Radiation detection device, information processing method, and computer program

Abstract

Provided are a radiation detection device in which malfunctioning of the radiation detection device can be suppressed, an information processing method, and a computer program.　The radiation detection device comprises an illumination unit that turns on to illuminate a sample, a radiation detection element for detecting radiation generated from the sample, a voltage application unit that applies a voltage to the radiation detection element, and a control unit. The control unit, after causing the voltage application unit to stop voltage application to the radiation detection element, turns on the illumination unit, and, after turning off the illumination unit, causes the voltage application unit to start voltage application to the radiation detection element.

Description

Radiation detection device, information processing method, and computer program

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

[0002] A radiation detection element operates to detect radiation such as X-rays when an external voltage is applied to it. For example, a radiation detection element using a semiconductor can detect radiation incident on the semiconductor when a voltage is applied to the semiconductor. In response to the detection of radiation, a current signal is output from the radiation detection element. A radiation detection device that includes a radiation detection element and detects radiation emitted from a sample also includes an illumination unit that illuminates the sample for observation of the sample. Patent Document 1 discloses an example of a radiation detection device that includes an illumination unit and a radiation detection element that detects secondary electrons.

[0003] JP 2019-133787 A

[0004] X-ray analysis is a technique for analyzing a sample by irradiating the sample with radiation such as electron beams or X-rays and detecting characteristic X-rays emitted from the sample. In X-ray analysis, an X-ray detection element is used as the radiation detection element, and an illumination unit is also used to illuminate the sample. When illumination light from the illumination unit is incident on the X-ray detection element, the current signal increases, degrading the accuracy of radiation detection. Furthermore, the increase in the current signal can cause the radiation detection device to malfunction. In this way, the incidence of illumination light on the X-ray detection element can cause malfunctions in the radiation detection device.

[0005] The present invention has been made in consideration of the above circumstances, and its object is to provide a radiation detection device, an information processing method, and a computer program that can suppress malfunctions in the radiation detection device.

[0006] A radiation detection device according to one aspect of the present invention includes an illumination unit that is turned on to illuminate a sample, a radiation detection element that detects radiation emitted from the sample, a voltage application unit that applies a voltage to the radiation detection element, and a control unit, wherein the control unit turns on the illumination unit after causing the voltage application unit to stop applying a voltage to the radiation detection element, and turns off the illumination unit after causing the voltage application unit to start applying a voltage to the radiation detection element.

[0007] In one aspect of the present invention, the radiation detection device turns on the illumination unit that illuminates the sample after stopping application of voltage to the radiation detection elements to enable radiation detection. Even if illumination light is incident on the radiation detection elements, the radiation detection elements are not operating and no current signal is output from the radiation detection elements. The radiation detection device also starts applying voltage to the radiation detection elements after turning off the illumination unit. Illumination light is not incident on the radiation detection elements that are now in a state where they can detect radiation. Therefore, the incidence of illumination light on the radiation detection elements does not cause an increase in the current signal from the radiation detection elements, and no malfunctions occur due to the increase in the current signal.

[0008] A radiation detection device according to one embodiment of the present invention further includes a start instruction receiving unit that receives a start instruction to start detecting radiation, and when the start instruction receiving unit receives the start instruction, the control unit turns off the illumination unit, and after the illumination unit is turned off, causes the voltage application unit to start applying voltage to the radiation detection element.

[0009] In one aspect of the present invention, when a radiation detection device receives a radiation detection start instruction, the radiation detection device turns off the illumination unit and starts applying voltage to the radiation detection elements. Simply by inputting the start instruction by the user, radiation detection is automatically performed while preventing illumination light from entering the radiation detection elements.

[0010] In one embodiment of the radiation detection device of the present invention, after detecting radiation using the radiation detection element, the control unit causes the voltage application unit to stop applying voltage to the radiation detection element, and after the application of voltage to the radiation detection element has stopped, turns on the illumination unit.

[0011] In one aspect of the present invention, after detecting radiation, the radiation detection device stops applying voltage to the radiation detection elements and turns on the illumination unit, making it possible to observe the sample while preventing illumination light from entering the operating radiation detection elements.

[0012] In a radiation detection device according to one aspect of the present invention, the control unit turns on the illumination unit after a predetermined waiting time has elapsed since the application of voltage to the radiation detection element has stopped.

[0013] In one aspect of the present invention, the radiation detection device turns on the illumination unit after a predetermined standby time has elapsed since the application of voltage to the radiation detection elements was stopped. The standby time is the time it takes for a capacitor for stabilizing the voltage to discharge and for the voltage applied from the capacitor to the radiation detection elements to change to a voltage at which the radiation detector does not operate. Even if illumination light is incident on the radiation detection elements, the radiation detection elements are not operating to detect radiation, and no adverse effects are caused by the illumination light.

[0014] A radiation detection device according to one aspect of the present invention further includes a housing that houses the radiation detection element therein, the housing having an unblocked opening.

[0015] 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 covered by a window material. Radiation that passes through the opening is incident on 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.

[0016] A radiation detection device according to one aspect of the present invention is characterized in that it further includes an irradiation unit that irradiates the sample with radiation, a spectrum generation unit that generates a spectrum of the radiation detected using the radiation detection element, and a display unit that displays the spectrum generated by the spectrum generation unit.

[0017] In one aspect of the present invention, the radiation detection device irradiates a sample with radiation, generates a spectrum of the radiation emitted from the sample, and displays the generated spectrum on a display unit, allowing a user to check the spectrum of the radiation emitted from the sample.

[0018] A radiation detection device according to one aspect of the present invention further comprises: an openable sample chamber in which the sample is placed; a radiation detector placed inside the sample chamber and having the radiation detection element; and an atmosphere adjustment unit that adjusts the atmosphere inside the closed sample chamber by reducing the pressure inside the sample chamber or filling it with a specific gas, and introduces air from outside the sample chamber into the sample chamber in the atmosphere-adjusted state, wherein the radiation detector has a temperature adjustment unit that adjusts the temperature of the radiation detection element and a temperature sensor that measures the temperature inside the radiation detector, and the control unit controls the atmosphere adjustment unit to adjust the timing of introducing air from outside the sample chamber into the sample chamber based on the temperature measured by the temperature sensor.

[0019] In one aspect of the present invention, the radiation detection device measures the temperature inside the radiation detector and controls the timing of introducing external air into the sample chamber based on the measured temperature. If external air is introduced into the sample chamber while the radiation detection element disposed inside the sample chamber is cooled, gas or moisture will be adsorbed to the radiation detection element. By controlling the timing of introducing air so as not to introduce external air into the sample chamber when the radiation detection element is cooled, adsorption of gas or moisture to the radiation detection element is suppressed.

[0020] In one form of the radiation detection device of the present invention, the control unit is characterized in that, when the temperature measured by the temperature sensor exceeds a predetermined temperature threshold, the control unit causes the atmosphere adjustment unit to introduce air from outside the sample chamber into the inside of the sample chamber.

[0021] In one aspect of the present invention, the radiation detection device introduces external air into the sample chamber when the temperature inside the radiation detector is high. When the temperature inside the radiation detector is high, the temperature of the radiation detection element is also high, making it difficult for gas or moisture to be adsorbed onto the radiation detection element.

[0022] A radiation detection device according to one embodiment of the present invention further includes an introduction instruction receiving unit that receives an introduction instruction to introduce air from outside the sample chamber into the interior of the sample chamber, and the control unit is characterized in that when the introduction instruction receiving unit receives the introduction instruction, it causes the temperature adjustment unit to heat the radiation detection element.

[0023] In one aspect of the present invention, the radiation detection device heats the radiation detection element when an introduction instruction for introducing external air into the sample chamber is received. By heating the radiation detection element, the temperature of the radiation detection element can be quickly increased, and the time required to introduce external air into the sample chamber can be shortened.

[0024] A radiation detection device according to one embodiment of the present invention further includes an output unit that outputs a standby instruction to wait for the sample chamber to be opened, and the control unit causes the output unit to output the standby instruction during a period before the atmosphere adjustment unit introduces air from outside the sample chamber into the interior of the sample chamber.

[0025] In one aspect of the present invention, the radiation detection device outputs a standby instruction to instruct the user to wait before opening the sample chamber during a period before introducing outside air into the sample chamber. By outputting the standby instruction, the user is prevented from forcibly opening the sample chamber.

[0026] A radiation detection device according to one aspect of the present invention further includes a gas pressure sensor that measures the gas pressure inside the sample chamber, and the control unit is configured to cause the temperature adjustment unit to start cooling the radiation detection element when the atmosphere adjustment unit starts adjusting the atmosphere and the gas pressure measured by the gas pressure sensor becomes equal to or lower than a predetermined pressure threshold.

[0027] In one aspect of the present invention, the radiation detection device measures the gas pressure in the sample chamber and starts cooling the radiation detection element when the gas pressure falls below a predetermined pressure threshold. When the sample chamber is depressurized, gas or moisture is less likely to be adsorbed to the cooled radiation detection element, and even if a specific gas is adsorbed to the radiation detection element, malfunctions are less likely to occur. This reduces malfunctions in the radiation detector.

[0028] In one form of the radiation detection device of the present invention, the control unit is characterized in that, when the atmosphere adjustment unit starts atmosphere adjustment and the specific gas has been supplied into the inside of the sample chamber for a predetermined period of time, the control unit causes the temperature adjustment unit to start cooling the radiation detection element.

[0029] In one aspect of the present invention, the radiation detection device starts cooling the radiation detection element when a specific gas has been supplied into the sample chamber for a predetermined period of time. When a sufficient amount of the specific gas, such as an inert gas, is supplied to the sample chamber, moisture is less likely to be adsorbed onto the cooled radiation detection element, and even if the specific gas is adsorbed onto the radiation detection element, malfunctions are less likely to occur. This reduces malfunctions of the radiation detector.

[0030] An information processing method according to one embodiment of the present invention is an information processing method for controlling a radiation detection device that includes an illumination unit that is turned on to illuminate a sample, a radiation detection element that detects radiation emitted from the sample, and a voltage application unit that applies a voltage to the radiation detection element, and is characterized in that it causes the voltage application unit to stop applying a voltage to the radiation detection element, and after the voltage application to the radiation detection element has stopped, it turns on the illumination unit, turns off the illumination unit, and after the illumination unit has been turned off, it causes the voltage application unit to start applying a voltage to the radiation detection element.

[0031] A computer program according to one aspect of the present invention causes a computer that controls a radiation detection device including an illumination unit that is turned on to illuminate a sample, a radiation detection element that detects radiation emitted from the sample, and a voltage application unit that applies a voltage to the radiation detection element to execute processing to stop application of voltage to the radiation detection element by the voltage application unit, turn on the illumination unit after application of voltage to the radiation detection element has stopped, turn off the illumination unit, and, after the illumination unit has been turned off, start application of voltage to the radiation detection element by the voltage application unit.

[0032] In one aspect of the present invention, the application of voltage to the radiation detection element to enable radiation detection is stopped, and then the illumination unit that illuminates the sample is turned on. Even if illumination light is incident on the radiation detection element, the radiation detection element is not operating, and no current signal is output from the radiation detection element. Furthermore, the illumination unit is turned off, and then the application of voltage to the radiation detection element is started. Illumination light is not incident on the radiation detection element, which is now in a state where it is able to detect radiation. Therefore, the incidence of illumination light on the radiation detection element does not cause an increase in the current signal from the radiation detection element, and no malfunction occurs due to the increase in the current signal.

[0033] According to the present invention, problems with the radiation detection device caused by illumination light being incident on the radiation detection elements are suppressed, and the present invention therefore has excellent effects such as enabling stable radiation detection.

[0034] 1 is a block diagram showing an example of the functional configuration of a radiation detection device; 2 is a schematic cross-sectional view showing the configuration of a radiation detector; 3 is a schematic cross-sectional view showing a radiation detection element and a collimator; 4 is a block diagram showing an example of the internal configuration of a control unit; 5 is a flowchart showing an example of the procedure of processing executed by the control unit; and 6 is a flowchart showing an example of the procedure of processing executed by the control unit.

[0035] The present invention will be described in detail below with reference to the drawings illustrating embodiments thereof. FIG. 1 is a block diagram showing an example of the functional configuration of a radiation detection apparatus 100. The radiation detection apparatus 100 is, for example, an X-ray fluorescence analyzer. The radiation detection apparatus 100 includes a sample stage 21 on which a sample 6 is placed, an irradiation unit 22 that irradiates the sample 6 with radiation such as an electron beam or X-rays, an illumination unit 23 that illuminates the sample 6, an imaging unit 24 that images the sample 6, and a radiation detector 1. The illumination unit 23 has a light source such as an LED (light-emitting diode) and can be turned on and off. When the light source is turned on, the illumination unit 23 illuminates the sample 6 placed on the sample stage 21. The imaging unit 24 images the sample 6 illuminated by the illumination unit 23. For example, the imaging unit 24 includes an optical system and an image sensor. Radiation is irradiated from the irradiation unit 22 to the sample 6, and characteristic X-rays such as fluorescent X-rays are generated in the sample 6. The radiation detector 1 detects the characteristic X-rays generated from the sample 6. In the drawing, the radiation and characteristic X-rays are indicated by arrows. The radiation detection device 100 may be configured to hold the sample 6 by a method other than placing it on the sample stage 21.

[0036] The radiation detection device 100 includes a sample chamber 2. The sample chamber 2 is box-shaped and has an openable and closable lid 20. When the lid 20 is closed, the sample chamber 2 is sealed. An opening / closing unit 41 that drives the lid 20 to open and close is connected to the lid 20. Inside the sample chamber 2, a sample stage 21, an irradiation unit 22, at least a light source of an illumination unit 23, an imaging unit 24, and a radiation detector 1 are arranged. The sample 6 is placed inside the sample chamber 2 by being placed on the sample stage 21. The irradiation unit 22 may be configured to irradiate radiation onto the sample 6 placed inside the sample chamber 2 from outside the sample chamber 2. The illumination unit 23 may be configured to illuminate the sample 6 placed inside the sample chamber 2 from outside the sample chamber 2. The imaging unit 24 may be configured to image the sample 6 placed inside the sample chamber 2 from outside the sample chamber 2.

[0037] The radiation detector 1 includes a radiation detection element 11, a preamplifier 12, and a temperature sensor 13. A part of the preamplifier 12 may be included inside the radiation detector 1, with the other part being located outside the radiation detector 1. The temperature sensor 13 measures the temperature inside the radiation detector 1. For example, the temperature sensor 13 is configured using a thermistor or a thermocouple. The radiation detector 1 is connected to a voltage application unit 42 that applies a voltage required for radiation detection to the radiation detection element 11, and a signal processing unit 43. The voltage application unit 42 also applies a voltage required for the preamplifier 12 to operate, to the preamplifier 12. An analysis unit 44 is connected to the signal processing unit 43. The analysis unit 44 is configured using a computer.

[0038] The radiation detection device 100 includes a control unit 3. The control unit 3 is connected to the irradiation unit 22, illumination unit 23, imaging unit 24, radiation detector 1, opening / closing unit 41, voltage application unit 42, signal processing unit 43, and analysis unit 44. The control unit 3 controls the operations of the irradiation unit 22, illumination unit 23, imaging unit 24, radiation detector 1, opening / closing unit 41, voltage application unit 42, signal processing unit 43, and analysis unit 44. An operation unit 45 and a display unit 46 are connected to the control unit 3 and the analysis unit 44. 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. The display unit 46 displays an image. The display unit 46 is, for example, a liquid crystal display or an EL display (electroluminescent display).

[0039] A drive unit 54 that drives the sample stage 21 is connected to the sample stage 21. The drive unit 54 is configured using, for example, a stepping motor. The sample stage 21 moves when the drive unit 54 drives the sample stage 21. For example, the sample stage 21 moves in the horizontal direction. When the sample stage 21 moves, the sample 6 placed on the sample stage 21 moves. Note that the radiation detection device 100 may not be provided with the drive unit 54.

[0040] The sample chamber 2 is connected to a pressure reducing unit 51 that reduces the pressure inside the sample chamber 2 and a gas supply unit 53 that supplies gas to the inside of the sample chamber 2. The radiation detection device 100 also includes a gas pressure sensor 52 that measures the pressure of the gas inside the sample chamber 2. The pressure reducing unit 51 reduces the pressure inside the sample chamber 2 when the lid unit 20 is closed. The pressure reducing unit 51 can also return the gas pressure inside the sample chamber 2 to the same gas pressure as outside the sample chamber 2 by introducing air outside the sample chamber 2 into the sample chamber 2. The pressure reducing unit 51 is configured using, for example, a vacuum pump and a leak valve.

[0041] The gas supply unit 53 supplies inert gas or dry air to the inside of the reduced pressure sample chamber 2. This fills the inside of the sample chamber 2 with inert gas or dry air. The inert gas or dry air corresponds to a specific gas. For example, the inert gas is helium. The gas supply unit 53 is configured using, for example, a gas tank that stores the inert gas or dry air, and an electromagnetic valve. The pressure reduction unit 51, the gas supply unit 53, and the gas pressure sensor 52 are connected to the control unit 3. The control unit 3 controls the operation of the pressure reduction unit 51 and the gas supply unit 53.

[0042] The pressure reducing unit 51 and the gas supply unit 53 correspond to an atmosphere adjusting unit. The pressure reducing unit 51 and the gas supply unit 53 adjust the atmosphere inside the sample chamber 2 by filling the inside of the sample chamber 2 with an inert gas or dry air. The radiation detection device 100 may be configured without using the gas supply unit 53. In this configuration, the radiation detection device 100 may not be provided with the gas supply unit 53. In this configuration, the pressure reducing unit 51 corresponds to the atmosphere adjusting unit and adjusts the atmosphere by reducing the pressure inside the sample chamber 2. Alternatively, the radiation detection device 100 may be configured without using the pressure reducing unit 51. In this configuration, the radiation detection device 100 may not be provided with the pressure reducing unit 51. In this configuration, the gas supply unit 53 supplies an inert gas or dry air to push out and discharge air from inside the sample chamber 2, thereby filling the inside of the sample chamber 2 with the inert gas or dry air. In this manner, the gas supply unit 53 in this configuration adjusts the atmosphere.

[0043] FIG. 2 is a schematic cross-sectional view showing the configuration of the radiation detector 1. The radiation detector 1 is an SDD (Silicon Drift Detector). The radiation detector 1 includes a housing 17 shaped like a cylinder with a truncated cone connected to one end. The housing 17 includes a plate-like bottom plate covered with a cap-like cover. An opening 171 is formed at the tip of the housing 17. The opening 171 does not include a window having a window material, and is not blocked. The radiation detection element 11, the collimator 14, the circuit board 15, the temperature adjustment unit 16, and the cold finger 18 are arranged inside the housing 17. The housing 17 accommodates the radiation detection element 11, the collimator 14, the circuit board 15, and the temperature adjustment unit 16. The temperature adjustment unit 16 cools and heats the radiation detection element 11. The temperature adjustment unit 16 is configured using, for example, a Peltier element.

[0044] The radiation detection element 11 is mounted on the surface of the circuit board 15, and is disposed at a position facing the opening 171. The collimator 14 is cylindrical with both ends open, and is made of a radiation-shielding material. The collimator 14 is disposed between the radiation detection element 11 and the opening 171. One end of the collimator 14 faces the opening 171, and the other end faces the surface of the radiation detection element 11. Radiation mainly passes through the opening 171 and enters the inside of the housing 17, and the collimator 14 blocks part of the radiation. The radiation detection element 11 detects radiation that is not blocked by the collimator 14 and enters the housing 17.

[0045] A circuit is formed on the circuit board 15, and the preamplifier 12 and the temperature sensor 13 are mounted on the circuit board 15. The preamplifier 12 and the temperature sensor 13 are omitted in FIG. 2 . The temperature sensor 13 may measure the temperature of the radiation detection element 11. The back surface of the circuit board 15 is in thermal contact with one end of the temperature adjustment unit 16, either directly or via an intervening material. The other end of the temperature adjustment unit 16 is in thermal contact with the cold finger 18. The cold finger 18 has a flat portion with which the temperature adjustment unit 16 is in thermal contact and a portion that penetrates the bottom plate of the housing 17. When the temperature adjustment unit 16 cools the radiation detection element 11, heat from the radiation detection element 11 is absorbed by the temperature adjustment unit 16 through the circuit board 15, conducted from the temperature adjustment unit 16 to the cold finger 18, and dissipated to the outside of the radiation detector 1 through the cold finger 18.

[0046] The radiation detector 1 has a plurality of lead pins 19 penetrating the bottom plate portion of the housing 17. The lead pins 19 are connected to the circuit board 15 by a method such as wire bonding. The application of voltage to the radiation detection element 11 by the voltage application unit 42 and the output of a signal from the preamplifier 12 are performed through the lead pins 19. The temperature sensor 13 is connected to the control unit 3 via the lead pins 19. The radiation detector 1 may further include other components.

[0047] FIG. 3 is a schematic cross-sectional view showing the radiation detection element 11 and the collimator 14. The radiation detection element 11 is a silicon drift type radiation detection element. The radiation detection element 11 is generally flat. The radiation detection element 11 includes a plate-shaped semiconductor portion 112 made of Si (silicon). The semiconductor portion 112 is composed of n-type Si. The radiation detection element 11 has an incident surface 111 located on the incident side where radiation to be detected is incident, and an electrode surface 116 located on the back side of the incident surface 111. A portion of the incident surface 111 is covered by the collimator 14. The radiation detection element 11 is arranged so that the electrode surface 116 faces the circuit board 15 and the incident surface 111 faces the opening 171.

[0048] An electrode layer 113 is provided on a portion of the semiconductor portion 112 on the side of the incident surface 111. The electrode layer 113 is doped with a dopant that makes Si a different type of semiconductor from the components of the semiconductor portion 112. The component of the electrode layer 113 is p-type Si, for example, p+Si, in which Si is doped with a specific dopant such as boron. The electrode layer 113 is formed on most of the area along the incident surface 111, including the portion corresponding to the center of the incident surface 111 in a planar view. For example, the shape of the electrode layer 113 is circular in a planar view. The electrode layer 113 is formed on all areas of the incident surface 111 corresponding to the portions not covered by the collimator 14. There are portions on the periphery of the area along the incident surface 111 where the electrode layer 113 is not formed.

[0049] A signal output electrode 115, which is an electrode that outputs a signal when radiation is detected, is provided on a portion of the semiconductor portion 112 facing the electrode surface 116. The signal output electrode 115 is made of the same type of Si as the semiconductor portion 112. For example, the signal output electrode 115 is made of n+Si, which is Si doped with a specific dopant such as phosphorus. Furthermore, a plurality of curved electrodes 114, which are arranged in multiple rings in a planar view, are provided on a portion of the semiconductor portion 112 facing the electrode surface 116. The curved electrode 114 is made of a semiconductor of a different type from the semiconductor portion 112, and is p-type Si, which is Si doped with a specific dopant such as boron. For example, the curved electrode 114 is made of p+Si. The curved electrodes 114 are approximately concentric, and the signal output electrode 115 is located approximately at the center of the curved electrodes 114. That is, the plurality of curved electrodes 114 surround the signal output electrode 115, and the distance between the signal output electrode 115 and each curved electrode 114 is different.

[0050] Although four curved electrodes 114 are shown in FIG. 3 , more curved electrodes 114 are actually provided. The shape of the curved electrodes 114 may be a ring other than a circular ring, and the multiple curved electrodes 114 do not have to be concentric. The shape of the curved electrodes 114 may be a ring with a portion missing. The signal output electrode 115 may be disposed at a position other than the center of the multiple curved electrodes 114. The radiation detection element 11 may have a configuration including multiple sets of the signal output electrode 115, multiple curved electrodes 114, and electrode layer 113.

[0051] The innermost curved electrode 114 and the outermost curved electrode 114 are connected to a voltage application unit 42. A voltage is applied from the voltage application unit 42 to the multiple curved electrodes 114 so that the innermost curved electrode 114 has the highest potential and the outermost curved electrode 114 has the lowest potential. The radiation detection element 11 is also configured so that a predetermined electrical resistance is generated between adjacent curved electrodes 114 that are at different distances from the signal output electrode 115. For example, an electrical resistance channel connecting two curved electrodes 114 is formed by adjusting the components of the portion located between adjacent curved electrodes 114. In other words, the multiple curved electrodes 114 are connected in a daisy chain via electrical resistance. When a voltage is applied, each curved electrode 114 has a potential that monotonically increases in order from the outer curved electrode 114 to the inner curved electrode 114. That is, the potential of the curved electrodes 114 increases in order from the curved electrodes 114 farthest from the signal output electrode 115 to the curved electrodes 114 closest to the signal output electrode 115. Note that the plurality of curved electrodes 114 may include a pair of adjacent curved electrodes 114 having the same potential.

[0052] The potentials of the multiple curved electrodes 114 generate an electric field (potential gradient) within the semiconductor portion 112, where the potential is gradually higher the closer to the signal output electrode 115 and lower the farther from the signal output electrode 115. The electrode layer 113 is connected to a voltage application unit 42. A voltage is applied to the electrode layer 113 from the voltage application unit 42 so that the potential of the electrode layer 113 becomes the potential between the innermost curved electrode 114 and the outermost curved electrode 114. In this way, an electric field is generated within the semiconductor portion 112, where the potential is gradually higher the closer to the signal output electrode 115.

[0053] Radiation is irradiated from the irradiation unit 22 onto the sample 6, and characteristic X-rays such as fluorescent X-rays are generated in the sample 6 and enter the radiation detector 1. The radiation consisting of characteristic X-rays mainly passes through the opening 171 and enters the inside of the radiation detector 1. A portion of the radiation that enters the inside of the radiation detector 1 is blocked by the collimator 14. The radiation that is not blocked by the collimator 14 enters the radiation detection element 11. The radiation that enters the radiation detection element 11 enters the semiconductor part 112.

[0054] Radiation incident on the semiconductor portion 112 is absorbed within the semiconductor portion 112, and an amount of charge corresponding to the energy of the absorbed radiation is generated within the semiconductor portion 112. The generated charges are electrons and holes. The generated charges move due to the electric field inside the semiconductor portion 112, and one type of charge concentrates and flows into the signal output electrode 115. In this embodiment, electrons generated by the incidence of radiation move and flow into the signal output electrode 115. The charge that has flowed into the signal output electrode 115 is output as a current signal.

[0055] The signal output electrode 115 is connected to the preamplifier 12. The signal output by the signal output electrode 115 is input to the preamplifier 12. The preamplifier 12 converts the current signal into a voltage signal. The preamplifier 12 outputs a signal with an intensity corresponding to the energy of the radiation. The preamplifier 12 is connected to the signal processing unit 43. When the preamplifier 12 outputs a signal, the radiation detector 1 outputs a signal with an intensity corresponding to the energy of the radiation to the signal processing unit 43.

[0056] The radiation detector 1 may include a control board that controls the application of voltage from the voltage application unit 42 to the preamplifier 12. This control board performs processing to stop the application of voltage from the voltage application unit 42 to the preamplifier 12 when the intensity of the signal output by the preamplifier 12 exceeds a predetermined threshold. The control board stops the operation of the preamplifier 12 by stopping the voltage application. When illumination light is incident on the radiation detection element 11 and the intensity of the current signal output from the radiation detection element 11 via the preamplifier 12 increases significantly, a malfunction such as a breakdown may occur. The control board prevents the occurrence of a malfunction such as a breakdown of the preamplifier 12 by stopping the operation of the preamplifier 12 when the output current signal is too large. The control board may be arranged outside the radiation detector 1.

[0057] The signal processing unit 43 receives the signal output by the radiation detector 1 and detects the signal intensity, thereby detecting a signal value corresponding to the energy of the radiation detected by the radiation detector 1. The signal processing unit 43 counts the signals for each signal value and outputs data indicating the relationship between the signal value and the count number to the analysis unit 44.

[0058] The analysis unit 44 receives data indicating the relationship between the signal value output by the signal processing unit 43 and the count number. The analysis unit 44 generates a spectrum of the radiation incident on the radiation detector 1 based on the data from the signal processing unit 43. Since the signal value corresponds to the radiation energy and the count number corresponds to the number of times radiation is detected, the radiation spectrum can be obtained from the relationship between the signal value and the count number. The spectrum indicates the relationship between the radiation energy and intensity. The process of counting the signals output by the radiation detector 1 for each signal value may be performed by the analysis unit 44 instead of the signal processing unit 43. The radiation spectrum may be generated by the signal processing unit 43. The analysis unit 44 stores spectral data representing the radiation spectrum. The signal processing unit 43 and the analysis unit 44 correspond to a spectrum generation unit. The display unit 46 displays the radiation spectrum. The user can check the spectrum of the characteristic X-rays generated from the sample 6. The analysis unit 44 may further perform information processing based on the radiation spectrum. For example, the analysis unit 44 performs qualitative or quantitative analysis of elements contained in the sample 6 based on the spectrum of characteristic X-rays from the sample 6 .

[0059] FIG. 4 is a block diagram showing an example of the internal configuration of the control unit 3. The control unit 3 is configured using a computer such as a personal computer. The control unit 3 includes a calculation unit 31, a memory 32, a reading unit 33, a storage unit 34, and an interface unit 35. The calculation unit 31 is configured using, for example, a central processing unit (CPU), a graphics processing unit (GPU), or a multi-core CPU. The calculation unit 31 may also be configured using a quantum computer. The memory 32 stores temporary data generated in conjunction with calculations. The memory 32 is, for example, a random access memory (RAM). The reading unit 33 reads information from a recording medium 30 such as an optical disc or a portable memory. The storage unit 34 is non-volatile, for example, a hard disk or a non-volatile semiconductor memory.

[0060] The calculation unit 31 causes the reading unit 33 to read the computer program 341 recorded on the recording medium 30, and stores the read computer program 341 in the memory unit 34. The calculation unit 31 executes processing required for the control unit 3 in accordance with the computer program 341. The computer program 341 may be downloaded from outside the control unit 3. Alternatively, the computer program 341 may be pre-stored in the memory unit 34. In these cases, the control unit 3 does not need to include the reading unit 33. The control unit 3 may be composed of multiple computers. Alternatively, the control unit 3 and the analysis unit 44 may be composed of the same computer.

[0061] An operation unit 45 and a display unit 46 are connected to the control unit 3. Other parts of the radiation detection device 100 are connected to the interface unit 35. A user operates the operation unit 45 to input various instructions, such as an instruction to start measurement, to the control unit 3. The control unit 3 accepts the instructions input using the operation unit 45. The display unit 46 displays an image. The control unit 3 outputs information necessary for radiation detection by displaying an image including information on the display unit 46. The control unit 3 accepts information necessary for control by accepting signals from each part of the radiation detection device 100 through the interface unit 35. The control unit 3 controls the operation of each part by transmitting control signals to each part of the radiation detection device 100 through the interface unit 35.

[0062] In the radiation detection device 100, the opening 171 is not blocked by a window material, and radiation that passes through the opening 171 is detected. Because the detected radiation does not need to pass through a window material, the radiation detection device 100 has high sensitivity for detecting low-energy radiation. On the other hand, in order to perform operations such as replacing the sample 6, it is necessary to open the sample chamber 2 and introduce outside air into the sample chamber 2. When outside air is introduced into the sample chamber 2, the air passes through the opening 171 and enters the radiation detector 1, causing gas or moisture to be adsorbed by the radiation detection element 11, which can cause malfunctions. The control unit 3 executes an information processing method for controlling the radiation detection device 100 to suppress malfunctions.

[0063] 5 and 6 are flowcharts illustrating exemplary processing procedures executed by the control unit 3. Hereinafter, steps are abbreviated as S. The control unit 3 executes the following processes by having the calculation unit 31 execute information processing in accordance with the computer program 341. With the sample 6 placed on the sample stage 21 and the lid 20 closed to close the sample chamber 2, the control unit 3 receives an instruction for atmosphere adjustment (S1). In S1, the calculation unit 31 displays an image for receiving the instruction for atmosphere adjustment on the display unit 46, and the user operates the operation unit 45 to receive the instruction for atmosphere adjustment. For example, an image including buttons for instructing atmosphere adjustment is displayed, and the user operates the operation unit 45 to select a button on the image to input the instruction for atmosphere adjustment. Buttons indicating the type of atmosphere adjustment, such as "depressurization," "vacuuming," or "gas replacement," may be displayed as buttons for instructing atmosphere adjustment. The radiation detection device 100 may also include hardware for receiving instructions for atmosphere adjustment, such as a push button.

[0064] The control unit 3 then starts adjusting the atmosphere inside the sample chamber 2 (S2). In a configuration that does not use the gas supply unit 53, in S2 the calculation unit 31 controls the decompression unit 51 to start adjusting the atmosphere by sending a control signal to the decompression unit 51 through the interface unit 35. The control unit 3 performs the atmosphere adjustment by decompressing the inside of the sample chamber 2 until the gas pressure inside the sample chamber 2 reaches a predetermined target value.

[0065] In the embodiment using the gas supply unit 53, in S2, the calculation unit 31 controls the decompression unit 51 and the gas supply unit 53 to start atmosphere adjustment by sending control signals to the decompression unit 51 and the gas supply unit 53 via the interface unit 35. In atmosphere adjustment, the control unit 3 causes the decompression unit 51 to decompress the interior of the sample chamber 2 until the gas pressure inside the sample chamber 2 reaches a predetermined target pressure, and then causes the gas supply unit 53 to supply an inert gas or dry air into the interior of the sample chamber 2. The inert gas or dry air may be supplied from the gas supply unit 53 without decompressing the interior of the sample chamber 2. By supplying the inert gas or dry air, the interior of the sample chamber 2 is filled with the inert gas or dry air.

[0066] The gas pressure sensor 52 measures the gas pressure inside the sample chamber 2, and the control unit 3 acquires the gas pressure measured by the gas pressure sensor 52. The gas pressure sensor 52 outputs a signal indicating the measured gas pressure, and the control unit 3 acquires the gas pressure by receiving the signal from the gas pressure sensor 52 via the interface unit 35.

[0067] The control unit 3 then determines whether the gas pressure measured by the gas pressure sensor 52 is equal to or less than a predetermined pressure threshold, or whether a predetermined target time has elapsed since the supply of inert gas or dry air into the sample chamber 2 began (S3). In a configuration that does not use the gas supply unit 53, the calculation unit 31 determines in S3 whether the gas pressure is equal to or less than the pressure threshold. The pressure threshold is a value that is lower than atmospheric pressure and equal to or greater than the target pressure. The pressure threshold is pre-stored in the storage unit 34 or is included in the computer program 341. The pressure threshold is, for example, 200 Pa. The fact that the gas pressure is equal to or less than the pressure threshold means that the inside of the sample chamber 2 has already been depressurized.

[0068] In the embodiment using the gas supply unit 53, the calculation unit 31 measures the time that has elapsed since the supply of inert gas or dry air into the sample chamber 2 began. In S3, the calculation unit 31 determines whether the time that has elapsed since the supply of inert gas or dry air began has reached a predetermined target time. The value of the target time is pre-stored in the storage unit 34 or is included in the computer program 341. The fact that the target time has elapsed since the supply of inert gas or dry air began means that a certain amount of inert gas or dry air has filled the sample chamber 2.

[0069] If the gas pressure measured by the gas pressure sensor 52 exceeds the pressure threshold, or if the time elapsed since the supply of inert gas or dry air into the sample chamber 2 started is less than the target time (S3: NO), the control unit 3 repeats the process of S3. In a configuration that does not use the gas supply unit 53, the calculation unit 31 repeats the process of S3 if the gas pressure exceeds the pressure threshold. In a configuration that uses the gas supply unit 53, the calculation unit 31 repeats the process of S3 if the time elapsed since the supply of inert gas or dry air started is less than the target time. Note that the radiation detection device 100 may be configured to determine in S3 whether the gas pressure measured by the gas pressure sensor 52 is less than the pressure threshold, or whether the time elapsed since the supply of inert gas or dry air started exceeds the target time.

[0070] If the gas pressure measured by the gas pressure sensor 52 is equal to or lower than the pressure threshold, or if a target time has elapsed since the supply of inert gas or dry air into the sample chamber 2 began (S3: YES), the control unit 3 starts cooling the radiation detection element 11 (S4). In a configuration that does not use the gas supply unit 53, the calculation unit 31 causes the temperature adjustment unit 16 to start cooling the radiation detection element 11 when the gas pressure is equal to or lower than the pressure threshold. In a configuration that uses the gas supply unit 53, the calculation unit 31 causes the temperature adjustment unit 16 to start cooling the radiation detection element 11 when a target time has elapsed since the supply of inert gas or dry air began. In S4, for example, the calculation unit 31 controls the temperature adjustment unit 16 by transmitting a control signal to the radiation detector 1 via the interface unit 35, thereby applying a voltage to a Peltier element included in the temperature adjustment unit 16 to cool the radiation detection element 11.

[0071] In a configuration that does not use the gas supply unit 53, the inside of the sample chamber 2 is already depressurized when cooling of the radiation detection element 11 begins. Because gases such as water vapor present inside the sample chamber 2 are diluted due to the depressurization, gas or moisture is unlikely to be adsorbed by the cooled radiation detection element 11. In a configuration that uses the gas supply unit 53, the inside of the sample chamber 2 is filled with inert gas or dry air when cooling of the radiation detection element 11 begins. Because the water vapor present inside the sample chamber 2 is diluted, moisture is unlikely to be adsorbed by the cooled radiation detection element 11. Even if inert gas or dry air is adsorbed by the cooled radiation detection element 11, the inert gas and dry air are unlikely to cause malfunctions in the radiation detection element 11. This prevents malfunctions of the radiation detector 1 caused by gas or moisture being adsorbed by the cooled radiation detection element 11.

[0072] The control unit 3 then determines whether the atmosphere adjustment inside the sample chamber 2 has been completed (S5). In a configuration that does not use the gas supply unit 53, the calculation unit 31 acquires the gas pressure measured by the gas pressure sensor 52 in S5 and determines that the atmosphere adjustment has been completed when the gas pressure has dropped to a target value. Furthermore, the calculation unit 31 determines that the atmosphere adjustment has not yet been completed when the gas pressure exceeds the target value. In a configuration that uses the gas supply unit 53, the calculation unit 31 determines that the atmosphere adjustment has been completed when the elapsed time since the start of the supply of inert gas or dry air into the sample chamber 2 reaches a predetermined reference time in S5. Furthermore, the calculation unit 31 determines that the atmosphere adjustment has not yet been completed when the elapsed time is less than the reference time. The reference time is equal to or greater than the target time. In the atmosphere adjustment, it is desirable that the pressure of the inert gas or dry air inside the sample chamber 2 be equal to or greater than one atmosphere. Maintaining a pressure equal to or greater than one atmosphere prevents external air from entering the sample chamber 2. The reference time is set in advance so that the pressure of the supplied inert gas or dry air becomes equal to or greater than one atmosphere inside the sample chamber 2. If the atmosphere adjustment is not completed (S5: NO), the control unit 3 repeats the process of S5. Note that the control unit 3 may omit the process of S5.

[0073] If the atmosphere adjustment is completed (S5: YES), the control unit 3 turns on the illumination unit 23 (S6). In S6, the calculation unit 31 controls the illumination unit 23 so as to supply a current necessary for lighting to the light source included in the illumination unit 23 by transmitting a control signal to the illumination unit 23 via the interface unit 35. The control unit 3 may display on the display unit 46 that the atmosphere adjustment has been completed. The radiation detection device 100 may include hardware for notifying that the atmosphere adjustment has been completed, such as a lamp that is turned on when the atmosphere adjustment has been completed.

[0074] The illumination unit 23 is turned on to illuminate the sample 6. At stage S6, a voltage required for detecting radiation is not applied to the radiation detection element 11. Because no voltage is applied and the radiation detection element 11 is not operating, even if illumination light is incident on the radiation detection element 11, the current signal from the radiation detection element 11 does not increase and no adverse effects occur.

[0075] The control unit 3 then photographs the sample 6 (S7). In S7, the calculation unit 31 causes the photographing unit 24 to photograph the sample 6 by transmitting a control signal to the photographing unit 24 via the interface unit 35. The photographing unit 24 photographs the illuminated sample 6 and transmits photographic data representing the photographed image to the control unit 3. The control unit 3 accepts the photographic data via the interface unit 35, and the calculation unit 31 causes the photographed image to be displayed on the display unit 46. The user can observe the sample 6 by visually checking the displayed observation image.

[0076] The control unit 3 then prepares for radiation detection (S8). In S8, the control unit 3 controls the drive unit 54 to move the sample 6 to a position where radiation will be irradiated. For example, multiple samples 6 are placed on the sample stage 21, and one of the samples 6 is placed at the position where radiation will be irradiated. For example, by moving the sample 6, the portion of the sample 6 that is irradiated with radiation is changed. The control unit 3 also controls the irradiation unit 22 to adjust the focus of the radiation irradiated by the irradiation unit 22. For example, a user visually checking the captured image of the sample 6 operates the operation unit 45 to input a control instruction to the control unit 3, and the control unit 3 moves the sample 6 and adjusts the focus of the radiation in accordance with the control instruction. In S8, the control unit 3 may perform other control to prepare for radiation detection.

[0077] At least some of the processes in S6 to S8 may be performed in parallel with the atmosphere adjustment process. In a configuration that does not use the gas supply unit 53, the process in S6 may be performed in parallel with the depressurization of the interior of the sample chamber 2, and the processes in S7 and S8 may be performed after the process in S3 or S5 is completed. In a configuration that uses the gas supply unit 53, the processes in S6 to S8 may be performed in parallel with the supply of an inert gas or dry air to the interior of the sample chamber 2.

[0078] The control unit 3 then determines whether the radiation detection element 11 has been sufficiently cooled (S9). In S9, the calculation unit 31 acquires the temperature measured by the temperature sensor 13 and makes a determination based on the acquired temperature. The temperature sensor 13 outputs a signal indicating the measured temperature, and the control unit 3 acquires the temperature by receiving the signal from the temperature sensor 13 via the interface unit 35. The calculation unit 31 determines that the radiation detection element 11 has been sufficiently cooled if the acquired temperature is equal to or lower than a reference temperature, and determines that the radiation detection element 11 has not yet been sufficiently cooled if the acquired temperature exceeds a predetermined reference temperature. The reference temperature is stored in advance in the storage unit 34 or is included in the computer program 341. The calculation unit 31 may make a determination based on whether the acquired temperature is lower than the reference temperature.

[0079] If the radiation detection element 11 has not yet been sufficiently cooled (S9: NO), the control unit 3 repeats the process of S9. When the radiation detection element 11 has not yet been sufficiently cooled, the control unit 3 prohibits the start of radiation detection. The control unit 3 may notify the user that the radiation detection element 11 is being cooled or that radiation detection cannot be started. For example, the control unit 3 displays an image including the text "Cooling" on the display unit 46. The radiation detection device 100 may include dedicated hardware for notifying the user that the radiation detection element 11 is being cooled or that radiation detection cannot be started.

[0080] If the radiation detection element 11 has been sufficiently cooled (S9: YES), the control unit 3 receives a start instruction to start radiation detection (S10). At this time, the control unit 3 ends the process of leaving the radiation detection element 11 in the cooling state or the inability to start radiation detection. In S10, the user operates the operation unit 45, causing the control unit 3 to receive the start instruction. The process of S10 corresponds to the start instruction receiving unit. The radiation detection device 100 may be provided with hardware for receiving a start instruction, such as a push button.

[0081] The control unit 3 then turns off the illumination unit 23 (S11). In S11, the calculation unit 31 controls the illumination unit 23 to stop supplying current to the light source by sending a control signal to the illumination unit 23 via the interface unit 35. After the illumination unit 23 is turned off, the control unit 3 causes the voltage application unit 42 to start applying a voltage to the radiation detection elements 11 (S12). In S12, the calculation unit 31 controls the voltage application unit 42 to apply a voltage to the radiation detection elements 11 by sending a control signal to the voltage application unit 42 via the interface unit 35. As described above, the voltage application unit 42 applies a voltage between the electrode layer 113, the innermost curved electrode 114, and the outermost curved electrode 114.

[0082] Application of a voltage to the radiation detection elements 11 puts the radiation detection elements 11 into a state where they can detect radiation. Because voltage application begins after the illumination unit 23 is turned off, illumination light from the illumination unit 23 is not incident on the radiation detection elements 11 that are now in a state where they can detect radiation. The illumination light does not cause an increase in the current signal from the radiation detection elements 11, and the illumination light does not have any adverse effects.

[0083] The control unit 3 then detects radiation (S13). In S13, the control unit 3 controls the irradiation unit 22 to irradiate radiation by transmitting a control signal to the irradiation unit 22 via the interface unit 35. The irradiation unit 22 irradiates the sample 6 with radiation, and characteristic X-rays are generated from the sample 6. The radiation consisting of characteristic X-rays is incident on the radiation detection element 11 in the radiation detector 1, and the radiation detection element 11 outputs a current signal corresponding to the radiation. As described above, the preamplifier 12 converts the current signal into a voltage signal, the signal processing unit 43 counts the signals for each signal value corresponding to the radiation energy, and the analysis unit 44 generates a radiation spectrum. In this way, the characteristic X-rays generated from the sample 6 are detected, and a characteristic X-ray spectrum is generated. Through the processes of S10 to S13, radiation detection is automatically performed while preventing illumination light from entering the radiation detection element 11, simply by the user inputting a start command.

[0084] The control unit 3 then stops applying voltage to the radiation detection elements 11 (S14). In S14, the calculation unit 31 controls the voltage application unit 42 to stop applying voltage by sending a control signal to the voltage application unit 42 via the interface unit 35. The voltage application unit 42 stops applying voltage. By stopping the application of voltage, the radiation detection elements 11 enter a state in which they cannot detect radiation.

[0085] After a predetermined waiting time has elapsed since the application of voltage to the radiation detection element 11 was stopped, the control unit 3 turns on the illumination unit 23 (S15). In S15, after the application of voltage from the voltage application unit 42 to the radiation detection element 11 is stopped, the calculation unit 31 waits for the predetermined waiting time. The value of the waiting time is pre-stored in the storage unit 34 or is included in the computer program 341. After the waiting time has elapsed, the calculation unit 31 controls the illumination unit 23 by sending a control signal to the illumination unit 23 via the interface unit 35 to supply the light source with the current required for lighting. The illumination unit 23 turns on, illuminating the sample 6. Because the illumination unit 23 turns on after the application of voltage to the radiation detection element 11 is stopped, the radiation detection element 11 does not perform radiation detection operation even if illumination light is incident on the radiation detection element 11. Therefore, the current signal from the radiation detection element 11 does not increase due to the illumination light, and no adverse effects occur.

[0086] The voltage application unit 42 includes a capacitor to remove noise contained in the voltage applied to the radiation detection elements 11 and to stabilize the voltage. The capacitor may be disposed between the voltage application unit 42 and the radiation detection elements 11. When the application of voltage from the voltage application unit 42 to the radiation detection elements 11 is stopped, it takes some time for the capacitor to discharge and the voltage of the capacitor does not change immediately, so the voltage applied to the radiation detection elements 11 does not change immediately either. For this reason, if the illumination unit 23 is turned on immediately after the application of voltage from the voltage application unit 42 to the radiation detection elements 11 is stopped, illumination light may be incident on the radiation detection elements 11 in an operating state, and the illumination light may cause an increase in the current signal from the radiation detection elements 11.

[0087] Therefore, after the voltage application unit 42 stops applying voltage to the radiation detection element 11, the control unit 3 waits for a predetermined waiting time before turning on the illumination unit 23. The waiting time is the time it takes for the capacitor to discharge and for the voltage applied to the radiation detection element 11 to change to a voltage at which the radiation detector does not operate. For example, the waiting time is 2 to 3 seconds. After the waiting time has elapsed, the radiation detection element 11 does not perform any operation for radiation detection. After the waiting time has elapsed, the control unit 3 turns on the illumination unit 23. Even if illumination light is incident on the radiation detection element 11, the radiation detection element 11 is not performing any operation for radiation detection, so the illumination light does not cause an increase in the current signal from the radiation detection element 11, and no adverse effects are caused by the illumination light.

[0088] After the illumination unit 23 is turned on in S15, the imaging unit 24 images the sample 6, and the display unit 46 can display the captured image. By visually checking the captured image, the user can observe the sample 6 after radiation detection has been performed. In this way, after radiation detection has been performed, it is possible to observe the sample 6 while preventing illumination light from entering the operating radiation detection elements 11.

[0089] The control unit 3 then determines whether or not to end radiation detection (S16). In S16, for example, the calculation unit 31 determines to end radiation detection when it receives an instruction to end detection by the user operating the operation unit 45. For example, the calculation unit 31 determines to end radiation detection when a predetermined number of radiation detections have been performed. For example, the calculation unit 31 determines to end radiation detection when a predetermined time has elapsed since the start of radiation detection. If radiation detection is not to be ended (S16: NO), the calculation unit 31 returns to S7 and repeats the process for detecting radiation.

[0090] When radiation detection is to be ended (S16: YES), the control unit 3 receives an introduction instruction to introduce air from outside the sample chamber 2 into the sample chamber 2 (S17). In S17, the user operates the operation unit 45, and the control unit 3 receives the introduction instruction. The process of S17 corresponds to the introduction instruction receiving unit. Note that the radiation detection device 100 may be provided with hardware for receiving the introduction instruction, such as a push button.

[0091] The control unit 3 then outputs a standby instruction to instruct the device to wait for the sample chamber 2 to be opened (S18). In S18, the calculation unit 31 outputs the standby instruction by displaying an image including the standby instruction on the display unit 46. For example, the calculation unit 31 displays an image indicating in text that the device is waiting for the sample chamber 2 to be opened on the display unit 46. Note that the radiation detection device 100 may be provided with hardware for outputting the standby instruction, such as a dedicated display for displaying an image indicating in text that the device is waiting for the sample chamber 2 to be opened.

[0092] Immediately after the introduction instruction is received, the inside of the sample chamber 2 is in a depressurized state, making it difficult to open the sample chamber 2. Furthermore, the radiation detection element 11 is in a cooled state, and if the sample chamber 2 is opened, air outside the sample chamber 2 will enter the radiation detector 1, causing gas or moisture to be adsorbed by the radiation detection element 11. By outputting the standby instruction, the user is prevented from forcibly opening the sample chamber 2. The processing of S18 corresponds to the output unit.

[0093] The control unit 3 then causes the temperature adjustment unit 16 to heat the radiation detection element 11 (S19). In S19, the calculation unit 31 controls the temperature adjustment unit 16 by transmitting a control signal to the radiation detector 1 via the interface unit 35, so as to apply a voltage to the Peltier element included in the temperature adjustment unit 16 to heat the radiation detection element 11. By heating the radiation detection element 11, the temperature of the radiation detection element 11 can be quickly increased, and the time required to introduce external air into the sample chamber 2 can be shortened.

[0094] The temperature sensor 13 measures the temperature inside the radiation detector 1, and the control unit 3 acquires the temperature measured by the temperature sensor 13 (S20). The temperature sensor 13 outputs a signal indicating the measured temperature, and the control unit 3 acquires the temperature by receiving the signal from the temperature sensor 13 via the interface unit 35.

[0095] The control unit 3 then determines whether the acquired temperature exceeds a predetermined temperature threshold (S21). In S21, the control unit 3 makes a determination by comparing the temperature measured by the temperature sensor 13 with the temperature threshold. The temperature threshold is a temperature higher than 0°C. The temperature threshold is pre-stored in the storage unit 34 or included in the computer program 341. The temperature threshold is, for example, 20°C. When the temperature measured by the temperature sensor 13 exceeds the temperature threshold, it means that the temperature of the radiation detection element 11 has become sufficiently high that gas adsorption or moisture adsorption to the radiation detection element 11 is unlikely to occur. Note that the radiation detection device 100 may be configured to determine whether the temperature is equal to or higher than the temperature threshold in S21.

[0096] If the acquired temperature is equal to or lower than the temperature threshold (S21: NO), the control unit 3 returns the process to S20. If the acquired temperature exceeds the temperature threshold (S21: YES), the control unit 3 introduces external air into the sample chamber 2 (S22). In a configuration in which the gas supply unit 53 is not used, the calculation unit 31 controls the decompression unit 51 to introduce external air into the sample chamber 2 by sending a control signal to the decompression unit 51 via the interface unit 35 in S22. The decompression unit 51 stops the decompression and introduces external air into the sample chamber 2, thereby returning the gas pressure inside the sample chamber 2 to the same gas pressure as outside. For example, the decompression unit 51 introduces external air into the sample chamber 2 by stopping the vacuum pump and opening the leak valve.

[0097] In the embodiment using the gas supply unit 53, in S22, the calculation unit 31 controls the decompression unit 51 and the gas supply unit 53 by sending control signals to them via the interface unit 35, thereby controlling them to introduce external air into the sample chamber 2. The gas supply unit 53 stops the supply of inert gas or dry air, and the decompression unit 51 introduces external air into the sample chamber 2, thereby returning the gas pressure inside the sample chamber 2 to the same gas pressure as outside. For example, the decompression unit 51 introduces external air into the sample chamber 2 by opening the leak valve while the gas supply unit 53 stops the supply of inert gas or dry air and the vacuum pump is stopped.

[0098] After introducing outside air into the sample chamber 2, the control unit 3 terminates output of the standby instruction (S23). In S23, for example, the calculation unit 31 terminates display of the image including the standby instruction on the display unit 46. The control unit 3 then opens the lid unit 20 (S24). In S24, the calculation unit 31 controls the opening / closing unit 41 to open the lid unit 20 by sending a control signal to the opening / closing unit 41 via the interface unit 35. When the opening / closing unit 41 opens the lid unit 20, the sample chamber 2 enters an open state. In S24, instead of automatically opening the lid unit 20, a process may be performed that allows the user to manually open the lid unit 20. With the sample chamber 2 open, operations such as removing or replacing the sample 6 are performed. After S24 is completed, the control unit 3 terminates processing.

[0099] While the lid 20 is open or while external air is being introduced through the leak valve of the pressure reducing unit 51, external air is introduced into the sample chamber 2. If the temperature of the external air is low, the radiation detection element 11 may be cooled by the air. The control unit 3 controls the temperature adjustment unit 16 so that the temperature measured by the temperature sensor 13 is equal to or higher than the temperature threshold while the lid 20 is open or while external air is being introduced into the sample chamber 2. For example, the control unit 3 causes the temperature adjustment unit 16 to heat the radiation detection element 11 when the temperature measured by the temperature sensor 13 is equal to or lower than the temperature threshold, and causes the temperature adjustment unit 16 to stop heating when the temperature exceeds the temperature threshold. This prevents the radiation detection element 11 from being cooled by external air, and prevents gas or moisture from being adsorbed onto the radiation detection element 11.

[0100] As described above in detail, in this embodiment, the radiation detection device 100 measures the temperature inside the radiation detector 1, and controls the timing of introducing external air into the sample chamber 2 based on the temperature inside the radiation detector 1. Specifically, when the temperature inside the radiation detector 1 is low, the radiation detection device 100 does not introduce external air into the sample chamber 2, and when the temperature inside the radiation detector 1 is high, the radiation detection device 100 introduces external air into the sample chamber 2.

[0101] In this embodiment, the housing 17 of the radiation detector 1 has an opening 171 that is not blocked by a window material, and radiation that passes through the opening 171 is detected. Because the detected radiation does not need to pass through a window material, the radiation detection device 100 can detect radiation that cannot pass through a window material due to its low energy. Therefore, the radiation detection device 100 has improved sensitivity in detecting low-energy radiation. On the other hand, gas enters the radiation detector 1 through the opening 171. If air enters the radiation detector 1 while the radiation detection element 11 is cooled for radiation detection, gas or moisture will be adsorbed by the radiation detection element 11. During radiation detection, the sample chamber 2 is depressurized or filled with inert gas or dry air, preventing the radiation detection element 11 from adsorbing gas or moisture. However, if external air is introduced into the sample chamber 2 while the radiation detection element 11 is cooled, gas or moisture may be adsorbed by the radiation detection element 11, causing a problem.

[0102] In this embodiment, when the temperature inside the radiation detector 1 is low, the radiation detection device 100 waits without introducing external air into the sample chamber 2, and only after the temperature inside the radiation detector 1 has risen does it introduce external air into the sample chamber 2 and open the sample chamber 2. When the temperature inside the radiation detector 1 is high, the temperature of the radiation detection element 11 is also high, making it difficult for gas or moisture to be adsorbed to the radiation detection element 11. Therefore, it is unlikely that a malfunction or other problem will occur in the radiation detector 1 due to gas or moisture being adsorbed to the radiation detection element 11. Therefore, malfunctions in the radiation detector 1 are suppressed, and the radiation detection device 100 can stably detect radiation.

[0103] Furthermore, in this embodiment, the radiation detection device 100 controls the timing of turning on the illumination unit 23 for illuminating the sample 6 and the timing of applying a voltage required for radiation detection to the radiation detection elements 11. Specifically, the radiation detection device 100 turns on the illumination unit 23 after stopping the application of a voltage to the radiation detection elements 11, and starts applying a voltage to the radiation detection elements 11 after turning off the illumination unit 23.

[0104] If light is incident on the radiation detection element 11 while the radiation detection element 11 is operating to detect radiation, the current signal output by the radiation detection element 11 will increase, which may result in problems such as a deterioration in the accuracy of radiation detection or a malfunction of the radiation detection device. Illumination light from the illumination unit 23 may pass through the opening 171 and be incident on the radiation detection element 11.

[0105] In this embodiment, voltage application to the radiation detection elements 11 begins after the illumination unit 23 is turned off, so that illumination light does not enter the radiation detection elements 11 that are now in a state where they can detect radiation. Furthermore, because the illumination unit 23 is turned on after the voltage application to the radiation detection elements 11 is stopped, even if illumination light enters the radiation detection elements 11, the radiation detection elements 11 are not operating and do not output a current signal. Therefore, the incidence of illumination light from the illumination unit 23 on the radiation detection elements 11 does not increase the current signal from the radiation detection elements 11, and no malfunctions occur due to the increase in the current signal. Therefore, malfunctions in the radiation detection device 100 are suppressed. The radiation detection device 100 can stably detect radiation.

[0106] The radiation detection device 100 may control the application of voltage from the voltage application unit 42 to the preamplifier 12 in the same manner as the application of voltage to the radiation detection element 11. That is, the control unit 3 causes the voltage application unit 42 to start applying voltage to the preamplifier 12 at the same timing as the start of voltage application to the radiation detection element 11. The control unit 3 also causes the voltage application unit 42 to stop applying voltage to the preamplifier 12 at the same timing as the stop of voltage application to the radiation detection element 11. This prevents malfunctions in the preamplifier 12 caused by illumination light. Note that the application of voltage from the voltage application unit 42 to the preamplifier 12 may be performed continuously while the radiation detection device 100 is operating.

[0107] The radiation detection device 100 may have a configuration in which the temperature adjustment unit 16 includes a heater. In this configuration, in the process of S19, the temperature adjustment unit 16 heats the radiation detection element 11 using the heater. By using the heater, the temperature of the radiation detection element 11 can be increased more quickly. The temperature adjustment unit 16 may have a mechanism for adjusting the temperature other than a Peltier element or a heater. Alternatively, the radiation detection device 100 may have a configuration in which the temperature adjustment unit 16 only performs cooling and does not perform heating. In this configuration, heating is not performed in S19, cooling is terminated, and the temperature of the radiation detection element 11 naturally increases.

[0108] In the present embodiment, the radiation detection element 11 is formed of a semiconductor made of Si, but the radiation detection element 11 may be formed of a semiconductor other than Si. In the present embodiment, the semiconductor portion 112 is formed of an n-type semiconductor, and the electrode layer 113 and the curved electrode 114 are formed of a p-type semiconductor, but the radiation detection element 11 may be formed of a semiconductor portion 112 made of a p-type semiconductor, and the electrode layer 113 and the curved electrode 114 are formed of an n-type semiconductor. In the present embodiment, the radiation detection element 11 is formed of a silicon drift type radiation detection element, but the radiation detection element 11 may be formed of a semiconductor other than a silicon drift type radiation detection element. Therefore, the radiation detector 1 may be a radiation detector other than an SDD.

[0109] In the present embodiment, the radiation detector 1 includes the collimator 14, but the radiation detector 1 may not include the collimator 14. The radiation detector 1 may not include the opening 171, but may include a window having a window material, and detect radiation that has passed through the window. In the present embodiment, the radiation detection element 11 is housed in the housing 17, but the radiation detector 1 may not include the housing 17. In the present embodiment, the radiation detection device 100 includes the irradiation unit 22, but the radiation detection device 100 may not include the irradiation unit 22. In the present embodiment, the radiation detection device 100 detects characteristic X-rays from the sample 6 as radiation, but the radiation detection device 100 may detect radiation other than X-rays. Alternatively, the radiation detection device 100 may use a radiation detection element 11 other than a semiconductor element. For example, the radiation detection device 100 may use a photomultiplier tube as the radiation detection element 11.

[0110] The present invention is not limited to the above-described embodiments, 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.

[0111] The matters described in each embodiment can be combined with each other. Furthermore, the independent claims and dependent claims described in the claims can be combined with each other in any and all combinations, regardless of the reference format. Furthermore, the claims use a format in which a claim references two or more other claims (multiple claim format), but this is not limited to this. A multiple claim (multi-multi claim) that references at least one other multiple claim may also be used.

[0112] REFERENCE SIGNS LIST 100 Radiation detection device 1 Radiation detector 11 Radiation detection element 13 Temperature sensor 16 Temperature adjustment unit 17 Housing 171 Opening 2 Sample chamber 20 Lid 22 Irradiation unit 23 Illumination unit 24 Photography unit 3 Control unit 341 Computer program 46 Display unit 51 Decompression unit (atmosphere adjustment unit) 52 Gas pressure sensor 53 Gas supply unit (atmosphere adjustment unit) 6 Sample

Claims

1. an illumination unit that is turned on to illuminate the sample; a radiation detection element for detecting radiation generated from the sample; A voltage application unit that applies a voltage to the radiation detection element; A control unit. The control unit is After the voltage application unit stops applying a voltage to the radiation detection element, the illumination unit is turned on; After turning off the illumination unit, the voltage application unit starts applying a voltage to the radiation detection element. A radiation detection device comprising:

2. a start instruction receiving unit that receives a start instruction to start detecting radiation, The control unit is When the start instruction receiving unit receives the start instruction, turning off the illumination unit; After the illumination unit is turned off, the voltage application unit starts applying a voltage to the radiation detection element.

2. The radiation detection device according to claim 1 .

3. The control unit is After detecting radiation using the radiation detection element, the voltage application unit stops applying a voltage to the radiation detection element; After the application of voltage to the radiation detection element is stopped, the illumination unit is turned on.

2. The radiation detection device according to claim 1 .

4. The control unit is After a predetermined waiting time has elapsed since the application of voltage to the radiation detection element was stopped, the illumination unit is turned on.

2. The radiation detection device according to claim 1 .

5. A housing that accommodates the radiation detection element therein is further provided. The housing has an unobstructed opening.

2. The radiation detection device according to claim 1 .

6. an irradiation unit that irradiates the sample with radiation; a spectrum generating unit that generates a spectrum of radiation detected by the radiation detection element; a display unit that displays the spectrum generated by the spectrum generation unit; The radiation detection device according to claim 1 , further comprising:

7. an openable sample chamber in which the sample is placed; a radiation detector disposed inside the sample chamber and having the radiation detection element; and an atmosphere adjustment unit that adjusts the atmosphere of the sample chamber by reducing the pressure inside the sample chamber in a closed state or by filling the sample chamber with a specific gas, and introduces air outside the sample chamber into the sample chamber in a state where the atmosphere has been adjusted; The radiation detector comprises: a temperature adjusting unit for adjusting the temperature of the radiation detection element; a temperature sensor for measuring an internal temperature of the radiation detector; The control unit is The atmosphere adjustment unit is controlled so as to adjust a timing for introducing air from outside the sample chamber into the inside of the sample chamber based on the temperature measured by the temperature sensor.

7. The radiation detection apparatus according to claim 1, wherein the radiation detection apparatus is a radiation detector.

8. The control unit is When the temperature measured by the temperature sensor exceeds a predetermined temperature threshold, the atmosphere adjustment unit is caused to introduce air from outside the sample chamber into the inside of the sample chamber.

8. The radiation detection device according to claim 7.

9. an introduction instruction receiving unit that receives an introduction instruction for instructing to introduce air outside the sample chamber into the inside of the sample chamber; The control unit is When the introduction instruction receiving unit receives the introduction instruction, the temperature adjusting unit heats the radiation detection element.

9. The radiation detection device according to claim 8.

10. an output unit that outputs a standby instruction that instructs the user to wait for the sample chamber to be opened; The control unit is The output unit is caused to output the standby instruction during a period before the atmosphere adjustment unit introduces air outside the sample chamber into the inside of the sample chamber.

8. The radiation detection device according to claim 7.

11. a gas pressure sensor for measuring a gas pressure inside the sample chamber; The control unit is When the atmosphere adjustment unit starts adjusting the atmosphere and the gas pressure measured by the gas pressure sensor becomes equal to or lower than a predetermined pressure threshold, the temperature adjustment unit starts cooling the radiation detection element.

8. The radiation detection device according to claim 7.

12. The control unit is When the atmosphere adjustment unit starts adjusting the atmosphere and the specific gas is supplied to the inside of the sample chamber for a predetermined period of time, the temperature adjustment unit starts cooling the radiation detection element.

8. The radiation detection device according to claim 7.

13. 1. An information processing method for controlling a radiation detection device including an illumination unit that is turned on to illuminate a sample, a radiation detection element that detects radiation generated from the sample, and a voltage application unit that applies a voltage to the radiation detection element, comprising: The voltage application unit stops applying a voltage to the radiation detection element, After the application of voltage to the radiation detection element is stopped, the illumination unit is turned on. Turning off the illumination unit, After the illumination unit is turned off, the voltage application unit starts applying a voltage to the radiation detection element.

23. An information processing method comprising:

14. A computer that controls a radiation detection device including an illumination unit that is turned on to illuminate a sample, a radiation detection element that detects radiation generated from the sample, and a voltage application unit that applies a voltage to the radiation detection element, Stopping the application of voltage to the radiation detection element by the voltage application unit; After the application of voltage to the radiation detection element is stopped, the illumination unit is turned on. Turn off the illumination unit, After the illumination unit is turned off, the voltage application unit starts applying a voltage to the radiation detection element. A computer program characterized by executing a process.