic, the thickness of the container 20 is, for example, 1 mm or more, may be 5 mm or more, or may be 10 mm or more. The thickness of the container 20 is, for example, 30 mm or less, may be 25 mm or less, or may be 20 mm or less.

[0034] When the container 20 contains a metal, the thickness of the container 20 is, for example, 2 mm or more, may be 3 mm or more, or may be 5 mm or more. The thickness of the container 20 is, for example, 20 mm or less, may be 15 mm or less, or may be 10 mm or less.

[0035] The electron detector 30, the drift electrode 40, and the radiation detector 50 are arranged in this order from the first section 21 toward the second section 22. That is, the drift electrode 40 is located closer to the second section 22 than the electron detector 30. The radiation detector 50 is located closer to the second section 22 than the drift electrode 40. "Component A is located closer to the second section 22 than component B" means that component A is located on the side indicated by the arrow S2 in FIG. 1 relative to component B. The arrow S2 represents the direction from the first section 21 toward the second section 22. The distance from component B to the second section 22 may be longer or shorter than the distance from component B to component A.

[0036] The electron detector 30 may be closer to the first section 21 than to the second section 22. The drift electrode 40 and the radiation detector 50 may be closer to the second section 22 than to the first section 21.

[0037] The electron detector 30, the drift electrode 40 and the radiation detector 50 will now be described in detail.

[0038] When radiation entering the inside of the container 20 collides with a gas, Compton scattering may occur. When Compton scattering occurs, recoil electrons are generated. In addition, ionized electrons are generated along the trajectory of the recoil electrons. The electron detector 30 detects the ionized electrons. By detecting the ionized electrons, the trajectory and energy of the recoil electrons can be calculated.

[0039] FIG. 3 is a perspective view showing an example of the electron detector 30. The electron detector 30 may include a plurality of collecting electrodes 31 and a support substrate 32 supporting the collecting electrodes 31. The collecting electrodes 31 face the drift electrode 40. The support substrate 32 includes a surface extending in a direction intersecting with the first direction D1. The collecting electrodes 31 detect ionized electrons attracted to the electron detector 30 by an electric field. The plurality of collecting electrodes 31 may be arranged in a direction intersecting with the first direction D1. For example, the support substrate 32 may include a surface extending in a direction perpendicular to the first direction D1. The plurality of collecting electrodes 31 may be arranged in a second direction D2 and a third direction D3 perpendicular to the first direction D1. The second direction D2 and the third direction D3 may be perpendicular to each other.

[0040] Collecting electrode 31 includes a material having electrical conductivity. Examples of materials that can be used for collecting electrode 31 include metals such as copper (Cu), gold (Au), silver (Ag), platinum (Pt), palladium (Pd), rhodium (Rh), tin (Sn), aluminum (Al), nickel (Ni), chromium (Cr), titanium (Ti), molybdenum (Mo), tungsten (W), and tantalum (Ta), as well as alloys using these metals. Preferably, metals having high electrical conductivity, such as copper (Cu), gold (Au), and silver (Ag), are used.

[0041] The electrons detected by the collecting electrode 31 are processed as an electric signal. The electron detector 30 may include a circuit, wiring, etc. for processing the electric signal. The electric signal may be transmitted to the outside of the container 20 via, for example, a cable, a hermetic connector, a wiring board, etc. (not shown) connected to the electron detector 30.

[0042] Although not shown, a plurality of electron detectors 30 may be arranged in the second direction D2 or the third direction D3, thereby expanding the area in which electrons can be detected.

[0043] The drift electrode 40 is disposed so as to face the electron detector 30. For example, the drift electrode 40 faces the electron detector 30 in a first direction D1. That is, the drift electrode 40 includes a surface extending in a direction perpendicular to the first direction D1. The drift electrode 40 has a lower potential than the potential of the collector electrode 31 of the electron detector 30. Therefore, as shown in FIG. 2, an electric field E1 is generated between the electron detector 30 and the drift electrode 40, which is directed from the electron detector 30 to the drift electrode 40. Ionization electrons accompanying recoil electrons generated by Compton scattering are attracted toward the electron detector 30 by the electric field E1.

[0044] The drift electrode 40 includes a conductive material. For example, the drift electrode 40 includes a metal with a specific gravity of less than 4, such as aluminum or an aluminum alloy. This makes it possible to suppress the influence of the drift electrode 40 on radiation passing through the drift electrode 40, compared to when the drift electrode 40 includes a metal with a high specific gravity.

[0045] The thickness of the drift electrode 40 is, for example, 0.01 mm or more, may be 0.1 mm or more, or may be 0.3 mm or more. The thickness of the drift electrode 40 is, for example, 2.0 mm or less, may be 1.0 mm or less, or may be 0.5 mm or less. The smaller the thickness of the drift electrode 40, the more the influence of the drift electrode 40 on the radiation passing through the drift electrode 40 can be suppressed.

[0046] The radiation detector 50 detects the scattered radiation. In the present embodiment, the radiation scattered between the electron detector 30 and the drift electrode 40 is detected by the radiation detector 50 after passing through the drift electrode 40. The radiation detector 50 can detect the position and energy of the radiation that reaches the radiation detector 50.

[0047] 4 is a perspective view showing an example of a radiation detector 50. The radiation detector 50 may include a plurality of detection elements 51 and a circuit board 52 supporting the detection elements 51. The plurality of detection elements 51 may be aligned in a direction intersecting the first direction D1. For example, the plurality of detection elements 51 may be aligned in a second direction D2 and a third direction D3 perpendicular to the first direction D1.

[0048] The detection element 51 may have any configuration as long as it can detect radiation. For example, the detection element 51 may include a scintillator that is excited by the scattered radiation to emit fluorescence, and a photodetector that detects the fluorescence. The photodetector may include, for example, an avalanche photodiode. The detector element 51 may include a semiconductor detector element for detecting the scattered radiation. The semiconductor detector element may comprise, for example, a semiconductor including cadmium zinc telluride.

[0049] The radiation detector 50 may include a first detection element 51 capable of detecting radiation having an energy within a first range, and a second detection element 51 capable of detecting radiation having an energy within a second range different from the first range. This allows the range of radiation energies that the radiation detector 50 can detect to be expanded.

[0050] The radiation detected by the detection element 51 is processed as an electronic signal by the circuit board 52. The circuit board 52 may include a circuit, wiring, etc. for processing the electrical signal. The electrical signal may be transmitted to the outside of the container 20 via, for example, a cable, a hermetic connector, a wiring board, etc. (not shown) connected to the circuit board 52.

[0051] The radiation detector 50 is electrically insulated from the drift electrode 40. For example, the distance K1 between the radiation detector 50 and the drift electrode 40 is set so as to ensure electrical insulation. A gas, an insulator, or the like may be located between the drift electrode 40 and the radiation detector 50. This makes it possible to suppress the occurrence of defects such as discharge between the drift electrode 40 and the radiation detector 50.

[0052] Although not shown, a plurality of radiation detectors 50 may be arranged in the second direction D2 or the third direction D3, thereby expanding the area in which radiation can be detected.

[0053] The electrical components located inside the container 20, such as the electron detector 30, the drift electrode 40, and the radiation detector 50, are preferably arranged so as to prevent defects such as discharge from occurring between the electrical components and the inner surface of the container 20. For example, the arrangement and potential of the electrical components are preferably determined so that the electric field generated between the electrical components located inside the container 20 and the inner surface of the container 20 is 2.5 kV / cm or less.

[0054] (Method of manufacturing the detection device) Next, an example of a method for manufacturing the detection device 10 will be described.

[0055] First, electrical components to be placed inside the container 20, such as the electron detector 30, the drift electrode 40, the radiation detector 50, the cable, and the connector, are prepared. Then, a first reduced pressure baking process is performed on these electrical components. For example, the inside of the container used in the process is controlled to an atmosphere at a pressure lower than atmospheric pressure, and the electrical components are heated inside the container. This makes it possible to suppress outgassing from the electrical components during use of the detection device 10. The pressure of the atmosphere is, for example, 0.1 atmosphere or less. During the reduced pressure baking process, the pressure may be maintained at 0.1 atmosphere or less by evacuating the inside of the container. The heating temperature is, for example, 60° C. or more, and may be 100° C. or more. The heating temperature may be 125° C. or less. The heating time may be 2 hours or more, or may be 12 hours or more. The first reduced pressure baking process may also be performed on the container 20 of the detection device 10 in the same manner.

[0056] Next, the electrical component that has been subjected to the first reduced pressure baking process is placed inside the container 20. Thereafter, the electrical component inside the container 20 may be subjected to a second reduced pressure baking process.

[0057] Preferably, electrical components such as the electron detector 30, drift electrode 40, radiation detector 50, cables, and connectors are made of components that are less likely to generate outgassing. For example, components that include hollow parts, such as aluminum electrolytic capacitors, are prone to generating outgassing. In consideration of this, it is preferable to use multilayer ceramic capacitors instead of aluminum electrolytic capacitors.

[0058] (Function of the detection device) Next, an example of the operation of the detection device 10 will be described with reference to Fig. 5. In Fig. 5, the container 20 is omitted.

[0059] In Fig. 5, the symbol R1 represents radiation that has passed through the first portion 21 of the container 20 and entered the inside of the container 20. The radiation R1 is, for example, a charged particle, a gamma ray, an X-ray, a neutron, or an ultraviolet light. After passing through the electron detector 30, the radiation R1 reaches the space between the electron detector 30 and the drift electrode 40. The symbol R2 represents radiation that has reached the space between the electron detector 30 and the drift electrode 40. Due to scattering and attenuation that occur when passing through the electron detector 30, the energy of the radiation R2 may be lower than the energy of the radiation R1.

[0060] When radiation R2 collides with the gas, Compton scattering may occur. Symbol P represents the position where scattering occurs. Position P is also referred to as the scattering point. Symbol R3 represents the scattered radiation. After passing through the drift electrode 40, radiation R3 reaches the radiation detector 50. Symbol R4 represents the radiation that reaches the radiation detector 50. Due to scattering and attenuation that occurs when passing through the drift electrode 40, the energy of radiation R4 may be lower than the energy of radiation R3. Radiation R4 is detected by one of the multiple detection elements 51. This allows the arrival position and energy of radiation R4 to be calculated.

[0061] Reference R5 denotes a recoil electron generated by Compton scattering. An electron cloud is formed in the trajectory of the recoil electron R5. Each electron in the electron cloud is attracted toward the electron detector 30 by the electric field E1. For example, as shown in FIG. 5, electrons e1 and e2, which are generated in sequence along the trajectory of the recoil electron R5, are attracted toward the electron detector 30. The electrons e1 and e2 are detected by a collector electrode 31 corresponding to the positions of the electrons e1 and e2. This makes it possible to calculate the positions and energies of the electrons e1 and e2. In addition, the trajectory and energy of the recoil electron R5, as well as the scattering point P, can be calculated.

[0062] In this embodiment, as described above, the radiation detector 50 is located inside the container 20. Therefore, compared to a case where the radiation detector 50 is located outside the container 20, scattering, attenuation, and the like of the radiation can be suppressed before it reaches the radiation detector 50. Therefore, information about the radiation R3 scattered in the space between the electron detector 30 and the drift electrode 40 can be obtained more accurately.

[0063] Moreover, in this embodiment, the radiation detector 50 faces the drift electrode 40. If the drift electrode 40 is thin and the specific gravity of the metal constituting the drift electrode 40 is small, the radiation passing through the drift electrode 40 is less affected by the drift electrode 40. This also contributes to reducing the difference between the energy of the radiation R4 reaching the radiation detector 50 and the energy of the scattered radiation R3. It also contributes to reducing the difference between the radiation dose of the radiation R4 reaching the radiation detector 50 and the radiation dose of the scattered radiation R3. Therefore, information about the scattered radiation R3 can be obtained more accurately.

[0064] This embodiment is particularly useful when the energies of the radiation R1, R2 before being scattered are unknown.

[0065] Various modifications can be made to the first embodiment described above. Below, the modified examples will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the first embodiment will be used for parts that can be configured similarly to the first embodiment, and duplicated descriptions will be omitted. Also, if it is clear that the effects obtained in the first embodiment can also be obtained in the modified examples, the description may be omitted.

[0066] (First Modification) 6 is a cross-sectional view showing a detection device 10 according to a first modification. The detection device 10 may include an electron amplifier 60 located between the electron detector 30 and the drift electrode 40. The electron amplifier 60 is disposed so as to face the electron detector 30 and the drift electrode 40 in, for example, a first direction D1.

[0067] The electron amplifier 60 is configured to generate electron avalanche amplification. For example, the electron amplifier 60 includes a substrate 63 including a front surface 631 and a rear surface 632, a first electrode 61 located on the front surface 631, and a second electrode 62 located on the rear surface 632. The first electrode 61 faces the electron detector 30. The second electrode 62 faces the drift electrode 40. The substrate 63 is formed with a plurality of through holes 64 penetrating from the front surface 631 to the rear surface 632. As shown in FIG. 6, the through holes 64 overlap with the collecting electrodes 31 of the electron detector 30 in a direction facing the drift electrode 40, for example, in a first direction D1. A plurality of collecting electrodes 31 may overlap one through hole 64.

[0068] The potential of the second electrode 62 is higher than the potential of the drift electrode 40. Therefore, an electric field E2 is generated between the second electrode 62 and the drift electrode 40, from the second electrode 62 to the drift electrode 40. The potential of the first electrode 61 is higher than the potential of the second electrode 62. Therefore, an electric field E3 is generated between the first electrode 61 and the second electrode 62, from the first electrode 61 to the second electrode 62.

[0069] Consider the case where Compton scattering of the radiation incident on the inside of the vessel 20 from the first section 21 occurs between the electron amplifier 60 and the drift electrode 40. Electrons in the electron cloud formed in the trajectory of the recoil electron are attracted toward the electron amplifier 60 by the electric field E2.

[0070] The electrons attracted to the electron amplifier 60 collide with the gas and ionize the gas. The ionized electrons are amplified in an avalanche manner inside the through-hole 64 and are attracted as an electron group toward the first electrode 61. The electrons that have passed through the through-hole 64 are detected by the collecting electrode 31. According to this modification, the amount of electrons to be measured is increased by using the electron amplifier 60. Therefore, the position of the electrons can be detected with higher accuracy.

[0071] (Second Modification) 7 is a cross-sectional view showing a detection device 10 according to a second modification. The detection device 10 may include an auxiliary drift electrode 70 located between the electron detector 30 and the drift electrode 40. The auxiliary drift electrode 70 includes a surface 71 extending in a direction in which the electron detector 30 and the drift electrode 40 face each other. For example, the surface 71 extends in a first direction D1.

[0072] The auxiliary drift electrode 70 is provided to enhance the uniformity of the distribution of the electric field between the electron detector 30 and the drift electrode 40. The auxiliary drift electrode 70 may surround the space between the electron detector 30 and the drift electrode 40. Although not shown, the auxiliary drift electrode 70 may include a plurality of electrodes arranged along the first direction D1. For example, the auxiliary drift electrode 70 may have a so-called cage-like structure in which the space between the electron detector 30 and the drift electrode 40 is surrounded by a plurality of electrodes. The auxiliary drift electrode 70 may be fixed by a material such as an insulating resin.

[0073] The auxiliary drift electrode 70 includes a conductive material, similar to the drift electrode 40. For example, the auxiliary drift electrode 70 may include a metal having a specific gravity of less than 4, such as aluminum.

[0074] (Third Modification) Fig. 8 is a cross-sectional view showing a detection device 10 according to a third modified example. As shown in Fig. 8, the radiation detector 50 may be located outside the container 20. For example, the radiation detector 50 may be located outside the second section 22. The radiation detector 50 may face the drift electrode 40 with the second section 22 interposed therebetween.

[0075] According to this modification, by disposing the radiation detector 50 outside the container 20, it is possible to prevent outgassing from the radiation detector 50 from affecting the environment inside the container 20. This makes it possible, for example, to increase the density of the electron cloud formed in the trajectory of the recoil electrons R5. Furthermore, when an electron amplifier 60 is provided inside the container 20, it is possible to further promote the amplification of electrons by the electron amplifier 60.

[0076] In this modification, radiation R3 scattered in the space between the electron detector 30 and the drift electrode 40 passes through the drift electrode 40 and the second part 22 of the container 20, and then reaches the radiation detector 50. In order to suppress scattering, attenuation, and the like of radiation in the second part 22, it is preferable that the thickness of the second part 22 is small.

[0077] (Fourth Modification) 9 is a cross-sectional view showing a detection device 10 according to a fourth modified example. The detection device 10 may include an adsorbent 81 located inside the container 20. The adsorbent 81 can adsorb outgassing generated from electrical components located inside the container 20. For example, the adsorbent 81 can adsorb water vapor, oxygen, and the like. The adsorbent 81 is, for example, a getter material of an active metal such as titanium or zirconium or an alloy, an adsorption material such as zeolite or silica gel, or a getter pump.

[0078] The adsorbent 81 is preferably disposed in a position where it does not interfere with radiation. For example, the adsorbent 81 may be disposed on the side 23 of the container 20.

[0079] (Fifth Modification) 10 is a cross-sectional view showing a detection device 10 according to a fifth modified example. The detection device 10 may include a device for removing outgassing generated from an electrical component located inside the container 20. For example, the detection device 10 may include a circulation path 82 connected to the container 20, and a pump 83 and a filter 84 inserted in the circulation path 82.

[0080] Pump 83 draws the gas inside container 20 into circulation path 82. Filter 84 removes unnecessary components such as water vapor and oxygen from the gas drawn into circulation path 82. The gas from which the unnecessary components have been removed is returned to the inside of container 20.

[0081] (Sixth Modification) Fig. 11 is a cross-sectional view showing a detection device 10 according to a sixth modified example. As shown in Fig. 11, the drift electrode 40 may include a plurality of through holes 41. The through holes 41 may overlap with the detection elements 51 in the direction in which the drift electrode 40 and the radiation detector 50 face each other, for example, in the first direction D1.

[0082] In this modification, part of the radiation R3 scattered by Compton scattering passes through the through-holes 41 of the drift electrode 40 and then reaches the radiation detector 50. This makes it possible to suppress scattering, attenuation, and the like of the radiation in the drift electrode 40 compared to when the radiation passes through the drift electrode 40. This makes it possible to obtain more accurate information about the scattered radiation R3.

[0083] Although several modified examples of the first embodiment have been described above, it is of course possible to apply a plurality of modified examples in appropriate combination.

[0084] Second embodiment Next, a second embodiment of the present disclosure will be described. In the second embodiment, the same parts as those in the first embodiment are given the same reference numerals and detailed description will be omitted. In addition, if it is clear that the effects obtained in the first embodiment can also be obtained in this embodiment, the description may be omitted.

[0085] FIG. 12 is a perspective view showing an example of the detection device 10. FIG. 13 is a cross-sectional view of the detection device 10 of FIG. 12. The detection device 10 includes a container 20, a drift electrode 40, an electron detector 30, and a radiation detector 50 located inside the container 20. The drift electrode 40, the electron detector 30, and the radiation detector 50 are arranged in this order from the first part 21 toward the second part 22. That is, the drift electrode 40 is located closer to the first part 21 than the electron detector 30. The radiation detector 50 is located closer to the second part 22 than the electron detector 30. "The component A is located closer to the first part 21 than the component B" means that the component A is located on the side indicated by the arrow S1 in FIG. 12 with respect to the component B. The arrow S1 indicates the direction from the second part 22 toward the first part 21. The distance from the component B to the first part 21 may be longer or shorter than the distance from the component B to the component A.

[0086] The drift electrode 40 may be closer to the first section 21 than to the second section 22. The electron detector 30 and the radiation detector 50 may be closer to the second section 22 than to the first section 21.

[0087] The radiation detector 50 is electrically insulated from the electron detector 30. For example, a distance K2 between the radiation detector 50 and the electron detector 30 is set so as to ensure electrical insulation. A gas, an insulator, or the like may be located between the electron detector 30 and the radiation detector 50. This makes it possible to suppress the occurrence of defects such as discharge between the electron detector 30 and the radiation detector 50.

[0088] (Function of the detection device) Next, an example of the operation of the detection device 10 will be described with reference to Fig. 14. In Fig. 14, the container 20 is omitted.

[0089] The radiation R1 incident on the inside of the container 20 passes through the drift electrode 40 and then reaches the space between the electron detector 30 and the drift electrode 40. The symbol R2 represents the radiation that has reached the space between the electron detector 30 and the drift electrode 40. Due to scattering and attenuation that occurs when passing through the drift electrode 40, the energy of the radiation R2 may be lower than the energy of the radiation R1.

[0090] The radiation R3 scattered in the space between the electron detector 30 and the drift electrode 40 passes through the electron detector 30 and then reaches the radiation detector 50. The symbol R4 represents the radiation that reaches the radiation detector 50. Due to scattering and attenuation that occurs when passing through the electron detector 30, the energy of the radiation R4 may be lower than the energy of the radiation R3. The radiation R4 is detected by one of the multiple detection elements 51. This makes it possible to calculate the arrival position and energy of the radiation R4.

[0091] Each electron in the electron cloud formed in the trajectory of the recoil electron R5 is attracted toward the electron detector 30 by the electric field E1. For example, electrons e1 and e2 are detected by the collector electrode 31 corresponding to the positions of the electrons e1 and e2. This allows the positions and energies of the electrons e1 and e2 to be calculated. In addition, the trajectory and energy of the recoil electron R5, as well as the scattering point P, can be calculated.

[0092] In the present embodiment, as in the first embodiment, the radiation detector 50 is located inside the container 20. Therefore, scattering and attenuation of the radiation before it reaches the radiation detector 50 can be suppressed compared to when the radiation detector 50 is located outside the container 20. Therefore, information about the radiation R3 scattered in the space between the electron detector 30 and the drift electrode 40 can be obtained more accurately.

[0093] In addition, in this embodiment, the drift electrode 40 is located closer to the first section 21 than the electron detector 30. When the drift electrode 40 contains a metal with a low specific gravity, the radiation passing through the drift electrode 40 is less affected by the drift electrode 40. Therefore, the rate of energy reduction of the radiation R2 reaching the space between the electron detector 30 and the drift electrode 40 is smaller than when the electron detector 30 is located closer to the first section 21 than the drift electrode 40. In other words, the rate of the difference between the energy of the radiation R1 incident on the container 20 and the energy of the radiation R2 reaching the space between the electron detector 30 and the drift electrode 40 relative to the radiation R1 is smaller. Also, the difference between the radiation dose of the radiation R1 and the radiation dose of the radiation R2 is smaller. Therefore, the probability that the expected Compton scattering occurs in the space between the electron detector 30 and the drift electrode 40 can be increased. Furthermore, by reducing the rate of energy reduction of the radiation R2, the probability that the scattered radiation R3 expected as a measurement value moves toward the second section 22 can be increased.

[0094] On the other hand, in the present embodiment, the scattered radiation R3 reaches the radiation detector 50 after passing through the electron detector 30. Therefore, compared to the first embodiment, the scattered radiation is more likely to be scattered and attenuated before it reaches the radiation detector 50. Taking this into consideration, when radiation having energy that is clearly smaller than the expected energy is detected, the radiation detector 50 may ignore this information. This makes it possible to prevent an erroneous calculation of the scattering point P.

[0095] This embodiment is particularly useful when the types of radiation R1 and R2 before scattering are known. According to this embodiment, by increasing the probability that the expected Compton scattering occurs in the space between the electron detector 30 and the drift electrode 40, information on the amount, distribution, etc. of radiation can be efficiently obtained.

[0096] Various modifications can be made to the second embodiment described above. For example, as in the first modification of the first embodiment, the detection device 10 may include an electron amplifier 60 located between the electron detector 30 and the drift electrode 40. As in the second modification of the first embodiment, the detection device 10 may include an auxiliary drift electrode 70 located between the electron detector 30 and the drift electrode 40. As in the fourth modification of the first embodiment, the detection device 10 may include an adsorbent 81 located inside the container 20. As in the fifth modification of the first embodiment, the detection device 10 may include a device for removing outgassing from electrical components located inside the container 20. As in the sixth modification of the first embodiment, the drift electrode 40 may include a plurality of through holes 41.

[0097] As in the third modified example of the first embodiment, the radiation detector 50 may be located outside the container 20. For example, as shown in Fig. 20, the radiation detector 50 may be located outside the second section 22. The radiation detector 50 may face the electron detector 30 with the second section 22 in between.

[0098] Although several modified examples of the second embodiment have been described above, it is of course possible to apply a plurality of modified examples in appropriate combination.

[0099] Third embodiment Next, a third embodiment of the present disclosure will be described. In the third embodiment, the same parts as those in the first embodiment are given the same reference numerals and detailed descriptions are omitted. In addition, if it is clear that the effects obtained in the first embodiment can also be obtained in this embodiment, the description may be omitted.

[0100] Fig. 15 is a perspective view showing an example of the detection device 10. Fig. 16 is a cross-sectional view of the detection device 10 of Fig. 15. The detection device 10 includes a container 20, an electron detector 30, a drift electrode 40, and a radiation detector 50 located inside the container 20.

[0101] The electron detector 30 and the drift electrode 40 face each other in a direction intersecting the first direction D1. For example, the electron detector 30 and the drift electrode 40 may face each other in a second direction D2 perpendicular to the first direction D1.

[0102] The radiation detector 50 detects radiation scattered in the space between the electron detector 30 and the drift electrode 40. The radiation detector 50 may be closer to the second section 22 than to the first section 21. In the example shown in Fig. 15 and Fig. 16, the radiation detector 50 does not overlap the electron detector 30 and the drift electrode 40 in the second direction D2. Although not shown, the radiation detector 50 may overlap the electron detector 30 and the drift electrode 40 in the second direction D2.

[0103] (Function of the detection device) Next, an example of the operation of the detection device 10 will be described with reference to Fig. 17. In Fig. 17, the container 20 is omitted.

[0104] Radiation R1 entering the inside of the container 20 from the first portion 21 reaches the space between the electron detector 30 and the drift electrode 40. Symbol R2 represents the radiation that has reached the space between the electron detector 30 and the drift electrode 40.

[0105] The radiation R3 scattered in the space between the electron detector 30 and the drift electrode 40 reaches the radiation detector 50. The symbol R4 represents the radiation that reaches the radiation detector 50.

[0106] Each electron in the electron cloud formed in the trajectory of the recoil electron R5 is attracted toward the electron detector 30 by the electric field E1. For example, electrons e1 and e2 are detected by the collector electrode 31 corresponding to the positions of the electrons e1 and e2. This allows the positions and energies of the electrons e1 and e2 to be calculated. In addition, the trajectory and energy of the recoil electron R5, as well as the scattering point P, can be calculated.

[0107] In the present embodiment, as in the first embodiment, the radiation detector 50 is located inside the container 20. Therefore, scattering and attenuation of the radiation before it reaches the radiation detector 50 can be suppressed compared to when the radiation detector 50 is located outside the container 20. Therefore, information about the radiation R3 scattered in the space between the electron detector 30 and the drift electrode 40 can be obtained more accurately.

[0108] In addition, in this embodiment, the radiation R1 incident on the inside of the container 20 can reach the space between the electron detector 30 and the drift electrode 40 without passing through electrical components such as the electron detector 30 and the drift electrode 40. Therefore, unlike the cases of the first and second embodiments described above, the energy and radiation amount of the radiation R1 incident on the container 20 are equivalent to the energy and radiation amount of the radiation R2 reaching the space between the electron detector 30 and the drift electrode 40. Therefore, it is possible to increase the probability that the expected Compton scattering occurs in the space between the electron detector 30 and the drift electrode 40. In addition, since the radiation R2 is equivalent to the radiation R1, it is possible to increase the probability that the scattered radiation R3 expected as a measurement value travels toward the second section 22.

[0109] Furthermore, in this embodiment, the radiation R3 scattered in the space between the electron detector 30 and the drift electrode 40 can reach the radiation detector 50 without passing through electrical components such as the electron detector 30 and the drift electrode 40. Therefore, unlike the cases of the first and second embodiments described above, the energy and radiation amount of the scattered radiation R3 are equivalent to the energy and radiation amount of the radiation R4 that reaches the radiation detector 50. Therefore, more accurate information on the scattered radiation R3 can be obtained.

[0110] Various modifications can be made to the above-mentioned third embodiment. Below, the modified examples will be described with reference to the drawings as necessary. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the first embodiment will be used for parts that can be configured similarly to the third embodiment, and duplicated descriptions will be omitted. Also, if it is clear that the effects obtained in the third embodiment can also be obtained in the modified example, the description may be omitted.

[0111] (First Modification) 18 is a cross-sectional view showing a detection device 10 according to a first modified example. The detection device 10 may include an electron amplifier 60 located between the electron detector 30 and the drift electrode 40. The electron amplifier 60 is disposed to face the electron detector 30 and the drift electrode 40 in, for example, the second direction D2. By using the electron amplifier 60, the amount of electrons to be measured increases. Therefore, the position of the electrons can be detected with higher accuracy.

[0112] (Second Modification) Fig. 19 is a cross-sectional view showing a detection device 10 according to a third modified example. As shown in Fig. 19, the radiation detector 50 may be located outside the container 20. For example, the radiation detector 50 may be located outside the second section 22. The radiation detector 50 may face the second section 22.

[0113] According to this modification, by disposing the radiation detector 50 outside the container 20, it is possible to prevent outgassing from the radiation detector 50 from affecting the environment inside the container 20. This makes it possible, for example, to increase the density of the electron cloud formed in the trajectory of the recoil electrons R5. Furthermore, when an electron amplifier 60 is provided inside the container 20, it is possible to further promote the amplification of electrons by the electron amplifier 60.

[0114] (Other variations) As in the second modification of the first embodiment, the detection device 10 may include an auxiliary drift electrode 70 located between the electron detector 30 and the drift electrode 40. As in the fourth modification of the first embodiment, the detection device 10 may include an adsorbent 81 located inside the container 20. As in the fifth modification of the first embodiment, the detection device 10 may include a device for removing outgassing from electrical components located inside the container 20. As in the sixth modification of the first embodiment, the drift electrode 40 may include a plurality of through holes 41.

[0115] Although several modified examples of the third embodiment have been described above, it is of course possible to apply a plurality of modified examples in appropriate combination.

[0116] Next, a common modification will be described. The common modification can be applied to any of the first, second and third embodiments.

[0117] (First common modification example) Fig. 21 is a perspective view showing a container 20 according to the first common modified example. As shown in Fig. 21, the container 20 may include a first portion 21, a side portion 23, and a corner 24 located between the first portion 21 and the side portion 23. The first portion 21 may extend flat. The corner 24 may include a surface that extends in a direction different from the first portion 21 and the side portion 23.

[0118] 22 is a cross-sectional view showing an example in which a container 20 according to the first common modification is applied to the first embodiment. The first part 21 includes an outer surface 211 and an inner surface 212. The outer surface 211 may face an object 5. The object 5 emits radiation. The detection device 10 can detect radiation that passes through the first part 21 and enters the inside of the container 20.

[0119] As shown in FIG. 22, the outer surface 211 may be flat. Preferably, the outer surface 211 is flat in a range F1. For example, the difference between the positions of points P1 and P2 in the facing direction is 10 mm or less. This allows the distance from the object 5 to the electron detector 30 to be shortened. This allows the measurement resolution to be improved. The range F1 is a range that overlaps with the electron detector 30 when viewed along the direction in which the electron detector 30 and the drift electrode 40 face each other (hereinafter also referred to as the facing direction). When viewed along the facing direction, the point P1 on the outer surface 211 overlaps with the center point of the electron detector 30. When viewed along the facing direction, the point P2 on the outer surface 211 overlaps with the end of the electron detector 30.

[0120] The symbol K3 represents the distance between the electron detector 30 and the inner surface 212 of the first part 21 in the facing direction. By shortening the distance K3, the distance from the object 5 to the electron detector 30 can be shortened. The distance K3 is, for example, 10 mm or less, may be 5 mm or less, or may be 2 mm or less. The distance K3 may be 0 mm. That is, the electron detector 30 may be in contact with the inner surface 212.

[0121] 22, the inner surface 212 may be flat and extend outward, thereby reducing the distance K3 across the entire area of ​​the electron detector 30.

[0122] 22, the corners 24 may be curved so as to protrude toward the outside of the container 20. This can increase the rigidity of the container 20.

[0123] Fig. 23 is a cross-sectional view showing another example in which the container 20 according to the first common modification is applied to the first embodiment. As shown in Fig. 23, the radiation detector 50 may be located outside the second section 22. The radiation detector 50 may face the drift electrode 40 with the second section 22 interposed therebetween.

[0124] FIG. 24 is a cross-sectional view showing an example in which the container 20 according to the first common modification is applied to the second embodiment. Preferably, the outer surface 211 spreads flatly in the range F2. For example, the difference between the position of the point P3 and the position of the point P4 in the facing direction is 10 mm or less. This allows the distance from the object 5 to the drift electrode 40 to be shortened. Therefore, the measurement resolution can be improved. The range F2 is a range that overlaps with the drift electrode 40 when viewed along the facing direction. The point P3 on the outer surface 211 overlaps with the center point of the drift electrode 40 when viewed along the facing direction. The point P4 on the outer surface 211 overlaps with the end of the drift electrode 40 when viewed along the facing direction.

[0125] The symbol K4 represents the distance between the drift electrode 40 and the inner surface 212 of the first part 21. By shortening the distance K4, the distance from the object 5 to the drift electrode 40 can be shortened. The distance K4 is, for example, 100 mm or less, and may be 70 mm or less, or may be 50 mm or less. On the other hand, if the drift electrode 40 comes into contact with the inner surface 212, the drift electrode 40 is electrically connected to the container 20. Therefore, it is preferable to maintain the distance K4 at a constant value or more, or to place an insulator between the drift electrode 40 and the inner surface 212. The distance K4 is, for example, 10 mm or more, and may be 20 mm or more, or may be 30 mm or more.

[0126] Fig. 25 is a cross-sectional view showing another example in which the container 20 according to the first common modification is applied to the second embodiment. As shown in Fig. 25, the radiation detector 50 may be located outside the second section 22. The radiation detector 50 may face the electron detector 30 with the second section 22 in between.

[0127] FIG. 26 is a cross-sectional view showing an example in which the container 20 according to the first common modification is applied to the third embodiment. Preferably, the outer surface 211 spreads flatly in the range F3. For example, the difference between the position of the point P5 and the position of the point P6 in the surface direction of the side portion 23 is 10 mm or less. This allows the distance between the space between the electron detector 30 and the drift electrode 40 (hereinafter also referred to as the facing space) and the object 5 to be shortened. Therefore, the measurement resolution can be improved. The range F3 is a range that overlaps with the facing space when viewed along the surface direction of the side portion 23. The point P5 on the outer surface 211 overlaps with the center point of the facing space when viewed along the surface direction of the side portion 23. The point P6 on the outer surface 211 overlaps with the surface of the electron detector 30 facing the drift electrode 40 or the surface of the drift electrode 40 facing the electron detector 30 when viewed along the surface direction of the side portion 23.

[0128] Fig. 27 is a cross-sectional view showing another example in which the container 20 according to the first common modification is applied to the third embodiment. As shown in Fig. 27, the radiation detector 50 may be located outside the second section 22. The radiation detector 50 may face the second section 22.

[0129] (Second common modification) 28 and 29 are a perspective view and a cross-sectional view showing an auxiliary drift electrode 70 according to a second common modification. The auxiliary drift electrode 70 may include a plurality of ring electrodes 72. The plurality of ring electrodes 72 are arranged in the opposing direction. The ring electrode 72 includes a first ring surface 73 facing the drift electrode 40 and a second ring surface 74 located on the opposite side of the first ring surface 73.

[0130] FIG. 30 is a plan view showing the ring electrode 72. An opening 721 is formed in the ring electrode 72. The opening 721 overlaps with the electron detector 30 in the facing direction. The ring electrode 72 does not have to overlap with the electron detector 30 in the facing direction. The ring electrode 72 may overlap with the drift electrode 40 in the facing direction. The ring electrode 72 has a width W1 in a plan view. The width W1 is, for example, 5 mm or more, may be 6 mm or more, or may be 8 mm or more. The width W1 is, for example, 30 mm or less, may be 25 mm or less, or may be 20 mm or less. The width W1 is the difference between the radius R11 of the circle constituting the outer edge of the ring electrode 72 and the radius R12 of the circle constituting the inner edge of the ring electrode 72.

[0131] The ring electrode 72 may be made of a conductive wire. For example, a wire having a first end and a second end is first prepared. The wire is then deformed into a circular or polygonal shape, and the first end and the second end are connected. This results in the ring electrode 72. In this case, the width W1 of the ring electrode 72 corresponds to the cross-sectional dimension of the wire. For example, if the cross-section of the wire is circular, the width W1 of the ring electrode 72 is equal to the diameter of the cross-section of the wire. The material of the wire is, for example, a metal.

[0132] The auxiliary drift electrode 70 may include a spacer 75 disposed between two adjacent ring electrodes 72 in the facing direction. The spacer 75 determines a distance K5 between the two adjacent ring electrodes 72 in the facing direction. The distance K5 is determined according to the number of ring electrodes 72, the voltage between the electron detector 30 and the drift electrode 40, and the like. The distance K5 is, for example, 2 mm or more, may be 5 mm or more, or may be 8 mm or more. The distance K5 is, for example, 30 mm or less, may be 20 mm or less, or may be 15 mm or less.

[0133] The drift electrode 40 may be attached to an auxiliary drift electrode 70. For example, the auxiliary drift electrode 70 may include a spacer 75 located between the drift electrode 40 and a ring electrode 72. The structure including the drift electrode 40 and the plurality of ring electrodes 72 may also be referred to as a drift cage 45.

[0134] As shown in FIG. 29, the auxiliary drift electrode 70 may include a wiring 76 that electrically connects two adjacent ring electrodes 72 in the facing direction. The auxiliary drift electrode 70 may include a wiring 76 that electrically connects the drift electrode 40 and the ring electrode 72 adjacent in the facing direction. The auxiliary drift electrode 70 may include a resistor 77 inserted in the path of the wiring 76. By electrically connecting two adjacent ring electrodes 72, the voltage between the two ring electrodes 72 can be adjusted. This allows the potential of the ring electrodes 72 arranged in the facing direction to be changed in stages. For example, it is assumed that the potential of the drift electrode 40 is −4000V, the potential of the electron detector 30 is 0V, and 20 ring electrodes 72 are arranged between the drift electrode 40 and the electron detector 30. In this case, the potential of the multiple ring electrodes 72 arranged from the drift electrode 40 toward the electron detector 30 can be changed in stages such as −3800V, −3600V, −3400V, . . . This makes it possible to improve the uniformity of the electric field formed in the space between the drift electrode 40 and the electron detector 30.

[0135] The voltage between two adjacent ring electrodes 72 in the facing direction is, for example, 50 V or more, may be 100 V or more, or may be 150 V or more. The voltage between two adjacent ring electrodes 72 in the facing direction is, for example, 500 V or less, may be 400 V or less, or may be 300 V or less.

[0136] 29 , the auxiliary drift electrode 70 may be supported by an intermediate substrate 90. The intermediate substrate 90 may support the electron detector 30. For example, the intermediate substrate 90 may include a first substrate 91 that supports the electron detector 30 and a second substrate 92 that supports the auxiliary drift electrode 70. The second substrate 92 may be located between the first substrate 91 and the auxiliary drift electrode 70. When the detection device 10 includes an electron amplifier 60, the electron amplifier 60 may also be supported by the intermediate substrate 90.

[0137] 31 is a cross-sectional view showing an example in which the auxiliary drift electrode 70 according to the second common modification is applied to the second embodiment. The radiation detector 50 may be located outside the container 20. In this case, the relay substrate 90 may be disposed on the second part 22. By supporting the auxiliary drift electrode 70 using the relay substrate 90 in the second part 22, the drift electrode 40 can be opposed to the first part 21 without being fixed to the first part 21.

[0138] 31 , the relay substrate 90 may include a third substrate 93 extending from the inside to the outside of the container 20. The relay substrate 90 may include a wire 95 electrically connecting the electron detector 30 and the first substrate 91. An electrical signal of the electron detector 30 is transmitted to the outside of the container 20 via the wire 95, the first substrate 91, and the third substrate 93.

[0139] (Other Aspects) Another aspect of the present disclosure is a detection device for detecting radiation, comprising: a container including a first portion, a second portion facing the first portion in a first direction, and a side portion extending from the first portion toward the second portion, the container containing a gas; an electron detector located inside the vessel for detecting electrons generated by Compton scattering; a drift electrode located inside the container on the second portion side of the electron detector and facing the electron detector; a radiation detector located closer to the second portion than the drift electrode and configured to detect scattered radiation.

[0140] In the detection device according to another aspect of the present disclosure, the radiation detector may be located inside the container.

[0141] In a detection apparatus according to another aspect of the present disclosure, the radiation detector may be located outside the container.

[0142] In a detection device according to another aspect of the present disclosure, the first part may include a flat outer surface that extends in an area that overlaps the electron detector when viewed along the direction in which the electron detector and the drift electrode face each other.

[0143] In the detection device according to another aspect of the present disclosure, the distance between the inner surface of the first portion and the electron detector may be 10 mm or less.

[0144] Another aspect of the present disclosure is a detection device for detecting radiation, comprising: a container including a first portion, a second portion facing the first portion in a first direction, and a side portion extending from the first portion toward the second portion, the container containing a gas; an electron detector located inside the vessel for detecting electrons generated by Compton scattering; a drift electrode located inside the container on the first portion side of the electron detector and facing the electron detector; The detection device further comprises a radiation detector located closer to the second part than the electron detector and configured to detect scattered radiation.

[0145] In the detection device according to another aspect of the present disclosure, the radiation detector may be located inside the container.

[0146] In a detection apparatus according to another aspect of the present disclosure, the radiation detector may be located outside the container.

[0147] In a detection device according to another aspect of the present disclosure, the first part may include a flat outer surface that extends in an area that overlaps the drift electrode when viewed along the direction in which the electron detector and the drift electrode face each other.

[0148] In the detection device according to another aspect of the present disclosure, the distance between the inner surface of the first portion and the drift electrode may be not less than 10 mm and not more than 100 mm.

[0149] In the detection device according to another aspect of the present disclosure, the drift electrode may include a plurality of through holes.

[0150] Another aspect of the present disclosure is a detection device for detecting radiation, comprising: a container including a first portion, a second portion facing the first portion in a first direction, and a side portion extending from the first portion toward the second portion, the container containing a gas; an electron detector located inside the vessel for detecting electrons generated by Compton scattering; a drift electrode located inside the container and facing the electron detector in a direction intersecting the first direction; a radiation detector that is closer to the second portion than to the first portion and detects scattered radiation.

[0151] In the detection device according to another aspect of the present disclosure, the radiation detector may be located inside the container.

[0152] In a detection apparatus according to another aspect of the present disclosure, the radiation detector may be located outside the container.

[0153] A detection apparatus according to another aspect of the present disclosure may include an electron amplifier located between the electron detector and the drift electrode and facing the electron detector and the drift electrode.

[0154] In accordance with another aspect of the present disclosure, there is provided a detection apparatus, the electron detector including a plurality of collecting electrodes; The electron amplifier may include a substrate having a front surface and a back surface, and having a through hole formed therein that overlaps with the collecting electrode in a direction facing the drift electrode, a first electrode located on the front surface, and a second electrode located on the back surface.

[0155] A detection device according to another aspect of the present disclosure may include an auxiliary drift electrode including a plurality of ring electrodes arranged along the direction in which the electron detector and the drift electrode face each other, and a spacer positioned between two adjacent ring electrodes.

[0156] A detection device according to another aspect of the present disclosure may include an auxiliary drift electrode including a plurality of ring electrodes aligned along a direction in which the electron detector and the drift electrode face each other and a spacer positioned between two adjacent ring electrodes, and an intermediate substrate supporting the auxiliary drift electrode and the electron detector. The drift electrode may be attached to the auxiliary drift electrode so as to face the electron detector. The intermediate substrate may be disposed on the second portion.

[0157] In a detection device according to another aspect of the present disclosure, the radiation detector may include a scintillator that is excited by the scattered radiation and emits fluorescence, and a photodetector that detects the fluorescence.

[0158] In the detection apparatus according to another aspect of the present disclosure, the radiation detector may include a semiconductor detection element that detects the scattered radiation.

[0159] In a detection device according to another aspect of the present disclosure, the side of the container may have a cylindrical shape.

[0160] A detection device according to another aspect of the present disclosure may include an adsorbent material located within the container.

[0161] A detection device according to another aspect of the present disclosure may include a circulation path connected to the container, and a pump and a filter inserted in the circulation path. [Explanation of symbols]

[0162] 5. Object 10. Detection Device 20 containers 21 Part 1 22 Part 2 23 Side 24 Corners 25 Part 1 26 Part 2 30 Electron Detector 31 Collecting electrode 32 Support substrate 40 Drift electrode 41 Through hole 45 Drift Cage 50 Radiation Detector 51 Detector element 52 Circuit Board 60 Electronic Amplifier 61 1st electrode 62 2nd electrode 63 Base material 64 Through hole 70 Auxiliary drift electrode 72 Ring Electrode 73 Ring 1st Side 74 Ring 2nd Side 75 Spacer 76 Wiring 77 Resistor 81 Adsorbents 82 Circulation path 83 Pump 84 Filters 90 Relay board 91 First board 92 Second board 93 Third Board 95 Wire

Claims

1. A detection device for detecting radiation, comprising: a container including a first portion, a second portion opposite the first portion in a first direction, and a side portion extending from the first portion to the second portion, the container containing a gas; an electron detector located inside the vessel for detecting electrons generated by Compton scattering; a drift electrode located inside the container on the second portion side of the electron detector and facing the electron detector; a radiation detector located on the second portion side of the drift electrode and detecting scattered radiation; an auxiliary drift electrode located between the electron detector and the drift electrode; the auxiliary drift electrode includes a plurality of ring electrodes arranged along a direction in which the electron detector and the drift electrode face each other, and a spacer positioned between two adjacent ring electrodes; the radiation detector is located outside the container; The container comprises plastic and has a thickness of 30 mm or less, or comprises metal and has a thickness of 20 mm or less.

2. The detection device of claim 1 , wherein the distance between the inner surface of the first portion and the electron detector is 10 mm or less.

3. A detection device for detecting radiation, comprising: a container including a first portion, a second portion opposite the first portion in a first direction, and a side portion extending from the first portion to the second portion, the container containing a gas; an electron detector located inside the vessel for detecting electrons generated by Compton scattering; a drift electrode located inside the container on the first portion side of the electron detector and facing the electron detector; a radiation detector located closer to the second section than the electron detector and detecting scattered radiation; an auxiliary drift electrode located between the electron detector and the drift electrode; the auxiliary drift electrode includes a plurality of ring electrodes arranged along a direction in which the electron detector and the drift electrode face each other, and a spacer positioned between two adjacent ring electrodes; the radiation detector is located outside the container; The container comprises plastic and has a thickness of 30 mm or less, or comprises metal and has a thickness of 20 mm or less.

4. The detection device includes: an auxiliary drift electrode including a plurality of ring electrodes arranged along a direction in which the electron detector and the drift electrode face each other, and a spacer positioned between two adjacent ring electrodes; a relay substrate supporting the auxiliary drift electrode and the electron detector; the drift electrode is attached to the auxiliary drift electrode so as to face the electron detector; The detection device according to claim 3 , wherein the relay substrate is disposed on the second portion.

5. The detection device according to claim 3 , wherein the distance between the inner surface of the first portion and the drift electrode is not less than 10 mm and not more than 100 mm.

6. The detection device according to claim 1 , wherein the first portion includes an outer surface that extends flat in a range overlapping the electron detector when viewed along a direction in which the electron detector and the drift electrode face each other.

7. The radiation detector includes a plurality of detection elements, The detection device according to claim 1 , wherein the drift electrode includes a plurality of through holes overlapping the detection elements in the first direction.

8. A detection device for detecting radiation, comprising: a container including a first portion, a second portion opposite the first portion in a first direction, and a side portion extending from the first portion to the second portion, the container containing a gas; an electron detector located inside the vessel for detecting electrons generated by Compton scattering; a drift electrode located inside the container and facing the electron detector in a direction intersecting the first direction; a radiation detector that is closer to the second portion than to the first portion and detects scattered radiation; an auxiliary drift electrode located between the electron detector and the drift electrode; a spacer disposed between adjacent two of the ring electrodes, the spacer being located between the adjacent two of the ring electrodes; and a spacer disposed between the adjacent two of the ring electrodes, the spacer being located between the adjacent two of the ring electrodes.

9. A detection device for detecting radiation, comprising: a container including a first portion, a second portion opposite the first portion in a first direction, and a side portion extending from the first portion to the second portion, the container containing a gas; an electron detector located inside the vessel for detecting electrons generated by Compton scattering; a drift electrode located inside the container and facing the electron detector in a direction intersecting the first direction; a radiation detector that is closer to the second portion than to the first portion and detects scattered radiation, The radiation detector is located within the vessel.

10. The detection apparatus of claim 8 , wherein the radiation detector is located outside the container.

11. 11. A detection device according to claim 1, further comprising an electron amplifier located between the electron detector and the drift electrode and facing the electron detector and the drift electrode.

12. the electron detector includes a plurality of collecting electrodes; 12. The detection device according to claim 11, wherein the electron amplifier comprises: a substrate having a front surface and a back surface, the substrate having a through hole formed therein that overlaps with the collector electrode in a direction facing the drift electrode; a first electrode located on the front surface; and a second electrode located on the back surface.

13. The detection device according to claim 1 , wherein the radiation detector includes a scintillator that is excited by the scattered radiation to emit fluorescence, and a photodetector that detects the fluorescence.

14. 14. The detection apparatus of claim 1, wherein the radiation detector comprises a semiconductor detector element for detecting the scattered radiation.

15. 15. The detection device of claim 1, wherein the side of the container has a cylindrical shape.

16. 16. The detection device according to claim 1, further comprising a circulation path connected to the container, and a pump and a filter inserted in the circulation path.

Images