X-ray imaging device and method

Abstract

The invention relates to an X-ray imaging device and method.The X-ray imaging device comprises a first moving device, an angle adjusting device, a rotating device, a second moving device and a sample table, the first moving device is used for enabling the angle adjusting device and the rotating device to move along the X axis and the Z axis, and the angle adjusting device is used for enabling the rotating device to rotate around the X axis and the Z axis; the rotating device is used for rotating the second moving device and the sample table around the Y axis; the sample table is used for fixing a sample; a crystal and a detector are sequentially arranged on the downstream of the sample table, synchrotron radiation X-rays penetrate through a sample on the sample table, then enter the crystal and generate asymmetric Bragg diffraction, and the detector is movably located in the diffraction direction so as to receive diffracted X-rays. According to the X-ray imaging device and method, complex optical elements are not needed, the light path structure is simple, and high-resolution large-view-field imaging is achieved while the manufacturing cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of X-ray imaging, and more particularly to an X-ray imaging device and method. Background Art

[0002] Synchrotron radiation is a continuous spectrum electromagnetic wave from far infrared to X-ray range released when charged particles near the beam move along a flat track in a magnetic field. It has the advantages of wide spectrum, high intensity, high collimation, high coherence, high polarization, precise controllability, etc., so it is widely used in life medicine, environmental testing, material flaw detection and other fields. The continuous advancement of science and technology has put forward new requirements for X-ray imaging. For example, the observation of organelles and macromolecules in life sciences and the tracking of the detailed structure of lithium dendrites in materials science require higher spatial resolution and larger imaging field of view.

[0003] Traditional X-ray imaging methods include (1) full-field transmission X-ray imaging, (2) scanning transmission X-ray imaging, and (3) X-ray coherent diffraction imaging. The spatial resolution of full-field transmission or scanning transmission X-ray imaging can reach the nanometer scale, but its imaging system is complex and requires high-precision X-ray optical elements. The resolution of X-ray coherent diffraction imaging can reach the atomic scale, and the imaging structure is simple, but it has high requirements for the coherence of the light source and the image reconstruction algorithm.

[0004] Therefore, there is an urgent need to develop a large-field, high-resolution imaging method that has no requirements for light source coherence, has a simple and stable structure (no need for precision X-ray optical elements), has a resolution and field of view that exceeds that of the detector, and can load a variety of imaging contrasts. Summary of the invention

[0005] The object of the present invention is to provide an X-ray imaging device and method to achieve large-field-of-view, high-resolution X-ray imaging without requiring light source coherence.

[0006] Based on the above-mentioned purpose, on one hand, the present invention provides an X-ray imaging device, including a first moving device, an angle adjustment device, a rotating device, a second moving device and a sample stage, wherein the angle adjustment device is arranged on the first moving device, the rotating device is arranged on the angle adjustment device, the second moving device is arranged on the rotating device, and the sample stage is arranged on the second moving device, the first moving device is used to move the angle adjustment device and the rotating device along the X-axis and the Z-axis, the angle adjustment device is used to rotate the rotating device around the X-axis and the Z-axis, the rotating device is used to rotate the second moving device and the sample stage around the Y-axis, and the sample stage is used to fix the sample; a crystal and a detector are arranged in sequence downstream of the sample stage, and the synchrotron radiation X-rays pass through the sample on the sample stage and are incident on the crystal, and generate asymmetric Bragg diffraction, and the detector is movably located in the diffraction direction to receive the diffracted X-rays.

[0007] Furthermore, the crystal is configured horizontally or vertically.

[0008] Furthermore, the sample stage is a fixed plate or a fixture.

[0009] Furthermore, the crystal is made of one of single crystal silicon, single crystal germanium, single crystal diamond and sapphire.

[0010] Furthermore, the crystal is located on a first translation stage, and the first translation stage is used to move the crystal into or out of the optical path and adjust the posture of the crystal to adjust the incident angle of the X-ray.

[0011] Furthermore, the detector is located on a second translation stage, and the second translation stage is used to move the detector into or out of the optical path and adjust the posture of the detector.

[0012] The X-ray imaging device of the present invention does not require complex optical elements and has a simple optical path structure, thereby achieving high-resolution and large-field imaging while reducing manufacturing costs; a single crystal is used, and the crystal configuration can be adjusted to improve diffraction efficiency and enhance imaging quality.

[0013] Another aspect of the present invention provides an X-ray imaging method, which uses the X-ray imaging device as described above to perform imaging and comprises the following steps:

[0014] S100: moving the rotating device into the optical path by means of a first moving device, and making the rotating plane of the rotating device perpendicular to the X-ray by means of an angle adjusting device;

[0015] S200: moving the rotating device by the first moving device so that the rotation center of the rotating device is collinear with the X-ray, and determining a pixel position of the rotation center of the rotating device in the detector;

[0016] S300: fixing the sample to be tested divided into a plurality of areas on a sample table;

[0017] S400: for each area of ​​the sample to be tested, the sample to be tested is moved by the second moving device so that the area is displayed at the pixel position of the rotation center in the detector; then the sample to be tested is rotated by the rotating device, and a one-dimensional magnified image of the area is obtained by the detector at every preset angle; each one-dimensional magnified image of the area is reconstructed to obtain a two-dimensional magnified image of the area;

[0018] S500: splicing the two-dimensional magnified images of each region to obtain a complete two-dimensional magnified image of the sample to be tested.

[0019] Furthermore, step S100 specifically includes:

[0020] S110: introducing a visible light, and adjusting the visible light to be collinear with the X-ray;

[0021] S120: closely attaching a layer of reflective mirror to the rotating surface of the rotating device;

[0022] S130: rotating the rotating device around the X-axis and / or around the Y-axis by using the angle adjustment device, so that the reflected light of the visible light on the reflector coincides with the incident light;

[0023] S140: removing the reflecting mirror.

[0024] Furthermore, step S200 specifically includes:

[0025] S210: fixing a calibration target with a characteristic mark on the sample stage, and moving the rotating device by the first moving device so that the visible light irradiates near the rotation center of the rotating device;

[0026] S220: moving the detector into the optical path, and moving the calibration target to the vicinity of the rotation center of the rotating device by the second moving device, so as to form an image of the calibration target on the detector;

[0027] S230: rotating the rotating device, and during the rotation process, moving the rotating device by the first moving device and moving the calibration target on the sample stage by the second moving device, so that the pixel position of the calibration target in the detector remains stationary;

[0028] S240: moving the crystal into the optical path, adjusting the posture of the crystal so that the angle between the crystal and the X-ray is the Bragg angle, and moving the detector to be perpendicular to the diffraction direction of the X-ray to form an enlarged image of the calibration target on the detector;

[0029] S250: Rotate the rotating device, and during the rotation process, move the rotating device by the first moving device and move the calibration target on the sample stage by the second moving device, so that the pixel position of the identification feature of the calibration target in the detector remains unchanged, and record the pixel position of the identification feature in the detector at this time as the pixel position of the rotation center in the detector.

[0030] Furthermore, the calibration target has rotational symmetry.

[0031] The X-ray imaging method of the present invention can position the sample at the rotation center of the rotating device through the first moving device, the angle adjustment device, the rotating device and the second moving device, and make the X-rays irradiate the sample vertically to obtain a one-dimensional magnified image of the sample when the rotating device rotates at different angles, thereby reconstructing a two-dimensional magnified image of the sample based on the one-dimensional magnified image at each angle. The X-ray imaging method of the present invention does not require complex optical elements and can achieve high-resolution and large-field-of-view imaging at a low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic structural diagram of an X-ray imaging device according to an embodiment of the present invention;

[0033] Figure 2 is a top view of an X-ray imaging device according to an embodiment of the present invention;

[0034] Figure 3 FIG. 4 is a flow chart of an X-ray imaging method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings and described in detail.

[0036] like Figure 1 and Figure 2As shown, an embodiment of the present invention provides an X-ray imaging device, including a first moving device 10, an angle adjustment device 20, a rotating device 30, a second moving device 40 and a sample stage 50, wherein the angle adjustment device 20 is arranged on the first moving device 10, the rotating device 30 is arranged on the angle adjustment device 20, the second moving device 40 is arranged on the rotating device 30, and the sample stage 50 is arranged on the second moving device 40, the first moving device 10 is used to move the angle adjustment device 20 and the rotating device 30 along the X-axis and the Z-axis, the angle adjustment device 20 is used to rotate the rotating device 30 around the X-axis and around the Z-axis, the rotating device 30 is used to rotate the second moving device 40 and the sample stage 50 around the Y-axis, and the sample stage 50 is used to fix the sample; a crystal 60 and a detector 70 are arranged in sequence downstream of the sample, and the synchrotron radiation X-ray passes through the sample on the sample stage 50 and is incident on the crystal 60, and generates asymmetric Bragg diffraction, and the detector 70 is located in the diffraction direction to receive the diffracted X-ray, thereby realizing large field of view and high resolution imaging of the sample.

[0037] In some embodiments, the crystal 60 is a beveled crystal, which can be configured horizontally or vertically to achieve asymmetric Bragg diffraction, thereby achieving high-resolution imaging.

[0038] During imaging, the crystal 60 and the detector 70 can be first moved into the optical path, and the posture of the crystal 60 can be adjusted so that the angle between its surface and the X-ray (i.e., the incident angle of the X-ray) is the Bragg angle. At the same time, the posture of the detector 70 can be adjusted so that the detector 70 is perpendicular to the diffraction direction so that the diffracted X-ray can be vertically incident on the receiving surface of the detector 70; then the rotating device 30 is moved by the first moving device 10 so that the X-ray passes through its rotation center, and the posture of the rotating device 30 is adjusted by the angle adjustment device 20 so that its rotation plane is perpendicular to the X-ray (i.e., perpendicular to the Y-axis direction in the figure), and then the area to be tested of the sample on the sample stage 50 is moved to the rotation center of the rotating device 30 by the second moving device 40. In this way, the X-ray can be irradiated on the sample The detector 70 can image the area to be tested of the sample, and then the sample is rotated around the Y axis by the rotating device 30. Each time the preset angle (for example, β degrees) is rotated, the detector 70 can obtain a one-dimensional magnified image. After rotating 360 degrees, 360 / β magnified images can be obtained. These magnified images are processed by a preset reconstruction algorithm to obtain a two-dimensional high-resolution image of the area to be tested of the sample. Then, the sample stage 50 can be moved by the second moving device 40 to move other areas of the sample to the rotation center of the rotating device 30. The same method can be used to obtain two-dimensional high-resolution images of other areas of the sample. Then, the two-dimensional high-resolution images of all areas of the sample are spliced ​​to obtain a two-dimensional high-resolution image of the sample.

[0039] In some embodiments, the sample stage 50 may be a fixed plate, and the sample may be fixed on the fixed plate by bonding. The material of the fixed plate includes but is not limited to a rigid material such as boron but with high X-ray transmittance, so that the fixed plate has rigidity and high transmittance. In other embodiments, the sample stage 50 may also be a clamp or any other suitable tool for fixing the sample.

[0040] In some embodiments, the material of the crystal 60 includes but is not limited to high-quality single crystal silicon, single crystal germanium, single crystal diamond, sapphire and other crystal materials with perfect lattice structure and X-ray diffraction efficiency.

[0041] The asymmetric coefficient (i.e., magnification coefficient) of the crystal 60 is: M=sin(θ+α) / sin(θ-α), where θ is the Bragg angle of the crystal 60, and α is the bevel angle of the crystal 60 (i.e., the angle between the crystal Bragg diffraction index plane and the crystal surface). The Bragg angle and bevel angle of the crystal 60 can be directly provided by the manufacturer, or measured by the X-ray imaging device of the present invention, and the measurement method is as follows:

[0042] The rotating device 30 and the sample thereon are moved out of the optical path by the first moving device 10, and the crystal to be tested 60 and the detector 70 are moved into the optical path. The crystal to be tested 60 is rotated around the X-axis so that the surface of the crystal to be tested 60 forms different angles with the X-rays, and the intensity of the diffracted light at different angles is recorded by the detector 70 to obtain the rocking curve of the crystal to be tested 60. The angle corresponding to the peak value (i.e., the maximum intensity) of the rocking curve is the Bragg angle θ1 in the first direction. Then, the crystal to be tested 60 is rotated 180 degrees around the Z-axis to measure the angle of the crystal to be tested at this time. The rocking curve of the crystal 60 is obtained, and the Bragg angle θ2 in the second direction is obtained, thereby obtaining the bevel angle of the crystal 60 to be measured as α=1 / 2(θ1+θ2), the asymmetric coefficient in the first direction is M1=sin(θ1+α) / sin(θ1-α), and the asymmetric coefficient in the second direction is M2=sin(θ2+α) / sin(θ2-α). When M is greater than 1, it means that when the crystal 60 is placed along this direction, the sample will be magnified, and when M is less than 1, it means that when the crystal is placed along this direction, the sample will be reduced. In the present invention, the crystal can be placed along the direction where M is greater than 1 to achieve magnified imaging of the sample.

[0043] In some embodiments, the crystal 60 may be located on a first translation stage (not shown in the figure), and the detector 70 may be located on a second translation stage (not shown in the figure). The first translation stage is used to move the crystal 60 into or out of the optical path and adjust the posture of the crystal 60 (for example, rotating the crystal 60 around the X-axis) to adjust the incident angle of the X-ray; the second translation stage is used to move the detector 70 into or out of the optical path and adjust the posture of the detector 70 so that the diffracted light is perpendicular to the detector 70.

[0044] In some embodiments, the rotating device 30 may be a hollow cylinder, and the second moving device 40 may be embedded in the hollow portion thereof. The rotation center of the rotating device 30 is the axis of the hollow cylinder, and the rotating surface is the circular surface of the hollow cylinder.

[0045] In some embodiments, the detector 70 can be a photodiode or an X-ray array detector, and different detectors can be switched through the second translation stage as needed. For example, when measuring the rocking curve of the crystal 60, the photodiode can be moved into the optical path, and when imaging the sample, the X-ray array detector can be moved into the optical path.

[0046] The X-ray imaging device of the embodiment of the present invention does not require complex optical elements and has a simple optical path structure, thereby achieving high-resolution and large-field-of-view imaging while reducing manufacturing costs; a single crystal is used, and the crystal configuration can be adjusted to improve diffraction efficiency and enhance imaging quality.

[0047] like Figure 3 As shown, an embodiment of the present invention further provides an X-ray imaging method, which uses the X-ray imaging device of the above embodiment to perform imaging, and includes the following steps:

[0048] S100: The rotating device 30 is moved into the optical path by the first moving device 10, and the rotating plane of the rotating device 30 is made perpendicular to the X-ray by the angle adjusting device 20.

[0049] In some embodiments, step S100 specifically includes the following steps:

[0050] S110: introducing a beam of visible light (such as laser), and adjusting the visible light to be collinear with the X-ray;

[0051] S120: closely attaching a layer of reflective mirror to the rotating surface of the rotating device 30;

[0052] S130: rotating the rotating device 30 around the X-axis and / or around the Y-axis by the angle adjustment device 20, so that the reflected light of the visible light on the reflector coincides with the incident light;

[0053] S140: Remove the reflector on the rotating device 30.

[0054] In step S110, the X-ray spot can be first adjusted to be smaller (for precise positioning), and then multiple exposure papers are placed in sequence on the X-ray optical path. The X-rays will leave traces on each exposure paper, and then holes are punched at the traces of the X-rays on each exposure paper. Then, the posture of the visible light is adjusted so that it passes through all the holes in sequence, so that the visible light and the X-rays can be made collinear.

[0055] S200 : Move the rotating device 30 by the first moving device 10 so that the rotation center of the rotating device 30 is collinear with the X-ray, and determine the pixel position of the rotation center of the rotating device 30 in the detector 70 .

[0056] In some embodiments, step S200 specifically includes:

[0057] S210: Fixing a calibration target with a characteristic mark on the sample stage 50, and moving the rotating device 30 by the first moving device 10 so that the visible light is irradiated near the rotation center of the rotating device 30;

[0058] S220: moving the detector 70 into the optical path, and moving the calibration target to the vicinity of the rotation center of the rotating device 30 by the second moving device 40, so as to form an image of the calibration target on the detector 70;

[0059] S230: rotating the rotating device 30, and during the rotation process, moving the rotating device 30 by the first moving device 10 and moving the calibration target on the sample stage 50 by the second moving device 40, so that the pixel position of the calibration target in the detector 70 remains stationary;

[0060] S240: Move the crystal 60 into the optical path, and adjust the posture of the crystal 60 so that the angle between it and the X-ray is the Bragg angle, and move the detector 70 to be perpendicular to the diffraction direction of the X-ray to form an enlarged image of the calibration target on the detector 70;

[0061] S250: Rotate the rotating device 30, and during the rotation process, move the rotating device 30 by the first moving device 10 and move the calibration target on the sample stage 50 by the second moving device 40, so that the pixel position of the identification feature of the calibration target in the detector 70 remains stationary, and record the pixel position of the identification feature in the detector 70 at this time as the pixel position of the rotation center in the detector 70.

[0062] Step S230 is used to preliminarily determine the position of the rotation center, and steps S240-S250 are used to accurately determine the position of the rotation center. After the pixel position of the rotation center in the detector 70 is determined, the calibration target can be removed.

[0063] S300 : Fixing the sample to be tested divided into a plurality of regions on the sample stage 50 .

[0064] The sample to be tested may be relatively large and cannot be imaged entirely on the detector 70 , so the sample to be tested may be divided into a plurality of regions first so that each region can be imaged separately.

[0065] S400: For each area of ​​the sample to be tested, the sample to be tested is moved by the second moving device 40 so that the area is displayed at the pixel position with the rotation center in the detector 70; then the sample to be tested is rotated by the rotating device 30, and a one-dimensional magnified image of the area is obtained by the detector 70 at every preset angle; each one-dimensional magnified image of the area is reconstructed to obtain a two-dimensional magnified image of the area.

[0066] S500: splicing the two-dimensional magnified images of each area to obtain a complete two-dimensional magnified image of the sample to be tested.

[0067] In some embodiments, the calibration target has rotational symmetry, for example, it may be a metal sphere.

[0068] The X-ray imaging method of the embodiment of the present invention can position the sample at the rotation center of the rotating device 30 through the first moving device 10, the angle adjustment device 20, the rotating device 30 and the second moving device 40, and make the X-rays irradiate the sample vertically to obtain a one-dimensional magnified image of the sample when the rotating device 30 rotates at different angles, thereby reconstructing a two-dimensional magnified image of the sample based on the one-dimensional magnified image at each angle. The X-ray imaging method of the present invention does not require complex optical elements and can achieve high-resolution and large-field-of-view imaging at low cost.

[0069] The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. The above embodiment of the present invention can also be modified in various ways. That is, all simple, equivalent changes and modifications made according to the claims and the description of the present invention fall within the scope of protection of the claims of the present invention. The contents not described in detail in the present invention are all conventional technical contents.

Claims

1. An X-ray imaging device, characterized in that: The invention comprises a first moving device, an angle adjustment device, a rotating device, a second moving device and a sample stage, wherein the angle adjustment device is arranged on the first moving device, the rotating device is arranged on the angle adjustment device, the second moving device is arranged on the rotating device, and the sample stage is arranged on the second moving device, the first moving device is used to move the angle adjustment device and the rotating device along the X-axis and the Z-axis, the angle adjustment device is used to rotate the rotating device around the X-axis and the Z-axis, the rotating device is used to rotate the second moving device and the sample stage around the Y-axis, and the sample stage is used to fix the sample; a crystal and a detector are arranged in sequence downstream of the sample stage, and the synchrotron radiation X-rays pass through the sample on the sample stage and are incident on the crystal to generate asymmetric Bragg diffraction, and the detector is movably located in the diffraction direction to receive the diffracted X-rays.

2. The X-ray imaging device according to claim 1, characterized in that: The crystal is arranged horizontally or vertically.

3. The X-ray imaging device according to claim 1, characterized in that: The sample stage is a fixed plate or a fixture.

4. The X-ray imaging device according to claim 1, characterized in that: The crystal is made of one of single crystal silicon, single crystal germanium, single crystal diamond and sapphire.

5. The X-ray imaging device according to claim 1, characterized in that: The crystal is located on a first translation stage, and the first translation stage is used to move the crystal into or out of an optical path and adjust the posture of the crystal to adjust the incident angle of the X-ray.

6. The X-ray imaging device according to claim 1, characterized in that: The detector is located on a second translation stage, and the second translation stage is used to move the detector into or out of an optical path and adjust the posture of the detector.

7. An X-ray imaging method, characterized in that: Imaging is performed using an X-ray imaging device as claimed in any one of claims 1 to 6 and includes the following steps: S100: moving the rotating device into the optical path by means of a first moving device, and making the rotating plane of the rotating device perpendicular to the X-ray by means of an angle adjusting device; S200: moving the rotating device by the first moving device so that the rotation center of the rotating device is collinear with the X-ray, and determining a pixel position of the rotation center of the rotating device in the detector; S300: fixing the sample to be tested divided into a plurality of areas on a sample table; S400: for each area of ​​the sample to be tested, the sample to be tested is moved by the second moving device so that the area is displayed at the pixel position of the rotation center in the detector; then the sample to be tested is rotated by the rotating device, and a one-dimensional magnified image of the area is obtained by the detector at every preset angle; each one-dimensional magnified image of the area is reconstructed to obtain a two-dimensional magnified image of the area; S500: splicing the two-dimensional magnified images of each area to obtain a complete two-dimensional magnified image of the sample to be tested.

8. The X-ray imaging method according to claim 7, characterized in that: Step S100 specifically includes: S110: introducing a visible light, and adjusting the visible light to be collinear with the X-ray; S120: closely attaching a layer of reflective mirror to the rotating surface of the rotating device; S130: rotating the rotating device around the X-axis and / or around the Y-axis by using the angle adjustment device, so that the reflected light of the visible light on the reflector coincides with the incident light; S140: removing the reflecting mirror.

9. The X-ray imaging method according to claim 8, characterized in that: Step S200 specifically includes: S210: fixing a calibration target with a characteristic mark on the sample stage, and moving the rotating device by the first moving device so that the visible light irradiates near the rotation center of the rotating device; S220: moving the detector into the optical path, and moving the calibration target to the vicinity of the rotation center of the rotating device by the second moving device, so as to form an image of the calibration target on the detector; S230: rotating the rotating device, and during the rotation process, moving the rotating device by the first moving device and moving the calibration target on the sample stage by the second moving device, so that the pixel position of the calibration target in the detector remains stationary; S240: moving the crystal into the optical path, adjusting the posture of the crystal so that the angle between the crystal and the X-ray is the Bragg angle, and moving the detector to be perpendicular to the diffraction direction of the X-ray to form an enlarged image of the calibration target on the detector; S250: Rotate the rotating device, and during the rotation process, move the rotating device by the first moving device and move the calibration target on the sample stage by the second moving device, so that the pixel position of the identification feature of the calibration target in the detector remains unchanged, and record the pixel position of the identification feature in the detector at this time as the pixel position of the rotation center in the detector.

10. The X-ray imaging method according to claim 9, characterized in that: The calibration target has rotational symmetry.

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