JP4177677B2 - X-ray equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an X-ray apparatus in which the atmosphere of an X-ray optical system is replaced with a light element gas.
[0002]
[Prior art]
When X-ray measurement is performed in the atmosphere, slight X-ray absorption occurs due to elements contained in the air, which may be a factor that hinders high-precision measurement such as trace element analysis. As a countermeasure, a measurement method in which the atmosphere of the X-ray optical system is replaced with an element having little X-ray absorption is considered.
[0003]
As a method of replacing the measurement chamber in which the X-ray optical system is installed with helium He, 1) a method of injecting helium after evacuating the measurement chamber (for example, refer to Patent Document 1), and 2) gradually introducing helium into the measurement chamber. There is a method (for example, refer to Patent Document 2) for extruding the air and pushing out the air inside.
[0004]
[Patent Document 1]
JP-A-60-173448 [Patent Document 2]
Japanese Patent Laid-Open No. 10-54810
[Problems to be solved by the invention]
In the method 1), complete helium replacement is realized because the air in the measurement chamber is exhausted. However, in order to maintain a vacuum in the measurement chamber, very high airtightness is required, and it becomes difficult to handle a liquid sample in particular.
[0006]
In the method 2), it takes a long time until the replacement of air and helium is completed. During that time, helium is also discharged together with air, so that a large amount of helium gas is wasted.
[0007]
Furthermore, in both methods, it is necessary to always supply a small amount of helium in order to compensate for the gradual outflow of helium from the gap in the measurement chamber even after helium replacement. Since helium is generally expensive, a large amount of helium consumption leads to an increase in measurement cost.
[0008]
The objective of this invention is providing the X-ray apparatus which can improve the utilization efficiency of light element gas.
[0009]
[Means for Solving the Problems]
The present invention includes an X-ray optical system through which X-rays pass,
A sealing member for sealing the periphery of the X-ray optical system;
A light element gas supply means for supplying a light element gas having a specific gravity smaller than air into the sealing member;
Exhaust means for exhausting the internal gas of the sealing member to the outside;
A float member provided inside the sealing member and having a specific gravity smaller than that of air;
Gas supply amount adjusting means for adjusting the supply amount of the light element gas according to the displacement of the float member ,
The light element gas is an X-ray apparatus according to claim helium gas der Rukoto.
[0010]
According to the present invention, when the light element gas is supplied to the inside of the sealing member, the light element gas stays in the upper part of the sealing member and the air stays in the lower part, so that the float member has a boundary between the light element gas and air. It will be located nearby. As the light element gas gradually leaks to the outside and decreases, the float member gradually rises. Then, the gas supply amount adjusting means that operates according to the displacement of the float member increases the supply amount of the light element gas and replenishes the reduced amount of gas. On the contrary, when the retention amount of the light element gas is increased, the float member is gradually lowered, so that the supply amount of the light element gas is decreased. In this way, the float member functions as a sensor for detecting the retention amount of the light element gas, and by interlocking with the gas supply amount adjusting means, automatic flow control of the light element gas can be realized and consumption of the light element gas can be saved.
Further, by using helium gas as the atmospheric gas of the X-ray optical system, X-ray absorption and scattering caused by the atmospheric gas can be reduced, so that highly sensitive and accurate measurement can be performed.
[0011]
Further, the present invention is characterized in that an X-ray window member capable of passing X-rays is attached to the sealing member.
[0012]
According to the present invention, by providing an X-ray window member on the sealing member, X-rays are introduced into the sealing member from an X-ray apparatus (for example, an X-ray source) installed outside, or inside the sealing member. To an external X-ray apparatus (for example, an X-ray detector), and the degree of freedom of the overall arrangement of the X-ray optical system can be increased. As the X-ray window member, a material having low X-ray absorption, such as a beryllium Be plate or a polymer film, is preferable.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a configuration diagram showing a first embodiment of the present invention. The X-ray apparatus 1 seals the periphery of the X-ray optical system 3 and the X-ray optical system 3 combining X-ray optical elements such as an X-ray tube, a diffraction element, a slit, an X-ray filter, and an X-ray detector. The closed box 2 or the like.
[0015]
The sealed box 2 is provided with an introduction pipe 15 for introducing helium gas into the box and an exhaust pipe 16 for discharging the air remaining in the sealed box 2 to the outside. A gas cylinder storing helium gas, a regulator for stabilizing the flow rate, and the like are connected to the introduction pipe 15, and a flow rate control valve 14 for controlling the gas flow rate is connected in the middle. The exhaust port 16a of the exhaust pipe 16 is installed near the bottom of the sealed box 2 so that air having a specific gravity greater than that of helium gas is discharged first.
[0016]
Furthermore, a float 10 having a specific gravity smaller than that of air is provided inside the sealed box 2. The float 10 is configured such that the inside of a hollow container made of plastic, light metal, or the like is evacuated or filled with hydrogen gas or helium gas. Alternatively, a configuration in which the hollow container of the float 10 and the introduction pipe 15 are connected by a flexible pipe, an exhaust hole is formed in the hollow container, and the inside of the float 10 is always filled with helium gas is possible. is there.
[0017]
With such a configuration, the float 10 is positioned near the boundary surface C between the upper space A in which helium gas stays and the lower space B in which air stays. Therefore, the height of the float 10 reflects the residence amount of helium gas.
[0018]
The float 10 is attached to a link member 11 supported so as to be angularly displaceable around a fulcrum 12, and a link member 13 connected to the link member 11 is connected to an operation portion of the flow control valve 14. When the helium gas retention amount decreases and the float 10 rises due to the link members 11 and 13, the opening degree of the flow control valve 14 decreases, and conversely, when the helium gas retention amount increases and the float 10 descends. The flow control valve 14 operates to increase the opening degree. Therefore, automatic flow rate control of helium gas can be realized by adjusting the float 10 to a desired height in a state where the leak amount and supply amount of the helium gas are balanced.
[0019]
By installing the X-ray window member 4 that allows X-rays to pass through the opening of the sealed box 2, introduction or extraction of X-rays can be performed with the external X-ray device 20 while preventing leakage of helium gas. become. Such a configuration is suitable when the X-ray apparatus 20 is large-scale, when it is desired to keep the atmosphere gas different from helium, or when the volume of the sealed box 2 is desired to be as small as possible.
[0020]
In the above description, the example in which the float 10 and the flow control valve 14 are mechanically linked by the link members 11 and 13 has been described. However, the displacement of the float 10 is changed optically, electrically, magnetically, and the like. The flow control valve 14 may be configured to electrically operate using a sensor that detects as follows. Alternatively, the flow control valve 14 may be adjusted by detecting a change in buoyancy acting on the float 10.
[0021]
Moreover, since helium gas stays in the upper part, all or part of the bottom part of the sealed box 2 may be open.
[0022]
FIG. 2 is a block diagram showing a second embodiment of the present invention. The X-ray fluorescence analyzer includes an X-ray tube 30 for generating X-rays, a spectroscopic crystal 31 for separating a single characteristic X-ray from the X-rays generated from the X-ray tube 30, and a spectroscopic crystal 31. A slit 32 for extracting X-rays diffracted in a predetermined direction, a shutter 33 for blocking the X-rays by an external signal, a moving stage 34 for adjusting the position and posture of the sample SP, and an upper part of the moving stage 34 A slit 35 for limiting the passage position of the X-rays passing through the X-ray, an X-ray detector 36 for detecting the intensity of the X-rays that have passed through the slit 35, and an X-ray detector 37 for detecting the fluorescent X-rays generated from the sample SP. And a cooling container 38 for storing liquid nitrogen or the like for cooling the X-ray detector 37.
[0023]
Among these, the sample SP, the moving stage 34, and the X-ray detector 37 are installed inside the sealed box 2 to constitute the X-ray apparatus 1, and the rest are installed outside the sealed box 2. As shown in FIG. 1, the sealed box 2 includes an introduction pipe 15 for introducing helium gas into the sealed box, and an exhaust pipe 16 for discharging the air remaining inside the sealed box 2 to the outside. A flow rate control valve 14 for controlling the flow rate of helium gas and a float 10 for operating the flow rate control valve 14 are installed.
[0024]
X-rays introduced into the sealed box 2 via one X-ray window member 4 are incident on the surface of the sample SP at a total reflection angle. The X-ray incident angle with respect to the sample SP is finely adjusted by the moving stage 34 adjusting the posture of the sample SP. The X-ray reflected by the sample SP is taken out through the other X-ray window member 4 and reaches the X-ray detector 36 through the slit 35. The sample SP generates fluorescent X-rays by X-ray excitation and is detected by the X-ray detector 37.
[0025]
In such an X-ray apparatus, high-accuracy and high-sensitivity measurement can be realized by sealing a portion where the X-ray passes through a sealed box 2 and replacing it with helium gas.
[0026]
FIG. 3 is a block diagram showing a third embodiment of the present invention. The configuration of this apparatus is the same as the configuration of FIG. 2, but the X-ray optical system from the X-ray tube 30 to the X-ray detector 36 is housed in the same sealed box 2 and the X-ray window member 4 is omitted. is doing. In such an X-ray apparatus, by introducing helium gas from the introduction tube 15 into the sealed box 2, the upper space A where the X-ray optical system is located is replaced with helium gas, thereby realizing high-precision and high-sensitivity measurement. it can.
[0027]
FIG. 4 is a block diagram showing a fourth embodiment of the present invention. The configuration of this apparatus is the same as the configuration of FIG. 2, but the X-ray optical system from the X-ray tube 30 to the sample SP is housed in the same sealed box 2, and the slit 35 and the X-ray detector 36 are sealed. It is installed outside the box 2. In such an X-ray apparatus, by introducing helium gas from the introduction tube 15 into the sealed box 2, the upper space A where the X-ray optical system is located is replaced with helium gas, thereby realizing high-precision and high-sensitivity measurement. it can.
[0028]
FIG. 5 is a block diagram showing a fifth embodiment of the present invention. The configuration of this apparatus is the same as the configuration of FIG. 2, but the X-ray optical system from the sample SP to the X-ray detector 36 is housed in the same sealed box 2, and the X-ray tube 30, the spectroscopic crystal 31, A slit 32 and a shutter 33 are installed outside the sealed box 2. In such an X-ray apparatus, by introducing helium gas from the introduction tube 15 into the sealed box 2, the upper space A where the X-ray optical system is located is replaced with helium gas, thereby realizing high-precision and high-sensitivity measurement. it can.
[0029]
In the above description, an example of a fluorescent X-ray analyzer is shown as an applicable X-ray apparatus. However, other X-ray diffraction apparatuses and extended X-ray absorption fine structure analysis (Extended
X-ray Absorption Fine Structure (abbreviation EXAFS) apparatus can also be applied.
[0030]
【The invention's effect】
As described in detail above, according to the present invention, the automatic flow control of the light element gas can be realized by linking the operation of the float member and the gas supply amount adjusting means, and the consumption of the light element gas can be saved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a first embodiment of the present invention.
FIG. 2 is a configuration diagram showing a second embodiment of the present invention.
FIG. 3 is a block diagram showing a third embodiment of the present invention.
FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention.
FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 X-ray apparatus 2 Sealed box 3 X-ray optical system 4 X-ray window member 10 Float 11 Link member 12 Support point 14 Flow control valve 15 Introducing pipe 16 Exhaust pipe 20 X-ray apparatus

Claims (2)

An X-ray optical system through which X-rays pass;
A sealing member for sealing the periphery of the X-ray optical system;
A light element gas supply means for supplying a light element gas having a specific gravity smaller than air into the sealing member;
Exhaust means for exhausting the internal gas of the sealing member to the outside;
A float member provided inside the sealing member and having a specific gravity smaller than that of air;
Gas supply amount adjusting means for adjusting the supply amount of the light element gas according to the displacement of the float member ,
X-ray apparatus the light element gas and said helium gas der Rukoto.   The X-ray apparatus according to claim 1, wherein an X-ray window member capable of passing X-rays is attached to the sealing member.

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