Fine-adjustable bicrystal monochromator for X-ray diffractometer

Abstract

The utility model discloses a fine-adjustable bicrystal monochromator for an X-ray diffractometer, belongs to the technical field of X-rays, and aims to solve the problem that a traditional U-shaped crystal monochromator is high in price due to the fact that the difficulty of a processing mode is high and the yield is low in the prior art. The utility model relates to a fine-adjustable bicrystal monochromator for an X-ray diffractometer. The fine-adjustable bicrystal monochromator comprises a U-shaped bicrystal fixing piece; a first crystal; the crystal adjusting mechanism is arranged below the first crystal, the crystal adjusting mechanism is fixed on one side of the U-shaped double-crystal fixing piece, and the first crystal swings around the X axis, the Y axis and the Z axis through the crystal adjusting mechanism; the crystal face of the second crystal and the crystal face of the first crystal are oppositely arranged; the first crystal and the second crystal are complete crystals of the same kind, and two opposite crystal faces have the same parallelism; the balancing weight is arranged below the second crystal; and the balancing weight is fixed on the other side of the U-shaped double-crystal fixing piece.

Description

Technical Field

[0001] This invention belongs to the field of X-ray technology, specifically relating to a finely adjustable dual-crystal monochromator for an X-ray diffractometer. Background Technology

[0002] Since the 1950s, influenced by technological advancements and the development of instrument science, various characterization and testing methods have emerged, powerfully promoting major scientific discoveries and basic research experiments. Among them, X-ray diffraction technology is widely popular due to its speed, high precision, and non-destructive testing capabilities. An X-ray diffractometer is a primary characterization method that utilizes the principle of X-ray diffraction to accurately determine the crystal structure, texture, and stress of substances, and is widely used in the semiconductor industry.

[0003] Dual-crystal monochromators are often used to convert multicolor X-rays or neutrons into monochromatic rays. Crystal monochromators utilize Bragg diffraction of X-rays by a single crystal to obtain monochromatic rays. In X-ray diffractometers, since characteristic X-rays are generated, good monochromatic effects are already achieved. The main purpose of using crystal monochromators is to eliminate interference from β-line and Kα2-line wavelengths and to improve the collimation of the light source to meet the testing requirements of high-resolution X-ray diffraction. Therefore, crystal monochromators are an indispensable key component of X-ray diffractometers. Traditional crystal monochromators are obtained by cutting a U-shaped groove along a certain crystal plane on a single crystal, followed by grinding and polishing the upper and lower surfaces of the U-shaped crystal. This manufacturing method is difficult and has a low yield, resulting in high prices for traditional U-shaped crystal monochromators. This U-groove cutting process is a necessary compromise to obtain dispersion-free single crystals. This is because crystal monochromators need to satisfy the condition that X-rays diffracted by the first crystal are also diffracted by the second crystal. To meet this condition, the first and second crystals must be taken from the same single crystal; during cutting, the two crystals must be cut along the same crystal plane; and they must be polished to the same degree of parallelism. Utility Model Content

[0004] The purpose of this invention is to propose a finely adjustable dual-crystal monochromator for X-ray diffractometers, which solves the problems of high processing difficulty and low yield in existing technologies, resulting in the high price of traditional U-shaped crystal monochromators.

[0005] To achieve the above objectives, the present invention provides a finely adjustable dual-crystal monochromator for an X-ray diffractometer, comprising:

[0006] U-shaped bicrystalline fastener;

[0007] First crystal;

[0008] A crystal adjustment mechanism is provided below the first crystal. The crystal adjustment mechanism is fixed to one side of the U-shaped double crystal fixing member. The first crystal can swing around the X-axis, Y-axis and Z-axis through the crystal adjustment mechanism.

[0009] The second crystal has its crystal faces facing each other as the crystal faces of the first crystal; the first crystal and the second crystal are the same type of complete crystal, and the two opposing crystal faces have the same parallelism.

[0010] And a counterweight block disposed below the second crystal, the counterweight block being fixed to the other side of the U-shaped twin crystal fixing member.

[0011] The crystal adjustment mechanism includes:

[0012] A horizontal swing adjustment mechanism is used to drive the first crystal to swing horizontally around the y-axis.

[0013] A vertical swing adjustment mechanism drives the horizontal swing adjustment mechanism and the first crystal as a whole to swing vertically around the x-axis.

[0014] And a rotation adjustment mechanism fixed on one side of the U-shaped twin crystal fixing member, the rotation adjustment mechanism driving the vertical swing adjustment mechanism, the horizontal swing adjustment mechanism and the first crystal as a whole to rotate around the z-axis.

[0015] The horizontal swing adjustment mechanism includes:

[0016] Horizontal swing housing;

[0017] And a horizontal swing shaft, which is driven by a motor to rotate relative to the horizontal swing housing, and the horizontal swing shaft is fixedly connected to the lower part of the first crystal.

[0018] The vertical swing adjustment mechanism includes:

[0019] Vertically swinging housing;

[0020] And a vertical swing shaft, which is driven by a motor to rotate relative to the vertical swing housing, and the vertical swing shaft and the horizontal swing housing of the horizontal swing adjustment mechanism are fixedly connected.

[0021] The rotation adjustment mechanism includes a first rotating disk with its axis arranged along the z-direction. The first rotating disk is disposed on one side of the U-shaped double crystal fixing member through a driving mechanism. The first rotating disk and the vertical swing housing of the vertical swing adjustment mechanism are fixedly connected.

[0022] The dual-crystal monochromator also includes a second rotating disk disposed below the U-shaped dual-crystal fixing member, which drives the U-shaped dual-crystal fixing member to rotate.

[0023] The beneficial effects of this invention are as follows: The first and second crystals of this adjustable X-ray diffractometer's dual-crystal monochromator are taken from the same complete crystal and cut along the same crystal plane before polishing. The first and second crystals do not require U-shaped cutting; instead, they are obtained using conventional cutting methods to obtain single crystal wafers, which are then finely adjusted to achieve a dispersion-free arrangement. Compared to traditional U-shaped dual-crystal monochromators, this invention's dual-crystal monochromator is easier to manufacture, lower in cost, and can be used in larger-scale instruments. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of a finely adjustable dual-crystal monochromator for an X-ray diffractometer according to the present invention.

[0025] Figure 2 This is a schematic diagram of the optical path of a dual-crystal monochromator for a finely adjustable X-ray diffractometer according to the present invention.

[0026] Figure 3 This is a schematic diagram illustrating the crystal adjustment structure for adjusting the orientation of the first crystal in a dual-crystal monochromator for a finely adjustable X-ray diffractometer according to the present invention.

[0027] Among them: 1. U-shaped double crystal fixing component, 2. first crystal, 3. crystal adjustment mechanism, 301. horizontal swing shaft, 302. vertical swing shaft, 303. first rotating disk, 4. second crystal, 5. counterweight, 6. second rotating disk. Detailed Implementation

[0028] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0029] See Figure 1 and Figure 2 The present invention provides a finely adjustable dual-crystal monochromator for an X-ray diffractometer, comprising:

[0030] U-shaped bicrystalline fastener 1;

[0031] First crystal 2;

[0032] A crystal adjustment mechanism 3 is disposed below the first crystal 2. The crystal adjustment mechanism 3 is fixed to one side of the U-shaped double crystal fixing member 1. The first crystal 2 can be oscillated around the X-axis, Y-axis and Z-axis through the crystal adjustment mechanism 3.

[0033] The second crystal 4 has its crystal facets facing the crystal facets of the first crystal 2. The first crystal 2 and the second crystal 4 are the same type of complete crystals and are cut along the same crystal facet direction and then ground and polished. The two opposing crystal faces have the same parallelism.

[0034] And a counterweight 5 disposed below the second crystal 4, the counterweight 5 being fixed to the other side of the U-shaped twin crystal fixing member 1.

[0035] The crystal adjustment mechanism 3 includes:

[0036] A horizontal swing adjustment mechanism is used to drive the first crystal 2 to swing horizontally around the y-axis.

[0037] A vertical swing adjustment mechanism drives the X-axis swing adjustment mechanism and the first crystal 2 to swing vertically around the x-axis.

[0038] And a rotation adjustment mechanism fixed on one side of the U-shaped twin crystal fixing member 1, the rotation adjustment mechanism driving the vertical swing adjustment mechanism, the horizontal swing adjustment mechanism and the first crystal 2 to rotate around the Z-axis as a whole.

[0039] The horizontal swing adjustment mechanism includes:

[0040] Horizontal swing housing;

[0041] And a horizontal swing shaft 301, which is driven by a motor to rotate relative to the horizontal swing housing, and the horizontal swing shaft 301 is fixedly connected to the lower part of the first crystal 2.

[0042] The vertical swing adjustment mechanism includes:

[0043] Vertically swinging housing;

[0044] And a vertical swing shaft 302, which is driven by a motor to rotate relative to the vertical swing housing, and the vertical swing shaft 302 is fixedly connected to the horizontal swing housing of the horizontal swing adjustment mechanism.

[0045] The rotation adjustment mechanism includes a first rotating disk 303 with its axis arranged along the z-direction. The first rotating disk 303 is mounted on one side of the U-shaped bicrystalline fixing member 1 via a drive mechanism. The first rotating disk 303 is fixedly connected to the vertical swing housing of the vertical swing adjustment mechanism. There are many structural forms for the drive mechanism that drives the first rotating disk 303. It can be directly driven by a motor coaxially mounted on the back of the first rotating disk 303, or by a motor mounted in the x-direction driving a pair of bevel gears to rotate and transmit power to the rotating shaft of the first rotating disk 303.

[0046] See Figure 3 All axes are referenced to the first crystal 2. The horizontal oscillation is the ω (omega) direction, the vertical oscillation is the χ direction, and the Z-axis oscillation is the φ (phi) direction.

[0047] The dual-crystal monochromator also includes a second rotating disk 6 disposed below the U-shaped dual-crystal fixing member 1, which drives the U-shaped dual-crystal fixing member to rotate.

[0048] The adjustment method of the dual-crystal monochromator of this invention is as follows:

[0049] (a) Adjust the Theta axis and 2Theta axis of the diffractometer to 0°, with no sample or central slit at the sample stage, and remove all slits at the front of the detector.

[0050] (b) Fix the dual-crystal monochromator in the optical path and adjust the second rotating disk 6 so that the incident angle is approximately the incident angle corresponding to the crystal orientation;

[0051] (c) Adjust the vertical swing axis 302 to make the detector signal the strongest;

[0052] (d) Adjust the horizontal swing axis 301 to make the detector signal the strongest;

[0053] (e) Adjust the first rotating disk 303 to make the detector signal the strongest;

[0054] (f) Repeat steps (c) to (e) until the detector signal no longer increases. At this point, the first crystal 2 and the second crystal 4 are in a completely parallel, dispersion-free state.

[0055] (g) Adjust the first rotating disk 303 to make the detector signal strongest;

[0056] (h) Place the central slit into the sample position in the optical path and adjust the height of the Theta axis to make the detector signal strongest.

[0057] The specific implementation of the dual-crystal monochromator of this utility model is as follows:

[0058] 1. After adjustment by the horizontal swing axis 301, the vertical swing axis 302 and the first rotating disk 303, the first crystal 2 and the second crystal 4B finally achieve a dispersion-free arrangement;

[0059] 2. After the first crystal 2 and the second crystal 4 are rotated by a specific angle by the second rotating disk 6 where the U-shaped double crystal fixing member 1 is located, a double crystal monochromator is obtained;

[0060] 3. After a beam of X-rays passes through the entrance slit, stray light is removed. After passing through the collimating lens, the beam becomes parallel characteristic X-rays. After passing through the double crystal monochromator, it becomes highly collimated characteristic X-rays. Finally, it exits onto the sample, and the resulting diffraction signal is received by the detector, that is, the X-ray diffraction information is recorded.

Claims

1. A finely adjustable dual-crystal monochromator for an X-ray diffractometer, characterized in that, include: U-shaped bicrystalline fastener (1); First crystal (2); A crystal adjustment mechanism (3) is provided below the first crystal (2). The crystal adjustment mechanism (3) is fixed on one side of the U-shaped double crystal fixing member (1). The first crystal (2) can swing around the X-axis, Y-axis and Z-axis through the crystal adjustment mechanism (3). The second crystal (4) has its crystal planes facing each other as the crystal planes of the first crystal (2); the first crystal (2) and the second crystal (4) are the same type of complete crystals, and the two facing crystal planes have the same parallelism. And a counterweight (5) disposed below the second crystal (4), the counterweight (5) being fixed to the other side of the U-shaped twin crystal fastener (1).

2. The adjustable dual-crystal monochromator for an X-ray diffractometer according to claim 1, characterized in that, The crystal adjustment mechanism (3) includes: A horizontal swing adjustment mechanism drives the first crystal (2) to swing horizontally around the y-axis. The vertical swing adjustment mechanism drives the horizontal swing adjustment mechanism and the first crystal (2) to swing vertically around the x-axis as a whole. And a rotation adjustment mechanism fixed on one side of the U-shaped twin crystal fixing member (1), the rotation adjustment mechanism driving the vertical swing adjustment mechanism, the horizontal swing adjustment mechanism and the first crystal (2) to rotate around the z-axis as a whole.

3. The adjustable dual-crystal monochromator for an X-ray diffractometer according to claim 2, characterized in that, The horizontal swing adjustment mechanism includes: Horizontal swing housing; And a horizontal swing shaft (301), which is driven by a motor to rotate relative to the horizontal swing housing, and the horizontal swing shaft (301) is fixedly connected to the lower part of the first crystal (2).

4. The adjustable dual-crystal monochromator for an X-ray diffractometer according to claim 2, characterized in that, The vertical swing adjustment mechanism includes: Vertically swinging housing; And a vertical swing shaft (302), which is driven by a motor to rotate relative to the vertical swing housing, and the vertical swing shaft (302) is fixedly connected to the horizontal swing housing of the horizontal swing adjustment mechanism.

5. A finely adjustable dual-crystal monochromator for an X-ray diffractometer according to claim 2, characterized in that, The rotation adjustment mechanism includes a first rotating disk (303), which is disposed on one side of the U-shaped double crystal fixing member (1) by a driving mechanism. The first rotating disk (303) is fixedly connected to the vertical swing housing of the vertical swing adjustment mechanism.

6. A finely adjustable dual-crystal monochromator for an X-ray diffractometer according to any one of claims 1-5, characterized in that, The dual-crystal monochromator also includes a second rotating disk (6) disposed below the U-shaped dual-crystal fixing member (1), through which the U-shaped dual-crystal fixing member (1) is driven to swing.

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