Fluorescent x-ray analysis device

Abstract

Provided is a fluorescent X-ray analysis device capable of reducing the amount of consumption of a gas constituting a measurement atmosphere. A fluorescent X-ray analysis device (1) is provided with: a sample chamber (11) that places a sample (41); a measurement chamber (12) that is disposed adjacent to the sample (41) of the sample chamber (11); an X-ray tube (20) that irradiates X-rays (23) toward the sample (11); and a detector (30) that detects the X-rays (23) reflected by the sample (41), in which the detector (30) is provided with: a passage (36) that is located inside the measurement chamber (12) and through which the reflected X-rays (23) pass; and a hole (33) that connects the passage (36) and the outside of the detector (30).

Description

TECHNICAL FIELD

[0001] The present application relates to a fluorescent X-ray analysis device. BACKGROUND

[0002] An energy dispersive fluorescent X-ray analysis device is a device that detects fluorescent X-rays generated from the surface of a sample by irradiating X-rays to the sample, and thereby can analyze the kind and concentration of elements constituting the sample. A wide variety of samples represented by solids and liquids can be analyzed non-destructively and simply. In the fluorescent X-ray analysis device, in order to detect light elements that are easily affected by the measurement atmosphere, it is necessary to make the sample chamber and the measurement chamber vacuum and perform measurement. On the contrary, in order to measure a sample that generates gas or a liquid sample, it is effective to replace the sample chamber and the measurement chamber with helium gas.

[0003] However, in the case of replacing the sample chamber and the measurement chamber filled with air with helium gas, even if the sample chamber and the measurement chamber are set to a helium gas atmosphere, there is a problem that the measurement is affected by a small amount of air remaining in the measurement chamber.

[0004] In order to solve this problem, for example, a fluorescent X-ray analysis device for improving the replacement rate of helium gas is disclosed in International Publication No. 2014 / 192173 (Patent Literature 1). In this document, a first introduction pipe and a second introduction pipe for introducing helium gas are provided, and it is possible to reliably replace helium gas accumulated in the introduction port, the detection port with the atmosphere.

[0005] Prior art documents

[0006] Patent documents

[0007] Patent Literature 1: International Publication No. 2014 / 192173 SUMMARY

[0008] Problems to be solved by the invention

[0009] However, in the device of Patent Literature 1, if measurement is performed while supplying helium gas as an atmosphere gas to the detection port, there is a problem that the consumption amount of helium gas increases.

[0010] Therefore, the present application was completed in order to solve the above problems, and an object thereof is to provide a fluorescent X-ray analysis device capable of reducing the consumption amount of gas constituting a measurement atmosphere.

[0011] Solution to the problem

[0012] The first aspect of the present application includes: a sample chamber that holds a sample; a measurement chamber that is disposed adjacent to the sample of the sample chamber; an X-ray tube that irradiates X-rays to the sample; and a detector that detects X-rays reflected by the sample, wherein the detector is provided with: a passage that is located in the measurement chamber and through which the reflected X-rays pass; and a hole that connects the passage and the outside of the detector.

[0013] Effects of the invention

[0014] The fluorescent X-ray analysis device according to the present application includes: a sample chamber that holds a sample; a measurement chamber that is disposed adjacent to the sample of the sample chamber; an X-ray tube that irradiates X-rays to the sample; and a detector that detects X-rays reflected by the sample, wherein the detector is provided with: a passage that is located in the measurement chamber and through which the reflected X-rays pass; and a hole that connects the passage and the outside of the detector, and thus even if gas is accumulated in the passage, the gas can be discharged through the hole. As a result, even if gas that constitutes an atmosphere is not supplied during measurement, gas remaining in the detector can be prevented, and the amount of gas that constitutes an atmosphere can be reduced.

[0015] Also, the hole can extend from the passage toward the outside of the detector in a manner having a downward component in the vertical direction. In this case, in a lighter atmosphere gas such as helium, heavier air flows in the hole that extends in a manner having a downward component in the vertical direction, and thus air can be smoothly discharged from the passage.

[0016] Also, the hole can extend from the passage toward the outside of the detector in a manner away from the X-ray tube at an outlet thereof. In this case, since the hole extends in a manner away from the X-ray tube near the outlet, scattered X-rays generated from the periphery of the X-ray tube can be prevented from entering the detector from the outlet of the hole.

[0017] Also, the hole can extend in a letter L shape. In this case, by forming the hole in a letter L shape along the detector, a hole that can prevent the intrusion of X-rays can be easily formed. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a cross-sectional view of a fluorescent X-ray analysis device 1 according to an embodiment.

[0019] Figure 2 is a view that shows a top end portion of the detector 30.

[0020] Figure 3 is a cross-sectional view of a detector of a comparative example shown for the purpose of explaining the air accumulation portion 39.

[0021] Figure 4 is a cross-sectional view of a top end portion of the detector 30 according to another embodiment.

[0022] Figure 5 is a cross-sectional view of a top end portion of the detector 30 according to still another embodiment. DETAILED DESCRIPTION

[0023] (Embodiment)

[0024] (Overall Structure)

[0025] Figure 1 is a cross-sectional view of a fluorescent X-ray analysis device 1 according to an embodiment. As shown in Figure 1 the fluorescent X-ray analysis device 1 has a shielding wall 10 defining a sample chamber 11 and a measurement chamber 12, an X-ray tube 20 mounted to the shielding wall 10, and a detector 30 mounted to the shielding wall 10 on a side opposite the X-ray tube 20.

[0026] The shielding wall 10 has a function of shielding X-rays so that X-rays generated from the X-ray tube 20 and radiated into the measurement chamber 12 and the sample chamber 11 do not leak to the outside. The sample chamber 11 and the measurement chamber 12 are surrounded by the shielding wall 10. The sample chamber 11 and the measurement chamber 12 are separated from each other by a partition wall 13. A plurality of ventilation paths 14 are provided in the partition wall 13. The ventilation paths 14 communicate the sample chamber 11 and the measurement chamber 12, and thus the sample chamber 11 and the measurement chamber 12 are the same pressure.

[0027] A case 40 containing a sample 41 is arranged in the sample chamber 11. The sample 41 can be either of a solid and a liquid. A not-shown film is provided on a bottom surface of the case 40. The sample 41 is placed on the film. In the case where the sample 41 is a solid, it can be a larger block or a powder.

[0028] The measurement chamber 12 is provided in a lower portion of the sample chamber 11. X-rays 23 generated at an X-ray generation point 22 of the X-ray tube 20 are irradiated to a lower surface 42 of the sample 41 after passing through a not-shown band-pass filter and a primary collimator, and the X-ray tube 20 is used to irradiate the X-rays 23 to the sample 41, mounted to an outer side of the shielding wall 10.

[0029] The pressure in the sample chamber 11 and the measurement chamber 12 can be adjusted by a rotary pump 110 and a valve 120. Specifically, when the valve 120 is opened and the rotary pump 110 is driven, the sample chamber 11 and the measurement chamber 12 can be made vacuum by the action of the rotary pump 110.

[0030] The pressure of helium gas in the sample chamber 11 and the measurement chamber 12 can be adjusted by a helium gas cylinder 130 and a valve 140. Specifically, by opening the valve 140 to supply helium gas from the helium gas cylinder 130, the sample chamber 11 and the measurement chamber 12 can be made a helium gas atmosphere.

[0031] The detector 30 has a housing 31. The top end of the housing 31 is inserted into the measurement chamber 12, and the other part is not inserted into the measurement chamber 12.

[0032] Figure 2 is a view showing the top end part of the detector 30. As shown in Figure 2 , the housing 31 of the detector 30 is cylindrical. A secondary collimator 32 as a detector cover is provided at the top end part of the housing 31. A passage 36 for allowing X-rays reflected by the sample 41 to pass therethrough is provided in the secondary collimator 32.

[0033] As shown in Figure 1 , the X-rays 23 are reflected by the sample 41 in principle, but are also reflected in a part other than the sample 41. The X-rays reflected by the part other than the sample reflect the physical properties of the substance, and therefore if they are introduced into the detector 30, the correct physical properties of the sample 41 cannot be determined.

[0034] In order to prevent this, the secondary collimator 32 having the passage 36 extending in the axial direction is provided at the top end of the housing 31. The inner diameter and the length of the passage 36 are thereby adjusted so as to allow only the X-rays 23 reflected by the lower surface 42 of the sample 41 to pass through the passage 36.

[0035] A window member 34 composed of beryllium is provided at the top end of the housing 31, for example. The window member 34 allows the X-rays to pass therethrough without attenuation, and has a function of dividing the inside of the housing 31 from the measurement chamber 12.

[0036] A light-receiving element 35 composed of a semiconductor is provided on the inside of the housing 31, for example. In the case where the light-receiving element 35 is a semiconductor, electron-hole pairs are generated when the X-rays pass through the inside of the light-receiving element 35, and by measuring the current and the voltage generated thereby, the physical properties of the sample can be determined on the basis of the X-rays.

[0037] A hole 33 for connecting the passage 36 with the outside of the detector 30 is provided in the secondary collimator 32. The hole 33 is formed by cutting the secondary collimator 32 with a drill, for example. The hole 33 can also be composed of a tube, for example.

[0038] (EFFECTS)

[0039] In the case where the sample chamber 11 and the measurement chamber 12 in the air atmosphere are filled with helium lighter than air, the valve 140 is opened, and helium is supplied from the helium cylinder 130 to the sample chamber 11 and the measurement chamber 12. In this case, in order to remove the air from the sample chamber 11 present in the upper part and introduce helium, the helium is then filled into the measurement chamber 12. The helium should originally enter into the secondary collimator 32 from the passage 36 when the layer of the helium descends to the level of the secondary collimator 32.

[0040] Figure 3is a cross-sectional view of a detector of a comparative example shown for the purpose of explaining the air accumulation portion 39. Since air is heavier than helium, in a state where air is accumulated between the secondary collimator 32 and the window member 34, the air does not escape from the passage. That is, the air accumulation portion 39 shown in the drawing is generated. In this state, there is a layer of air directly in front of the window member 34. X-rays of weak energy are attenuated in this air accumulation portion 39. The transmittance of a layer of air (20°C, one atmosphere) 1 mm in the optical path length of F-Ka rays (667 eV) is 29%. In contrast, the transmittance of a layer of helium (20°C, one atmosphere) 1 mm in the optical path length of F-Ka rays (667 eV) is 99.6%. Therefore, when performing fluorescent X-ray analysis under a helium atmosphere, it is necessary to not form this air accumulation portion 39. Figure 3

[0041] As a first method of not forming the air accumulation portion inside the secondary collimator 32, the sample chamber 11 and the measurement chamber 12 are depressurized to exhaust air in advance, and then the air is completely exhausted when helium is introduced, so air does not accumulate inside the secondary collimator 32. However, in this method, an air exhaust pump is required. Since a sample such as a liquid sample is prohibited from being in a vacuum atmosphere, analysis is performed in a helium atmosphere, so it is not possible to form a vacuum atmosphere in advance. In addition, it is difficult to install an air exhaust system in terms of cost.

[0042] As a second method, a nozzle of the secondary collimator 32 is provided and connected to a helium line, and by causing helium to flow strongly and directly into the secondary collimator 32, it is possible to diffuse air accumulated inside the secondary collimator 32. However, the tip end of the detector 30 is a portion where various mechanisms are concentrated, and there are problems in terms of assembly and maintenance of the device when a nozzle is provided in this portion. Furthermore, a certain degree of flow rate and flow volume of helium is required in order to diffuse the air accumulation portion 39, and as a result, more helium than necessary is consumed, and operating costs are incurred.

[0043] In order to diffuse the air accumulation portion 39 without generating the above problems, a hole 33 for exhausting air is provided as shown in Figure 2 The hole 33 is disposed from the passage 36 toward the outside of the detector 30 in such a manner as to have a downward component in the vertical direction indicated by the arrow 180. In the measurement chamber 12, helium is filled, and when the layer of helium reaches the secondary collimator 32, air is exhausted from the hole 33. As a result, there is no air directly in front of the window member 34, and it is possible to solve the problem of X-ray attenuation.

[0044] (Another Embodiment (One))

[0045] Figure 4 is a cross-sectional view of the tip end portion of the detector 30 according to another embodiment. As shown in Figure 4 ​As shown, in this embodiment, the hole 33 of the detector 30 has a first portion 33a extending in a direction orthogonal to the length direction of the housing 31, and a second portion 33b connected to the first portion 33a and extending in the length direction of the housing 31.

[0046] The hole 33 is provided in a letter L shape. The first portion 33a and the second portion 33b of the hole 33 are formed so as to have a vertical downward component in the direction from the passage 36 toward the outside of the detector 30 in order to make the flow of air smooth. In addition, the second portion 33b constituting the outlet of the hole 33 extends away from the X-ray tube 20 in the direction of the flow of air described above.

[0047] In the hole 33 thus configured, the second portion 33b extends away from the X-ray tube 20, and thus becomes a shape in which scattered X-rays from the X-ray tube 20 are less likely to enter. As a result, it is possible to prevent scattered X-rays from being detected by the detector 30, and thus to improve the accuracy of measurement.

[0048] (Another Embodiment (One))

[0049] Figure 4 is a sectional view of the tip portion of the detector 30 according to another embodiment. As Figure 4 shown, in this embodiment, the hole 33 of the detector 30 has a first portion 33a extending in a direction orthogonal to the length direction of the housing 31, and a second portion 33b connected to the first portion 33a and extending in the length direction of the housing 31.

[0050] The hole 33 is provided in a letter L shape. The first portion 33a and the second portion 33b of the hole 33 are formed so as to have a vertical downward component in the direction from the passage 36 toward the outside of the detector 30 in order to make the flow of air smooth. In addition, the second portion 33b constituting the outlet of the hole 33 extends away from the X-ray tube 20 in the direction of the flow of air described above. The length of the second portion 33b can be as long as possible as long as the conductivity of the hole 33 as a whole is not deteriorated. In addition, the hole 33 can not only be in a letter L shape, but also can be provided in a curved shape.

[0051] In the hole 33 thus configured, the second portion 33b extends away from the X-ray tube 20, and thus becomes a shape in which scattered X-rays from the X-ray tube 20 are less likely to enter. As a result, it is possible to prevent scattered X-rays from being detected by the detector 30, and thus to improve the accuracy of measurement. The larger the aspect ratio (length / inner diameter of the hole 33) of the hole 33, the less likely it is for scattered X-rays to enter, and thus it is preferable to make the aspect ratio as large as possible.

[0052] (Another Embodiment (Two))

[0053] Figure 5 is a sectional view of the top end portion of the detector 30 according to still another embodiment. As shown in the drawing, in this embodiment, not only is a hole 33 provided on the lower side of the top end of the secondary collimator 32, but a hole 133 is also provided on the upper side, in this respect differing from the secondary collimator 32 shown in Figure 5 Figure 2

[0054] By providing the hole 133, it is easy to exhaust the helium gas inside the secondary collimator 32. Specifically, in the case where the helium gas atmosphere is changed to an atmospheric gas atmosphere after the measurement is completed, since the helium gas is lighter, the helium gas remaining inside the secondary collimator 32 in the upper portion of the window member 34 is difficult to exhaust. This helium gas can cause some influence in the measurement. By the presence of the hole 133, it is easy to exhaust the helium gas from the position inside the secondary collimator 32 and in the upper portion of the window member 34. Further, although two holes 33, 133 are provided in this example, it is not necessary to provide two holes 33, 133, and only the hole 133 can be provided.

[0055] The above-described embodiments have been explained, but the embodiments shown here can be variously modified. For example, although the sample 41 is disposed on the upper side of the X-ray tube 20 and the detector 30 in Figure 1 , the sample 41 can be disposed on the lower side of the X-ray tube 20 and the detector 30. In this case, the X-rays radiated from the X-ray tube 20 are reflected on the upper surface of the sample 41, and the reflected X-rays are detected by the detector 30.

[0056] Those skilled in the art will appreciate that the above-described multiple exemplary embodiments are concrete examples of the following aspects.

[0057] (1) A fluorescent X-ray analysis apparatus according to an aspect includes: a sample chamber that places a sample; a measurement chamber that is disposed adjacent to the sample of the sample chamber; an X-ray tube that radiates X-rays to the sample; and a detector that detects X-rays reflected by the sample, the detector being provided with: a passage that is located in the measurement chamber and through which the reflected X-rays pass; and a hole that connects the passage and the outside of the detector.

[0058] In the fluorescent X-ray analysis apparatus according to the aspect 1, the hole that connects the passage and the outside of the detector is provided in the detector, so even in the case where a gas is accumulated in the passage, the gas can be exhausted via the hole. As a result, it is not necessary to continuously supply the gas that constitutes the atmosphere during the measurement, and the consumption of the gas can be reduced.

[0059] (2) The fluorescent X-ray analysis apparatus according to the aspect 1 can also be such that the hole extends from the passage toward the outside of the detector in a manner having a downward component in the vertical direction.

[0060] ​​The fluorescent X-ray analysis apparatus according to item 2, in which heavier air in a helium atmosphere flows in the hole extending in a manner having a downward component in the vertical direction, so that air can be smoothly discharged from the passage.

[0061] (3) The fluorescent X-ray analysis apparatus according to item 1 or 2, in which the hole has a second portion extending from the passage toward the outside of the detector in a manner away from the X-ray tube at the outlet thereof. Figure 4

[0062] The fluorescent X-ray analysis apparatus according to item 3, in which the hole extends in a manner away from the X-ray tube near the outlet, so that scattered X-rays generated from the periphery of the X-ray tube can be prevented from entering from the outlet of the hole.

[0063] (4) The fluorescent X-ray analysis apparatus according to item 3, in which the hole extends in a letter L shape.

[0064] The fluorescent X-ray analysis apparatus according to item 4, in which the hole extending in a letter L shape along the detector can be easily formed so as to prevent the intrusion of X-rays.

[0065] It should be understood that the embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present application is not shown by the above description but is shown by the claims, and is intended to include all modifications within the meaning and range of equivalency of the claims.

[0066] Explanation of reference signs

[0067] 1. An X-ray analysis apparatus; 10, a shielding wall; 11, a sample chamber; 12, a measurement chamber; 13, a partition wall; 14, a ventilation passage; 20, an X-ray tube; 22, an X-ray generation point; 23, an X-ray; 30, a detector; 31, 40, a housing; 32, a secondary collimator; 33, 133, a hole; 33a, a first portion; 33b, a second portion; 34, a window member; 35, a light receiving element; 36, a passage; 41, a sample; 42, a lower surface; 110, a rotary pump; 120, 140, a valve; 130, a helium gas cylinder; 180, an arrow.​

Claims

1. A fluorescent X-ray analysis device, wherein, The fluorescent X-ray analysis device is provided with: a sample chamber in which a sample is placed; a measurement chamber disposed adjacent to the sample in the sample chamber; an X-ray tube that irradiates X-rays toward the sample; and a detector that detects X-rays reflected by the sample, a collimator is provided at the detector, the collimator having a passage that passes through the measurement chamber and through which the reflected X-rays pass, and a hole that connects the passage and the outside of the detector, the collimator is disposed at a top end portion of a housing of the detector, a window member is provided at the top end of the housing, a top end of the passage is on the sample chamber side of the passage, and a rear end of the passage is on the window member side of the passage, the hole connects the rear end of the passage and the outside of the detector, a gas in the passage is discharged to the outside of the detector via the hole.

2. The fluorescent X-ray analysis device according to claim 1, wherein the hole extends from the passage toward the outside of the detector in a manner having a downward component in the vertical direction.

3. The fluorescent X-ray analysis device according to claim 1, wherein the hole extends from the passage toward the outside of the detector in a manner away from the X-ray tube at an exit thereof.

4. The fluorescent X-ray analysis device according to claim 3, wherein the hole extends in a letter L shape.

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