JP2727939B2 - 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 a linear condensing X-ray spectrometer for moving a spectroscopic element on a straight line passing through an X-ray generation point, and more particularly to a vertical linear condensing X-ray spectrometer.

[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. FIG. 8 shows the configuration of the conventional linear focusing X-ray spectrometer of FIG. In FIG. 7, the X-ray spectrometer includes a first moving axis and a second moving axis passing through an X-ray generation point on a sample, and a spectroscopic element arranged on a table moving on the first moving axis. And a third axis rotatably installed at the intersection (D) and an X-ray detector provided on the third axis as constituent elements, a distance between the sample and the spectroscopic element on a Rowland circle, It is composed of a link mechanism for keeping the distance between the spectroscopic element and the detector equal, and a link mechanism for always restricting the slit point of the X-ray detector on a Rowland circle. The X-ray detector is installed on a table rotatably mounted on the axis so as to always face the direction of the spectral element by the link mechanism. Conventionally, X
As means for restraining the movement of the line detector, various means other than the above-described configuration have been proposed. Usually, the detector is supported in a cantilever state with respect to a link mechanism. FIG.
FIG. 7 is a diagram showing a state of attachment of a conventional X-ray detector to a link mechanism, and shows only a detector housing 10 and a support member 20 (substrate) of the detector. In the figure, a detector housing 10 has a slit 1 for transmitting X-rays dispersed by a spectral element.
2 is formed, and is slidably attached to a driving shaft 30 installed on the support member 20 on the link mechanism side by a guide portion 15 such as a bearing. The guide portion 15 is provided on only one side of the detector housing 10 and is supported by the cantilever with respect to the driving shaft 30 on the support member 20 side.

[0003]

However, in the above-mentioned conventional X-ray spectrometer, particularly in a vertical X-ray spectrometer,
Since the detector is cantilevered, the unsupported side of the detector is lowered by the weight of the detector itself and the detector is tilted. When the detector is tilted, the slit for entering the spectral X-ray formed on the detector is also shifted from its original position, and there is a problem that the spectral X-ray does not enter the slit. Further, one end of the detector may come into contact with the support member 20 due to the inclination. In order to prevent the inclination of the slit due to the inclination of the detector, the supporting portion of the support mechanism that supports the detector needs to have a large configuration that can sufficiently withstand the weight of the detector. However, in general, various measurement devices are installed near the sample of the X-ray spectrometer,
There is not enough space to install other mechanisms,
In order to make a sufficient amount of spectral X-rays incident on the detector,
It is desired to reduce the size of the device. Therefore, usually, it is not possible to provide a support portion sufficient to withstand the weight of the detector. In addition, a support wall facing the detector is provided on the unsupported side of the detector, and a mechanism that assists the support force of the support portion such that the detector slides along the support wall can be considered. The angle of the detector with respect to the support wall may change with the movement. In such a case, in order to keep the angle between the slit of the detector and the incident X-ray constant, the surface of the support wall is formed with a high flatness, and the support wall and the detector are highly parallelized. It is required to be installed in degrees.
However, it is difficult to mount the support wall with high accuracy in a measurement room where there is not enough space. Also, if warpage occurs in the dynamic shaft 30 due to low flatness of the surface of the support wall and low parallelism between the support wall and the detector, the distance from the support member 2 increases in accordance with the movement of the detector. Things can happen. Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional X-ray spectrometer and to provide an X-ray spectrometer capable of preventing the inclination of the slit of the detector with respect to the incident X-ray by a simple configuration. And

[0004]

According to the present invention, there is provided an X-ray spectroscope in which a detector detects X-rays separated by a spectroscopic element moving on a straight line passing through an origin, wherein a slit for receiving X-rays is formed. The two link mechanisms are arranged in parallel with the detector in between, and the fulcrum on the extension of both ends of the slit is supported by the link mechanism to support the detector. The movement of the detector is restricted by the two link mechanisms. By doing so, the above object is achieved. In the present invention, the link mechanism restricts the movement of the detector. For example, when R is a rolling radius and θ is an angle formed by a straight line connecting the origin and the spectral element, the link mechanism is represented by polar coordinates r = 2Rsin2θ. It can be a link groove with a curve or a part of it as a locus,
It is formed by making the two link grooves have the same shape. In the present invention, the fulcrum has a function of rotatably supporting the detector on the link mechanism. For example, a rotation support member such as a bearing can be used.

[0005]

According to the above construction, the detector is provided with a rotation supporting member on the extension of both ends on the longitudinal axis of the slit to form a fulcrum, and the two fulcrums form the fulcrum on both sides of the detector. From above, and move along the link mechanism while rotating on the link mechanism such as a link groove. Thereby, the movement of the detector is restricted by the link mechanism, and the slit of the detector always keeps a constant relationship with the incident X-ray, so that the influence of the incidence of the X-ray due to the inclination of the slit can be eliminated.

[0006]

[Configuration of Example]

(Mechanism for Changing the X-ray Incidence Angle in the Embodiment of the Present Invention) In an X-ray spectrometer, in order to perform X-ray spectroscopy while keeping the direction of taking out X-rays from the X-ray generation point always constant, By moving the spectroscopic element along a straight line and simultaneously rotating the spectroscopic element itself, X
A mechanism for changing the angle of incidence of the line is required. X of the present invention
In the line spectrometer, the mechanism includes (a) 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 to each other, and a slit of the detector. It is composed of a mechanism for pointing the direction of the spectral element (hereinafter referred to as mechanism a) and (b) a mechanism for determining the angle of the spectral element so as to be in contact with the Rowland circle (hereinafter referred to as mechanism b).

(Structure of Mechanism a) First, the principle of the mechanism a will be described with reference to FIG. 6 which illustrates the mechanism of the X-ray spectrometer of the present invention. In FIG. 6, a sample 1 is placed at the origin of the x-axis, and X-rays radiated from the sample 1 by the electron beam 2 in the direction of the y-axis in the direction of the angle α with respect to the x-axis (direction of the X-axis) The line is detected by the detector 1 after being separated by the spectral element 4 arranged on the X-axis. At this time, the X-ray generation point on the sample S in FIG.
(Origin), assuming that the center position of the spectroscopic element 4 is a point T and the slit position of the detector 1 is a point P, the points O, T, and P are always located on the Rowland circle. The distance OT and the distance TP between the point T and the point P are set to be equal distances, the spectroscopic element 4 is in contact with the Rowland circle at the point T, and the slit of the detector 1 is directed in the direction of the point T. A focused X-ray spectrometer can be configured.

As a configuration for this purpose, the following configurations (A) and (B) are used in the embodiment of the present invention. (A) When R is the radius of a Rowland circle and the X axis is an angle of θ = 0, a link mechanism that uses a curve represented by polar coordinates r = 2Rsin2θ or a part thereof as a locus.

The point P on the Roland circle is r = 2Rsi
It becomes a point on the curve represented by n2θ, and this r = 2Rsi
When the link mechanism is configured so that the detector 1 moves on a curve represented by n2θ, the detector 1 exists on a Rowland circle. This link mechanism is, for example, r = 2R
It can be constituted by a link groove having a locus of a curve represented by sin2θ. (B) When the moving point T moving on the X-axis at a distance t from the origin O is one end point, and the point P at the slit position of the detector 5 is the other end point, the moving point T and the point A link mechanism that restricts the distance to P from the origin of the moving point T so that the distance t is equal, and the slit points in the direction of the spectral element. This link mechanism can be realized by, for example, a combination of a linear slide mechanism that can be rotated around the point of the spectral element and a wire mechanism that expands and contracts as much as the spectral element moves. By the mechanism (A) and the link mechanism of the mechanism (B), 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. Are oriented in the direction of the spectral element.

(Structure of mechanism b) Next, the principle of the mechanism b will be described. The radius is R and the central angle is 2 ° (X on sample 1)
By setting the spectroscopic element 4 at the intersection of the X-axis and the arc formed by the X-axis passing through the line generating point and the X-axis, the angle can be determined so that the spectroscopic element 4 is in contact with the Roland circle. it can. As a configuration for this, a moving point on the X axis passing through the point O and a moving point on the moving axis passing through the point O and having an angle of ψ with the X axis passing through the point O are defined by a radius R. Central angle 2
A link mechanism consisting of an arc or a chord at both ends of the arc of ψ can be used. By combining the configurations a and b, X
In a X-ray spectrometer, the 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-rays incident on the spectroscopic element, thereby extracting the X-ray from the X-ray generation point X with the direction always constant
The rays can be separated and detected.

(Structure of mechanism of one embodiment of X-ray spectrometer) Next, referring to FIG. 2, one structure of the mechanism of the X-ray spectrometer of the present invention will be described. In FIG. 2, a sample placed at the position of the origin O is irradiated with an electron beam irradiated in the y-axis direction.
The X-rays emitted in the axial direction are split by the spectroscopic element 4 slidably provided on the X-axis, and are incident on the slit 12 of the detector 1. The spectroscopic element 4 is mounted on the moving member 31, and the spectroscopic element 4 is moved in the X-axis direction by moving the moving member 31 along the moving axis 32. On the other hand, the detector 5 is provided with the link groove 2 fixed to the support substrate 22.
4 so as to be slidable. In addition,
The shape of the link groove 24 is the polar coordinate r shown in the mechanism (A).
= 2R sin2θ. Further, the moving member 31 has a moving shaft 33 which is curved at an angle に 対 し て with respect to the X axis on the extension thereof,
The link mechanism (B) is formed by slidably engaging the guide portion 35 of the detector 1 with 3. As a result, the moving shaft 33 moves together with the moving member 11, restricting the detector 1 to linear movement, and always pointing the slit of the detector 1 toward the spectroscopic element 4.

(Configuration of Support Mechanism of Embodiment of the Present Invention) Next, referring to FIG. 1, one configuration of a support mechanism of the X-ray spectrometer of the present invention will be described. In FIG. 1, a support mechanism 2 for supporting a detector housing 11 of a detector 1 of an X-ray spectrometer is constituted by two link mechanisms which are arranged in parallel to face each other with the detector housing 11 interposed therebetween. You. As the two link mechanisms, a link groove having a locus of a curve represented by r = 2Rsin2θ described in (A) can be used. One link mechanism is constituted by a first substrate 21 on which a first link groove 23 is formed, and the other link mechanism is constituted by a first substrate 22 on which a second link groove 24 is formed.

The first link groove 23 and the second link groove 24
Are link grooves each having a locus of a curve represented by r = 2Rsin2θ, and are two grooves of the first substrate 21 and the first substrate 22.
The two substrates are installed by arranging the substrates in parallel with the detector 1 interposed therebetween, and have a symmetrical positional relationship with the detector 1 interposed therebetween. One end of a first bearing 13 and a second bearing 14 are attached to a surface of the detector housing 11 facing the first substrate 21 and the first substrate 22, respectively.
And the other end of the second bearing 14 are inserted into grooves of the first link mechanism 23 and the second link mechanism 24 and are slidably mounted. Further, the detector 1 has a slit 12 formed on the same axis as the first bearing 13 and the second bearing 14. Is set so that the X-rays separated by the above-mentioned method enter through the slit 12. A guide 35 is formed at one end of the detector 1 and is engaged with a guide groove 36 formed in the axial direction of the driving shaft 33. The guide portion 35 and the guide groove 36 are connected to the detector 1.
A mechanism for performing the movement along the moving axis 33 is provided.

[Operation of the Embodiment] (Operation of the Support Mechanism of the Embodiment of the Present Invention) Next, FIG. 3 is a sectional view of the support mechanism of the embodiment of the present invention, and FIG. 4 shows the support mechanism of the embodiment of the present invention. The operation of the support mechanism of the embodiment will be described in detail with reference to the perspective view of FIG. 5 and the operation diagram of the support mechanism of the embodiment of the present invention in FIG. 3 and 4, a slit 12 is formed in the lateral direction at the front of the detector housing 11,
The first bearing 13 and the second bearing 14 are mounted on the same axis as the longitudinal axis of the slit 12. The slit 12, the first bearing 13, and the second bearing 14
The slit 12 is always kept on the same axis with respect to the rotation of the detector housing 11 about the axis of the first bearing 13 and the second bearing 14 as the axis of rotation. The first link groove 23 and the second link groove 24 are provided near the center of the groove.
3 and the other end of the second bearing 14 are inserted and slidably supported. The first bearing 13 and the second bearing 14 can be constituted by, for example, a bearing with a flange, and the detector 1 can be moved along the link groove by the bearing. This movement is accompanied by the movement of the drive shaft 33 and the guide groove 36.
Is performed by a guide unit 35 that slides along. In addition, a smooth member such as a bearing may be provided in a portion between the guide portion 35 and the guide groove 36. Further, the first link groove 23 and the second link groove 24 are arranged symmetrically with respect to the detector 1, and the slit 12 on the detector 1 side is formed.
The center of the two link grooves can be aligned on the axis of the first bearing 13 and the second bearing 14.
By this alignment, the detector housing 11 is moved to the first and second positions.
The slits 12 are slidably held along the link grooves by the substrates 21 and 22 and can be rotated about the same axis as the longitudinal direction of the slit 12 as a central axis. This detector 1
By setting the rotation axis and the longitudinal axis of the slit 12 to be the same axis, the X-rays separated by the spectral element 4 can always pass through the slit 12 regardless of the rotation of the detector housing 11. .

In the operation diagram of FIG. 5, the axes (a), (b) and (c) are considered as the rotation axis of the detector. Shaft (a)
Is the rotation axis of the detector 1 and the axis in the length direction of the slit 12. When the axis (a) is rotated about the axis (a) as shown by the arrow (A), the slit is always on the axis (a) and the slit does not tilt with respect to the incident X-ray. for that reason,
The X-rays split by the spectroscopic element 4 always pass through the slit. The axis (b) is an axis orthogonal to the axis (a) in the length direction of the slit 12. When this axis (b) is rotated as a rotation axis as shown by an arrow (B), a phenomenon occurs in which the slit position shifts back and forth from the convergence position of the incident X-ray at a position distant from the rotation axis and passes through the slit. However, according to the configuration of the present invention, the rotation axis restricts rotation about the axis of the axis (b).
The influence of the rotation of the shaft (b) can be prevented. The axis (c) is an axis in the longitudinal direction of the detector 1 and is an axis orthogonal to the axis (a) in the longitudinal direction of the slit 12. When a rotational motion about this axis (c) occurs, the X-rays and the slit intersect at an angle, and the amount of X-rays passing through the slit decreases. According to the support mechanism of the present invention, since the detector 1 is supported by the two bearings on both sides thereof, rotation about this axis (c) is prevented, and X-rays enter the slit in this rotation direction. There is no effect. Therefore, as described above, since the rotational movement about the axes (b) and (c) in FIG. 5 is restricted, the influence of X-ray incidence on the slit can be eliminated, and the first substrate and the second substrate can be eliminated. Mounting error or the first
With respect to rotation of the detector due to a formation error of the link groove or the first link groove, it is possible to prevent the inclination of the slit with respect to the X-rays separated by the spectral element.

FIG. 9 is a block diagram of another embodiment of the present invention. In another embodiment of the present invention, a rail structure is used instead of the groove structure of the above-described embodiment as two link mechanisms that support the detector with the detector interposed therebetween. A first link rail 25 and a second link rail 26 are provided on the first board 21 and the second board 22, and the detector housing 11 is supported by both rails via a guide portion such as a bearing. The rotation shaft is provided on the slit 12.

(Modification) In the above-described embodiment, the case where X-rays are incident on the slit has been described. However, the present invention is not limited to X-rays but can be applied to all wavelengths. Also,
The present invention is not limited to the vertical type and can be applied to a spectroscope having another configuration.

[0018]

As described above, according to the present invention,
In the X-ray spectrometer, the inclination of the slit of the detector with respect to the incident X-ray can be prevented with a simple configuration.

[Brief description of the drawings]

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

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

FIG. 3 is a sectional view of a support mechanism according to the embodiment of the present invention.

FIG. 4 is a perspective view of a support mechanism according to the embodiment of the present invention.

FIG. 5 is an operation diagram of the support mechanism according to the embodiment of the present invention.

FIG. 6 is a diagram illustrating a mechanism of the X-ray spectrometer of the present invention.

FIG. 7 is a configuration diagram of a conventional linear focusing X-ray spectrometer.

FIG. 8 is a diagram illustrating a state in which a conventional X-ray detector is attached to a link mechanism.

FIG. 9 is a sectional view of a support mechanism according to another embodiment of the present invention.

[Description of Signs] 1 ... Detector, 2 ... Support mechanism, 3 ... Moving mechanism, 4 ... Spectroscopy element, 11 ... Detector housing, 12 ... Slit, 13 ... First bearing, 14 ... Second bearing, 21 ... First substrate, 2
2 ... second substrate, 23 ... first link groove, 24 ... second link groove.

Claims (1)

(57) [Claims] 1. An X-ray spectrometer for detecting, by a detector, X-rays separated by a spectroscopic element moving on a straight line passing through an origin, wherein the X-ray spectrometer is provided with two slits for receiving X-rays. Two link mechanisms are arranged in parallel, and the fulcrum on the extension of both ends of the slit is supported by the two link mechanisms to support the detector, and the movement of the detector is restrained by the two link mechanisms. An X-ray spectrometer characterized by the above.