X-ray imaging apparatus and method

Abstract

The application relates to an X-ray imaging device and method, which 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 moving the angle adjusting device and the rotating device along X and Z axes, the angle adjusting device is used for rotating the rotating device around the X and Z axes, the rotating device is used for rotating the second moving device and the sample table around the Y axis, and the sample table is used for fixing a sample; a crystal and a detector are sequentially arranged downstream of the sample table, the synchrotron X-ray is incident on the crystal after passing through the sample on the sample table and generates asymmetric Bragg diffraction, and the detector is movably arranged on a diffraction direction to receive the diffraction X-ray. The X-ray imaging device and method of the application do not need complex optical elements, the light path structure is simple, the manufacturing cost is reduced, and high-resolution large-field imaging is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of X-ray imaging technology, and more particularly to an X-ray imaging device and method. BACKGROUND

[0002] Synchrotron radiation is a continuous spectrum of electromagnetic waves from far infrared to X-ray range released by charged particles moving along an orbit in a magnetic field, which has the advantages of wide spectrum, high intensity, high collimation, high coherence, high polarization, precise controllability, etc., and is widely used in the fields of life medicine, environmental detection, material flaw detection, etc. The continuous progress of science and technology puts forward new requirements for X-ray imaging, such as observation of organelles and macromolecules in life science, and tracking of lithium dendrite details in material science, which all 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, (3) X-ray coherent diffraction imaging, etc. The spatial resolution of full-field transmission or scanning transmission X-ray imaging can reach nanometer scale, but the imaging system is complex and requires high-precision X-ray optical elements. The resolution of X-ray coherent diffraction imaging can reach atomic scale, and the imaging structure is simple, but it has high requirements for source coherence and image reconstruction algorithm.

[0004] Therefore, it is urgent to develop a large-field-of-view high-resolution imaging method which has no requirement for source coherence, simple and stable structure (without the need for precise X-ray optical elements), resolution and field of view beyond the detector, and can load multiple imaging contrasts. SUMMARY

[0005] The present application aims to provide an X-ray imaging device and method to realize large-field-of-view high-resolution X-ray imaging without requirement for source coherence.

[0006] In order to achieve the above object, the present application provides an X-ray imaging device, which comprises a first moving device, an angle adjusting device, a rotating device, a second moving device and a sample table, the angle adjusting device is arranged on the first moving device, the rotating device is arranged on the angle adjusting device, the second moving device is arranged on the rotating device, the sample table is arranged on the second moving device, the first moving device is used for moving the angle adjusting device and the rotating device along the X-axis and the Z-axis, the angle adjusting device is used for rotating the rotating device 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, and the sample table is used for fixing a sample; a crystal and a detector are arranged downstream of the sample table in sequence, and the synchrotron X-ray is incident on the crystal after passing through the sample on the sample table and generates asymmetric Bragg diffraction, and the detector is movably arranged on a diffraction direction to receive the diffraction X-ray.

[0007] Further, the crystal is horizontally arranged or vertically arranged.

[0008] Further, the sample table is a fixed plate or a clamp.

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

[0010] Further, the crystal is arranged on a first displacement table, the first displacement table is used for moving the crystal into or out of the light path and adjusting the attitude of the crystal to adjust the incident angle of the X-ray.

[0011] Further, the detector is arranged on a second displacement table, the second displacement table is used for moving the detector into or out of the light path and adjusting the attitude of the detector.

[0012] The X-ray imaging device of the present application does not need complex optical elements, and the light path structure is simple, which reduces the manufacturing cost and realizes high-resolution large-field imaging; a single crystal is used, and the arrangement of the crystal can be adjusted to improve the diffraction efficiency and improve the imaging quality.

[0013] The present application further 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 light path by the first moving device, and making the rotation surface of the rotating device perpendicular to the X-ray by the angle adjusting device;

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

[0016] S300: fixing the sample to be tested divided into multiple regions on a sample table;

[0017] S400: for each region of the sample to be tested, moving the sample to be tested by the second moving device to make the region show in the pixel position of the detector with the rotation center; then rotating the sample to be tested by the rotating device, and every interval of a preset angle, acquiring a one-dimensional magnified image of the region by the detector; reconstructing each one-dimensional magnified image of the region to obtain a two-dimensional magnified image of the region;

[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] Further, the step S100 specifically comprises:

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

[0021] S120: closely attaching a reflecting mirror on the rotation plane of the rotating device;

[0022] S130: rotating the rotating device around the X-axis and / or around the Y-axis by the angle adjusting device to make the reflected light of the visible light on the reflecting mirror coincide with the incident light;

[0023] S140: removing the reflecting mirror.

[0024] Further, the step S200 specifically comprises:

[0025] S210: fixing a calibration target with a characteristic mark on the sample table, and moving the rotating device by the first moving device to make the visible light irradiate near the rotation center of the rotating device;

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

[0027] S230: rotating the rotating device, and moving the rotating device by the first moving device and moving the calibration target on the sample table by the second moving device during the rotation to make the pixel position of the calibration target in the detector remain unchanged;

[0028] S240: moving the crystal into the light path, adjusting the posture of the crystal to make the included angle with the X-ray be the Bragg angle, and moving the detector to be perpendicular to the diffraction direction of the X-ray to form a magnified image of the calibration target on the detector;

[0029] S250: rotating the rotating device, and moving the rotating device by the first moving device and moving the calibration target on the sample stage by the second moving device during the rotation, so that the identification feature of the calibration target keeps still in the pixel position in the detector, recording 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] Further, the calibration target has rotational symmetry.

[0031] The X-ray imaging method of the present application can make the sample be located at the rotation center of the rotating device and make the X-ray be perpendicular to the sample by the first moving device, the angle adjusting device, the rotating device and the second moving device, so as to obtain the one-dimensional enlarged image of the sample at different angles of the rotating device, and to reconstruct the two-dimensional enlarged image of the sample according to the one-dimensional enlarged image at each angle. The X-ray imaging method of the present application can realize high-resolution large-field imaging without complex optical elements, and has low cost. BRIEF DESCRIPTION OF DRAWINGS

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

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

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

[0035] The preferred embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0036] As Figure 1 and Figure 2As shown, the embodiment of the present application provides an X-ray imaging device, which comprises a first moving device 10, an angle adjusting device 20, a rotating device 30, a second moving device 40 and a sample table 50, the angle adjusting device 20 is arranged on the first moving device 10, the rotating device 30 is arranged on the angle adjusting device 20, the second moving device 40 is arranged on the rotating device 30, and the sample table 50 is arranged on the second moving device 40, the first moving device 10 is used for moving the angle adjusting device 20 and the rotating device 30 along the X-axis and the Z-axis, the angle adjusting device 20 is used for rotating the rotating device 30 around the X-axis and the Z-axis, the rotating device 30 is used for rotating the second moving device 40 and the sample table 50 around the Y-axis, and the sample table 50 is used for fixing a sample; a crystal 60 and a detector 70 are arranged downstream of the sample in sequence, and the synchrotron X-ray is incident on the crystal 60 after passing through the sample on the sample table 50 and generates asymmetric Bragg diffraction, and the detector 70 is located on the diffraction direction to receive the diffraction X-ray, so that the large field of view and high resolution imaging of the sample is realized.

[0037] In some embodiments, the crystal 60 is a bevel cut crystal, which can be horizontally arranged or vertically arranged, and is used for realizing asymmetric Bragg diffraction, so as to realize high resolution imaging.

[0038] During imaging, the crystal 60 and the detector 70 can be first moved into the light path, and the posture of the crystal 60 is adjusted so that the included angle between the surface of the crystal 60 and the X-ray (i.e. the incident angle of the X-ray) is the Bragg angle, and the posture of the detector 70 is adjusted so that the detector 70 is perpendicular to the diffraction direction, so that the diffraction X-ray can be perpendicularly 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 the rotation center thereof, and the posture of the rotating device 30 is adjusted by the angle adjusting device 20 so that the rotation surface thereof is perpendicular to the X-ray (i.e. perpendicular to the Y-axis direction in the figure), and then the sample on the sample table 50 is moved to the rotation center of the rotating device 30 by the second moving device 40, so that the X-ray can irradiate the to-be-measured region of the sample, and the detector 70 can image the to-be-measured region of the sample, then the sample is rotated around the Y-axis by the rotating device 30, and a one-dimensional enlarged image can be obtained by the detector 70 every time the sample is rotated by a preset angle (for example, β degrees), and when the sample is rotated by 360 degrees, 360 / β enlarged images can be obtained, and the enlarged images are processed by using a preset reconstruction algorithm, so that a two-dimensional high resolution image of the to-be-measured region of the sample can be obtained; then the sample table 50 is moved by the second moving device 40, so that other regions of the sample are moved to the rotation center of the rotating device 30, and the two-dimensional high resolution images of the other regions of the sample can be obtained by using the same method, and then the two-dimensional high resolution images of all regions of the sample are spliced, so that a two-dimensional high resolution image of the sample can be obtained.

[0039] In some embodiments, the sample stage 50 can be a fixed plate on which the sample can be fixed by adhesion. The fixed plate can be made of a material that is rigid but has high X-ray transmittance, such as boron, so that the fixed plate has both rigidity and high transmittance. In other embodiments, the sample stage 50 can also be a clamp or any other suitable tool for fixing the sample.

[0040] In some embodiments, the crystal 60 can be made of a high-quality single crystal material that has a perfect lattice structure and high X-ray diffraction efficiency, such as high-quality single crystal silicon, single crystal germanium, single crystal diamond, and sapphire.

[0041] The asymmetry 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 off-cut angle of the crystal 60 (i.e., the angle between the Bragg diffraction index surface of the crystal and the surface of the crystal). The Bragg angle and the off-cut angle of the crystal 60 can be provided directly by the manufacturer or measured by the X-ray imaging device of the present application, and the measurement method is as follows:

[0042] The rotation device 30 and the sample thereon are moved out of the light path by the first moving device 10, the to-be-measured crystal 60 and the detector 70 are moved into the light path, the to-be-measured crystal 60 is rotated around the X-axis so that the surface of the to-be-measured crystal 60 forms different angles with the X-rays, and the intensities of the diffraction lights at different angles are recorded by the detector 70 to obtain the rocking curve of the to-be-measured crystal 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 to-be-measured crystal 60 is rotated 180 degrees around the Z-axis, the rocking curve of the to-be-measured crystal 60 at this time is measured, and the Bragg angle θ2 in the second direction is obtained. Thus, the off-cut angle of the to-be-measured crystal 60 is α = 1 / 2(θ1 + θ2), the asymmetry coefficient in the first direction is M1 = sin(θ1 + α) / sin(θ1 - α), and the asymmetry coefficient in the second direction is M2 = sin(θ2 + α) / sin(θ2 - α). When M is greater than 1, it indicates that the crystal 60 will be magnified when placed in this direction. When M is less than 1, it indicates that the crystal will be reduced when placed in this direction. In the present application, the crystal can be placed in the direction with M greater than 1 to achieve magnified imaging of the sample.

[0043] In some embodiments, the crystal 60 can be located on a first displacement stage (not shown in the figure), and the detector 70 can be located on a second displacement stage (not shown in the figure). The first displacement stage is used to move the crystal 60 into or out of the light path and adjust the posture of the crystal 60 (e.g., rotate the crystal 60 around the X-axis) to adjust the incident angle of the X-rays. The second displacement stage is used to move the detector 70 into or out of the light path and adjust the posture of the detector 70 so that the diffraction light is perpendicular to the detector 70.

[0044] In some embodiments, the rotating device 30 can be a hollow cylinder, the second moving device 40 can be embedded in the hollow part of the hollow cylinder, the rotation center of the rotating device 30 can be the axis of the hollow cylinder, and the rotating surface can be 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 by the second displacement table as needed, for example, when measuring the rocking curve of the crystal 60, the photodiode can be moved into the light path, and when imaging the sample, the X-ray array detector can be moved into the light path.

[0046] The X-ray imaging device of the embodiments of the present application does not need complex optical elements, and the light path structure is simple, which reduces the manufacturing cost while realizing high-resolution large-field imaging; a single crystal is used, and the crystal configuration can be adjusted to improve the diffraction efficiency and improve the imaging quality.

[0047] As shown in Figure 3 The embodiments of the present application also provide an X-ray imaging method, which uses the X-ray imaging device of the above embodiments for imaging, and includes the following steps:

[0048] S100: moving the rotating device 30 into the light path by the first moving device 10, and making the rotating surface of the rotating device 30 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 (for example, laser), and adjusting the visible light to be collinear with the X-ray;

[0051] S120: tightly attaching a layer of reflecting mirror on 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 adjusting device 20, so that the reflected light of the visible light on the reflecting mirror coincides with the incident light;

[0053] S140: removing the reflecting mirror on the rotating device 30.

[0054] In step S110, the spot of the X-ray can be first reduced (for accurate positioning), and then a plurality of exposure papers can be placed in sequence in the light path of the X-ray, the X-ray will leave traces on each exposure paper, then the X-ray traces on each exposure paper are punched, and then the posture of the visible light is adjusted to pass through all the holes in sequence, so that the visible light is collinear with the X-ray.

[0055] S200: Move the rotating device 30 by the first moving device 10 to make the rotation center of the rotating device 30 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, the step S200 specifically comprises:

[0057] S210: Fix the calibration target with the feature mark on the sample stage 50, and move the rotating device 30 by the first moving device 10 to make the visible light irradiate near the rotation center of the rotating device 30.

[0058] S220: Move the detector 70 into the light path, and move the calibration target near the rotation center of the rotating device 30 by the second moving device 40 to form the image of the calibration target on the detector 70.

[0059] S230: Rotate the rotating device 30, and move the rotating device 30 by the first moving device 10 and the calibration target on the sample stage 50 by the second moving device 40 during the rotation to keep the pixel position of the calibration target in the detector 70 unchanged.

[0060] S240: Move the crystal 60 into the light path, and adjust the posture of the crystal 60 to make the angle between the crystal 60 and the X-ray be the Bragg angle, and move the detector 70 to be perpendicular to the diffraction direction of the X-ray to form the enlarged image of the calibration target on the detector 70.

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

[0062] The step S230 is used to preliminarily determine the position of the rotation center, and the 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: Fix the to-be-tested sample divided into multiple regions on the sample stage 50.

[0064] The to-be-tested sample can be large and cannot be imaged on the detector 70 in whole, and therefore the to-be-tested sample can be divided into multiple regions to be imaged respectively.

[0065] S400: for each region of the sample to be measured, moving the sample to be measured by the second moving device 40 so that the region is displayed at the pixel position in the detector 70 with the rotation center; then rotating the sample to be measured by the rotating device 30, and every interval of a preset angle, acquiring a one-dimensional magnified image of the region by the detector 70; reconstructing each one-dimensional magnified image of the region to obtain a two-dimensional magnified image of the region.

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

[0067] In some embodiments, the calibration target has rotational symmetry, for example, can be a metal ball.

[0068] The X-ray imaging method of the embodiment of the present application can make the sample to be measured located at the rotation center of the rotating device 30 and make the X-ray vertically irradiate the sample by the first moving device 10, the angle adjusting device 20, the rotating device 30 and the second moving device 40, so as to obtain the one-dimensional magnified image of the sample at different angles of the rotating device 30, and then reconstruct the two-dimensional magnified image of the sample according to the one-dimensional magnified image at each angle. The X-ray imaging method of the present application can realize high-resolution large-field imaging without complex optical elements, and has low cost.

[0069] The above is only the preferred embodiment of the present application, and is not used to limit the scope of the present application. The above embodiment of the present application can be variously changed. Any simple, equivalent change and modification made according to the content of the claims and the description of the present application falls into the protection scope of the present application. The present application is not described in detail, which is the conventional technical content.

Claims

1. An X-ray imaging method, characterized in that, Imaging is performed using an X-ray imaging device, which includes a first moving device, an angle adjustment device, a rotating device, a second moving device, and a sample stage. The angle adjustment device is mounted on the first moving device, the rotating device is mounted on the angle adjustment device, the second moving device is mounted on the rotating device, and the sample stage is mounted 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 Z-axis, the angle adjustment device is used to rotate the rotating device around the X-axis and around the Z-axis, and the rotating device is used to rotate the second moving device and the sample stage around the Y-axis. The sample stage is used to fix the sample. A crystal and a detector are sequentially arranged downstream of the sample stage. Synchrotron radiation X-rays pass through the sample on the sample stage and then incident on the crystal, producing asymmetric Bragg diffraction. The detector is movably positioned in the diffraction direction to receive the diffracted X-rays. The X-ray imaging method includes the following steps: S100: The rotating device is moved into the optical path by the first moving device, and the rotating surface of the rotating device is made perpendicular to the X-ray by the angle adjustment device; S200: Move the rotating device using the first moving device so that the rotation center of the rotating device is collinear with the X-ray, and determine the pixel position of the rotation center of the rotating device in the detector; S300: Fix the test sample, which is divided into multiple regions, on the sample stage; S400: For each region of the sample to be tested, the sample to be tested is moved by the second moving device so that the region 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 region is acquired by the detector at every preset angle; the one-dimensional magnified images of the region are reconstructed to obtain a two-dimensional magnified image of the region. S500: The two-dimensional magnified images of each region are stitched together to obtain a complete two-dimensional magnified image of the sample to be tested; Step S100 specifically includes: S110: Introduce visible light and adjust the visible light to be collinear with the X-rays; S120: A reflector is tightly attached to the rotating surface of the rotating device; S130: The rotating device is rotated about the X-axis and / or about the Y-axis by means of the angle adjustment device, so that the reflected light of the visible light on the reflector coincides with the incident light; S140: Remove the reflector; Step S200 specifically includes: S210: Fix a calibration target with a characteristic mark on the sample stage, and move the rotating device through the first moving device so that the visible light shines on the vicinity of the rotation center of the rotating device; S220: Move the detector into the optical path, and move the calibration target to the vicinity of the rotation center of the rotating device through the second moving device, so as to form an image of the calibration target on the detector; S230: Rotate the rotating device, and during the rotation, move the rotating device through the first moving device and move the calibration target on the sample stage through the second moving device, so that the pixel position of the calibration target in the detector remains stationary. S240: Move the crystal into the optical path and adjust the orientation of the crystal so that the angle between it and the X-ray is the Bragg angle, and move the detector to be perpendicular to the diffraction direction of the X-ray so as to form a magnified image of the calibration target on the detector; S250: Rotate the rotating device, and during the rotation, move the rotating device through the first moving device and move the calibration target on the sample stage through the second moving device, so that the pixel position of the marking feature of the calibration target in the detector remains stationary, and record the pixel position of the marking feature in the detector at this time as the pixel position of the rotation center in the detector.

2. The X-ray imaging method according to claim 1, characterized in that, The crystals can be arranged horizontally or vertically.

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

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

5. The X-ray imaging method according to claim 1, characterized in that, The crystal is located on a first displacement stage, which is used to move the crystal into or out of the optical path and adjust the orientation of the crystal to adjust the incident angle of the X-rays.

6. The X-ray imaging method according to claim 1, characterized in that, The detector is located on a second displacement stage, which is used to move the detector into or out of the optical path and adjust the orientation of the detector.

7. The X-ray imaging method according to claim 1, characterized in that, The calibration target has rotational symmetry.

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