JP2861736B2 - X-ray spectrometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray spectroscope and, more particularly, to a linear condensing X-ray spectrometer that moves a spectroscopic element on a straight line passing through an X-ray generation point.

[0002]

2. Description of the Related Art An X-ray spectrometer is used for an apparatus such as an X-ray microanalyzer and the like. X-rays emitted from an X-ray generation point on a sample are separated by a spectroscopic element and incident on a detector. ing. As this X-ray spectrometer, a linear condensing X-ray spectrometer is known. In this linear condensing X-ray spectrometer, the direction of taking out X-rays from the X-ray generation point is always kept constant. In order to perform X-ray spectroscopy, the curved spectroscopic element is moved along a straight line, and at the same time, the spectroscopic element itself is rotated to change the incident angle of the X-ray incident on the spectroscopic element.

Conventionally, a configuration shown in FIG. 6 has been known for arranging a large number of spectroscopes around an X-ray generation point. In FIG. 6, the X-ray spectrometer is composed of components and a mechanism connecting the components, and is arranged along a first straight line (AA ′) passing through the X-ray generation point as a component. And the second moving axis passing through the X-ray generation point.
A second movement axis arranged along a straight line (A-A¨), and a light-splitting element arranged on a table moving on the first movement axis such that its lattice plane tangent is in contact with a Rowland circle; Second
A third straight line (DD ′) intersecting with the straight line (AA ′)
And a third axis rotatably installed at an intersection (D) of the second straight line and the third straight line on a table that moves along the second axis. There is an X-ray detector provided on a sliding table, and as a mechanism, an intersection (D) between the central portion (B) of the spectral element moving on the first axis, the second straight line, and the third axis. A) a first mechanism for linking the movement of the carriage on the first movement axis and the movement of the carriage on the second movement axis, in order to always keep the length between the movements of the spectroscopic element constant. The angle formed by the third axis and the second straight line is always the center part (B) of the spectral element even by the movement of the intersection (D).
A second mechanism for maintaining a relationship twice as large as an angle between a straight line connecting the first straight line and the intersection (D) and a second straight line (AA);
There is a third mechanism that always constrains the slit point of the line detector on the Rowland circle.

The first mechanism and the second mechanism constitute a mechanism for maintaining the distance between the sample and the spectroscopic element and the distance between the spectroscopic element and the detector on the Roland circle equal. doing.

[0005]

In the conventional X-ray spectrometer, (1) the distance between the sample and the spectroscopic element and the distance between the spectroscopic element and the detector are kept equal on the Rowland circle. And the mechanism for the detector to face the spectroscopic element are complicated.

(2) The mechanism of (1) is large, and there is a large mechanism below the sample surface and near the analysis point. Therefore, the size of the sample and the mechanism for supporting and moving the sample are limited. There is a problem.

Therefore, the present invention solves the above-mentioned problems of the conventional X-ray spectroscope, and the configuration for disposing the spectroscope around the X-ray generation point is such that the size of the sample and the sample are supported and moved. It is an object of the present invention to provide an X-ray spectroscope capable of increasing a movable range of a spectroscopic element without affecting a position where a mechanism is installed.

[0008]

In order to achieve the above object, the present invention provides an X-ray spectrometer for performing spectroscopy by a molecular element moving on a linear axis passing through an origin, wherein R is a radius of a Rowland circle, When a linear axis is set to an angle of θ = 0, a first link mechanism having a locus represented by a curve represented by polar coordinates r = 2Rsin2θ or a part thereof, a distance from an origin to the spectral element, and a first link mechanism from the spectral element. A second link mechanism for constraining the distance to the detector on the link mechanism to be equidistant, a dynamic axis passing through the origin and forming an angle with the linear axis, and one end rotatable with respect to the spectroscopic element. A third link mechanism having a connecting portion having a length of 2R sin ψ that allows the other end to move on the moving axis, wherein the angle と す る is a fixed angle smaller than the angle formed between the linear axis and the sample surface.

In the present invention, the first link mechanism is the second link mechanism.
Along with the link mechanism, the sample, the spectroscopic element, and the detector are arranged on the same Roland circle, and the distance between the sample and the spectroscopic element and the distance between the spectroscopic element and the detector are kept equal. The slit of the vessel is directed in the direction of the spectral element.

Further, in the present invention, the straight line having a length of 2R sinψ of the third link mechanism is a chord of an arc having a radius R and a central angle of 2ψ, and an arc having a radius R of 2Ｒ and a central angle of 2 ° instead of the straight line having a length of 2R sinψ. It can also be. Further, the third link mechanism determines the angle so that the spectral element contacts the Rowland circle.

In the present invention, the spectroscopic element refers to an element including a dispersive crystal, a multilayer film, a diffraction grating, and the like.

[0012]

According to the above structure, in an X-ray spectrometer that performs spectroscopy by a spectroscopic element that moves on a linear axis passing through the origin, R is the radius of a Rowland circle, and θ is the linear axis.
When the angle is 0, the X-ray detector is arranged on the first link mechanism having the locus represented by the polar coordinate r = 2Rsin2θ or a part thereof as the locus, and the distance from the origin to the spectral element and the distance from the spectral element The positional relationship between the spectroscopic element and the detector is defined by a second link mechanism that restricts the distance to the detector on the first link mechanism at an equal distance, and the first link mechanism and the second link mechanism determine the positional relationship between the spectroscopic element and the detector. The sample, the spectroscopic element, and the detector are arranged on the same Roland circle, the distance between the sample and the spectroscopic element, the distance between the spectroscopic element and the detector are kept equal, and the slit of the detector is Orient in the direction of the spectral element. Further, a length 2 having one end as the point of the spectroscopic element and the other end as a point on a straight line passing through the origin and forming an angle with the linear axis as ψ
The third link mechanism consisting of the straight line of Rsinψ allows the crystal surface of the light-splitting element to be in contact with the Rowland circle by setting the mounting angle of the light-splitting element to the angle between the direction of the crystal plane of the light-splitting element and the straight line having a length of 2R sinｓ. To decide.

Thus, in the linear condensing X-ray spectrometer, X-rays are separated while keeping the direction of extracting the X-rays from the X-ray generation point constant, and the curved spectroscopic element is formed along the straight line. While moving, the spectroscopic element itself is simultaneously rotated to change the incident angle of the X-ray incident on the spectroscopic element.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. However, the present invention is not limited to the embodiments.

[Configuration of Embodiment] In an X-ray spectrometer, X
In order to perform X-ray spectroscopy while keeping the direction in which the X-rays are taken out from the ray generation point constant, the spectroscopic element is moved by moving the spectroscopic element along a straight line and simultaneously rotating the spectroscopic element itself. A mechanism for changing the angle of incidence of X-rays incident on the light source is required. Therefore, in the following, the principle of the mechanism of the X-ray spectrometer of the present invention will be described in order to (a) keep the distance between the sample and the spectroscopic element equal to the distance between the spectroscopic element and the detector on the Roland circle. (B) a mechanism for determining the angle of the spectroscopic element so as to be in contact with the Rowland circle (hereinafter, referred to as a mechanism). b), and then a more specific embodiment of the mechanism based on the principle will be described.

(Structure of Mechanism a) First, the principle of the mechanism a will be described with reference to FIG. 4 which illustrates the principle of the mechanism of the X-ray spectrometer of the present invention.

In FIG. 4, when a sample 1 is placed at the origin of the x-axis and an electron beam 2 is incident from the y-axis direction, the sample 1 emits X-rays. The X-rays emitted from the sample 1 in the direction of the angle α with respect to the x-axis (the direction of the X-axis) are separated by the spectral element 4 arranged on the X-axis, and then detected by the detector 5. At this time, in the figure, assuming that the X-ray generation point on the sample 1 is point O (origin), the center position of the spectroscopic element 4 is point T, and the slit position of the detector 5 is point P, points O, T, and point P is always on the Roland circle, points O and T
, And a distance TP between the point T and the point P are made equal distances, and the spectroscopic element 4 is in contact with the Rowland circle at the point T,
By directing the slit of the detector 5 in the direction of the point T, it is possible to configure a linearly focused X-ray spectrometer.

For this purpose, the following embodiments (A) and (B) are used in the embodiment of the present invention.

(A) When R is the radius of the Rowland circle and the X-axis is an angle of θ = 0, a link mechanism having a locus represented by a polar coordinate r = 2R sin2θ or a part thereof as a locus.

(B) When a moving point T that moves on the X-axis at a distance t from the origin O is one end point and a point P at the slit position of the detector 5 is the other end point, the moving point T and point P
And a link mechanism in which the distance t from the origin of the moving point T is constrained to be equal, and the slit faces the direction of the spectral element.

First, the link mechanism (A) will be described. In FIG. 4, assuming that the radius of the Roland circle is R and the point located at a distance R from each of the points O, T, and P is Q, the triangle OTQ and the triangle PTQ are congruent, and the angle TOP is θ. Angle TQ
Together with O and the angle TQP, the angle becomes 2θ. Therefore,
The point P on the Roland circle is a point on the curve represented by r = 2Rsin2θ. If the link mechanism is configured such that the detector 5 moves on the curve represented by r = 2Rsin2θ, the detector 5 exists on the Rowland circle. This link mechanism can be constituted by a link groove having a locus of a curve represented by, for example, r = 2Rsin2θ.

Next, the link mechanism (B) will be described. In FIG. 4, the distance between the OT and the distance between the TPs is both set to t by the link mechanism, and the X-rays reaching the spectral element on the point T moving on the Rowland circle are:
Point P moving on the Rowland circle by the mechanism (A)
Converges to The link mechanism can be realized by, for example, a combination of a linear slide mechanism that can be rotated around a point of the spectral element and the point as an axis, and a wire mechanism that expands and contracts by an amount corresponding to the movement of the spectral element.

Thus, once the slit direction of the detector 5 is set in the direction of the point T on the link mechanism having the curve represented by the polar coordinate r = 2R sin2θ or a part thereof as the locus, the angle OPT always becomes the angle θ. Thus, the slit of the detector 5 faces the direction of the spectral element 4.

Therefore, the distance between the sample and the spectroscopic element and the distance between the spectroscopic element and the detector are kept equal on the Rowland circle by the link mechanisms of the mechanisms (A) and (B). Also, the slit of the detector is oriented in the direction of the spectral element.

(Structure of Mechanism b) Next, the principle of the mechanism b will be described with reference to FIG. 5 which illustrates the principle of the mechanism of the X-ray spectrometer of the present invention.

In FIG. 5, the X-ray generation point on the sample 1 is a point O (origin), the emission direction of the X-ray emitted from the point O is the X-axis (dynamic axis) 6, and the X-ray 6 A moving point at the center of the point 4 is point T, and a straight line passing through the point O and forming an angle with the X axis as ψ is a moving axis 9. A circle 21 passing through the points O and T and having a radius R
Considering the center (point U), the intersection of the circle 21 and the driving axis 9 is the point S, the line segment connecting the points T and S is the chord 20, and the line 21 connecting the points T and S is the circle 21. A part is an arc 10. It is assumed that the chord 20 and the arc 10 have a predetermined length.
As the point T moves on the moving axis 6, the point S becomes the moving axis 9
, The points T and S move on the circle 21. At this time, the triangle STU is an isosceles triangle in which the angle of the point U is 2 ° and the angles of the other two points T and S are (π−ψ), and the tangent angle of the circle 21 at the point T is The angle ψ.

Therefore, by disposing the spectral element 4 in contact with the arc 10 at the point T, the angle can be determined so that the spectral element 4 contacts the Rowland circle.

As a configuration for this, the following configuration (C) or (D) can be used in the embodiment of the present invention.

(C) A moving point T on the X axis passing through the point O and a moving point S on the moving axis 9 where the angle between the X axis and the X axis passing through the point O is ψ. A link mechanism comprising an arc in which T and point S are both ends of an arc having a radius R and a central angle of 2 °.

(D) A moving point T on the X axis passing through the point O and a moving point S on a moving axis 9 passing through the point O and forming an angle ψ with the X axis. A link mechanism consisting of a chord connecting point T and point S of an arc in which T and point S are both ends of an arc having a radius R and a central angle of 2 °.

In the above link mechanism, the link mechanism (C) is a link mechanism in which the arc 10 is formed by an arc of the same shape, and one end of the arc moves along a moving axis set on the X axis. By allowing the other end to move along a moving axis provided on a straight line forming an angle と with the X axis, the angle of the spectroscopic element 4 moving on the X axis is brought into contact with the Rowland circle. Can be determined.

In the link mechanism (D), the arc 10 is constituted by a string connecting both ends of the arc, and one end of the string is moved along a moving axis set on the X axis. By allowing the other end to move along a moving axis provided on a straight line forming an angle と with the X axis, the angle of the spectroscopic element 4 moving on the X axis is brought into contact with the Rowland circle. Can be determined.

Therefore, by combining the structures a and b, in the X-ray spectrometer, the spectroscopic element is moved along a straight line, and at the same time, the X-ray incident on the spectroscopic element is rotated by rotating the spectroscopic element itself. X-rays can be separated and detected by changing the incident angle of the X-rays and keeping the X-ray extraction direction from the X-ray generation point constant.

(One Embodiment of the Mechanism of the X-ray Spectrometer) Next, FIGS. 1 and 2 are diagrams showing the construction of the mechanism of the X-ray spectrometer of the present invention, and FIG. This will be described with reference to the wire connection diagram of FIG. FIG. 2 shows a state on the back side of FIG.

First, an embodiment of the mechanism of the X-ray spectrometer will be described with reference to FIGS. In FIGS. 1 and 2, the sample is set at the position of the origin O, and an electron beam is irradiated from the y-axis direction. The X-rays emitted from the sample in the X-axis direction are separated at a point T on the X-axis by the spectroscopic element 4 slidably provided in the X-axis direction, and converge on a point P of the detector 5. The spectroscopic element 4 is mounted on the moving member 11, and the moving of the spectroscopic element 4 in the X-axis direction is performed by moving the moving member 11 along the moving axis 6 provided in the X-axis direction. For the movement of the moving member 11, for example, the moving shaft 6 is constituted by a lead screw, the lead screw is rotated to feed the lead nut in the axial direction, and the moving member 11 fixed to the lead nut is moved in the axial direction. It is done by doing. Then, by the movement of the moving member 11, the spectroscopic element 4 and the moving shaft 9 fixed to the moving member 11 move.

On the other hand, this detector 5 is slidably mounted along a link groove 8 fixed to the apparatus, and the shape of the link groove 8 is the polar coordinate r = 2R sin2θ shown in the mechanism (A). It is formed according to the curve represented.

The moving member 11 has a moving shaft 9 on its extension, and slidably engages with the moving shaft 9 at a point S of the detector 5 to thereby provide the link mechanism (B). Is formed. In other words, the moving shaft 9 is rotatably supported on the same axis as the spectroscopic element 4 and moves together with the moving member 11. In the direction of.

Next, FIG. 3 shows the distance between the origin O and the point T and the distance between the point T and the point P in order to converge the X-ray reaching the spectral element on the point T to the point P. 2 shows a wire mechanism as an embodiment for realizing a link mechanism (B) in which both distances are t.

In FIG. 3, a wire 12 is moved from a wire fixing portion 13 installed at one end of the device to a point T on the moving member 11.
, And after winding the shaft provided at the point T, the shaft provided at the point P of the detector 5 is wound, and again passes through the point T and is fixed to the wire fixing portion 13. This wire 12 is connected to a spring 14
Thus, a certain tension is applied to the detector 5 and a certain load is applied to the rear of the detector 5 so that the detector 5 is pulled to prevent loosening. In addition, the spring 14 in the figure is shown in a simplified manner, and does not always apply a constant load. Further, the slit of the detector 5 is disposed on the point P in FIG. Then, as an initial setting, the distance between the origin O and T is made equal.

FIG. 2 shows link mechanisms C and D. The link mechanisms C and D are, for example, on the back side of the plate 15, for example, links which do not interfere with the operation of the link groove 8 and the coaxial 9. It is constituted by a groove 18 and a link 17. The link groove 18 is formed in the plate 15 at an angle of ψ with respect to the axis X.
7 has a length of 2R sin2ψ, one end of which is fixed to the link groove 18 and the other end of which is fixed to the spectral element 4 at an angle ψ. The link groove 18 and the link 1
The link mechanisms C and D according to 7 are not limited to this configuration, but can be configured with other configurations.

[Operation of Embodiment] Next, the operation of the embodiment of the present invention will be described.

In FIGS. 1 and 2, when an electron beam is incident on the sample from the y direction, the X-rays emitted from the sample in the X-axis direction are separated by the spectral element 4 on the X-axis. At this time, the spectroscopic element 4 moves the origin O on the sample and the point P of the detector 5 by the link mechanism (A) and the link mechanism (B).
Are arranged on the same Rowland circle, and the mounting angle of the spectral element 4 is determined by the link mechanism (D).
As a result, the angle becomes so as to be in contact with the Rowland circle, and the X-ray is directed toward the detector 5.

In this configuration, since the link mechanism is fixed to the plate 15, there is no large component movement, the operation is stable, and the adjustment is easy. Further, in the link mechanism (D), by making the angle ψ formed by the X axis and the link groove 18 smaller than the angle α formed by the X axis and the sample surface, the position occupied by the link mechanism (D) supports the sample and the sample. The sample stage to be moved can be set at a position where no interference occurs, and a large sample or sample stage can be used.

On the other hand, the position and the orientation of the detector 5 with respect to the X-rays are determined by the link mechanism (A) and the link mechanism (B) by the distance between the sample and the spectroscopic element and the distance between the spectroscopic element and the detector. The distance is kept equal, and the direction of the slit of the detector 5 is directed to the direction of the spectral element 4 which becomes the angle θ direction at the point P in FIG.

In the present invention, the spectroscopic element refers to an element in which a spectroscopic crystal, a multilayer film, a diffraction grating, and the like are put together.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0047]

As described above, according to the present invention,
The configuration for arranging the spectroscope around the X-ray generation point does not affect the size of the sample or the position where the mechanism for supporting and moving the sample is installed, and the movable range of the spectroscopic element is increased. An X-ray spectrometer capable of performing the above-described method can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a mechanism of an X-ray spectrometer of the present invention.

FIG. 2 is a configuration diagram illustrating a mechanism of the X-ray spectrometer of the present invention.

FIG. 3 is a wire connection diagram of the X-ray spectrometer of the present invention.

FIG. 4 is a diagram for explaining the principle of the mechanism of the X-ray spectrometer of the present invention.

FIG. 5 is a diagram illustrating the principle of the mechanism of the X-ray spectrometer of the present invention.

FIG. 6 is a configuration diagram of a conventional X-ray spectrometer.

[Explanation of symbols]

Reference Signs List 1 ... sample, 2 ... electron beam, 3 ... sample stage, 4 ... spectroscopic element, 5 ... detector, 6 ... moving axis, 7,17 ... link, 8,1
8 link groove, 9 dynamic axis, 10 arc, 11 moving member, 12 wire, 14 spring, 15 plate

Claims (1)

(57) [Claims] 1. An X-ray spectrometer for performing spectroscopy by a molecular element moving on a linear axis passing through an origin, wherein (a) R is a radius of a Rowland circle, and the linear axis is an angle of θ = 0, polar coordinates a first link mechanism having a curve represented by r = 2Rsin2θ or a part thereof as a trajectory; and (b) a distance from an origin to the spectral element and from the spectral element to a detector on the first link mechanism. A second link mechanism for constraining the distance to the same distance, (c) a moving axis passing through the origin and forming an angle with the linear axis, and one end rotatable in the spectroscopic element and the other end moving in the spectroscopic element. An X-ray having a third link mechanism having a connection portion having a length of 2R sinψ that can be moved on an axis, wherein the angle ψ is a fixed angle smaller than an angle formed between the linear axis and a sample surface. Spectrograph.