JP3654568B2 - X-ray analyzer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an X-ray analyzer used for examining, for example, elements contained in a sample, their amounts, and their distribution state.
[0002]
[Prior art]
An X-ray analyzer, for example, irradiates a sample placed on a sample stage with primary X-rays, and generates secondary X-rays such as fluorescent X-rays and scattered X-rays by an X-ray detector. By detecting and appropriately processing the detection output, the constituent elements and internal structure of the sample can be analyzed.
[0003]
By the way, as said X-ray-analysis apparatus, as shown by Unexamined-Japanese-Patent No. 8-15187, for example, while the sample chamber where a sample is arrange | positioned and the primary X-ray irradiated with respect to the said sample pass, this primary An X-ray irradiation chamber in which an X-ray detector for detecting secondary X-rays generated when the sample is irradiated with X-rays is partitioned by a diaphragm made of an X-ray transparent material, and the X-ray irradiation chamber There is an X-ray analyzer that is in a vacuum state.
[0004]
FIG. 4 shows the configuration of the main part of the X-ray analyzer described in the above publication. In this figure, reference numeral 41 denotes a main body block of the X-ray analyzer, below which is a sample chamber 42 and X-ray irradiation. The chamber 43 is formed in a state of being airtightly partitioned by a diaphragm 44 made of an X-ray transparent material.
[0005]
Then, the sample chamber 42 located below the left and right direction of the sample stage 46, for example paper for mounting a sample 45, is provided in the movable state in a direction perpendicular and vertical direction to the paper surface, The sample chamber 42 is maintained at atmospheric pressure. Further, in the X-ray irradiation chamber 43 located above the sample chamber 42, primary X-rays a generated by an X-ray generator (not shown) provided on the upper part of the main body block 41 are appropriately beam-diametered. When the sample 45 is irradiated with the emission end 47 of the X-ray guide tube (hereinafter referred to as XGT) for irradiating the sample 45 with the X-ray guide tube and the primary X-ray a. An X-ray detector 48 for detecting light X-rays (a type of secondary X-ray) b and an objective unit 49 of an optical microscope for confirming the irradiation position of the sample 45 are provided. This X-ray irradiation chamber 43 is maintained in a predetermined vacuum state.
[0006]
In the X-ray analysis apparatus having the above configuration, the inside of the X-ray irradiation chamber 43 as an X-ray path separated from the atmosphere side by the diaphragm 44 is in a vacuum state, so the influence of the atmosphere during measurement is greatly reduced. As a result, the transmittance of the primary X-ray a and the transmittance of the secondary X-ray b are greatly improved, the intensity of the low-energy fluorescent X-ray is greatly enhanced, and Na that cannot be detected by measurement in the atmosphere, Light elements such as Mg and Al can be easily detected. In addition, since the inside of the sample chamber 42 in which the sample stage 46 is provided is in an atmospheric pressure state, it is not necessary to perform evacuation each time the sample 45 is replaced. There is an advantage that time can be shortened.
[0007]
[Problems to be solved by the invention]
Meanwhile, as the diaphragm 44 definitive in the X-ray analyzer, the position on the sample stage 46 of the sample 45 from where confirmed by an optical microscope, in addition to be those transparent, the primary X-ray a and fluorescent X-ray It is required that the absorption rate of X-rays such as b is low, does not emit fluorescent X-rays depending on the composition of the film itself, and has a strength that can withstand a pressure of about atmospheric pressure. For example, there is a polyester resin film that satisfies the conditions, and its thickness is about several μm at most. However, since one side of the diaphragm 44, that is, the sample chamber 42 side is atmospheric pressure, and the other side, that is, the X-ray irradiation chamber 43 side is vacuum, atmospheric pressure is applied to the diaphragm 44 during measurement. Applied to the X-ray irradiation chamber 43 side. Therefore, conventionally, the diaphragm 44 is supported by a wire mesh-like reinforcing member 50 to suppress the bulge to a minimum.
[0008]
However, in the X-ray analysis apparatus using the wire mesh-like reinforcing member 50, the metal portion itself constituting the wire mesh hinders optical observation, and the diaphragm 44 is slightly swelled by the atmospheric pressure, and the mesh portion has an X In some cases, the beam irradiation chamber 43 bulges out, and illumination for sample observation is reflected at the bulged portion, so that the sample image cannot be grasped reliably. In addition, since the reinforcing member 50 is made of metal, when the secondary X-ray b hits it, a tertiary X-ray based on the metal element is generated, which appears as a system peak and causes an error in the X-ray analysis result. was there.
[0009]
The present invention has been made in consideration of the above-mentioned matters. The purpose of the present invention is to make it easy to see a sample when optically observing a sample and to prevent a system peak from interfering with measurement. It is an object to provide an X-ray analyzer that can perform X-ray analysis in a reliable and accurate manner.
[0010]
[Means for Solving the Problems]
To achieve the above object, according to the present invention, the sample chamber is disposed sample Ru held at atmospheric pressure, with the primary X-ray irradiated to pass through to the sample, irradiating the primary X-rays on the sample An X-ray irradiation chamber in which an X-ray detector for detecting secondary X-rays generated when the X-ray is generated is partitioned by an X-ray permeable diaphragm, and the X-ray irradiation chamber is in a vacuum state. In the analyzer, the diaphragm is reinforced by a transparent resin reinforcing member in which an X-ray passage hole is formed in a part thereof (Claim 1).
[0011]
Preferably, the reinforcing member is formed of a resin material that does not contain an element number of Na to U , for example, a resin such as polycarbonate or PET (polyethylene terephthalate ) .
[0012]
In the X-ray analysis apparatus having the above-described configuration, the reinforcing member that reinforces the X-ray permeable diaphragm is not made of metal as in the conventional case. The system peak is not generated. Therefore, desired X-ray analysis can be performed reliably and accurately.
[0013]
Moreover, a portion of the reinforcing member, since the hole for the X-ray passes is formed, it is possible to prevent absorption of primary X-rays and secondary X-rays by the reinforcing member, more of the desired X-ray analysis It can be performed reliably and accurately. In addition, the hole of the reinforcing member is formed in a tear shape having a small diameter on the primary X-ray side at a position corresponding to the path of the primary X-ray toward the sample and the path of the secondary X-ray toward the X-ray detector. (Claim 3).
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. 1 to 3 show one embodiment of the present invention. First, in FIGS. 1 and 2, reference numeral 1 denotes a main body block of an X-ray analyzer, and an X-ray tube 2 or An X-ray generator 3 containing a power supply unit (not shown) and the like is provided. Reference numeral 4 denotes a seal portion interposed between the main body block 1 and the X-ray generator 3 . An insertion hole through which XGT 5 for guiding the primary X-rays a emitted from the X-ray generator 3 with an appropriate beam diameter and irradiating it to a sample (described later) is inserted into the main body block 1. 6 and a space 7 connected to the insertion hole 6 is formed.
[0015]
Reference numeral 8 denotes an X-ray shielding wall provided below the main body block 1, more specifically below the lower end of the XGT 5. An opening 9 having an appropriate size is provided at a position corresponding to the lower end 5 a of the XGT 5. Is formed. Below this X-ray shielding wall 8, an atmospheric pressure space 11 is formed which is airtightly separated from the space 7 on the main body block 1 side by a thin diaphragm 10 made of an X-ray transparent material. The diaphragm 10 (the mounting structure of which will be described later) is made of an X-ray transparent material (for example, polyethylene resin) having the same characteristics as the diaphragm 44 described in the prior art. The space 7 of the above the membrane 10 is X-ray irradiation chamber, and the space 11 below the diaphragm 10 becomes the sample chamber.
[0016]
In the sample chamber 11, a sample stage 13 on which the sample 12 is placed is driven by a drive mechanism (not shown) in the X direction (direction perpendicular to the paper surface), the Y direction (left and right direction on the paper surface), and the Z direction ( It is provided so that it can move linearly in each of the vertical directions of the drawing. An opening / closing door (not shown) for inserting / removing the sample 12 is provided at an appropriate position on the left side in the Y direction of the sample chamber 11.
[0017]
Further, the inside of the X-ray irradiation chamber 7 is maintained in an appropriate vacuum state together with the insertion hole 6, and the sample 12 is irradiated with the lower end portion 5a of the XGT 5 and the primary X-ray a (see FIG. 2). An X-ray detector 14 composed of a semiconductor detector for detecting fluorescent X-rays b (see FIG. 2) generated when the optical microscope 15 is detected and an objective portion 15a of the optical microscope 15 for confirming the irradiation position of the sample 12 are provided. ing. In FIG. 1, 16 is a tank containing a cooling medium for cooling the X-ray detector 14, and c in FIG. 2 is visible light.
[0018]
The structure for attaching the diaphragm 10 will be described with reference to FIGS. Now, it is assumed that the diaphragm 10 has a circular shape in a plan view, for example. Reference numeral 17 denotes a diaphragm mounting member, which is circular in plan view, and includes a bracket member 20 including a planar portion 18 having a slightly larger diameter than the diaphragm 10 and a cylindrical portion 19 inserted into the lower end portion of the main body block 1, and the plane of the bracket member 20 . It consists of an annular pressing member 23 which is fixed to the portion 18 by a screw member 21 and has a hole 22 having a diameter slightly smaller than that of the diaphragm 10 at the center.
[0019]
Further, a counterbore hole 24 having a diameter considerably smaller than that of the cylinder part 19 is formed in the flat part 18 of the bracket member 20 concentrically with the cylinder part 19, and a thin disk-shaped reinforcing member 25 is formed in the counterbore hole 24. Is provided. More specifically, as shown in FIG. 3A, the counterbore hole 24 is formed so that the inner diameter on the flat surface portion 18 side can accommodate the reinforcing member 25, and the inner diameter on the cylindrical portion 19 side is the reinforcing member. It is slightly smaller than the outer diameter of 25. And the screw hole 26 is provided in the said plane part 18 at appropriate intervals.
[0020]
The holding member 23 is provided with screw insertion holes 27 at appropriate intervals around the hole 22 so as to correspond to the screw holes 26.
[0021]
Similar to the diaphragm 10, the reinforcing member 25 is sufficiently resistant to atmospheric pressure, has sufficient mechanical strength to maintain the diaphragm 10 in a predetermined horizontal state, and has primary X-rays a and secondary X-rays. It does not absorb or reflect b, does not hinder the transmission of the X-rays a and b as much as possible, and has transparency that allows visible light to pass sufficiently. It is preferable to form with the material which does not contain the above elements. Examples of such a material include resins such as polycarbonate and PET. In this embodiment, the material is made of polycarbonate, and is considerably thicker than the diaphragm 10 having a thickness (for example, about 0.5 mm) that provides sufficient mechanical strength. It is formed in a small-diameter disk shape.
[0022]
The reinforcing member 25 is provided with a hole 28 in a part thereof, as shown in FIGS. 3 (A) and 3 (B). This hole 28 is a path of the primary X-ray a irradiated from the lower tip 5a of the XGT 5 toward the sample 12 and the X-ray of the secondary X-ray b generated in the sample 12 when the sample 12 is irradiated with the primary X-ray a. At a position corresponding to the path to the detector 14, a teardrop shape having a small diameter on the primary X-ray a side and a large diameter on the secondary X-ray b side is formed. By forming such a hole 28 in the reinforcing member 25, the absorption of the primary X-ray a and the secondary X-ray b by the reinforcing member 25 can be eliminated, and a decrease in analysis accuracy can be prevented.
[0023]
The diaphragm 10 and the reinforcing member 25 configured as described above are held by the diaphragm attaching member 17 as follows. That is, the reinforcing member 25 is inserted into the counterbore hole 24 of the bracket member 20 from the flat portion 18 side, the O-ring 29 is fitted into the groove formed in the flat portion 18, and the diaphragm 10 is brought into contact with the flat portion 18 and pressed from the outside. The pressing member 23 is fixed to the bracket member 20 with the screw member 21 by applying the member 23. Thereby, the diaphragm 10 and the reinforcing member 25 are held by the diaphragm holding member 17. In particular, since the reinforcing member 25 contacts the contact portion 18a in the counterbore hole 24, the reinforcing member 25 does not protrude toward the cylindrical portion 19 side.
[0024]
As shown in FIG. 2, the diaphragm holding member 17 incorporating and holding the diaphragm 10 and the reinforcing member 25 is inserted into the lower end portion of the body block 1 so that the diaphragm 10 faces the sample chamber 11, and is in a predetermined state. It is attached with. In FIG. 2, 30 is an O-ring as a seal member.
[0025]
And when analyzing the sample 12 with the X-ray analyzer of the said structure, the vacuum degree of the X-ray irradiation chamber 7 is good, for example to be 1 Torr or less, More preferably, it is 0.1 Torr or less. The sample chamber 11 is maintained at atmospheric pressure. Furthermore, it is preferable to adjust the height of the sample stage 13 so that the distance between the diaphragm 10 and the sample 12 is 1 mm or less. This is because the influence of absorption by the atmosphere can be minimized as much as possible by reducing the distance between the diaphragm 10 and the sample 12 as much as possible.
[0026]
In the X-ray analyzer having the above-described configuration, the X-ray irradiation chamber 7 and the sample chamber 11 are partitioned by the X-ray permeable diaphragm 10 and the inside of the X-ray irradiation chamber 7 is in a vacuum state. In addition to the excellent operational effects as in the conventional X-ray analyzer, the following excellent operational effects can be obtained. That is, the reinforcing member 25 is provided in the diaphragm holding member 17 together with the diaphragm 10, and the reinforcing member 25 is in the hole 24 formed in the flat portion 18 of the bracket member 20 constituting the diaphragm holding member 17. Since the diaphragm 10 is provided so as to be in contact with 18a, the diaphragm 10 is not deformed such as bulging in the hole 24.
[0027]
Further, unlike the conventional case, the reinforcing member 25 is not made of a metal, but is made of a transparent resin having a good X-ray transmission and a transparency that allows a sufficient amount of visible light to pass. When optically observing using 15 or the like, it becomes easy to see and the material does not contain metal, so that a system peak that hinders measurement does not occur. Therefore, desired X-ray analysis can be performed reliably and accurately. And since the resin which comprises the said reinforcement member 25 does not contain especially the element to Na-U, the element to Na-U can be analyzed accurately.
[0028]
Then, by forming a teardrop shaped hole 28 at a position corresponding to the path of the secondary X-ray b toward the path and the X-ray detector 14 of the primary X-ray a toward the sample 12 of the reinforcing member 25, the primary X The line a and the secondary X-ray b can be prevented from being absorbed by the reinforcing member 25, and a desired X-ray analysis can be performed reliably and accurately.
[0029]
In the above-described embodiment, only the fluorescent X-ray is detected as the secondary X-ray b generated in the sample 12 when the sample 12 is irradiated with the primary X-ray a. An X-ray detector for detecting the line may be provided.
[0030]
Further, a collimator may be used instead of XGT5.
[0031]
【The invention's effect】
As described above, in the present invention, the diaphragm that partitions the sample chamber and the X-ray irradiation chamber is reinforced by the transparent resin reinforcing member partially formed with an X-ray passage hole. Therefore, when the sample is optically observed, this is easy to see, and the material does not contain metal, so that a system peak that hinders measurement does not occur. Therefore, desired X-ray analysis can be performed reliably and accurately. In particular , as the resin constituting the reinforcing member, it is possible to accurately analyze the elements from Na to U by forming a resin material that does not contain the elements from Na to U , for example, a resin such as polycarbonate or PET. .
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an example of an X-ray analysis apparatus according to the present invention.
FIG. 2 is an enlarged view showing a main part of the X-ray analysis apparatus.
FIGS. 3A and 3B are diagrams for explaining a diaphragm holding structure in the X-ray analyzer, wherein FIG. 3A is a longitudinal sectional view, and FIG. 3B is an exploded perspective view;
FIG. 4 is a diagram for explaining a conventional technique.
[Explanation of symbols]
7 ... X-ray irradiation chamber, 10 ... diaphragm, 12 ... sample, 11 ... sample chamber, 14 ... X-ray detector, 25 ... reinforcing member, 28 ... hole, a ... primary X-ray, b ... secondary X-ray.

Claims (4)

A sample chamber that will be held at atmospheric pressure sample is placed, with the primary X-ray irradiated to pass through to the sample, detecting the secondary X-rays generated when the primary X-ray is irradiated to the sample with X-ray detector and is arranged X-ray irradiation chamber to partition the X-ray transparent membrane that, in X-ray analysis apparatus formed by the X-ray irradiation chamber in a vacuum state, the diaphragm, a portion An X-ray analyzer characterized by being reinforced by a transparent resin reinforcing member having an X-ray passage hole formed therein . The X-ray analysis apparatus according to claim 1, wherein the reinforcing member is formed of a resin material that does not include an element number Na to U. The holes of the reinforcing member, according to claim primary X-rays side in the corresponding position in the path of the secondary X-rays toward the path and the X-ray detector of the primary X-ray toward the sample is formed on the teardrop shaped whose diameter 1 Or the X-ray analyzer according to 2 ; The X-ray analyzer according to any one of claims 1 to 3, further comprising an optical microscope that optically observes the irradiation position of the sample.

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