JPH04315099A - Monochrometer for x-ray diffraction device - Google Patents

Abstract

PURPOSE:To obtain a monochrometer with small whole shape and very easy assembling and disassembling capability. CONSTITUTION:A spectral diffraction crystal 3 fixed on a crystal support tip 33 is contained in the crystal chamber 15 in a main block 14. Above the crystal support tip 33, a mechanism for swinging the crystal 3 for rotation, a mechanism for moving it back and forth, and a mechanism for moving it up and down are provided altogether. Below the main block 14, a mechanism for inciting the crystal 3 to rotation and swinging is provided. By moving the crystal with the four mechanisms, a desired surface of the crystal 3 can be brought on the X-ray beam path L. If the unit above the main block 14 is removed from the main block 14, the crystal 3 can be taken outside.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monochromator used in an X-ray diffraction apparatus. In particular, the present invention relates to a monochromator suitable for an X-ray diffraction apparatus that measures a single crystal sample and requires highly accurate measurement.

0002

2. Description of the Related Art As an X-ray diffraction apparatus used for analyzing the structure of a single crystal sample, an X-ray diffraction apparatus having a so-called four-axis goniometer is already known. In this X-ray diffraction device, a monochromator is used to extract X-rays of a single wavelength from an X-ray bundle containing X-rays of all wavelengths (i.e., white X-rays) emitted from an ) and irradiate the single crystal sample with the monochromatic X-rays. On the other hand, by rotating the single crystal sample around four different axes, the incident angle of the X-rays incident on the single crystal sample is changed to various angles, and diffracted X-rays are measured.

[0003] The above-mentioned X-ray diffraction apparatus is required to perform measurements with extremely high precision. That is, the X-rays made monochromatic by the monochromator must have exactly a single wavelength of X-rays, and must also be of high intensity. Generally, in a monochromator, a spectroscopic crystal made of a single crystal such as graphite is used as an element for monochromating white X-rays. In order to obtain high-intensity X-rays with an accurate single wavelength as described above, it is necessary to use a high-quality spectroscopic crystal that is uniform and has no disturbance in its crystal structure. In this case, it is very difficult to obtain a good-quality spectroscopic crystal as a whole, and usually by moving the spectroscopic crystal up and down with respect to the X-ray,
High-quality parts of the two spectroscopic crystals are selected and used.

[0004] In order to obtain monochromatic X-rays with high intensity, it is necessary to rotate the spectroscopic crystal (θ rotation) around a vertical axis perpendicular to the direction of X-ray travel, or to rotate the crystal along an axis extending in the direction of X-ray travel. It is necessary to rotate the spectroscopic crystal around the center (tilt rotation) or move the spectroscopic crystal back and forth.

[0005] In this way, in the above-mentioned type of monochromator, the spectroscopic crystal can be rotated by θ, tilted, moved up and down,
Unless it is moved back and forth, it is not possible to obtain monochromatic X-rays with an accurate single wavelength and high intensity. However, it is very difficult to install each of these mechanisms in one monochromator due to space issues. Therefore, in the past, all of the above mechanisms were installed in a monochromator, either by omitting one of the mechanisms or accepting that it would become larger and more complicated, even though it would degrade performance. .

[0006]

[Problem to be Solved by the Invention] A conventional monochromator that excludes one of the four moving mechanisms described above is
There was a problem in that it was not possible to obtain sufficient results in obtaining monochromatic X-rays with an accurate single wavelength and high intensity. Furthermore, in a conventional monochromator equipped with all of the above-mentioned moving mechanisms, its shape is significantly large, and all of the moving mechanisms cannot be operated unless the cover and other component parts are removed from the monochromator body. There was a problem. The present invention has been made in view of the above-mentioned problems in conventional monochromators, and is equipped with all the movement mechanisms of the θ rotation, tilt rotation, vertical movement mechanism, and back and forth movement mechanism for the spectroscopic crystal, The range of spectroscopic crystals that can be used can be expanded, the overall shape is small, disassembly and assembly are easy, and all of the above moving mechanisms can be operated without removing element members such as covers. The purpose is to provide a monochromator.

[0007]

[Means for Solving the Problems] In order to achieve the above object, a monochromator according to the present invention is arranged on an X-ray optical path (L), is rotatable around the X-ray optical path, and has an internal structure. A support body (12) having a through hole for passing X-rays, a main block (14) integral with the support body, and a main block (14) provided inside the main block so as to extend in a direction perpendicular to the X-ray optical path. the crystal chamber (15), which is a space with an open top end; and the tilt adjustment pin (23), which is fixed to the bottom of the main block and projects downward.
and a tilt adjustment member (25) that biases the tilt adjustment pin.
, a θ rotation block (17) rotatably arranged at the upper end of the main block, equipped with a through hole communicating with the crystal chamber, and further equipped with a θ rotation adjustment pin (18); a θ rotation adjustment member (micrometer head 20) that biases the rotation block in the circumferential direction;
A slide block (26) that covers the through hole of the θ rotation block from above and is movable in a direction parallel to the X-ray optical path, and a front-rear position adjustment member (26) that moves the slide block.
8), a hanging block (31) which is integral with the slide block and extends into the crystal chamber of the main block through the through hole of the θ rotation block, and a hanging block (31) which is integral with the hanging block and placed inside the crystal chamber. a guide member (22); a crystal support chip (33) to which a spectroscopic crystal (3) is fixed, which is disposed so as to be movable in a direction perpendicular to the X-ray optical path within the crystal chamber while being guided by the guide member; It passes through the hanging block and extends in a direction perpendicular to the X-ray optical path, one end of which is screwed into the crystal support chip, the other end of which protrudes outside the slide block, and the vertical position can be adjusted at the protruding end. It is characterized by having a vertical position adjustment rod (30) to which the member (29) is fixed.

[0008]

[Operation] The spectroscopic crystal fixed to the crystal support chip can have its tilt angle adjusted by adjusting the tilt adjustment member, and its angular position in the θ rotation direction by adjusting the θ rotation adjustment member. By adjusting the longitudinal position adjusting member, the longitudinal position can be adjusted, and by adjusting the vertical position adjusting member, the vertical position can be adjusted. By appropriately adjusting the four types of positions in this way, it becomes possible to avoid the defective part of the spectroscopic crystal and selectively use only the normal part of the spectroscopic crystal. Intense monochromatic X-rays can be obtained by precisely aligning the beam with the optical axis. Each adjustment mechanism is arranged within a compact monochromator so that it does not take up any unnecessary space and yet each functions accurately. Furthermore, by removing the parts above the main block from the main block, the spectroscopic crystal can be easily removed from the crystal chamber along with the hanging block, guide member, and crystal support chip, and can be easily reinstalled into the crystal chamber. can do.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically shows an embodiment of a monochromator according to the present invention and an X-ray diffraction apparatus using the monochromator. In the same figure, white X-rays emitted from an X-ray source 2 in an X-ray tube 1 enter a spectroscopic crystal 3 placed in a monochromator 6, are diffracted by the crystal, and are converted into single-wavelength X-rays. line,
That is, they are emitted as characteristic X-rays. This characteristic X-ray is incident on the single crystal sample 4 and is diffracted by the sample when diffraction conditions are satisfied between it and a crystal lattice plane within the sample. This diffracted X-ray is received by the X-ray detector 5 and its intensity is measured. The sample 4 is supported by a so-called 4-axis goniometer, which allows Φ to oscillate about the vertical axis Φ,
Swings in various directions are performed, including Χ rocking around the horizontal axis Χ (Chi) and Ω rocking around the Ω axis that integrally supports the Φ and Χ axes. In addition, the 4-axis goniometer is
The X-ray detector 5 is rotated by 2θ around the Ω axis. By measuring the intensity of diffracted X-rays from the sample 4 with the X-ray detector 5 while the single-crystal sample 4 is oscillated about each axis using a 4-axis goniometer, the crystal structure in the single-crystal sample 4, such as lattice defects, can be detected. etc. are analyzed.

In the X-ray diffraction apparatus described above, it is an important requirement that the monochromator 6 obtain pure characteristic X-rays containing no impure wavelength components. In this example,
By improving the structure for supporting the spectroscopic crystal 3, it is possible to obtain characteristic X-rays that do not contain impurity wavelength components and have high intensity. The structure for supporting the spectroscopic crystal 3 will be described below.

In FIG. 1, bearings 8,
A base member 9 is provided via 8. The upper end 9a of the base member 9 is disc-shaped, and a bracket 10 is fixedly placed on the upper left end thereof. This bracket 10 has two bearings 11, 11, by which a support body 12 is rotatably supported around the X-ray optical path. A through hole 13 is provided in the center of the support 12 to allow the X-rays from the X-ray source 2 to pass therethrough. A generally cylindrical main block 14 is fixed to the right end of the support 12. Inside the main block 14, a crystal chamber 15, which is a space with a circular cross section extending in a direction perpendicular to the X-ray optical path, is formed. This crystal chamber 1
5 has its lower end sealed by the bottom surface of the main block 14, while its upper end is open.

A tilt adjustment pin 23 is provided on the bottom surface of the main block 14 and projects downward, and extends into the upper end 9a of the base member. Figure 2 (arrow II in Figure 1)
As shown in (cross-sectional view taken along line II), the upper end 9a of the base member is provided with a compression spring 24 that comes into contact with the left side of the tilt adjustment pin 23 and a tilt adjustment screw 25 that comes into contact with the right side of the pin 23. ing. When the tilt adjustment screw 25 is turned, the tilt adjustment pin 23 is moved to the screw 25 or the spring 24.
The main block 14, which is integral with the pin 23, swings and rotates around the support 12 and, therefore, the X-ray optical path. Hereinafter, this rotation will be referred to as tilt rotation.

At the upper end of the main block 14 in FIG.
A disk-shaped θ rotation block 17 is rotatably provided via two bearings 16, 16 about an axis perpendicular to the X-ray optical path. On the lower left side of the θ rotation block 17, there is a θ
A rotation adjustment pin 18 is fixed. As shown in FIG. 3 (a plan view taken along arrow III in FIG. 1), an arcuate groove 19 is formed in the portion of the main block 14 that corresponds to the pin 18. A θ rotation adjustment pin 18 is housed. As shown in FIG. 3, a micrometer head 20 is fixedly provided at the left end of the main block 14, and a spindle 20a of the micrometer head 20 protrudes into the groove 19 to pin the θ rotation adjustment pin. 18 from the side. A compression spring 21 is housed in the groove 19, and the spring force of this spring presses the θ rotation adjustment pin 18 against the spindle 20a. When the knob 20b of the micrometer head 20 is turned, the spindle 20a moves forward and backward. Due to this forward and backward movement, the θ rotation adjustment pin 18 and the θ rotation block 17 integrated therewith swing and rotate as indicated by arrows AA'. Hereinafter, this rotation will be referred to as θ rotation.

As shown in FIG. 1, a so-called dovetail groove 22 is formed at the upper end of the θ rotation block 17. As shown in FIG. As shown in FIG. 3, this dovetail groove 22
extends diametrically. A slide block 26 is placed on the θ rotation block 17, and a guide protrusion 27 provided on the lower surface of the slide block 26 fits into the dovetail groove 22 described above. In FIG. 2, a compression spring 27 is provided between the left end of the slide block 26 and the θ rotation block 17. Also, θ rotation block 1
A longitudinal position adjusting screw 28 provided on the upper surface of the right end portion of the slide block 7 is in contact with the right side surface of the slide block 26. When the longitudinal position adjustment screw 28 is turned, the slide block 26 is biased by the screw 28 or the spring 27 and moves in the left-right direction in FIG. 2, that is, in the longitudinal direction. In the figure, since the operator stands on the right side, the right side will be called the front side.

In FIG. 2, a hanging block 31 is fixedly provided on the lower surface of the slide block 26. As shown in FIG. This hanging block 31 is processed into a shape approximately as shown in FIG. 5, and hangs downward in FIG. Hanging block lower end 31
As shown in FIG. 5, a has the shape of a cylindrical member divided in half, and a cylindrical guide member 32 is fixed to the outer periphery of the circumferential portion by screws or the like. Figure 2
As shown in FIG.
Crystal support chip 3 shaped like a cylindrical member split in half
3 is placed. The above spectroscopic crystal 3 is fixed to the planar side wall portion of the crystal support chip 33 by brazing or the like. In FIG. 2, a vertical position adjustment rod 30, which is an elongated bar, is provided slightly to the left of the center of the slide block 26. This rod 30 passes through the slide block 26 and the hanging block 31 and extends downward, so that it can freely move up and down. The upper end of this rod 30 protrudes above the slide block 26, and a vertical position adjustment knob 2 is attached to the protruding end.
9 is fixed. Further, a screw block 34 is fixed to the lower end of the rod 30, and the screw block 34
is screwed into a screw hole provided at the upper end of the crystal support chip 33. Furthermore, a compression spring 35 is provided on the outer periphery of the rod 30 between the crystal support chip 33 and the hanging block 31.
is provided. When you turn the vertical position adjustment knob 29,
The screw block 34 at the lower end of the rod 30 rotates, and the crystal support chip 33 screwed onto it and the spectroscopic crystal 3 fixed thereto move in the vertical direction.

The monochromator 6 having the above configuration will be explained below.
The effect of this will be explained. In FIG. 2, when the tilt adjustment screw 25 at the bottom is turned by an appropriate angle, the main block 14 in FIG. 1 is tilted and rotated about the X-ray optical path L. Since the spectroscopic crystal 3 is integrated with the main block 14 via the crystal support chip 33, the hanging block 31, the slide block 26, and the θ rotation block 17,
When the main block 14 swings and rotates as described above, the spectroscopic crystal 3 also swings and rotates integrally with the main block 14. Thereby, the inclination angle position of the spectroscopic crystal 3 about the X-ray optical path L is adjusted. In FIG. 3, when the micrometer knob 20b is turned by an appropriate angle, the θ rotation adjustment pin 18 and the θ rotation block 17 to which the pin is fixed rotate θ, that is, about the axis perpendicular to the X-ray optical path L. Rock and rotate. Since the spectroscopic crystal 3 is integrated with the θ rotation block 17, it similarly rotates θ in accordance with the above-mentioned θ rotation of the θ rotation block 17. Thereby, the incident angle of the X-rays incident on the spectroscopic crystal 3 can be adjusted. In FIG. 2, when the longitudinal position adjustment screw 28 is turned by an appropriate angle, the slide block 26 moves in the right and left directions in the figure.
In other words, it moves in the front-back direction. Since the spectroscopic crystal 3 is integrated with the slide block 26, when the slide block 26 moves back and forth in this way, the spectrometer crystal 3 also moves back and forth together. Thereby, the position of the spectroscopic crystal in the direction across the X-ray optical path L is adjusted. In FIG. 2, when the vertical position adjustment knob 29 is turned by an appropriate angle, the crystal support chip 33 and therefore the spectroscopic crystal 3 are moved in the vertical direction. Thereby, the vertical position of the spectroscopic crystal 3 with respect to the X-ray optical path L is adjusted.

As described above, according to this embodiment, the installation position of the spectroscopic crystal 3 with respect to the X-ray optical path L can be adjusted independently in each direction: the front-rear direction, the up-down direction, the θ rotation direction, and the tilt rotation direction. can. Therefore, a desired surface of the spectroscopic crystal 3 can be moved to a diffraction position for diffracting X-rays. Therefore, even if the spectroscopic crystal 3 has a defect in a portion, it becomes possible to select and use a normal portion, thereby widening the range of spectroscopic crystals that can be used. Moreover, since each adjustment mechanism is integrated into a narrow space, the overall shape of the monochromator 6 is extremely small. In addition, members for adjusting the position of the spectroscopic crystal 3 in the rotational direction, that is, the micrometer knob 20b (FIG. 3) for adjusting the θ rotation and the tilt adjustment screw 25 (FIG. 2) are provided above and below the main block 14. It is set up separately. If these members are placed together above or below the main block 14, that is, arranged side by side, there is a risk that the operator will accidentally operate another member that is not intended, but this embodiment eliminates such concerns. . Further, when replacing the spectroscopic crystal 3, the θ rotation block 17 is removed from the main block 14. Then, slide block 2
6. The hanging block 31, crystal support chip 33, and spectroscopic crystal 3 are removed from the main block 14 as one unit. Therefore, disassembly and assembly operations become very easy.

FIG. 6 shows a modification of the crystal support chip 33. In this modification, the compression spring 3
Bolt 3 with hard ball 37 biased by 6
8 extends horizontally inside the crystal support chip 33. The crystal support chip 33 is biased to the right in the figure by the spring 36 via the ball 37 and pressed against the hanging block 31. As a result, the crystal support chip 3
It is possible to prevent the position of the spectroscopic crystal 3 fixed to the spectroscopic crystal 3 from varying.

Although the present invention has been described above using one embodiment, the present invention is not limited to that embodiment. For example, the shape of the guide member 32 is not limited to a cylindrical shape.
It may have a rectangular cylindrical shape.

[0020]

Effects of the Invention According to the present invention, since the spectroscopic crystal is provided with a θ rotation mechanism, a tilt rotation mechanism, a vertical movement mechanism, and a back and forth movement mechanism, it is possible to use a larger number of spectrometer crystals with defects in some parts. It is possible to obtain high intensity monochromatic X-rays. Furthermore, despite having so many mechanisms, the overall shape of the monochromator is very small and does not take up much space. Furthermore, the spectroscopic crystal can be attached and removed by a very simple operation of attaching or detaching one unit to or from the main block. Furthermore, all the moving mechanisms can be operated without removing any element parts.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of a monochromator according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG. 1;

FIG. 3 is a plan view according to arrow III in FIG. 2;

FIG. 4 is a perspective view showing essential parts of the above embodiment.

FIG. 5 is a perspective view showing other main parts of the above embodiment.

FIG. 6 is a side sectional view showing essential parts of another embodiment of the monochromator according to the present invention.

[Explanation of symbols]

12 Support
14 Main block 15 Crystal room
17θ rotation block 18 θ rotation adjustment pin
20 Micrometer head 23 Tilt adjustment pin
25 Tilt adjustment screw 26 Slide block
28 Vertical position adjustment screw 29 Vertical position adjustment knob
30 Vertical position adjustment rod 31 Hanging block
32 Guide member 33 Crystal support chip
38 Bolt with elastically biased ball

Claims (3)

[Claims] 1. A monochromator for an X-ray diffraction device that monochromates white X-rays using a spectroscopic crystal placed on the X-ray optical path, the monochromator being placed on the X-ray optical path and rotatable around the X-ray optical path; a support body provided with a through hole for passing X-rays therein; a main block integral with the support body; and provided inside the main block so as to extend in a direction perpendicular to the X-ray optical path; A crystal chamber which is a space with an opening at the top end, a tilt adjustment pin that is fixed to the bottom of the main block and projects downward, a tilt adjustment member that biases the tilt adjustment pin, and the top end of the main block. The θ rotation block is rotatably arranged in the θ rotation block and has a through hole communicating with the crystal chamber. a θ-rotation adjustment member that moves the θ-rotation block; a slide block that covers the through hole of the θ-rotation block from above and is movable in a direction parallel to the X-ray optical path; a front-rear position adjustment member that moves the slide block; There is a hanging block that passes through the through hole of the θ rotation block and extends into the crystallization chamber of the main block, a guide member that is integrated with the hanging block and is placed inside the crystallization chamber, and a guide member that extends into the crystallization chamber while being guided by the guide member. X
The crystal supporting chip is arranged to be movable in the direction perpendicular to the X-ray optical path, and extends through the crystal support chip to which the spectroscopic crystal is fixed, and the hanging block, and extends in the direction perpendicular to the X-ray optical path, and one end of the is screwed onto a crystal support chip, and has a vertical position adjustment rod whose other end projects outward from the slide block and to which a vertical position adjustment member is fixed to the projecting end. monochromator. 2. The monochrome X-ray diffraction apparatus according to claim 1, further comprising elastic pressing means provided in the crystal support chip for pressing the crystal support chip against either a hanging block or a guide member. meter. 3. The monochromator for an X-ray diffraction apparatus according to claim 1, wherein the θ rotation adjustment member and the tilt adjustment member are provided separately above and below the main block.