Radiation detection device, information processing method, and computer program

Abstract

To provide a radiation detection device capable of appropriately reducing a system peak, an information processing method and a computer program.SOLUTION: A radiation detection device includes a radiation detection element having a semiconductor part, and an information processing part. The information processing part calculates a spectrum of radiation made incident on an object in a specific band for absorbing radiation that generates characteristic X-rays in the object on the basis of the spectrum of the radiation made incident on the semiconductor part, an absorption property of the radiation in the object corresponding to components of the object through which the radiation transmits before being made incident on the semiconductor part, and the spectrum of the radiation made incident on the object, calculates a system peak by calculating the spectrum of the characteristic X-rays that is generated from the object and is made incident on the semiconductor part on the basis of the calculated spectrum, a generation characteristic of the characteristic X-rays at the object corresponding to the components of the object, and the amount of a material, and subtracts the calculated system peak from the spectrum of the radiation made incident on the semiconductor part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a radiation detection device, an information processing method, and a computer program for detecting radiation. [Background technology]

[0002] Some radiation detectors for detecting radiation such as X-rays include a radiation detection element using a semiconductor. When radiation is incident on the radiation detection element, an amount of charge corresponding to the energy of the radiation is generated in the semiconductor, a signal corresponding to the amount of charge is generated, and a radiation spectrum is generated that shows the relationship between the number of generated signals and the energy of the radiation. The radiation spectrum includes a so-called system peak caused by characteristic X-rays generated in the radiation detector, in addition to peaks caused by the radiation to be detected. In order to improve the accuracy of radiation detection, it is necessary to reduce the system peak. Patent Document 1 discloses a technique for subtracting the background caused by the system peak from the radiation spectrum. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-99749 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, a constant is subtracted from the spectrum as a background due to the system peak. However, it is difficult to appropriately reduce the system peak using the method of subtracting a constant. Another method for reducing the system peak is to shield the characteristic X-rays generated within the radiation detector. However, it is not possible to shield the characteristic X-rays generated from portions near the surface of the radiation detection element, such as a protective film, and a system peak is generated due to these characteristic X-rays.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a radiation detection device, an information processing method, and a computer program that can appropriately reduce the system peak. [Means for solving the problem]

[0006] A radiation detection apparatus according to one aspect of the present invention is a radiation detection apparatus comprising a radiation detection element having a semiconductor portion and an information processing unit, wherein the information processing unit calculates the spectrum of the radiation incident on the object in a specific band in which radiation that generates characteristic X-rays in the object is absorbed, based on the spectrum of the radiation incident on the semiconductor portion, the radiation absorption characteristics of the object depending on the components of the object through which the radiation passes before entering the semiconductor portion, and the amount of material through which the radiation passes in the object; calculates a spectrum of the characteristic X-rays generated from the object and incident on the semiconductor portion based on the calculated spectrum, the characteristic X-ray generation characteristics of the object depending on the components of the object, and the amount of material, and calculates a system peak by subtracting the calculated system peak from the spectrum of the radiation incident on the semiconductor portion.

[0007] In one aspect of the present invention, a radiation detection device calculates the spectrum of radiation incident on an object based on the spectrum of radiation incident on a semiconductor portion included in a radiation detection element, the components of the object through which the radiation passes before entering the semiconductor portion, and the amount of material in the object through which the radiation passes. The radiation detection device also calculates a system peak based on the spectrum of radiation incident on the object, the components of the object, and the amount of material in the object through which the radiation passes, and subtracts the system peak from the radiation spectrum. In this way, the radiation detection device corrects the radiation spectrum by subtracting the system peak from the radiation spectrum. The radiation detection device can obtain a system peak of appropriate intensity by calculating the system peak according to the components of the object through which the radiation passes before entering the semiconductor portion and the amount of material in the object through which the radiation passes.

[0008] In a radiation detection device according to one aspect of the present invention, the radiation detection element further has a surface layer that exists between an incident surface onto which radiation is incident and the semiconductor portion, and the information processing unit calculates the spectrum of the radiation that is incident on the surface layer in a specific band in which radiation that generates characteristic X-rays is absorbed by the surface layer based on the spectrum of the radiation that is incident on the semiconductor portion, the radiation absorption characteristics of the surface layer that depend on the components of the surface layer, and the thickness of the surface layer, calculates the spectrum of the characteristic X-rays generated from the surface layer based on the calculated spectrum, the characteristic X-ray generation characteristics of the surface layer that depend on the components of the surface layer, and the amount of material in the surface layer through which radiation passes, and calculates the spectrum of the characteristic X-rays that are incident on the semiconductor portion based on the spectrum of the characteristic X-rays generated from the surface layer, thereby calculating the system peak.

[0009] In one aspect of the present invention, radiation passes through a surface layer included in a radiation detection element before entering a semiconductor portion. The radiation detection device calculates the spectrum of radiation incident on the surface layer based on the spectrum of radiation incident on the semiconductor portion and the components and thickness of the surface layer. The attenuation of radiation in the surface layer can be calculated according to the components and thickness of the surface layer, and the spectrum of radiation incident on the surface layer can be calculated from the spectrum of radiation incident on the semiconductor portion. The radiation detection device calculates characteristic X-rays generated from the surface layer based on the spectrum of radiation incident on the surface layer, the components of the surface layer, and the amount of material in the surface layer through which the radiation passes, and calculates a system peak by calculating the spectrum of the characteristic X-rays incident on the semiconductor portion. The thickness of the surface layer can be used as the amount of material in the surface layer through which the radiation passes. The spectrum of the characteristic X-rays generated in the surface layer by the radiation can be calculated from the spectrum of radiation incident on the surface layer and the components and thickness of the surface layer, and the system peak can be obtained.

[0010] In a radiation detection device according to one aspect of the present invention, the surface layer is made up of a plurality of layers, and the information processing unit calculates a spectrum of radiation incident on each layer based on the order of the plurality of layers, the radiation absorption characteristics of each layer depending on the components of each layer, and the amount of material in each layer through which the radiation passes; calculates a spectrum of characteristic X-rays generated from each layer based on the spectrum of radiation incident on each layer, the characteristic X-ray generation characteristics of each layer depending on the components of each layer, and the amount of material in each layer through which the radiation passes; and calculates a spectrum of characteristic X-rays from each layer incident on the semiconductor portion based on the spectrum of the characteristic X-rays generated from each layer, the order of the plurality of layers, the radiation absorption characteristics of each layer depending on the components of each layer, and the amount of material in each layer through which characteristic X-rays from other layers pass.

[0011] In one embodiment of the present invention, the surface layer is made up of a plurality of layers. The spectrum of the radiation incident on each layer and the spectrum of the characteristic X-rays generated in each layer are determined depending on the order of the layers, the components of each layer, and the amount of material in each layer through which the radiation passes. The radiation detection device can calculate the system peak caused by the characteristic X-rays by calculating the characteristic X-rays generated in each layer and incident on the semiconductor part.

[0012] A radiation detection device according to one embodiment of the present invention further includes a housing that accommodates the radiation detection element, the housing having an unobstructed opening, the radiation detection element being arranged with the incident surface facing the opening, and the surface layer including a light-shielding film.

[0013] In one embodiment of the present invention, the radiation detection element is accommodated in a housing, and the housing has an opening that is not blocked by a window material, and radiation that passes through the opening enters the radiation detection element and is detected. The radiation detection device can detect radiation that is too low in energy to pass through the window material. The surface layer includes a light-shielding film, which prevents light from entering the interior of the radiation detection element. The radiation detection device can obtain a radiation spectrum in which the system peak caused by the light-shielding film is reduced by information processing.

[0014] In the radiation detection device according to one aspect of the present invention, the light-shielding film is made of aluminum, carbon, gold, beryllium, magnesium, or an alloy thereof.

[0015] In one embodiment of the present invention, the light-shielding film is made of aluminum, carbon, gold, beryllium, magnesium, or an alloy thereof. Such a light-shielding film effectively prevents light from entering the interior of the radiation detection element, thereby preventing noise caused by light.

[0016] A radiation detection device according to one aspect of the present invention further includes a radiation detector including the radiation detection element, and the information processing unit calculates the spectrum of the characteristic X-rays incident on the semiconductor portion using a correction coefficient specific to the radiation detector.

[0017] In one aspect of the present invention, a radiation detection device calculates the spectrum of characteristic X-rays incident on a semiconductor portion using a correction coefficient specific to the radiation detector. The correction coefficient is a coefficient for correcting the intensity of characteristic X-rays incident on the semiconductor portion according to the configuration of the radiation detector. By using the correction coefficient, it is possible to accurately calculate a system peak caused by the characteristic X-rays.

[0018] A radiation detection apparatus according to one aspect of the present invention further includes an irradiation unit that irradiates a sample with radiation, and a display unit that displays the spectrum of the radiation from which the system peak has been subtracted.

[0019] In one aspect of the present invention, a radiation detection device includes an irradiation unit and detects radiation such as fluorescent X-rays generated from a sample irradiated with radiation. Based on the spectrum of the radiation with reduced system peaks, it is possible to perform highly accurate analysis of elements contained in the sample. The radiation detection device displays the spectrum of the radiation with reduced system peaks on a display unit. A user can check the spectrum of the radiation with reduced system peaks.

[0020] An information processing method according to one aspect of the present invention is characterized in that it includes the steps of: calculating a spectrum of radiation incident on an object in a specific band in which radiation that generates characteristic X-rays is absorbed by the object, based on the spectrum of radiation incident on a semiconductor portion of a radiation detection element, radiation absorption characteristics of the object that depend on the components of the object through which the radiation passes before entering the semiconductor portion, and the amount of material through which the radiation passes in the object; calculating a spectrum of the characteristic X-rays that are generated from the object and incident on the semiconductor portion, based on the calculated spectrum, the characteristic X-ray generation characteristics of the object that depend on the components of the object, and the amount of material; and calculating a system peak by subtracting the calculated system peak from the spectrum of radiation that entered the semiconductor portion.

[0021] A computer program according to one aspect of the present invention causes a computer to perform the following steps: calculate a spectrum of radiation incident on an object in a specific band in which radiation that generates characteristic X-rays is absorbed by the object, based on the spectrum of radiation incident on a semiconductor portion of a radiation detection element, radiation absorption characteristics of the object that depend on the components of the object through which the radiation passes before entering the semiconductor portion, and the amount of material through which the radiation passes in the object; calculate a spectrum of the characteristic X-rays that are generated from the object and incident on the semiconductor portion, based on the calculated spectrum, the characteristic X-ray generation characteristics of the object that depend on the components of the object, and the amount of material; and calculate a system peak by subtracting the calculated system peak from the spectrum of radiation that entered the semiconductor portion.

[0022] In one aspect of the present invention, the spectrum of radiation incident on an object is obtained based on the spectrum of radiation incident on a semiconductor portion included in a radiation detection element, the components of the object through which the radiation passes before entering the semiconductor portion, and the amount of material in the object through which the radiation passes. A system peak is calculated based on the spectrum of radiation incident on the object, the components of the object, and the amount of material in the object through which the radiation passes, and the system peak is subtracted from the radiation spectrum. An appropriate system peak is obtained depending on the components of the object through which the radiation passes before entering the semiconductor portion and the amount of material in the object through which the radiation passes. By subtracting the obtained system peak from the radiation spectrum, a radiation spectrum with an appropriately reduced system peak is obtained. [Effects of the Invention]

[0023] The present invention has excellent effects such as being able to appropriately reduce system peaks in the spectrum of radiation detected using a radiation detection element. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 2 is a block diagram illustrating an example of the functional configuration of the radiation detection apparatus. [Figure 2] 1 is a schematic cross-sectional view showing a first example of the configuration of a radiation detector. [Figure 3] FIG. 10 is a schematic cross-sectional view showing a second example of the configuration of the radiation detector. [Figure 4] 1 is a schematic cross-sectional view showing an example of a radiation detection element and a collimator. [Figure 5] FIG. 2 is a block diagram showing an example of the internal configuration of an analysis device. [Figure 6] 10 is a graph showing an example of the spectrum of radiation incident on a semiconductor portion. [Figure 7] FIG. 4 is a conceptual diagram showing an example of the contents of characteristic data. [Figure 8] 1 is a graph showing the relationship between absorption coefficient and radiation energy. [Figure 9]10 is a flowchart showing a first example of an information processing procedure for correcting a spectrum of radiation, which is executed by an analysis device. [Figure 10] 1 is a graph showing an example of a spectrum of characteristic X-rays incident on a semiconductor portion. [Figure 11] 10 is a graph showing the spectrum of corrected radiation. [Figure 12] 10 is a flowchart showing a second example of the information processing procedure for correcting the spectrum of radiation, which is executed by the analysis device. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention will now be described in detail with reference to the drawings showing embodiments thereof. FIG. 1 is a block diagram showing an example of the functional configuration of a radiation detection apparatus 10. The radiation detection apparatus 10 is, for example, an X-ray fluorescence analyzer. The radiation detection apparatus 10 includes an irradiation unit 35 that irradiates a sample 52 with radiation such as an electron beam or X-rays, a sample stage 51 on which the sample 52 is placed, and a radiation detector 2. Radiation is irradiated from the irradiation unit 35 to the sample 52, causing radiation such as fluorescent X-rays to be generated in the sample 52, and the radiation detector 2 detects the radiation generated from the sample 52. In the figure, the radiation is indicated by arrows. Note that the radiation detection apparatus 10 may also be configured to hold the sample 52 by a method other than placing it on the sample stage 51.

[0026] The radiation detector 2 includes a radiation detection element 1 and a preamplifier 21. A portion of the preamplifier 21 may be included inside the radiation detector 2, with the other portion disposed outside the radiation detector 2. A signal processing unit 32 and a voltage application unit 31 that applies a voltage required for radiation detection to the radiation detection element 1 are connected to the radiation detector 2. An analysis device 4 is connected to the signal processing unit 32. The voltage application unit 31, the signal processing unit 32, the irradiation unit 35, and the analysis device 4 are connected to a control unit 33. The control unit 33 controls the operations of the voltage application unit 31, the signal processing unit 32, the irradiation unit 35, and the analysis device 4. A display unit 34 such as a liquid crystal display or an EL display (Electroluminescent Display) is connected to the analysis device 4. The control unit 33 may be configured to receive user operations and control each unit of the radiation detection device 10 in accordance with the received operations.

[0027] FIG. 2 is a schematic cross-sectional view showing a first example of the configuration of a radiation detector 2. The radiation detector 2 is an SDD (Silicon Drift Detector). The radiation detector 2 includes a housing 25 in the shape of a cylinder with a truncated cone connected to one end. The housing 25 is configured by a plate-like bottom plate covered with a cap-like cover. An opening 251 is formed at the tip of the housing 25. No window having a window material is provided in the opening 251, and the opening 251 is not blocked. The radiation detection element 1, the collimator 22, the circuit board 23, the cooling unit 24, and the cold finger 26 are arranged inside the housing 25. The housing 25 accommodates the radiation detection element 1, the collimator 22, the circuit board 23, and the cooling unit 24. The cooling unit 24 is, for example, a Peltier element.

[0028] The radiation detection element 1 is mounted on the surface of the circuit board 23, and is disposed at a position facing the opening 251. The collimator 22 is cylindrical with both ends open, and is made of a material that blocks radiation. The collimator 22 is disposed between the radiation detection element 1 and the opening 251. One end of the collimator 22 faces the opening 251, and the other end faces the surface of the radiation detection element 1. Radiation mainly passes through the opening 251 and enters the inside of the housing 25, and the collimator 22 blocks part of the radiation. The radiation detection element 1 detects radiation that enters without being blocked by the collimator 22.

[0029] A circuit is formed on the circuit board 23, and the preamplifier 21 is mounted on the circuit board 23. The preamplifier 21 is omitted from FIG. 2. The back surface of the circuit board 23 is in thermal contact with the heat absorption portion of the cooling unit 24, either directly or via an intervening object. The heat dissipation portion of the cooling unit 24 is in thermal contact with the cold finger 26. The cold finger 26 has a flat portion with which the heat dissipation portion of the cooling unit 24 is in thermal contact, and a portion that penetrates the bottom plate portion of the housing 25. Heat from the radiation detection element 1 is absorbed by the cooling unit 24 through the circuit board 23, conducted from the cooling unit 24 to the cold finger 26, and dissipated to the outside of the radiation detector 2 through the cold finger 26.

[0030] The radiation detector 2 has a plurality of lead pins 27 penetrating the bottom plate portion of the housing 25. The lead pins 27 are connected to the circuit board 23 by a method such as wire bonding. The application of voltage to the radiation detection element 1 by the voltage application unit 31 and the output of a signal from the preamplifier 21 are performed through the lead pins 27. The radiation detector 2 may further include other components.

[0031] 3 is a schematic cross-sectional view showing a second example of the configuration of the radiation detector 2. In this second example, the radiation detector 2 does not include the cooling unit 24 or the cold finger 26. The back surface of the circuit board 23 is in thermal contact with the bottom plate of the housing 25, either directly or via an intervening object. Heat from the radiation detection element 1 is conducted to the bottom plate of the housing 25 through the circuit board 23 and is released from the bottom plate to the outside of the radiation detector 2. In this second example as well, radiation mainly passes through the opening 251 and enters the inside of the housing 25 and then enters the radiation detection element 1.

[0032] FIG. 4 is a schematic cross-sectional view showing an example of a radiation detection element 1 and a collimator 22. The radiation detection element 1 is a silicon drift type radiation detection element. The radiation detection element 1 is generally flat. The radiation detection element 1 includes a plate-shaped semiconductor portion 11 made of Si (silicon). The semiconductor portion 11 is composed of n-type Si. The radiation detection element 1 has an incident surface 151 located on the incident side where radiation to be detected is incident, and an electrode surface 152 located on the back side of the incident surface 151. A portion of the incident surface 151 is covered with the collimator 22. The radiation detection element 1 is arranged so that the electrode surface 152 faces the circuit board 23 and the incident surface 151 faces the opening 251.

[0033] A surface layer 12 is provided in a portion of the radiation detection element 1 between the incident surface 151 and the semiconductor portion 11. The surface layer 12 is composed of multiple layers, including a light-shielding film 121, an oxide film 122, and an electrode layer 123. The electrode layer 123 is provided in a portion of the semiconductor portion 11 on the incident surface 151 side. The electrode layer 123 is doped with a dopant that makes Si a different type of semiconductor from the components of the semiconductor portion 11. The component of the electrode layer 123 is p-type Si doped with a specific dopant such as boron, e.g., p+Si. The electrode layer 123 functions as an electrode. The electrode layer 123 is formed in most of the area along the incident surface 151, including the portion corresponding to the center of the incident surface 151 in a planar view. For example, the shape of the electrode layer 123 is circular in a planar view. The electrode layer 123 is formed in the entire area of ​​the incident surface 151 that corresponds to the portion not covered by the collimator 22. At the periphery of the area along the incident surface 151, there is a portion where the electrode layer 123 is not formed.

[0034] An annular guard ring electrode 161 is provided on the outside of the electrode layer 123. The guard ring electrode 161 is disposed in a position surrounding the periphery of the electrode layer 123. The potential of the guard ring electrode 161 is a floating potential. Although a single guard ring electrode 161 is shown in FIG. 4, in reality, multiple annular guard ring electrodes 161 are provided. The guard ring electrode 161 prevents dielectric breakdown between the edge of the semiconductor portion 11 and the electrode layer 123. A ground electrode connected to a ground potential may be provided outside the guard ring electrode 161. If a ground electrode is provided, the guard ring electrode 161 prevents dielectric breakdown between the electrode layer 123 and the ground electrode.

[0035] The electrode layer 123 and the portion of the semiconductor portion 11 on the incident surface 151 side are covered with an oxide film 122. The oxide film 122 is composed of an oxide of Si. The electrode layer 123 is connected to the outside of the radiation detection element 1. For example, a metal electrode (not shown) that penetrates the oxide film 122 is connected to the electrode layer 123, and the guard ring electrode 161 is connected to the outside of the radiation detection element 1 via the metal electrode.

[0036] At least a portion of the oxide film 122 is covered with the light-shielding film 121. At least a portion of the oxide film 122 that is not overlapped with the collimator 22 in a plan view is covered with the light-shielding film 121. The light-shielding film 121 is made of a material having light-shielding properties. For example, the light-shielding film 121 is made of aluminum or carbon. The light-shielding film 121 may also be made of gold, beryllium, or magnesium. Alternatively, the light-shielding film 121 may be made of an alloy containing aluminum, carbon, gold, beryllium, or magnesium. The light-shielding film 121 effectively prevents light from entering the radiation detection element 1, thereby preventing noise from being generated by light. For example, the surface of the light-shielding film 121 forms the incident surface 151. The light-shielding film 121 may be further covered with a protective film.

[0037] A signal output electrode 13, which is an electrode that outputs a signal when radiation is detected, is provided on a portion of the semiconductor portion 11 facing the electrode surface 152. The signal output electrode 13 is made of the same type of Si as the semiconductor portion 11. For example, the signal output electrode 13 is made of n+Si, which is Si doped with a specific dopant such as phosphorus. Furthermore, a plurality of curved electrodes 14, which are arranged in multiple rings in a planar view, are provided on a portion of the semiconductor portion 11 facing the electrode surface 152. The curved electrode 14 is made of a semiconductor of a different type from the semiconductor portion 11, i.e., p-type Si, which is Si doped with a specific dopant such as boron. For example, the curved electrode 14 is made of p+Si. The curved electrodes 14 are approximately concentric, and the signal output electrode 13 is located approximately at the center of the curved electrodes 14. In other words, the curved electrodes 14 surround the signal output electrode 13, and the distances between the signal output electrode 13 and each curved electrode 14 are different.

[0038] Although four curved electrodes 14 are shown in FIG. 4, more curved electrodes 14 are actually provided. The shape of the curved electrodes 14 may be a ring other than a circular ring, and the multiple curved electrodes 14 do not have to be concentric. The shape of the curved electrodes 14 may be a ring with a portion missing. The signal output electrode 13 may be disposed at a position other than the center of the multiple curved electrodes 14. The radiation detection element 1 may have a configuration including multiple sets of the signal output electrode 13, multiple curved electrodes 14, and electrode layer 123.

[0039] An annular guard ring electrode 162 is provided outside the multiple curved electrodes 14, and an annular ground electrode 163 is provided outside the guard ring electrode 162. The ground electrode 163 is connected to a ground potential. The potential of the guard ring electrode 162 is a floating potential. The guard ring electrode 162 prevents dielectric breakdown between the curved electrode 14 and the ground electrode 163. Although a single guard ring electrode 162 is shown in FIG. 4, in practice, multiple annular guard ring electrodes 162 are provided. Note that the ground electrode 163 may not be provided, and a ground electrode may be provided on the incident surface 151 side. When the ground electrode 163 is not provided, the guard ring electrode 162 prevents dielectric breakdown between the edge of the semiconductor portion 11 and the curved electrode 14. A ground electrode must be provided on at least one of the incident surface 151 side and the electrode surface 152 side.

[0040] The guard ring electrodes 161 and 162 are made of a semiconductor of a different type from that of the semiconductor portion 11, that is, p-type Si. For example, the components of the guard ring electrodes 161 and 162 are p+Si. The guard ring electrodes 161 and 162 have the same polarity. The potential of the guard ring electrodes 161 and 162 may be a fixed potential.

[0041] The portion of the semiconductor portion 11 on the electrode surface 152 side is covered with an oxide film 124. The oxide film 124 is composed of an oxide of Si. A nitride film of Si may be provided instead of the oxide film 124. The oxide film 124 may be further covered with a protective film. The signal output electrode 13, the curved electrode 14, and the ground electrode 163 are connected to the outside of the radiation detection element 1. For example, metal electrodes (not shown) that penetrate the oxide film 124 are connected to the signal output electrode 13, the curved electrode 14, and the ground electrode 163, respectively. The signal output electrode 13, the curved electrode 14, and the ground electrode 163 are connected to the outside of the radiation detection element 1 via the metal electrodes.

[0042] The innermost curved electrode 14 and the outermost curved electrode 14 are connected to a voltage application unit 31. A voltage is applied from the voltage application unit 31 to the multiple curved electrodes 14 so that the innermost curved electrode 14 has the highest potential and the outermost curved electrode 14 has the lowest potential. The radiation detection element 1 is also configured so that a predetermined electrical resistance is generated between adjacent curved electrodes 14 that are at different distances from the signal output electrode 13. For example, an electrical resistance channel connecting two curved electrodes 14 is formed by adjusting the components of the portion located between adjacent curved electrodes 14. In other words, the multiple curved electrodes 14 are connected in a daisy chain via electrical resistance. When a voltage is applied, each curved electrode 14 has a potential that monotonically increases in order from the outer curved electrode 14 to the inner curved electrode 14. That is, the potential of the curved electrodes 14 increases in order from the curved electrodes 14 farthest from the signal output electrode 13 to the curved electrodes 14 closest to the signal output electrode 13. Note that the plurality of curved electrodes 14 may include a pair of adjacent curved electrodes 14 having the same potential.

[0043] The potentials of the multiple curved electrodes 14 generate an electric field (potential gradient) within the semiconductor section 11, where the potential is gradually higher the closer to the signal output electrode 13 and the potential is gradually lower the farther from the signal output electrode 13. The electrode layer 123 is connected to the voltage application section 31. A voltage is applied to the electrode layer 123 from the signal output electrode 13 so that the potential of the electrode layer 123 becomes the potential between the innermost curved electrode 14 and the outermost curved electrode 14. In this way, an electric field is generated within the semiconductor section 11, where the potential is gradually higher the closer to the signal output electrode 13.

[0044] Radiation is irradiated from the irradiation unit 35 onto the sample 52, and radiation such as fluorescent X-rays is generated in the sample 52 and enters the radiation detector 2. The radiation mainly passes through the opening 251 and enters the interior of the radiation detector 2. A portion of the radiation that enters the interior of the radiation detector 2 is blocked by the collimator 22. The radiation that is not blocked by the collimator 22 enters the radiation detection element 1 from the incident surface 151. The radiation that enters the radiation detection element 1 passes through the surface layer 12 and enters the semiconductor portion 11. The surface layer 12 is an object through which the radiation passes before entering the semiconductor portion 11, and the thickness of the surface layer 12 corresponds to the amount of material in the surface layer 12 through which the radiation passes.

[0045] Radiation incident on the semiconductor section 11 is absorbed within the semiconductor section 11, and an amount of charge corresponding to the energy of the absorbed radiation is generated within the semiconductor section 11. The generated charges are electrons and holes. The generated charges move due to the electric field inside the semiconductor section 11, and one type of charge flows into the signal output electrode 13 in a concentrated manner. In this embodiment, electrons generated by the incidence of radiation move and flow into the signal output electrode 13. The charge that flows into the signal output electrode 13 is output as a current signal.

[0046] The signal output electrode 13 is connected to a preamplifier 21. The signal output by the signal output electrode 13 is input to the preamplifier 21. The preamplifier 21 converts the current signal into a voltage signal. The preamplifier 21 outputs a signal with an intensity corresponding to the energy of the radiation. The preamplifier 21 is connected to a signal processing unit 32. When the preamplifier 21 outputs a signal, the radiation detector 2 outputs a signal with an intensity corresponding to the energy of the radiation. The signal processing unit 32 receives the signal output by the radiation detector 2 and detects the signal intensity, thereby detecting a signal value corresponding to the energy of the radiation detected by the radiation detector 2. The signal processing unit 32 counts the signals for each signal value and outputs data indicating the relationship between the signal value and the count number to the analysis device 4.

[0047] FIG. 5 is a block diagram showing an example of the internal configuration of the analysis device 4. The analysis device 4 is a computer such as a personal computer. The analysis device 4 includes a calculation unit 41, a memory 42, a reading unit 43, a storage unit 44, and an operation unit 45. The analysis device 4 is also connected to a signal processing unit 32, a control unit 33, and a display unit 34. The calculation unit 41 is configured using, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or a multi-core CPU. The calculation unit 41 may also be configured using a quantum computer. The memory 42 stores temporary data generated in conjunction with calculations. The memory 42 is, for example, a RAM (Random Access Memory). The reading unit 43 reads information from a recording medium 40 such as an optical disc or a portable memory.

[0048] The storage unit 44 is nonvolatile, and is, for example, a hard disk or nonvolatile semiconductor memory. The operation unit 45 receives input of information such as text by receiving operations from a user. The operation unit 45 is, for example, a touch panel, a keyboard, or a pointing device.

[0049] The calculation unit 41 causes the reading unit 43 to read the computer program 441 recorded on the recording medium 40, and stores the read computer program 441 in the memory unit 44. The calculation unit 41 executes the processing required for the analysis device 4 in accordance with the computer program 441. The computer program 441 may be downloaded from outside the analysis device 4. Alternatively, the computer program 441 may be pre-stored in the memory unit 44. In these cases, the analysis device 4 does not need to include the reading unit 43. The analysis device 4 may be composed of multiple computers. Alternatively, the control unit 33 and the analysis device 4 may be composed of the same computer.

[0050] The analysis device 4 receives data indicating the relationship between the signal value output by the signal processing unit 32 and the count number. The analysis device 4 generates a spectrum of the radiation incident on the semiconductor unit 11 based on the data from the signal processing unit 32. The signal value corresponds to the energy of the radiation and the count number corresponds to the number of times the radiation is detected, so the spectrum of the radiation can be obtained from the relationship between the signal value and the count number. The spectrum indicates the relationship between the energy and intensity of the radiation. The process of counting the signals output by the radiation detector 2 by signal value may be performed by the analysis device 4 instead of the signal processing unit 32. The generation of the spectrum of the radiation may be performed by the signal processing unit 32. The analysis device 4 stores spectral data representing the spectrum of the radiation in the memory unit 44.

[0051] FIG. 6 is a graph showing an example of the spectrum of radiation incident on the semiconductor part 11. The horizontal axis in the graph represents the radiation energy, and the vertical axis represents the radiation intensity. The radiation spectrum includes multiple peaks. More specifically, radiation having an energy corresponding to the components is generated from the sample 52, and the radiation spectrum includes peaks corresponding to the components of the sample 52. The radiation spectrum includes a system peak due to characteristic X-rays generated in the radiation detector 2. The position of the system peak is indicated by an arrow in FIG. 6. The analysis device 4 executes an information processing method for correcting the radiation spectrum. More specifically, the analysis device 4 executes a process of correcting the radiation spectrum by subtracting the system peak from the generated radiation spectrum. The analysis device 4 corresponds to an information processing unit.

[0052] As described above, radiation from the sample 52 passes through the opening 251, penetrates the surface layer 12, and enters the semiconductor portion 11. Because the opening 251 is not blocked, it does not affect the radiation passing through. A portion of the radiation is absorbed by the surface layer 12 as it passes through. This causes the radiation to attenuate. Furthermore, characteristic X-rays such as fluorescent X-rays are generated from the surface layer 12 that has absorbed the radiation. The characteristic X-rays enter the semiconductor portion 11 and are detected. In this way, the detected radiation contains characteristic X-rays from the surface layer 12, and the spectrum of the radiation is mixed with the spectrum of the characteristic X-rays. The spectrum of the characteristic X-rays from the surface layer 12 is the system peak.

[0053] The memory unit 44 stores characteristic data 442, which records numerical values ​​representing the radiation-related characteristics of the radiation detector 2. The numerical values ​​recorded in the characteristic data 442 are used in the information processing executed by the analysis device 4. FIG. 7 is a conceptual diagram showing an example of the content of the characteristic data 442. The characteristic data 442 records absorption coefficients representing the radiation absorption characteristics of the light-shielding film 121, the oxide film 122, and the electrode layer 123. If the intensity of the radiation incident on an object is I0, the intensity of the radiation that has passed through the object is I, the absorption coefficient of the object is μ, and the thickness of the object through which the radiation has passed is d, then the following equation (1) holds: I=I0exp(-μd) …(1)

[0054] The absorption coefficient varies depending on the radiation energy. Figure 8 is a graph showing the relationship between the absorption coefficient and the radiation energy. The horizontal axis in the graph represents the radiation energy, and the vertical axis represents the absorption coefficient for radiation of each energy. Generally, the higher the energy of radiation, the easier it is for it to penetrate an object, and the absorption coefficient tends to decrease as the radiation energy increases. However, the absorption coefficient increases sharply at a specific energy called the absorption edge. The energy of the absorption edge is the energy that causes electron transitions in an object. When radiation with an energy higher than the absorption edge is absorbed by an object, atoms in the object are excited and characteristic X-rays with an energy lower than the absorption edge are emitted. The specific band in which radiation that generates characteristic X-rays is absorbed by an object is called the absorption band. The absorption band is a band that includes energies higher than the absorption edge. When radiation included in the absorption band is absorbed by an object, characteristic X-rays with energies lower than the absorption band are emitted from the object. In other words, the system peak due to the characteristic X-rays from the object occurs in a band with energy lower than the absorption band.

[0055] The absorption coefficient differs depending on the components of the object. The characteristic data 442 records the absorption coefficients of the light-shielding film 121, the oxide film 122, and the electrode layer 123. The characteristic data 442 also records the absorption coefficient values ​​for each radiation energy, as shown in FIG. 8, for the light-shielding film 121, the oxide film 122, and the electrode layer 123. The characteristic data 442 records the absorption bands of the light-shielding film 121, the oxide film 122, and the electrode layer 123. The characteristic data 442 may also record an absorption edge. The characteristic data 442 may also record information other than the absorption coefficient as information representing the radiation absorption characteristics.

[0056] The characteristic data 442 records the characteristic X-ray generation characteristics of each of the light-shielding film 121, the oxide film 122, and the electrode layer 123. The characteristic X-ray generation characteristics indicate the energy of characteristic X-rays generated when radiation included in the absorption band is absorbed by an object. The characteristic X-ray generation characteristics are also made up of characteristic values ​​that indicate the intensity of characteristic X-rays generated when the intensity of radiation is absorbed. For example, the characteristic X-ray generation characteristics include the fluorescence yield or branching ratio.

[0057] The characteristic data 442 records the thicknesses of the light-shielding film 121, the oxide film 122, and the electrode layer 123. The thicker the light-shielding film 121, the oxide film 122, and the electrode layer 123, the greater the amount of material through which radiation passing through each layer passes. Therefore, the thickness of each layer corresponds to the amount of material through which radiation passes. The thickness of each layer affects the intensity of radiation absorbed by each layer. The thickness of each layer also affects the intensity of characteristic X-rays generated in each layer. The order of the light-shielding film 121, the oxide film 122, and the electrode layer 123 is also recorded. For example, the order from the semiconductor portion 11 to the semiconductor portion 11 is recorded.

[0058] The characteristic data 442 records a correction coefficient for correcting the intensity of the system peak. The characteristic X-rays generated in the surface layer 12 include those that do not enter the semiconductor portion 11. For example, in the radiation detection element 1 shown in FIG. 4, among the characteristic X-rays generated in the surface layer 12, those radiated toward the upper side of the figure, i.e., away from the semiconductor portion 11, do not enter the semiconductor portion 11. For example, if a component that reflects characteristic X-rays is disposed within the radiation detector 2, some of the characteristic X-rays radiated away from the semiconductor portion 11 may be reflected by this component and enter the semiconductor portion 11. In this way, the proportion of the characteristic X-rays generated by the light-shielding film 121 that enter the semiconductor portion 11 varies depending on the configuration of the radiation detector 2. Therefore, the intensity of the system peak also varies depending on the configuration of the radiation detector 2. The correction coefficient is a coefficient for correcting the intensity of the characteristic X-rays that enter the semiconductor portion 11 depending on the configuration of the radiation detector 2, and is a value specific to the radiation detector 2. The value of the correction coefficient is less than 1.

[0059] The various numerical values ​​recorded in the characteristic data 442 are obtained and recorded by theoretical calculation or experiment. The calculation unit 41 reads out the numerical values ​​recorded in the characteristic data 442 as necessary and performs the information processing described below using the read out numerical values. Note that some or all of the numerical values ​​representing the radiation-related characteristics of the radiation detector 2 may be stored outside the analysis device 4, and the calculation unit 41 may acquire the numerical values ​​stored outside the analysis device 4 and perform the information processing. For example, the numerical values ​​representing the radiation-related characteristics of the radiation detector 2 are stored in a database connected to the analysis device 4 via a communication network, and the characteristic data 442 records links for referencing each numerical value. The calculation unit 41 may use the link to acquire the numerical values ​​required for the information processing from the database.

[0060] The information processing executed by the analysis device 4 will be described below. FIG. 9 is a flowchart showing a first example of the procedure of information processing for correcting the spectrum of radiation executed by the analysis device 4. In the first example, only the characteristic X-rays from the light-shielding film 121 are treated as the cause of the system peak. The characteristic X-rays generated from the oxide film 122 and the electrode layer 123 are not taken into consideration because they have low intensity. Hereinafter, step will be abbreviated as S. The analysis device 4 executes the following processing by the calculation unit 41 executing information processing in accordance with the computer program 441.

[0061] The analysis device 4 calculates the spectrum of the radiation incident on the electrode layer 123 based on the spectrum of the radiation incident on the semiconductor section 11 (S11). In S11, for example, the calculation unit 41 calculates I0 in equation (1) by assuming that I is the intensity based on the spectrum of the generated radiation, I0 is the intensity of the radiation incident on the electrode layer 123, μ is the absorption coefficient of the electrode layer 123, and d is the thickness of the electrode layer 123. The calculation unit 41 calculates I0 for each energy to calculate the spectrum of the radiation incident on the electrode layer 123.

[0062] The analysis device 4 calculates the spectrum of the radiation incident on the oxide film 122 (S12). In S12, the calculation unit 41 calculates the spectrum of the radiation incident on the oxide film 122 based on the spectrum of the radiation incident on the electrode layer 123. For example, the calculation unit 41 calculates I0 in equation (1) by assuming that I is the intensity based on the spectrum of the radiation incident on the electrode layer 123, I0 is the intensity of the radiation incident on the oxide film 122, μ is the absorption coefficient of the oxide film 122, and d is the thickness of the oxide film 122. The calculation unit 41 calculates I0 for each energy to calculate the spectrum of the radiation incident on the oxide film 122.

[0063] The analysis device 4 calculates the spectrum of the radiation incident on the light-shielding film 121 (S13). In S13, the calculation unit 41 calculates the spectrum of the radiation incident on the light-shielding film 121 based on the spectrum of the radiation incident on the oxide film 122. For example, the calculation unit 41 calculates I0 in equation (1) by assuming that I is the intensity based on the spectrum of the radiation incident on the oxide film 122, I0 is the intensity of the radiation incident on the light-shielding film 121, μ is the absorption coefficient of the light-shielding film 121, and d is the thickness of the light-shielding film 121. The calculation unit 41 calculates I0 for each energy to calculate the spectrum of the radiation incident on the light-shielding film 121. The calculation of the spectrum of the radiation incident on each layer of the surface layer 12 in S11 to S13 is performed for each layer in order from the layer closest to the semiconductor portion 11.

[0064] The light-shielding film 121 generates characteristic X-rays when irradiated with radiation. Therefore, the radiation incident on the oxide film 122 includes the characteristic X-rays generated in the light-shielding film 121. The radiation spectrum calculated in S13 is calculated based on the spectrum of radiation, including the characteristic X-rays, incident on the oxide film 122. Therefore, it differs from the spectrum of radiation actually incident on the light-shielding film 121 and includes peaks due to the characteristic X-rays. As described above, when radiation with an energy higher than the absorption edge is absorbed by an object, characteristic X-rays with an energy lower than the absorption edge are generated. Therefore, the energy of the characteristic X-rays is lower than the absorption band in which the radiation that generates the characteristic X-rays is absorbed. The peaks due to the characteristic X-rays are not included in the absorption band. Therefore, the spectrum in the absorption band of the radiation spectrum calculated in S13 corresponds to the spectrum of radiation actually incident on the light-shielding film 121. The analyzer 4 may calculate only the spectrum in the absorption band in S13.

[0065] The analysis device 4 calculates the spectrum of the characteristic X-rays generated by the light-shielding film 121 (S14). In S14, the calculation unit 41 calculates the spectrum of the characteristic X-rays generated by the light-shielding film 121 based on the spectrum in the absorption band of the radiation incident on the light-shielding film 121, the generation characteristics of the characteristic X-rays in the light-shielding film 121, and the thickness of the light-shielding film 121. The generation characteristics of the characteristic X-rays indicate the energy of the characteristic X-rays and the intensity of the characteristic X-rays corresponding to the intensity in the absorption band of the radiation incident on the light-shielding film 121. Furthermore, the thicker the light-shielding film 121, the greater the amount of material in the light-shielding film 121 through which the radiation passes, and the greater the intensity of the generated characteristic X-rays. The thickness of the light-shielding film 121 corresponds to the amount of material in the light-shielding film 121 through which the radiation passes. The calculation unit 41 identifies the energy of the characteristic X-rays and calculates the intensity of the characteristic X-rays to calculate the spectrum of the characteristic X-rays.

[0066] The analyzer 4 calculates the spectrum of the characteristic X-rays incident on the semiconductor portion 11 (S15). In S15, the calculation unit 41 calculates the spectrum of the characteristic X-rays incident on the semiconductor portion 11 based on the spectrum of the characteristic X-rays generated in the light-shielding film 121, the absorption coefficients and thicknesses of the oxide film 122 and the electrode layer 123, and the correction coefficient. For example, the calculation unit 41 defines the intensity of the characteristic X-rays generated in the light-shielding film 121 as I0 and the intensity of the characteristic X-rays that have passed through the oxide film 122 and entered the electrode layer 123 as I, and calculates the intensity of the characteristic X-rays that have passed through the electrode layer 123 and entered the semiconductor portion 11 using the absorption coefficient and thickness of the oxide film 122. The calculation unit 41 also defines the intensity of the characteristic X-rays that have passed through the electrode layer 123 as I0 and the intensity of the characteristic X-rays that have passed through the electrode layer 123 and entered the semiconductor portion 11 as I, and calculates the intensity of the characteristic X-rays that have entered the semiconductor portion 11 using the absorption coefficient and thickness of the electrode layer 123. The thicker the oxide film 122 and the electrode layer 123, the greater the amount of material in the oxide film 122 and the electrode layer 123 through which the characteristic X-rays pass, and the lower the intensity of the characteristic X-rays incident on the semiconductor portion 11. The thickness of the oxide film 122 and the electrode layer 123 corresponds to the amount of material in the oxide film 122 and the electrode layer 123 through which the characteristic X-rays pass.

[0067] Furthermore, the calculation unit 41 corrects the intensity of the characteristic X-rays incident on the semiconductor unit 11 by multiplying the calculated intensity of the characteristic X-rays by a correction coefficient. By using the correction coefficient, the intensity of the characteristic X-rays incident on the semiconductor unit 11 is corrected in accordance with the configuration of the radiation detector 2. By using the correction coefficient, the intensity of the characteristic X-rays incident on the semiconductor unit 11 can be accurately calculated. Furthermore, by using the correction coefficient, it is possible to separate the absorption of the characteristic X-rays by the oxide film 122 and the electrode layer 123 from the influence on the characteristic X-rays by the configuration of the radiation detector 2. For example, even in radiation detection devices 10 that have the same radiation detection element 1 but different parts of the radiation detector 2 other than the radiation detection element 1, the intensity of the characteristic X-rays incident on the semiconductor unit 11 can be calculated using the same transmission ratio and a correction coefficient according to the configuration of the radiation detector 2.

[0068] By correcting the intensities of the characteristic X-rays corresponding to each energy, the calculation unit 41 calculates the spectrum of the characteristic X-rays incident on the semiconductor unit 11. The spectrum of the characteristic X-rays incident on the semiconductor unit 11 corresponds to the system peak caused by the characteristic X-rays. Therefore, the analysis device 4 calculates the system peak by calculating the spectrum of the characteristic X-rays incident on the semiconductor unit 11. FIG. 10 is a graph showing an example of the spectrum of the characteristic X-rays incident on the semiconductor unit 11. In the graph, the horizontal axis represents the energy of the characteristic X-rays, and the vertical axis represents the intensity of the characteristic X-rays. The spectrum of the characteristic X-rays shown in FIG. 10 corresponds to the system peak caused by the characteristic X-rays.

[0069] In addition, in S14, the analysis device 4 may perform a process of correcting the intensity of the characteristic X-rays generated in the light-shielding film 121 by multiplying the intensity of the characteristic X-rays by a correction coefficient. In S15, the analysis device 4 may use the correction coefficient to correct the intensity of the characteristic X-rays generated in the light-shielding film 121 or the intensity of the characteristic X-rays incident on the electrode layer 123. Alternatively, in S15, the analysis device 4 may calculate the intensity of the characteristic X-rays incident on the semiconductor portion 11 by a calculation that does not use the correction coefficient. For example, the generation characteristics of the characteristic X-rays may be set in advance to values ​​that take into account the influence of the configuration of the radiation detector 2, and the calculation unit 41 may calculate the intensity of the characteristic X-rays incident on the semiconductor portion 11 by a calculation that uses these generation characteristics.

[0070] The analysis device 4 corrects the spectrum of the radiation incident on the semiconductor section 11 using the calculated system peak (S16). In S16, the calculation section 41 corrects the spectrum of the radiation incident on the semiconductor section 11 by subtracting the system peak from the spectrum of the radiation incident on the semiconductor section 11. The calculation section 41 stores data representing the corrected spectrum of the radiation in the storage section 44.

[0071] Fig. 11 is a graph showing the corrected radiation spectrum. In the graph, the horizontal axis represents the radiation energy, and the vertical axis represents the radiation intensity. Compared to the radiation spectrum before correction as shown in Fig. 6, the system peak corresponding to the spectrum of characteristic X-rays as shown in Fig. 10 is reduced. Because the system peak is reduced, the spectrum after correction corresponds to the spectrum of radiation incident on the radiation detector 2.

[0072] The analysis device 4 displays the corrected radiation spectrum (S17). In S17, the calculation unit 41 displays an image including the corrected radiation spectrum on the display unit 34. The user can check the radiation spectrum with the system peak reduced. The analysis device 4 may also display the spectrum before correction. For example, the calculation unit 41 may display an image showing the spectrum before correction and the corrected spectrum side by side on the display unit 34. For example, the calculation unit 41 may perform a process of alternately switching between displaying the spectrum before correction and displaying the corrected spectrum in accordance with an instruction received by the user operating the operation unit 45. After S17 is completed, the analysis device 4 ends the information processing for correcting the radiation spectrum.

[0073] 12 is a flowchart showing a second example of the information processing procedure for correcting the radiation spectrum executed by the analysis device 4. In the second example, characteristic X-rays from the light-shielding film 121 and characteristic X-rays from the oxide film 122 are treated as causes of the system peak. The calculation unit 41 executes information processing in accordance with the computer program 441, causing the analysis device 4 to perform the following processing. The analysis device 4 calculates the spectrum of radiation incident on the electrode layer 123 based on the spectrum of radiation incident on the semiconductor section 11 (S201). In S201, the calculation unit 41 performs processing similar to S11. The analysis device 4 calculates the spectrum of radiation incident on the oxide film 122 (S202). In S202, the calculation unit 41 performs processing similar to S12. In S202, the analysis device 4 may calculate only the spectrum in the absorption band.

[0074] The analysis device 4 calculates the spectrum of the characteristic X-rays generated in the oxide film 122 (S203). In S203, the calculation unit 41 calculates the spectrum of the characteristic X-rays generated in the oxide film 122 based on the spectrum in the absorption band of the radiation incident on the oxide film 122, the generation characteristics of the characteristic X-rays in the oxide film 122, and the thickness of the oxide film 122. The calculation unit 41 calculates the spectrum of the characteristic X-rays by identifying the energy of the characteristic X-rays and calculating the intensity of the characteristic X-rays.

[0075] The analyzer 4 calculates the spectrum of the characteristic X-rays generated in the oxide film 122 and incident on the semiconductor portion 11 (S204). In S204, the calculation unit 41 calculates the spectrum of the characteristic X-rays incident on the semiconductor portion 11 based on the spectrum of the characteristic X-rays generated in the oxide film 122, the absorption coefficient and thickness of the electrode layer 123, and the correction coefficient. For example, the calculation unit 41 defines the intensity of the characteristic X-rays generated in the oxide film 122 as I0 and the intensity of the characteristic X-rays that have passed through the electrode layer 123 and incident on the semiconductor portion 11 as I, and calculates the intensity of the characteristic X-rays incident on the semiconductor portion 11 using the absorption coefficient and thickness of the electrode layer 123. Furthermore, the calculation unit 41 corrects the intensity of the characteristic X-rays incident on the semiconductor portion 11 by multiplying the calculated intensity of the characteristic X-rays by the correction coefficient. By correcting the intensities of the characteristic X-rays corresponding to each energy, the calculation unit 41 calculates the spectrum of the characteristic X-rays generated in the oxide film 122 and incident on the semiconductor portion 11.

[0076] The analysis device 4 calculates the spectrum of the radiation incident on the light-shielding film 121 (S205). In S205, the calculation unit 41 performs the same process as in S13. In S205, the analysis device 4 may calculate only the spectrum in the absorption band. The analysis device 4 calculates the spectrum of the characteristic X-rays generated in the light-shielding film 121 (S206). In S206, the calculation unit 41 performs the same process as in S14. The analysis device 4 calculates the spectrum of the characteristic X-rays generated in the light-shielding film 121 and incident on the semiconductor portion 11 (S207). In S207, the calculation unit 41 performs the same process as in S13.

[0077] The analysis device 4 calculates the system peak (S208). In S208, the calculation unit 41 calculates the system peak by adding together the spectrum of the characteristic X-rays generated in the oxide film 122 and incident on the semiconductor portion 11 and the spectrum of the characteristic X-rays generated in the light-shielding film 121 and incident on the semiconductor portion 11.

[0078] The analysis device 4 corrects the spectrum of the radiation incident on the semiconductor portion 11 using the calculated system peak (S209). In S209, the calculation unit 41 corrects the spectrum of the radiation incident on the semiconductor portion 11 by subtracting the system peak from the spectrum of the radiation incident on the semiconductor portion 11. In S208 and S209, the analysis device 4 may correct the spectrum without adding the spectrum of the characteristic X-rays from the oxide film 122 and the spectrum of the characteristic X-rays from the light-shielding film 121 together. In this process, the calculation unit 41 corrects the spectrum of the radiation incident on the semiconductor portion 11 by subtracting the spectrum of the characteristic X-rays from the oxide film 122 and the spectrum of the characteristic X-rays from the light-shielding film 121 from the spectrum of the radiation incident on the semiconductor portion 11. The calculation unit 41 stores data representing the corrected spectrum of the radiation in the storage unit 44.

[0079] The analysis device 4 displays the corrected radiation spectrum (S210). In S210, the calculation unit 41 performs the same process as in S17. After S210 is completed, the analysis device 4 ends the information processing for correcting the radiation spectrum.

[0080] The processes of S11 to S17 or S201 to S210 are executed as needed. For example, the analysis device 4 executes the processes of S11 to S17 or S201 to S210 each time a radiation spectrum is generated. The analysis device 4 may execute the processes of S11 to S17 or S201 to S210 when a correction instruction is received by the user operating the operation unit 45. The analysis device 4 may perform information processing to correct the radiation spectrum, treating characteristic X-rays from the light-shielding film 121, the oxide film 122, and the electrode layer 123 as causes of the system peak. The analysis device 4 may further perform information processing based on the corrected radiation spectrum. For example, the analysis device 4 may perform qualitative or quantitative analysis of elements contained in the sample 52 based on the corrected radiation spectrum.

[0081] As described above in detail, in this embodiment, the radiation detector 2 detects radiation emitted from the sample 52, and the analyzer 4 generates and corrects the radiation spectrum. More specifically, the analyzer 4 calculates the intensity of the radiation incident on the semiconductor portion 11, calculates a system peak according to the components and thickness of the surface layer 12, and subtracts the system peak from the radiation spectrum. By subtracting the system peak from the radiation spectrum, a spectrum with a reduced system peak is obtained. By calculating the system peak according to the components and thickness of the surface layer 12, a system peak of appropriate intensity is obtained. Therefore, the system peak can be appropriately reduced from the radiation spectrum.

[0082] By reducing the system peak, the spectrum of the radiation incident on the radiation detector 2 can be obtained. The user can check the spectrum of the radiation incident on the radiation detector 2. Based on the spectrum with the reduced system peak, it becomes possible to perform analysis with higher accuracy than before. For example, the analysis device 4 can perform qualitative analysis or quantitative analysis of elements contained in the sample 52 with high accuracy.

[0083] In the present embodiment, an example has been shown in which the thickness of each layer is used as a value corresponding to the amount of material through which radiation or characteristic X-rays pass, for example, the light-shielding film 121, the oxide film 122, and the electrode layer 123. When performing the processes of S11 to S17 or S201 to S210, the radiation detection device 10 may use a value other than thickness as a value corresponding to the amount of material through which radiation or characteristic X-rays pass, for example, the radiation detection device 10 may perform the processes of S11 to S17 or S201 to S210 using the amount of material in each layer along the path of the radiation or characteristic X-rays, or the density or mass fraction of each layer, as a value corresponding to the amount of material through which radiation or characteristic X-rays pass.

[0084] In this embodiment, the housing 25 has an opening 251 that is not blocked by a window material, and radiation that passes through the opening 251 is detected. Because the detected radiation does not need to pass through a window material, the radiation detection device 10 can detect radiation that is too low in energy to pass through a window material. On the other hand, light is more likely to pass through the opening 251 and enter the interior of the radiation detector 2. The light-shielding film 121 is required to prevent light from entering the interior of the radiation detection element 1 and generating noise, and a system peak occurs due to the light-shielding film 121. In this embodiment, it is possible to obtain a radiation spectrum with a reduced system peak through information processing while preventing the generation of noise due to light.

[0085] Although the present embodiment illustrates a configuration in which the surface layer 12 includes the light-shielding film 121, the oxide film 122, and the electrode layer 123, the surface layer 12 may include more layers. The radiation detector 2 may be configured to have no opening 251, but instead include a window having a window material, and detect radiation transmitted through the window. The radiation detection device 10 may be configured to treat an object other than the surface layer 12 as an object through which radiation passes before entering the semiconductor portion 11. That is, the radiation detection device 10 may be configured to subtract from the radiation spectrum a system peak due to characteristic X-rays generated from an object other than the surface layer 12. For example, the radiation detection device 10 subtracts from the radiation spectrum a system peak due to characteristic X-rays generated from the window or collimator 22 included in the radiation detector 2. In this configuration, the analysis device 4 can subtract from the radiation spectrum a system peak due to characteristic X-rays from the window or collimator 22 by performing a process similar to that for the surface layer 12.

[0086] In the present embodiment, the radiation detection element 1 is configured such that the semiconductor is Si, but the radiation detection element 1 may be configured such that it is made of a semiconductor other than Si. In the present embodiment, the semiconductor portion 11 is configured such that it is an n-type semiconductor, and the electrode layer 123 and the curved electrode 14 are configured such that it is a p-type semiconductor, but the radiation detection element 1 may be configured such that the semiconductor portion 11 is configured such that it is a p-type semiconductor, and the electrode layer 123 and the curved electrode 14 are configured such that it is an n-type semiconductor. In the present embodiment, the radiation detection element 1 is configured such that it is a silicon drift type radiation detection element, but the radiation detection element 1 may be an element other than a silicon drift type radiation detection element as long as it is a semiconductor element. Therefore, the radiation detector 2 may be a radiation detector other than an SDD.

[0087] In the present embodiment, the radiation detector 2 includes the collimator 22, but the radiation detector 2 may not include the collimator 22. In the present embodiment, the radiation detection element 1 is accommodated in the housing 25, but the radiation detector 2 may not include the housing 25. In the present embodiment, the radiation detection device 10 includes the irradiation unit 35 and the sample stage 51, but the radiation detection device 10 may not include the irradiation unit 35 or the sample stage 51. In the present embodiment, the horizontal axis of the radiation spectrum is energy, but the radiation detection device 10 may handle a spectrum in which the horizontal axis is a value other than energy, such as wavelength or wave number.

[0088] The present invention is not limited to the contents of the above-described embodiment, and various modifications are possible within the scope of the claims. In other words, embodiments obtained by combining technical means modified appropriately within the scope of the claims are also included in the technical scope of the present invention.

[0089] The matters described in each embodiment can be combined with each other. In addition, the independent claims and dependent claims described in the claims can be combined with each other in any combination, regardless of the reference format. Furthermore, although the claims use a format in which a claim references two or more other claims (multiple claim format), this is not limited to this format. A multiple claim (multi-multi claim) that references at least one other multiple claim may also be used. [Explanation of symbols]

[0090] 10 Radiation detection equipment 1. Radiation detection element 11 Semiconductor Department 12 Surface layer 121 Light-shielding film 122 Oxide film 123 Electrode layer 2. Radiation detectors 25 Housing 251 Opening 34 Display section 35 Irradiation unit 4 Analyzer 40 Recording Media 441 Computer Programs 52 samples

Claims

1. A radiation detection device including a radiation detection element having a semiconductor portion and an information processing unit, the radiation detection element further includes a surface layer located between an incident surface onto which radiation is incident and the semiconductor portion, The information processing unit calculating a spectrum of radiation incident on the surface layer in a specific band in which radiation that generates characteristic X-rays is absorbed by the surface layer based on the spectrum of radiation incident on the semiconductor portion, the radiation absorption characteristics of the surface layer depending on the components of the surface layer, and the thickness of the surface layer; calculating a spectrum of the characteristic X-rays generated from the surface layer based on the calculated spectrum, the generation characteristics of the characteristic X-rays in the surface layer according to the components of the surface layer, and the amount of material in the surface layer through which radiation penetrates; calculating a system peak by calculating a spectrum of the characteristic X-rays incident on the semiconductor portion based on the spectrum of the characteristic X-rays generated from the surface layer; The calculated system peak is subtracted from the spectrum of the radiation incident on the semiconductor portion. A radiation detection device characterized by:

2. The surface layer is composed of a plurality of layers, The information processing unit calculating a spectrum of radiation incident on each layer based on the order of the plurality of layers, the radiation absorption characteristics of each layer according to the components of each layer, and the amount of material in each layer through which the radiation penetrates; calculating a spectrum of characteristic X-rays generated from each layer based on the spectrum of radiation incident on each layer, the generation characteristics of characteristic X-rays in each layer according to the components of each layer, and the amount of material through which radiation passes in each layer; The spectrum of the characteristic X-rays from each layer incident on the semiconductor portion is calculated based on the spectrum of the characteristic X-rays generated from each layer, the order of the plurality of layers, the radiation absorption characteristics of each layer according to the components of each layer, and the amount of material in each layer through which the characteristic X-rays from other layers pass.

2. The radiation detection device according to claim 1.

3. Further comprising a housing for accommodating the radiation detection element; the housing has an unobstructed opening; the radiation detection element is disposed with the incident surface facing the opening, The surface layer includes a light-shielding film.

3. The radiation detection device according to claim 1, wherein the radiation detection device is a radiation detector.

4. The light-shielding film is made of aluminum, carbon, gold, beryllium, magnesium, or an alloy thereof.

4. The radiation detection device according to claim 3.

5. Further comprising a radiation detector including the radiation detection element, The information processing unit A spectrum of the characteristic X-rays incident on the semiconductor portion is calculated using a correction coefficient specific to the radiation detector.

3. The radiation detection device according to claim 1, wherein the radiation detection device is a radiation detector.

6. an irradiation unit that irradiates radiation onto the sample; a display unit that displays the spectrum of the radiation after the system peak has been subtracted; 3. The radiation detection device according to claim 1, further comprising:

7. calculating a spectrum of radiation incident on the surface layer in a specific band in which radiation that generates characteristic X-rays is absorbed by the surface layer based on the spectrum of radiation incident on the semiconductor part of the radiation detection element, the radiation absorption characteristics of the surface layer that are in accordance with the components of the surface layer that exists between the incident surface of the radiation detection element on which the radiation is incident and the semiconductor part, and the thickness of the surface layer; calculating a spectrum of the characteristic X-rays generated from the surface layer based on the calculated spectrum, the generation characteristics of the characteristic X-rays in the surface layer according to the components of the surface layer, and the amount of material in the surface layer through which radiation penetrates; calculating a system peak by calculating a spectrum of the characteristic X-rays incident on the semiconductor portion based on the spectrum of the characteristic X-rays generated from the surface layer; The calculated system peak is subtracted from the spectrum of the radiation incident on the semiconductor portion.

1. An information processing method comprising:

8. calculating a spectrum of radiation incident on the surface layer in a specific band in which radiation that generates characteristic X-rays is absorbed by the surface layer based on the spectrum of radiation incident on the semiconductor part of the radiation detection element, the radiation absorption characteristics of the surface layer that are in accordance with the components of the surface layer that exists between the incident surface of the radiation detection element on which the radiation is incident and the semiconductor part, and the thickness of the surface layer; calculating a spectrum of the characteristic X-rays generated from the surface layer based on the calculated spectrum, the generation characteristics of the characteristic X-rays in the surface layer according to the components of the surface layer, and the amount of material in the surface layer through which radiation penetrates; calculating a system peak by calculating a spectrum of the characteristic X-rays incident on the semiconductor portion based on the spectrum of the characteristic X-rays generated from the surface layer; The calculated system peak is subtracted from the spectrum of the radiation incident on the semiconductor portion. A computer program that causes a computer to execute a process.

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