Detection device

Abstract

To provide a detector of radiation in which variations do not occur in a detection result based on Compton scattering by the arrangement of a drift electrode, an electron detector and a radiation detector.SOLUTION: A detector for detecting radiation includes: a container which includes a first part, a second part opposing to the first part in the first direction, and a side part spreading from the first part toward the second part, and in which a gas is stored; an electron detector positioned inside the container, and for detecting electrons generated by Compton scattering; a drift electrode 40 positioned further on the second part side than the electron detector in the container, and opposing to the electron detector; a radiation detector positioned further on the second part side than the drift electrode 40, and for detecting scattered radiation; and an auxiliary drift electrode 70 which includes a plurality of ring electrodes 72 arranged along the direction in which the electron detector is opposed to the drift electrode 40, and a spacer 75 positioned between the adjacent two ring electrodes.SELECTED DRAWING: Figure 29

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a detection device for detecting radiation.

Background Art

[0002] As a device for detecting radiation, for example, as disclosed in Patent Documents 1 to 3, a detection device for detecting Compton-scattered radiation and electrons generated by Compton scattering is known. The detection device includes a container containing a gas, a drift electrode and an electron detector facing each other inside the container, and a radiation detector located outside the container.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

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

[0005] For example, in the detection devices described in Patent Documents 1 to 3, Compton-scattered radiation 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 of interaction between the radiation and the electron detector, the container, and the air outside the container. For example, the radiation may be photoelectrically absorbed, or radiation with different energies may be generated. It is also possible that Compton scattering occurs in the electron detector, the container, and the air outside the container. When these phenomena occur, the energy and position of the radiation detected by the radiation detector may not correspond to the Compton scattering that occurred between the drift electrode and the electron detector. This makes it easier for variability and errors in the detection results to occur.

[0006] The embodiments of this disclosure aim 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, A container containing gas, comprising a first part, a second part facing the first part in a first direction, and a side part extending from the first part toward the second part, An electron detector located inside the aforementioned container for detecting electrons generated by Compton scattering, A drift electrode located inside the container, on the side of the second part relative to the electron detector, and facing the electron detector, The system includes a radiation detector located on the second side of the drift electrode, which detects scattered radiation, The container is a detection device containing a radioactive plastic or a radioactive metal.

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

[0009] One embodiment of the present disclosure is a detection device for detecting radiation, A container containing gas, comprising a first part, a second part facing the first part in a first direction, and a side part extending from the first part toward the second part, An electron detector located inside the aforementioned container for detecting electrons generated by Compton scattering, A drift electrode located inside the container, on the side of the first part relative to the electron detector, and facing the electron detector, The system includes a radiation detector located on the second side of the electron detector, which detects scattered radiation, The container is a detection device containing a radioactive plastic or a radioactive metal.

[0010] A detection device according to one embodiment of the present disclosure may include an auxiliary drift electrode comprising a plurality of ring electrodes arranged in a direction in which the electron detector and the drift electrode face each other, and a spacer located between two adjacent ring electrodes, and a relay 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 relay substrate may be arranged on the second part.

[0011] In a detection device according to one embodiment of the present disclosure, the distance between the inner surface of the first part and the drift electrode may be 10 mm or more and 100 mm or less.

[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 a region overlapping the electron detector when viewed along the direction in which the electron detector and the drift electrode face each other.

[0013] In a 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 that overlap with the detection elements in a first direction.

[0014] One embodiment of the present disclosure is a detection device for detecting radiation, A container containing gas, comprising a first part, a second part facing the first part in a first direction, and a side part extending from the first part toward the second part, An electron detector located inside the aforementioned container 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, The detection device comprises a radiation detector located closer to the second part than the first part, which detects scattered radiation.

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

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

[0017] A detection device according to one 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 collection electrodes, and the electron amplifier may include a substrate having a front and a back surface, with through holes formed therein that overlap the collection electrodes in a direction facing the drift electrodes, a first electrode located on the front surface, and a second electrode located on the back surface.

[0019] In a detection device according to one embodiment 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.

[0020] In the detection device 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 an embodiment of the present disclosure, the side portion 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 into the circulation path.

[0023] According to an embodiment of the present disclosure, the detection accuracy of the radiation detector can be improved.

Brief Description of the Drawings

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

[0025] The embodiments described below are examples of embodiments of the present disclosure, and the present disclosure is not construed to be limited to these embodiments. Furthermore, in this specification, terms such as “substrate,” “base material,” “sheet,” and “film” are not distinguished from each other solely on the basis of differences in designation. For example, “substrate” and “base material” are concepts that also include components that may be called sheets or films. Moreover, terms used in this specification to specify shape, geometric conditions, and their degree, such as “parallel” and “orthogonal,” as well as values ​​of length and angle, are not bound by strict meaning, but are interpreted to include a range that can be expected to have similar functions.

[0026] In the drawings referenced herein, identical or similar parts are denoted by the same or similar reference numerals, and repeated descriptions may be omitted. Furthermore, the dimensional ratios in the drawings may differ from the actual ratios for illustrative purposes, and some components may be omitted from the drawings.

[0027] In this specification, if multiple candidate upper limits and multiple candidate lower limits are given for a certain parameter, the numerical range of that parameter may be constructed by combining any one candidate upper limit and any one candidate lower limit. For example, consider the case where it is stated that "Parameter B is, for example, A1 or greater, and may be A2 or greater, and may be A3 or greater. Parameter B is, for example, A4 or less, and may be A5 or less, and may be A6 or less." In this case, the numerical range of parameter B may be A1 or greater and A4 or less, A1 or greater and A5 or less, A1 or greater and A6 or less, A2 or greater and A4 or less, A2 or greater and A5 or less, A2 or greater and A6 or less, A3 or greater and A4 or less, A3 or greater and A5 or less, and A3 or greater and A6 or less.

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

[0029] (Detection device) The detection device 10 comprises 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. The container 20 contains at least a noble gas such as argon or xenon. In addition to the noble gas, the container 20 may also contain a quenching gas with quenching properties such as carbon dioxide or methane.

[0030] The container 20 includes a first surface 21, a second surface 22 facing the first surface 21 in a first direction D1, and a side surface 23 extending from the first surface 21 toward the second surface 22. The detection device 10 is intended to detect radiation incident into the interior of the container 20 through the first surface 21. The container 20 may be placed so that the second surface 22 faces or touches a surface such as a floor or table. As shown in Figure 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 cylinder, such as a cube or a rectangular parallelepiped. Although not shown, the first surface 21 may be curved so as to be convex toward the outside of the container 20.

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

[0032] The material of the container 20 is preferably one that allows radiation to pass through easily. This suppresses the absorption or scattering of radiation by the container 20 as it passes through it. The container 20 may include, for example, plastic or metal. The plastic may be fiber-reinforced plastic. If metal is used, the container 20 may be composed of a single metallic element or an alloy. As the metal, for example, aluminum or aluminum alloy can be used. To reduce the weight of the container 20, a metal with a specific gravity of less than 4 may be used.

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

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

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

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

[0038] When radiation incident inside container 20 collides with the gas, Compton scattering may occur. Compton scattering generates recoil electrons. Ionizing electrons are also generated along the tracks of these recoil electrons. The electron detector 30 detects these ionizing electrons. By detecting these ionizing electrons, the tracks and energies of the recoil electrons can be calculated.

[0039] Figure 3 is a perspective view showing an example of an electron detector 30. The electron detector 30 may include a plurality of collection electrodes 31 and a support substrate 32 that supports the collection electrodes 31. The collection electrodes 31 face the drift electrodes 40. The support substrate 32 includes a surface extending in a direction intersecting the first direction D1. The collection electrodes 31 detect ionizing electrons attracted to the electron detector 30 by an electric field. The plurality of collection electrodes 31 may be arranged in a direction intersecting 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 collection 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.

[0040] The collecting electrode 31 contains a conductive material. The material of the collecting electrode 31 can be a metal 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), or tantalum (Ta), or an alloy using these materials. Preferably, a metal with high conductivity, such as copper (Cu), gold (Au), or silver (Ag), is used.

[0041] Electrons detected by the collection electrode 31 are processed as electrical signals. The electron detector 30 may include circuits, wiring, etc., for processing the electrical signals. The electrical signals may be transmitted to the outside of the container 20 via, for example, a cable, hermetic connector, or wiring board (not shown) connected to the electron detector 30.

[0042] Although not shown in the diagram, multiple electron detectors 30 may be arranged in the second direction D2 or the third direction D3. This expands the area in which electrons can be detected.

[0043] The drift electrode 40 is positioned 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 plane extending in a direction perpendicular to the first direction D1. The drift electrode 40 has a potential lower than the potential of the collection electrode 31 of the electron detector 30. Therefore, as shown in Figure 2, an electric field E1 is generated between the electron detector 30 and the drift electrode 40, directed from the electron detector 30 to the drift electrode 40. Ionized electrons associated with recoil electrons generated by Compton scattering are attracted towards the electron detector 30 by the electric field E1.

[0044] The drift electrode 40 contains a conductive material. For example, the drift electrode 40 contains 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 the radiation passing through it, compared to when the drift electrode 40 contains 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 radiation passing through the drift electrode 40 is suppressed by the drift electrode 40.

[0046] The radiation detector 50 detects scattered radiation. In this embodiment, 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 it.

[0047] Figure 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 that supports the detection elements 51. The plurality of detection elements 51 may be arranged in a direction intersecting the first direction D1. For example, the plurality of detection elements 51 may be arranged in a second direction D2 and a third direction D3 that are orthogonal to the first direction D1.

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

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

[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 circuits, 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, hermetic connector, 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 to ensure electrical insulation. A gas, insulator, or the like may be located between the drift electrode 40 and the radiation detector 50. This helps to suppress defects such as discharge between the drift electrode 40 and the radiation detector 50.

[0052] Although not shown in the diagram, multiple radiation detectors 50 may be arranged in the second direction D2 or the third direction D3. This expands the area in which radiation can be detected.

[0053] It is preferable that electrical components located inside the container 20, such as the electron detector 30, drift electrode 40, and radiation detector 50, are arranged so as not to cause defects such as discharge between them and the inner surface of the container 20. For example, it is preferable that the arrangement and potential of the electrical components are 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 a detection device) Next, an example of a manufacturing method for the detection device 10 will be described.

[0055] First, electrical components to be placed inside the container 20, such as the electron detector 30, drift electrode 40, radiation detector 50, cables, and connectors, are prepared. Next, these electrical components are subjected to a first vacuum baking process. For example, the pressure inside the container used for the process is controlled to a pressure lower than atmospheric pressure, and the electrical components are heated inside the container. This suppresses outgassing from the electrical components while the detection device 10 is in use. The pressure of the atmosphere is, for example, 0.1 atmospheres or less. The pressure may be maintained at 0.1 atmospheres or less by evacuating the inside of the container during the vacuum baking process. The heating temperature is, for example, 60°C or higher, and may be 100°C or higher. The heating temperature may be 125°C or lower. The heating time may be 2 hours or more, and may be 12 hours or more. The container 20 of the detection device 10 may also be subjected to the same first vacuum baking process.

[0056] Next, the electrical components that have undergone the first vacuum baking process are placed inside the container 20. After that, the electrical components may undergo a second vacuum baking process inside the container 20.

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

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

[0059] In Figure 5, the symbol R1 represents radiation that has passed through the first part 21 of the container 20 and entered the interior of the container 20. Radiation R1 can be, for example, charged particles, gamma rays, X-rays, neutrons, or ultraviolet light. After passing through the electron detector 30, 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 occurs when passing through the electron detector 30, the energy of radiation R2 may be lower than the energy of radiation R1.

[0060] When radiation R2 collides with the gas, Compton scattering may occur. The symbol P represents the location where scattering occurred. Location P is also called the scattering point. The symbol R3 represents the scattered radiation. After passing through the drift electrode 40, radiation R3 reaches the radiation detector 50. The symbol R4 represents the radiation that reached 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 location and energy of radiation R4 to be calculated.

[0061] The symbol R5 represents a recoil electron generated by Compton scattering. An electron cloud is formed along the trajectory of the recoil electron R5. Each electron in the electron cloud is attracted towards the electron detector 30 by the electric field E1. For example, as shown in Figure 5, electrons e1 and e2, which are generated sequentially along the trajectory of the recoil electron R5, are attracted towards the electron detector 30. Electrons e1 and e2 are detected by the collection electrode 31 corresponding to the positions of electrons e1 and e2. This allows for the calculation of the positions and energies of electrons e1 and e2. Furthermore, 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 the case where the radiation detector 50 is located outside the container 20, scattering and attenuation of radiation before it reaches the radiation detector 50 can be suppressed. As a result, information about the scattered radiation R3 in the space between the electron detector 30 and the drift electrode 40 can be obtained more accurately.

[0063] Furthermore, in this embodiment, the radiation detector 50 faces the drift electrode 40. When the thickness of the drift electrode 40 is small 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, more accurate information about the scattered radiation R3 can be obtained.

[0064] This embodiment is particularly useful when the energies of radiation R1 and R2 before scattering are unknown.

[0065] Various modifications can be made to the first embodiment described above. Hereinafter, modifications will be described with reference to the drawings as necessary. In the following description and the drawings used therein, parts that can be configured similarly to the first embodiment will be given the same reference numerals as those used for the corresponding parts in the first embodiment, and redundant explanations will be omitted. Furthermore, if it is clear that the effects and advantages obtained in the first embodiment can also be obtained in the modifications, the explanation may be omitted.

[0066] (First variation) Figure 6 is a cross-sectional view showing a detection device 10 according to the 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 arranged, for example, to face the electron detector 30 and the drift electrode 40 in a first direction D1.

[0067] The electron amplifier 60 is configured to produce electron avalanche amplification. For example, the electron amplifier 60 includes a substrate 63 including a front surface 631 and a back surface 632, a first electrode 61 located on the front surface 631, and a second electrode 62 located on the back surface 632. The first electrode 61 faces the electron detector 30. The second electrode 62 faces the drift electrode 40. The substrate 63 has a plurality of through holes 64 that penetrate from the front surface 631 to the back surface 632. As shown in Figure 6, the through holes 64 overlap with the collection electrodes 31 of the electron detector 30 in the direction facing the drift electrode 40, for example in the first direction D1. Multiple collection electrodes 31 may overlap with a single 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, directed 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, directed from the first electrode 61 to the second electrode 62.

[0069] From Part 1, page 21, we consider the case where Compton scattering of radiation incident inside the container 20 occurs between the electron amplifier 60 and the drift electrode 40. The electrons in the electron cloud formed in the tracks of the recoil electrons are attracted towards the electron amplifier 60 by the electric field E2.

[0070] Electrons attracted to the electron amplifier 60 collide with the gas, ionizing it. The ionized electrons are amplified in an avalanche-like manner within the through-hole 64 and are attracted as a group towards the first electrode 61. Electrons that have passed through the through-hole 64 are detected by the collection electrode 31. According to this modified example, the amount of electrons measured increases by using the electron amplifier 60. Therefore, the position of the electrons can be detected with higher precision.

[0071] (Second variation) Figure 7 is a cross-sectional view showing a detection device 10 according to a second modified example. 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 that extends in the 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 improve the uniformity of the electric field distribution 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 in the figures, 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 an insulating material such as resin.

[0073] The auxiliary drift electrode 70, like the drift electrode 40, contains a conductive material. For example, the auxiliary drift electrode 70 may contain a metal with a specific gravity of less than 4, such as aluminum.

[0074] (Third variation) Figure 8 is a cross-sectional view showing a detection device 10 according to a third modified example. As shown in Figure 8, the radiation detector 50 may be located outside the container 20. For example, the radiation detector 50 may be located outside the second part 22. The radiation detector 50 may be facing the drift electrode 40 across the second part 22.

[0075] According to this modified example, by placing the radiation detector 50 outside the container 20, it is possible to prevent outgassing from the radiation detector 50 from affecting the internal environment of the container 20. This allows, for example, to increase the density of the electron cloud formed in the tracks of recoil electrons R5. Furthermore, if an electron amplifier 60 is provided inside the container 20, the amplification of electrons by the electron amplifier 60 can be further promoted.

[0076] In this modified example, the 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 before reaching the radiation detector 50. To suppress radiation scattering, attenuation, etc., in the second part 22, it is preferable that the thickness of the second part 22 be small.

[0077] (Fourth variation) Figure 9 is a cross-sectional view showing a detection device 10 according to the 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, etc. The adsorbent 81 may be, for example, a getter material of an active metal or alloy such as titanium or zirconium, an adsorbent material such as zeolite or silica gel, or a getter pump.

[0078] It is preferable that the adsorbent 81 is positioned in a location that does not interfere with radiation. For example, the adsorbent 81 may be positioned on the side 23 of the container 20.

[0079] (Fifth variation) Figure 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 electrical components 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 into the circulation path 82.

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

[0081] (Sixth variation) Figure 11 is a cross-sectional view showing a detection device 10 according to the sixth modified example. As shown in Figure 11, the drift electrode 40 may include a plurality of through holes 41. The through holes 41 may overlap with the detection element 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 modified example, a portion of the radiation R3 scattered by Compton scattering passes through the through-hole 41 of the drift electrode 40 before reaching the radiation detector 50. Therefore, compared to the case where the radiation passes through the drift electrode 40, scattering and attenuation of radiation in the drift electrode 40 can be suppressed. Consequently, more accurate information about the scattered radiation R3 can be obtained.

[0083] While we have described several modifications of the first embodiment described above, it is naturally possible to combine and apply multiple modifications as appropriate.

[0084] Second Embodiment Next, a second embodiment of the present disclosure will be described. In the second embodiment, the same reference numerals are used for parts identical to those in the first embodiment, and detailed descriptions are omitted. Furthermore, if it is clear that the effects and advantages obtained in the first embodiment can also be obtained in this embodiment, the description may be omitted.

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

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

[0087] The radiation detector 50 is electrically insulated from the electron detector 30. For example, the distance K2 between the radiation detector 50 and the electron detector 30 is set to ensure electrical insulation. A gas, insulator, or the like may be located between the electron detector 30 and the radiation detector 50. This helps to suppress malfunctions such as discharge between the electron detector 30 and the radiation detector 50.

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

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

[0090] 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 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 location and energy of radiation R4 to be calculated.

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

[0092] In this embodiment, as in the first embodiment, the radiation detector 50 is located inside the container 20. Therefore, compared to the case where the radiation detector 50 is located outside the container 20, scattering and attenuation of radiation before it reaches the radiation detector 50 can be suppressed. As a result, 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] Furthermore, in this embodiment, the drift electrode 40 is located on the side of 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, compared to the case where the electron detector 30 is located on the side of the first section 21 than the drift electrode 40, the rate of energy reduction of the radiation R2 that reaches the space between the electron detector 30 and the drift electrode 40 becomes smaller. In other words, the ratio of the difference between the energy of radiation R1 incident on the container 20 and the energy of radiation R2 that reaches the space between the electron detector 30 and the drift electrode 40 to radiation R1 becomes smaller. Also, the difference between the radiation dose of radiation R1 and the radiation dose of radiation R2 becomes smaller. Therefore, the probability of the expected Compton scattering occurring in the space between the electron detector 30 and the drift electrode 40 can be increased. In addition, by reducing the rate of energy reduction of radiation R2, the probability that the scattered radiation R3 expected as a measured value will be directed towards the second section 22 can be increased.

[0094] On the other hand, in this embodiment, the scattered radiation R3 passes through the electron detector 30 before reaching the radiation detector 50. Therefore, compared to the first embodiment, scattering and attenuation of the radiation are more likely to occur between the time the scattered radiation reaches the radiation detector 50 and the time it arrives. Taking this into consideration, the radiation detector 50 may ignore information if it detects radiation with an energy that is clearly lower than the expected energy. This can suppress the calculation of an incorrect 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 of the expected Compton scattering occurring in the space between the electron detector 30 and the drift electrode 40, information regarding the amount and distribution 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 generated 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] Similar to the third modification of the first embodiment, the radiation detector 50 may be located outside the container 20. For example, as shown in Figure 20, the radiation detector 50 may be located outside the second part 22. The radiation detector 50 may face the electron detector 30 across the second part 22.

[0098] While we have described several variations of the second embodiment described above, it is naturally possible to combine and apply multiple variations as appropriate.

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

[0100] Figure 15 is a perspective view showing an example of the detection device 10. Figure 16 is a cross-sectional view of the detection device 10 in Figure 15. The detection device 10 comprises 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 are facing each other in a direction intersecting the first direction D1. For example, the electron detector 30 and the drift electrode 40 may be facing each other in a second direction D2 that is 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 part 22 than to the first part 21. In the examples shown in Figures 15 and 16, the radiation detector 50 does not overlap with the electron detector 30 and the drift electrode 40 in the second direction D2. Although not shown, the radiation detector 50 may overlap with the electron detector 30 and the drift electrode 40 in the second direction D2.

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

[0104] The radiation R1 that enters the interior of the container 20 from part 1 21 reaches the space between the electron detector 30 and the drift electrode 40. The symbol R2 represents the radiation that reaches the space between the electron detector 30 and the drift electrode 40.

[0105] 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 reached the radiation detector 50.

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

[0107] In this embodiment, as in the first embodiment, the radiation detector 50 is located inside the container 20. Therefore, compared to the case where the radiation detector 50 is located outside the container 20, scattering and attenuation of radiation before it reaches the radiation detector 50 can be suppressed. As a result, 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] Furthermore, in this embodiment, 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 in the first and second embodiments described above, the energy and radiation dose of radiation R1 incident on the container 20 are equivalent to the energy and radiation dose of radiation R2 that reaches the space between the electron detector 30 and the drift electrode 40. This increases the probability that the expected Compton scattering will occur in the space between the electron detector 30 and the drift electrode 40. In addition, because radiation R2 is equivalent to radiation R1, the probability that the scattered radiation R3 expected as a measured value will be directed towards the second part 22 can be increased.

[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 in the first and second embodiments described above, the energy and radiation dose of the scattered radiation R3 are equivalent to the energy and radiation dose of the radiation R4 that reaches the radiation detector 50. Consequently, more accurate information regarding the scattered radiation R3 can be obtained.

[0110] Various modifications can be made to the third embodiment described above. Hereinafter, modifications will be described with reference to the drawings as necessary. In the following description and the drawings used therein, parts that can be configured similarly to the third embodiment will be given the same reference numerals as those used for the corresponding parts in the first embodiment, and redundant explanations will be omitted. Furthermore, if it is clear that the effects and advantages obtained in the third embodiment can also be obtained in the modifications, the explanation may be omitted.

[0111] (First variation) Figure 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 arranged, for example, to face the electron detector 30 and the drift electrode 40 in a second direction D2. By using the electron amplifier 60, the amount of electrons to be measured increases. Therefore, the position of electrons and other parameters can be detected with higher accuracy.

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

[0113] According to this modified example, by placing the radiation detector 50 outside the container 20, it is possible to prevent outgassing from the radiation detector 50 from affecting the internal environment of the container 20. This allows, for example, to increase the density of the electron cloud formed in the tracks of recoil electrons R5. Furthermore, if an electron amplifier 60 is provided inside the container 20, the amplification of electrons by the electron amplifier 60 can be further promoted.

[0114] (Other variations) Similar to 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. Similar to the fourth modification of the first embodiment, the detection device 10 may include an adsorbent 81 located inside the container 20. Similar to the fifth modification of the first embodiment, the detection device 10 may include a device for removing outgassing generated from electrical components located inside the container 20. Similar to the sixth modification of the first embodiment, the drift electrode 40 may include a plurality of through holes 41.

[0115] While we have described several variations of the third embodiment described above, it is naturally possible to combine and apply multiple variations as appropriate.

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

[0117] (First common variation) Figure 21 is a perspective view showing a container 20 relating to the first common modification. As shown in Figure 21, the container 20 may include a first section 21 and a side section 23, and a corner 24 located between the first section 21 and the side section 23. The first section 21 may be flat and wide. The corner 24 may include a surface that extends in a direction different from that of the first section 21 and the side section 23.

[0118] Figure 22 is a cross-sectional view showing an example in which a container 20 relating 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 the object 5. The object 5 emits radiation. The detection device 10 can detect radiation entering the interior of the container 20 through the first part 21.

[0119] As shown in Figure 22, the outer surface 211 may be flat. Preferably, the outer surface 211 is flat within range F1. For example, the difference between the positions of point P1 and point P2 in the opposing direction is 10 mm or less. This shortens the distance from the object 5 to the electron detector 30. Therefore, the measurement resolution can be increased. Range F1 is the range that overlaps 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 opposing direction). Point P1 on the outer surface 211 coincides with the center point of the electron detector 30 when viewed along the opposing direction. Point P2 on the outer surface 211 coincides with the edge of the electron detector 30 when viewed along the opposing direction.

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

[0121] As shown in Figure 22, the inner surface 212 may be flat and spread out. This allows the distance K3 to be shortened over the entire surface of the electron detector 30.

[0122] As shown in Figure 22, the corner 24 may be curved to protrude outward from the container 20. This can increase the rigidity of the container 20.

[0123] Figure 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 Figure 23, the radiation detector 50 may be located outside the second part 22. The radiation detector 50 may be facing the drift electrode 40 across the second part 22.

[0124] Figure 24 is a cross-sectional view showing an example in which a container 20 relating to the first common modification is applied to the second embodiment. Preferably, the outer surface 211 is flat in range F2. For example, the difference between the positions of point P3 and point P4 in the opposing direction is 10 mm or less. This makes it possible to shorten the distance from the object 5 to the drift electrode 40. Therefore, the measurement resolution can be increased. Range F2 is the range that overlaps the drift electrode 40 when viewed along the opposing direction. Point P3 on the outer surface 211 overlaps the center point of the drift electrode 40 when viewed along the opposing direction. Point P4 on the outer surface 211 overlaps the end of the drift electrode 40 when viewed along the opposing 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, but may also be 70 mm or less, or 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 will be electrically connected to the container 20. Therefore, it is preferable to maintain the distance K4 above a certain level, 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, but may also be 20 mm or more, or 30 mm or more.

[0126] Figure 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 Figure 25, the radiation detector 50 may be located outside the second part 22. The radiation detector 50 may be facing the electron detector 30 across the second part 22.

[0127] Figure 26 is a cross-sectional view showing an example in which a container 20 relating to the first common modification is applied to the third embodiment. Preferably, the outer surface 211 extends flatly in the range F3. For example, the difference between the position of point P5 and the position of point P6 in the planar direction of the side portion 23 is 10 mm or less. This makes it possible to shorten the distance between the space between the electron detector 30 and the drift electrode 40 (hereinafter also referred to as the opposing space) and the object 5. This makes it possible to improve the resolution of the measurement. Range F3 is the range that overlaps with the opposing space when viewed along the planar direction of the side portion 23. Point P5 on the outer surface 211 overlaps with the center point of the opposing space when viewed along the planar direction of the side portion 23. Point P6 on the outer surface 211 overlaps with the opposing surface of the electron detector 30 to the drift electrode 40 or the opposing surface of the drift electrode 40 to the electron detector 30 when viewed along the planar direction of the side portion 23.

[0128] Figure 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 Figure 27, the radiation detector 50 may be located outside the second part 22. The radiation detector 50 may be facing the second part 22.

[0129] (Second common variation) Figures 28 and 29 are perspective and cross-sectional views, respectively, of an auxiliary drift electrode 70 relating 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 along opposing directions. Each 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] Figure 30 is a plan view showing the ring electrode 72. The ring electrode 72 has an opening 721. The opening 721 overlaps with the electron detector 30 in the opposite direction. The ring electrode 72 does not have to overlap with the electron detector 30 in the opposite direction. The ring electrode 72 may overlap with the drift electrode 40 in the opposite direction. The ring electrode 72 has a width W1 in plan view. The width W1 is, for example, 5 mm or more, may be 6 mm or more, or 8 mm or more. The width W1 is, for example, 30 mm or less, may be 25 mm or less, or 20 mm or less. The width W1 is the difference between the radius R11 of the circle that constitutes the outer edge of the ring electrode 72 and the radius R12 of the circle that constitutes the inner edge of the ring electrode 72.

[0131] The ring electrode 72 may be made of a conductive wire. For example, first, a wire having a first end and a second end is prepared. Then, the wire is deformed into a circular or polygonal shape, and the first end and the second end are connected. This gives the ring electrode 72. In this case, the width W1 of the ring electrode 72 corresponds to the dimensions of the cross-section 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, metal.

[0132] The auxiliary drift electrode 70 may include a spacer 75 positioned between two adjacent ring electrodes 72 in the opposing direction. The spacer 75 determines the distance K5 between two adjacent ring electrodes 72 in the opposing 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, etc. The distance K5 may be, for example, 2 mm or more, 5 mm or more, or 8 mm or more. The distance K5 may be, for example, 30 mm or less, 20 mm or less, or 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 positioned between the drift electrode 40 and the ring electrode 72. The structure including the drift electrode 40 and the multiple ring electrodes 72 is also referred to as a drift cage 45.

[0134] As shown in Figure 29, the auxiliary drift electrode 70 may include wiring 76 that electrically connects two adjacent ring electrodes 72 in the opposing direction. The auxiliary drift electrode 70 may include wiring 76 that electrically connects an adjacent drift electrode 40 and a ring electrode 72 in the opposing 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 makes it possible to change the potential of ring electrodes 72 aligned in the opposing direction in steps. For example, suppose 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 aligned from the drift electrode 40 toward the electron detector 30 can be changed in steps 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 opposing direction is, for example, 50V or more, may be 100V or more, or 150V or more. The voltage between two adjacent ring electrodes 72 in the opposing direction is, for example, 500V or less, may be 400V or less, or 300V or less.

[0136] As shown in Figure 29, the auxiliary drift electrode 70 may be supported by the relay substrate 90. The relay substrate 90 may support the electron detector 30. For example, the relay 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. If the detection device 10 includes an electron amplifier 60, the electron amplifier 60 may also be supported by the relay substrate 90.

[0137] Figure 31 is a cross-sectional view showing an example in which an auxiliary drift electrode 70 relating to a 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 placed 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 positioned facing the first part 21 without fixing the drift electrode 40 to the first part 21.

[0138] As shown in Figure 31, the relay board 90 may include a third board 93 extending from the inside to the outside of the container 20. The relay board 90 may include a wire 95 that electrically connects the electron detector 30 and the first board 91. The electrical signal from the electron detector 30 is transmitted to the outside of the container 20 via the wire 95, the first board 91, and the third board 93.

[0139] (Other forms) Other aspects of this disclosure are detection devices for detecting radiation, A container containing gas, comprising a first part, a second part facing the first part in a first direction, and a side part extending from the first part toward the second part, An electron detector located inside the aforementioned container for detecting electrons generated by Compton scattering, A drift electrode located inside the container, on the side of the second part relative to the electron detector, and facing the electron detector, The detection device includes a radiation detector located on the side of the second part relative to the drift electrode, which detects scattered radiation.

[0140] In detection devices according to other embodiments of the present disclosure, the radiation detector may be located inside the container.

[0141] In detection devices according to other embodiments 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 an outer surface that extends flatly in a manner that overlaps the electron detector when viewed along the direction in which the electron detector and the drift electrode face each other.

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

[0144] Other aspects of this disclosure are detection devices for detecting radiation, A container containing gas, comprising a first part, a second part facing the first part in a first direction, and a side part extending from the first part toward the second part, An electron detector located inside the aforementioned container for detecting electrons generated by Compton scattering, A drift electrode located inside the container, on the side of the first part relative to the electron detector, and facing the electron detector, The detection device comprises a radiation detector located on the side of the second part relative to the electron detector, which detects scattered radiation.

[0145] In detection devices according to other embodiments of the present disclosure, the radiation detector may be located inside the container.

[0146] In detection devices according to other embodiments of the present disclosure, the radiation detector may be located outside the container.

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

[0148] In a detection device according to another aspect of the present disclosure, the distance between the inner surface of the first part and the drift electrode may be 10 mm or more and 100 mm or less.

[0149] In detection devices according to other embodiments of the present disclosure, the drift electrode may include a plurality of through holes.

[0150] Other aspects of this disclosure are detection devices for detecting radiation, A container containing gas, comprising a first part, a second part facing the first part in a first direction, and a side part extending from the first part toward the second part, An electron detector located inside the aforementioned container 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, The detection device comprises a radiation detector located closer to the second part than the first part, which detects scattered radiation.

[0151] In detection devices according to other embodiments of the present disclosure, the radiation detector may be located inside the container.

[0152] In detection devices according to other embodiments of the present disclosure, the radiation detector may be located outside the container.

[0153] A detection device 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 a detection device according to another aspect of the present disclosure, the electron detector includes a plurality of collection electrodes, The electron amplifier may include a substrate having a front and a back surface, with through holes formed therein that overlap the collection 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 comprising a plurality of ring electrodes arranged in a direction in which the electron detector and the drift electrode face each other, and a spacer located between two adjacent ring electrodes.

[0156] A detection device according to another aspect of the present disclosure may include an auxiliary drift electrode comprising a plurality of ring electrodes arranged in a direction in which the electron detector and the drift electrode face each other, and a spacer located between two adjacent ring electrodes, and a relay 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 relay substrate may be disposed on the second part.

[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 detection devices according to other aspects of the present disclosure, the radiation detector may include a semiconductor detection element for detecting 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 this disclosure may include an adsorbent located inside 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 into 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 detectors 31 Collection electrode 32 Support substrate 40 Drift electrodes 41 Through hole 45 Drift Cage 50 Radiation detectors 51 detection element 52 Circuit boards 60 Electronic Amplifiers 61 1st electrode 62 2nd electrode 63 Base material 64 Through holes 70 Auxiliary drift electrodes 72 ring electrodes 73 Ring, Front 1 74 Ring, side 2 75 Spacer 76 Wiring 77 Resistor 81 Adsorbent 82 Circulation path 83 Pumps 84 filters 90 relay board 91 First circuit board 92 Second board 93 Third board 95 wires

Claims

1. A detection device for detecting radiation, A container containing gas, comprising a first part, a second part facing the first part in a first direction, and a side part extending from the first part toward the second part, An electron detector located inside the aforementioned container for detecting electrons generated by Compton scattering, A drift electrode located inside the container, on the side of the second part relative to the electron detector, and facing the electron detector, The system includes a radiation detector located on the second side of the drift electrode, which detects scattered radiation, The container contains a radiotransparent plastic or a radiotransparent metal. The first part includes an outer surface that extends flat in the area overlapping the electron detector when viewed along the direction in which the electron detector and the drift electrode face each other, Only gas is located between the inner surface of the first part and the electron detector. Detection device.

2. A detection device for detecting radiation, A container containing gas, comprising a first part, a second part facing the first part in a first direction, and a side part extending from the first part toward the second part, An electron detector located inside the aforementioned container for detecting electrons generated by Compton scattering, A drift electrode located inside the container, on the side of the second part relative to the electron detector, and facing the electron detector, The system includes a radiation detector located on the second side of the drift electrode, which detects scattered radiation, The container contains a radiotransparent plastic or a radiotransparent metal. The first part includes an outer surface that extends flat in the area overlapping the electron detector when viewed along the direction in which the electron detector and the drift electrode face each other, The distance between the inner surface of the first part and the electron detector is 10 mm or less. Detection device.

3. The detection device according to claim 1 or 2, wherein the radiation detector is located outside the container.

4. The container includes a corner located between the first part and the side part. The detection device according to any one of claims 1 to 3, wherein the corner is curved so as to protrude outward from the container.

5. The detection device according to any one of claims 1 to 4, wherein the container includes plastic and has a thickness of 30 mm or less, or the container includes metal and has a thickness of 20 mm or less.

6. The detection device according to any one of claims 1 to 5, comprising an adsorbent located inside the container for adsorbing gas.

7. The detection device according to claim 6, wherein the adsorbent is arranged on the side of the container.

8. The aforementioned radiation detector includes a plurality of detection elements, The detection device according to any one of claims 1 to 7, wherein the drift electrode includes a plurality of through holes that overlap with the detection element in the first direction.

9. A detection device for detecting radiation, A container containing gas, comprising a first part, a second part facing the first part in a first direction, and a side part extending from the first part toward the second part, An electron detector located inside the aforementioned container for detecting electrons generated by Compton scattering, A drift electrode located inside the container, on the side of the second part relative to the electron detector, and facing the electron detector, The system includes a radiation detector located on the second side of the drift electrode, which detects scattered radiation, The container contains a radiotransparent plastic or a radiotransparent metal. The aforementioned radiation detector includes a plurality of detection elements, The drift electrode includes a plurality of through holes that overlap with the detection element in the first direction. Detection device.

10. A detection device for detecting radiation, A container containing gas, comprising a first part, a second part facing the first part in a first direction, and a side part extending from the first part toward the second part, An electron detector located inside the aforementioned container for detecting electrons generated by Compton scattering, A drift electrode located inside the container, on the side of the first part relative to the electron detector, and facing the electron detector, The system includes a radiation detector located on the second side of the electron detector, which detects scattered radiation, The container contains a radiotransparent plastic or a radiotransparent metal. The aforementioned radiation detector includes a plurality of detection elements, The drift electrode includes a plurality of through holes that overlap with the detection element in the first direction. Detection device.

11. The detection device according to claim 10, wherein the distance between the inner surface of the first part and the drift electrode is 10 mm or more and 100 mm or less.

12. The detection device according to any one of claims 1 to 11, comprising an electron amplifier positioned between the electron detector and the drift electrode and facing the electron detector and the drift electrode.

13. The electron detector includes a plurality of collection electrodes, The detection device according to claim 12, wherein the electron amplifier includes a substrate having a front and a back surface, and having through holes formed therein that overlap the collection 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.

14. The detection device according to any one of claims 1 to 13, wherein the radiation detector includes a scintillator that is excited by the scattered radiation and emits fluorescence, and a photodetector that detects the fluorescence.

15. The detection device according to any one of claims 1 to 14, wherein the radiation detector includes a semiconductor detection element for detecting the scattered radiation.

16. The detection device according to any one of claims 1 to 15, wherein the side of the container is cylindrical.

17. The detection device according to any one of claims 1 to 16, comprising a circulation path connected to the container, and a pump and a filter inserted into the circulation path.

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