CT imaging system

Abstract

The invention relates to the technical field of CT imaging, and discloses a CT imaging system which comprises a base, an electron beam generation structure, a deflection system and a sample detection mechanism, a vacuum chamber is formed in the base, and a transmission target is installed at one end of the vacuum chamber; the electron beam generation structure is mounted in the vacuum chamber and is used for generating electron beams; the deflection system is installed at the end, close to the transmission target, of the vacuum cavity and used for controlling the deflection direction and angle of the electron beam. According to the CT imaging system, electron beam deflection is projected, the triggering speed is high, the CT scanning efficiency is improved, X-ray energy absorbed by sample detection is reduced, and a sample is protected. Imaging of the sample at different angles can be achieved through electron beam deflection, a sample detection structure does not need to be moved, components of the whole CT imaging system are kept still in the imaging process, and the problem of imaging artifacts caused by a mechanical motion scanning mode of traditional static CT is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of CT imaging, and in particular to a CT imaging system. Background Art

[0002] Currently, third-generation CT systems utilize X-ray devices and detectors that rotate around the sample, or maintain a fixed position while the sample stage rotates to obtain an image. These systems require a precision mechanical rotation mechanism, which increases manufacturing, assembly, and control complexity, increasing costs. Furthermore, the presence of moving parts can lead to motion artifacts during imaging. Summary of the Invention

[0003] In light of this, the present invention provides a CT imaging system to address the current third-generation CT systems, which image the sample by rotating the X-ray device and detector around the sample, or by keeping the X-ray device and detector stationary while the sample stage rotates. These systems require a precision mechanical rotation mechanism, which increases the complexity of manufacturing, assembly, and control, thereby increasing costs. Furthermore, the presence of moving parts can lead to motion artifacts during imaging.

[0004] In a first aspect, the present invention provides a CT imaging system, comprising:

[0005] A base, wherein a vacuum chamber is provided in the base, and a transmission target is installed at one end of the vacuum chamber;

[0006] an electron beam generating structure, the electron beam generating structure being installed in the vacuum chamber and being used to generate an electron beam;

[0007] a deflection system, the deflection system being installed at one end of the vacuum chamber close to the transmission target, the deflection system being used to control the deflection direction and angle of the electron beam so that the electron beam bombards the transmission target at multiple angles;

[0008] The sample detection structure is used to place the sample, and the sample detection structure has a working state of receiving the X-ray beam transmitted through the sample and output by the transmission target to obtain sample projection data.

[0009] Beneficial effect: When it is necessary to detect the sample, the sample is placed in the area to be tested on the sample detection structure, and the electron beam generating structure generates an electron beam in the vacuum chamber. The electron beam passes through the deflection system, and the deflection system controls the electron beam to be deflected and bombard the transmission target to generate X-rays. The X-rays pass through the area to be tested and penetrate the sample. The sample detection structure receives the X-ray beam transmitted by the transmission target and penetrates the sample to obtain sample projection data. A CT imaging system of the present invention projects the electron beam deflection, has a fast triggering speed, improves the efficiency of CT scanning, reduces the X-ray energy absorbed by the sample detection, and protects the sample. Compared with the existing technology, the present invention utilizes electron beam deflection to realize imaging of the sample at different angles, does not need to move the sample detection structure, and the components of the entire CT imaging system remain stationary during the imaging process, solving the problem of imaging artifacts caused by the traditional static CT scanning method that relies on mechanical motion.

[0010] In an optional embodiment, the vacuum chamber includes a first chamber, and the deflection system is installed in the first chamber;

[0011] The deflection system includes a plurality of deflection coils, which are arranged in a circular array along the central axis of the first cavity.

[0012] In an optional embodiment, the number of deflection coils in the deflection yoke is an even number.

[0013] In an optional embodiment, the CT imaging system further includes a coil bobbin, wherein the coil bobbin is installed in the first chamber, and the deflection coil is fixed on the coil bobbin.

[0014] In an optional embodiment, the deflection coil gradually deviates from the central axis of the first chamber from an end away from the transmission target to an end close to the transmission target.

[0015] Beneficial effect: the deflection coil is close to the central axis of the first chamber at one end away from the transmission target, and is tilted outward at one end close to the transmission target, so that the electron beam deflection area is an inverted cone, thereby making the electron beam deflection range larger and covering a larger detection range.

[0016] In an optional embodiment, the vacuum chamber further includes a second chamber, a third chamber, and a transmission channel, wherein the second chamber is opened at an end of the transmission channel close to the transmission target, and the third chamber is opened at an end of the transmission channel away from the transmission target;

[0017] The central axis of the first chamber, the central axis of the second chamber, the central axis of the third chamber and the central axis of the transmission channel all coincide with each other;

[0018] The first chamber, the second chamber, the transmission channel and the third chamber are connected in sequence.

[0019] Beneficial Effects: The electron beam generating structure and deflection system are both located within a vacuum environment, preventing electron scattering and energy loss, ensuring a stable electron beam trajectory and efficient energy transmission. This extends the life of the electron source and prevents oxidation or contamination of the electron-emitting material in air, thereby reducing emission efficiency. The vacuum isolates oxygen and impurities, protecting the thermal stability and emission performance of the electron source. Maintaining magnetic field uniformity: Even when magnetic impurities in the air or airflow disturbances could disrupt the magnetic field distribution of the deflection coil, the vacuum environment ensures high-precision magnetic field control and prevents electron beam deflection distortion.

[0020] In an optional embodiment, the electron beam generating structure includes:

[0021] an electron beam gun, the electron beam gun being installed in the third chamber, with an emission end of the electron beam gun facing the transmission target;

[0022] A centering coil is installed in the second chamber and is used to focus the incident electron beam.

[0023] Beneficial effect: The centering coil is used to correct the initial position deviation of the electron beam, ensuring that the electron beam is accurately aligned with the system center or target path.

[0024] In an optional embodiment, the sample detection structure includes:

[0025] A sample delivery mechanism, configured to receive the sample;

[0026] The detector is used to receive the ray beam after penetrating the sample to obtain sample projection data.

[0027] Beneficial effect: Through the above arrangement, during the test of the sample, the deflection system, electron beam generating structure, sample feeding mechanism and detector remain stationary without mechanical movement. Even if maintenance is insufficient, no error will occur to affect the CT random inspection.

[0028] In an optional embodiment, the CT imaging system further includes a PLC structure connected to the deflection yoke to control the magnetic field force of the deflection coil.

[0029] Beneficial effects: The CT imaging system also includes a PLC structure, which is connected to the deflection system to control the magnetic field force of the deflection coil. For example: eight deflection coils are controlled by the PLC, and each two opposing deflection coils form a group. The PLC controls the deflection coils so that each group is energized in turn, forming a stepped rotating magnetic field. The electron beam passing through is successively affected by the force of each group of magnetic fields and deflected in turn to form a nearly circular trajectory. The electron beam with a nearly circular trajectory thus obtains a circular trajectory X-ray, and then completes a full cycle of X-ray scanning of the sample, forming an overall CT image of the sample on the detector. Similarly, a straight trajectory or an arbitrary trajectory can also be used, so as to obtain transmission projection imaging of the sample at different angles by the X-ray beam generated by the corresponding electron trajectory at different angles. The corresponding projection area is a circular trajectory, a straight trajectory area, or an arbitrary trajectory. The detector obtains a series of images of the sample projected at different angles.

[0030] In an optional embodiment, a vacuum generating hole is further provided on the base, and the vacuum generating hole is communicated with the vacuum chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 Schematic diagram of the overall structure of a CT imaging system according to an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of the internal structure of a CT imaging system according to an embodiment of the present invention;

[0034] Figure 3 for Figure 1 Cross-sectional view in the AA direction;

[0035] Figure 4 for Figure 1 Cross-sectional view in the middle BB direction;

[0036] Figure 5 Schematic diagram of the deflection of an electron beam in a circular trajectory according to an embodiment of the present invention;

[0037] Description of reference numerals:

[0038] 1. Base; 11. Vacuum chamber; 111. First chamber; 112. Second chamber; 113. Third chamber; 114. Transmission channel; 12. Vacuum generating hole;

[0039] 2. Transmission target;

[0040] 3. Electron beam generating structure; 31. Electron beam gun; 32. Centering coil;

[0041] 4. Deflection system; 41. Deflection coil; 42. Coil frame;

[0042] 5. Sample detection structure; 51. Sample delivery mechanism; 52. Detector;

[0043] 6. Electron beam;

[0044] 7. Ray beam

[0045] 8. Samples. DETAILED DESCRIPTION

[0046] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0047] Currently, third-generation CT systems utilize a rotating X-ray device and detector around the sample, or a rotating sample stage with the X-ray device and detector stationary to produce an image. These systems require a precision mechanical rotation mechanism, which increases manufacturing, assembly, and control complexity, thus increasing costs. Furthermore, the presence of moving parts can lead to motion artifacts during imaging.

[0048] In order to solve the above technical problems, the following Figures 1 to 5 , describing embodiments of the present invention.

[0049] According to an embodiment of the present invention, a CT imaging system is provided, comprising a base 1 , an electron beam generating structure 3 , a deflection system 4 and a sample detection structure 5 .

[0050] like Figures 1 to 4 As shown, the base 1 is placed vertically, and the sample detection structure 5 is installed above the base 1. A vacuum chamber 11 is defined within the base 1. A transmission target 2 is installed at the top of the vacuum chamber 11. An electron beam generating structure 3 is installed at the bottom of the vacuum chamber 11. The electron beam generating structure 3 emits an electron beam 6 toward the sample detection structure 5. A deflection system 4 is installed at one end of the vacuum chamber 11 near the transmission target 2.

[0051] When it is necessary to detect the sample 8, the sample 8 is placed in the area to be tested on the sample detection structure 5. The electron beam generating structure 3 generates an electron beam 6 in the vacuum chamber 11. The electron beam 6 passes through the deflection system 4. The deflection system 4 controls the electron beam 6 to be deflected and bombards the transmission target 2 to generate X-rays. The X-rays pass through the area to be tested and penetrate the sample 8. The sample detection structure 5 receives the X-ray beam 7 that penetrates the sample 8 and is output by the transmission target 2 to obtain projection data of the sample 8.

[0052] The CT imaging system of the present invention projects the deflection of the electron beam 6, achieving rapid triggering, improving CT scanning efficiency, reducing X-ray energy absorbed by the sample 8, and protecting the sample 8. Compared to existing technologies, the present invention utilizes the deflection of the electron beam 6 to image the sample 8 at different angles without moving the sample detection structure 5. The components of the entire CT imaging system remain stationary during imaging, thus resolving the imaging artifacts associated with traditional static CT scanning methods that rely on mechanical motion.

[0053] Specifically, such as Figures 1 to 4 As shown, the vacuum chamber 11 is provided with a first chamber 111, a second chamber 112, a transmission channel 114, and a third chamber 113 from top to bottom. The first chamber 111, the second chamber 112, the transmission channel 114, and the third chamber 113 are connected in sequence, and the central axis of the first chamber 111, the central axis of the second chamber 112, the central axis of the transmission channel 114, and the central axis of the third chamber 113 all coincide. The first chamber 111 is provided with an opening toward the sample detection structure 5, and the transmission target 2 is mounted at the opening of the first chamber 111. A vacuum generating hole 12 is provided on the side of the base 1 near the third chamber 113, and the vacuum generating hole 12 is connected to the third chamber 113. With the above arrangement, the transmission target 2 encloses the first chamber 111, and the interface of the external vacuum pumping device is connected to the vacuum generating hole 12 to evacuate the vacuum chamber 11.

[0054] like Figure 2 and Figure 4 As shown, the electron beam generating structure 3 includes an electron beam gun 31 and a centering coil 32. The electron beam gun 31 is mounted at the bottom end of the third chamber 113, away from the transmission target 2. The electron beam 6 emission end of the electron beam gun 31 faces upward, directly toward the transmission target 2, and is also located on the central axis of the third chamber 113. The centering coil 32 is mounted within the second chamber 112, with the central axis of the centering coil 32 coinciding with the central axis of the second chamber 112. The centering coil 32 is used to correct the initial position deviation of the electron beam 6, ensuring that the electron beam 6 is precisely aligned with the system center or the target path.

[0055] like Figures 1 to 4As shown, the deflection yoke 4 is mounted within the first chamber 111 and includes a plurality of deflection coils 41 mounted on a coil bobbin 42. The number of deflection coils 41 in the deflection yoke 4 is an even number. In the present invention, the deflection yoke 4 includes a total of eight deflection coils 41, forming four groups of deflection coils 41. The eight deflection coils 41 are arranged in a circular array along the central axis of the first chamber 111, such that two opposing deflection coils 41 are symmetrically arranged. Of course, a greater number of groups of deflection coils 41 may also be used.

[0056] Both the electron beam generating structure 3 and the deflection system 4 are located within a vacuum environment, which prevents electron scattering and energy loss, ensuring a stable trajectory and efficient energy transmission for the electron beam 6. This extends the life of the electron source and prevents oxidation or contamination of the electron-emitting material in air, thereby reducing emission efficiency. The vacuum isolates oxygen and impurities, protecting the thermal stability and emission performance of the electron source. Maintaining magnetic field uniformity: Even when magnetic impurities in the air or airflow disturbances could disrupt the magnetic field distribution of the deflection coil 41, the vacuum environment ensures high-precision magnetic field control and prevents distortion in the deflection of the electron beam 6.

[0057] In one embodiment, Figure 2 and Figure 4 As shown, the deflection coil 41 gradually deviates from the central axis of the first chamber 111 from the end away from the transmission target 2 to the end closer to the transmission target 2. That is, the end of the deflection coil 41 away from the transmission target 2 is closer to the central axis of the first chamber 111, while the end of the deflection coil 41 closer to the transmission target 2 is tilted outward, so that the area where the electron beam 6 is deflected forms an inverted cone shape, thereby increasing the deflection range of the electron beam 6 and covering a larger detection range.

[0058] The sample detection structure 5 includes a sample delivery mechanism 51 and a detector 52. The sample delivery mechanism 51 is used to receive the sample 8. The sample 8 is generally placed at the center of the sample delivery mechanism 51, but can also be placed at other positions. The detector 52 is installed at one end of the sample delivery mechanism 51 away from the base 1.

[0059] The working steps of the above structure are as follows:

[0060] First, the sample 8 is placed on the sample feeding mechanism 51 . The sample feeding mechanism 51 feeds the sample 8 to the center of the CT imaging system and then stops. At this time, the sample 8 is located between the base and the detector 52 , and the central axis of the vacuum chamber 11 passes through the sample 8 .

[0061] The electron beam gun 31 is activated and generates an electron beam 6 within the vacuum chamber 11. The electron beam 6 is emitted toward the sample delivery mechanism 51, passes through the third chamber 113 and the transmission channel 114, and enters the center of the centering coil 32. The centering coil 32 focuses the incident electron beam 6, centering it in the center of the vacuum chamber 11. The electron beam 6 then passes through the deflection system 4, where eight deflection coils 41 generate magnetic forces that deflect the electron beam 6 toward the projection target, generating X-rays. The sample delivery mechanism 51 delivers the sample 8 to the center of the test field of view. The X-rays penetrate the sample 8 and reach the detector 52. The detector 52 receives the X-ray beam 7 after passing through the sample 8, generating projection data of the sample 8. After processing, it presents a penetration image of the sample 8. Three-dimensional CT data reconstruction generates a 3D CT model of the sample 8. Image processing and judgment are performed on the 3D CT model to obtain the test results.

[0062] like Figure 5 As shown, the CT imaging system also includes a PLC structure connected to the deflection system 4 to control the magnetic field force of the deflection coils 41. For example, eight deflection coils 41 are controlled by the PLC, with each group of two opposing deflection coils 41 forming a group. The PLC controls the deflection coils 41 to sequentially energize each group, forming a stepped rotating magnetic field. The passing electron beam 6 is sequentially deflected by the force of each magnetic field group, forming a nearly circular trajectory. The electron beam 6 with a nearly circular trajectory thus produces circular X-rays, completing a complete X-ray scan of the sample 8 and forming a CT image of the entire sample 8 on the detector 52. Similarly, a linear or arbitrary trajectory can also be used, thereby producing transmission projection images of the sample 8 at different angles generated by the X-ray beam 7 generated by the corresponding electron trajectory. The corresponding projection area is a circular trajectory, a linear trajectory area, or an arbitrary trajectory. A series of images of the sample 8 projected at different angles are obtained on the detector 52. The use of eight deflection coils 41 provides a smoother magnetic field vector: the phase subdivision of the eight coils makes the magnetic field direction change closer to continuous rotation.

[0063] In the prior art, devices that utilize mechanical motion to test sample 8 require regular maintenance. Inadequate maintenance can easily affect the accuracy of the mechanical motion, thereby impacting the test results. However, the present invention utilizes the aforementioned configuration to ensure that during the testing of sample 8, the deflection system 4, electron beam generating structure 3, sample feed mechanism 51, and detector 52 remain stationary, eliminating mechanical motion. Even inadequate maintenance prevents errors from affecting CT spot checks.

[0064] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A CT imaging system, characterized in that: include: A base (1), wherein a vacuum chamber (11) is provided in the base (1), and a transmission target (2) is installed at one end of the vacuum chamber (11); An electron beam generating structure (3), the electron beam generating structure (3) being installed in the vacuum chamber (11), and the electron beam generating structure (3) being used to generate an electron beam (6); a deflection system (4), the deflection system (4) being installed at one end of the vacuum chamber (11) close to the transmission target (2), the deflection system (4) being used to control the deflection direction and angle of the electron beam (6) so that the electron beam (6) bombards the transmission target (2) at multiple angles; A sample detection structure (5) is provided, wherein the sample detection structure (5) is used for placing a sample (8), and the sample detection structure (5) has a working state of receiving an X-ray beam (7) transmitted by the transmission target (2) and penetrating the sample (8) to obtain projection data of the sample (8).

2. The CT imaging system according to claim 1, wherein: The vacuum chamber (11) includes a first chamber (111), and the deflection system (4) is installed in the first chamber (111); The deflection system (4) comprises a plurality of deflection coils (41), and the plurality of deflection coils (41) are arranged in a ring array along the central axis of the first chamber (111).

3. The CT imaging system according to claim 2, wherein: The number of deflection coils (41) in the deflection system (4) is an even number.

4. The CT imaging system according to claim 3, wherein: The CT imaging system further comprises a coil skeleton (42), wherein the coil skeleton (42) is installed in the first chamber (111), and the deflection coil (41) is fixed on the coil skeleton (42).

5. The CT imaging system according to claim 2, wherein: The deflection coil (41) gradually deviates from the central axis of the first chamber (111) from an end away from the transmission target (2) to an end close to the transmission target (2).

6. The CT imaging system according to claim 2, wherein: The vacuum chamber (11) further comprises a second chamber (112), a third chamber (113) and a transmission channel (114), wherein the second chamber (112) is opened at an end of the transmission channel (114) close to the transmission target (2), and the third chamber (113) is opened at an end of the transmission channel (114) away from the transmission target (2); The central axis of the first chamber (111), the central axis of the second chamber (112), the central axis of the third chamber (113), and the central axis of the transmission channel (114) all coincide with each other; The first chamber (111), the second chamber (112), the transmission channel (114) and the third chamber (113) are connected in sequence.

7. The CT imaging system according to claim 6, characterized in that: The electron beam generating structure (3) comprises: an electron beam gun (31), the electron beam gun (31) being installed in the third chamber (113), with an emission end of the electron beam gun (31) facing the transmission target (2); A centering coil (32) is installed in the second chamber (112) and is used to focus the incident electron beam (6).

8. The CT imaging system according to claim 1, wherein: The sample detection structure (5) comprises: a sample delivery mechanism (51), the sample delivery mechanism (51) being used to receive the sample (8); A detector (52) is used to receive the ray beam (7) after penetrating the sample (8) to obtain projection data of the sample (8).

9. The CT imaging system according to claim 2, wherein: The CT imaging system further comprises a PLC structure connected to the deflection system (4) to control the magnetic field force of the deflection coil (41).

10. The CT imaging system according to claim 1, wherein: The base (1) is also provided with a vacuum generating hole (12), and the vacuum generating hole (12) is connected to the vacuum chamber (11).

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