Under-beam X-ray conversion device

Abstract

The embodiment of the invention provides an under-beam X-ray conversion device. The under-beam X-ray conversion device comprises a tough-induced radiation target and a shielding device. The tough-induced radiation target comprises a target body, the shielding device is provided with an electron entrance port, a containing cavity and an X-ray exit port, the electron entrance port and the X-ray exit port are respectively communicated with the containing cavity, and the tough-induced radiation target is located in the containing cavity; the electron entrance port is located on one side of the shielding device along a first direction, and the X-ray exit port is located on one side of the shielding device along a second direction; wherein the first direction is perpendicular to the second direction. And the opening of the electron entrance port faces the target body, so that electrons entering the accommodating cavity from the electron entrance port can bombard the target body. The opening of the X-ray exit port faces the target body so that X-rays generated by the target body can be emitted out of the containing cavity. The under-beam X-ray conversion device provided by the embodiment of the invention is good in conversion efficiency.

Description

Technical Field

[0001] The present application relates to the field of nuclear technology, and in particular to an under-beam X-ray conversion device. Background Art

[0002] X-rays are bremsstrahlung radiation emitted by the transition of extranuclear electrons or the deceleration of high-speed charged particles bombarding matter. According to the energy level, X-rays can be divided into low-energy, medium-energy and high-energy X-rays. Low-energy and medium-energy X-rays can be generated by X-ray machines, with the highest energy reaching several hundred keV. Low-energy X-rays not only have a profound impact on physics, chemistry, biology, materials science and other disciplines, but also can provide a basis for diagnosis for doctors. Medium-energy X-rays can be used in industrial component inspection, radiographic flaw detection, medical radiotherapy and other fields. According to the GB / T12162.1 standard document, X-ray machines can be used to generate continuous spectrum filtered X-ray radiation fields in the energy range of about 7keV to 250keV, as well as fluorescent X-ray reference radiation fields in the energy range of 8keV-100keV. However, there is no reference standard for X-ray radiation fields at the MeV energy level.

[0003] In the related art, high-energy X-rays are generated by high-energy electrons fired from electron accelerators, and electron accelerators have been widely used in the fields of food preservation, sterilization of medical supplies, waste treatment, material modification, etc. However, the conversion efficiency of high-energy X-rays generated by high-energy electrons fired in the related art is poor. Summary of the invention

[0004] In view of this, the main purpose of the embodiments of the present application is to provide a beam-down X-ray conversion device with good conversion efficiency.

[0005] To achieve the above purpose, the technical solution of the embodiment of the present application is implemented as follows:

[0006] The embodiment of the present application provides a beam-down X-ray conversion device, comprising:

[0007] A bremsstrahlung target, the bremsstrahlung target comprising a target body;

[0008] A shielding device, the shielding device having an electron inlet, a containing cavity and an X-ray outlet, the electron inlet and the X-ray outlet are respectively connected to the containing cavity, and the bremsstrahlung target is located in the containing cavity; the electron inlet is located on one side of the shielding device along a first direction, and the X-ray outlet is located on one side of the shielding device along a second direction; wherein the first direction is perpendicular to the second direction;

[0009] The opening of the electron incident port faces the target body, so that the electrons entering the containing cavity from the electron incident port bombard the target body;

[0010] The opening of the X-ray outlet faces the target body, so that the X-rays generated by the target body can be emitted out of the accommodating cavity.

[0011] In one embodiment, the bremsstrahlung target includes a target shell, which is inclined relative to the plane where the electron entrance port is located and the plane where the X-ray exit port is located. The target shell has an installation cavity on one side close to the electron entrance port and the X-ray exit port, and the target body is arranged in the installation cavity.

[0012] In one embodiment, the target body is a tungsten target, and the material of the tungsten target is a tungsten alloy; and / or,

[0013] The target shell is an aluminum shell.

[0014] In one embodiment, the bremsstrahlung target is rotatably disposed in the accommodating cavity, and the under-beam X-ray conversion device further includes a driving component, at least a portion of which is located in the accommodating cavity and is drivingly connected to the bremsstrahlung target to drive the bremsstrahlung target to rotate.

[0015] In one embodiment, the bremsstrahlung target has an initial state of being located at an installation position. When the bremsstrahlung target is at the installation position, the bremsstrahlung target is tilted relative to a plane where the electron entrance port is located and a plane where the X-ray exit port is located. The driving assembly can drive the bremsstrahlung target to rotate along a first rotation direction and a second rotation direction; wherein the first rotation direction is opposite to the second rotation direction.

[0016] The rotation range of the bremsstrahlung target along the first rotation direction is greater than 0° and less than or equal to 45°; and / or,

[0017] A rotation range of the bremsstrahlung target along the second rotation direction is greater than 0° and less than or equal to 45°.

[0018] In one embodiment, the bremsstrahlung target includes a target shell, the target body is arranged on the target shell, and the under-beam X-ray conversion device includes a cooling coil, the cooling coil has a cooling water channel, and the cooling coil is arranged on a side of the target shell away from the target body.

[0019] In one embodiment, the shielding device comprises a shielding shell, the shielding shell comprises a shielding room and a plurality of lead bricks, the shielding room has the electron entrance port, the accommodating cavity and the X-ray exit port, and the lead bricks are respectively arranged on the outer peripheral sides of the shielding room; and / or,

[0020] Towards the outside of the accommodating cavity, the opening cross-section of the X-ray outlet gradually increases, and the inclination angle of the inner wall surface of the X-ray outlet relative to the central axis is greater than or equal to 4° and less than or equal to 12°; and / or,

[0021] The shielding device includes a shielding aperture, which is arranged on a side of the accommodating cavity close to the X-ray exit port. The shielding aperture has a beam limiting hole, which is correspondingly connected to the X-ray exit port. The opening cross-section of the beam limiting hole gradually increases toward the side away from the X-ray exit port, and the inclination angle of the inner wall surface of the beam limiting hole relative to the central axis is greater than or equal to 4° and less than or equal to 12°.

[0022] In one embodiment, the under-beam X-ray conversion device further comprises a first base frame, the first base frame comprises a support frame and a lifting bracket arranged on the support frame, the shielding device is arranged on the lifting bracket, and the lifting bracket can move in a height direction relative to the support frame.

[0023] In one embodiment, the first base frame further includes a screw lift, and the support frame and the lifting bracket are slidably connected via the screw lift;

[0024] The first base frame further includes a hand wheel, which is arranged on one side of the lifting bracket and is drivingly connected to the screw lifter, and the hand wheel drives the screw lifter to move so that the lifting bracket slides along the height direction; and / or,

[0025] The first base frame also includes a commutator, and the commutator cooperates with the screw lifter to switch the lifting bracket between rising and falling.

[0026] In one embodiment, the under-beam X-ray conversion device further comprises a second base frame and an ionization chamber clamping device, and the ionization chamber clamping device is arranged on the second base frame;

[0027] One of the ionization chamber clamping device and the second base frame has a slide groove, and the other has a slide rail, which extends in a horizontal direction and is perpendicular to the direction of the X-ray outlet. The slide groove slidably cooperates with the slide rail so that the ionization chamber clamping device can slide relative to the second base frame.

[0028] The embodiment of the present application provides an under-beam X-ray conversion device, which includes a bremsstrahlung target and a shielding device. The electron inlet and the X-ray outlet of the shielding device are respectively connected to the accommodating cavity, and the bremsstrahlung target is located in the accommodating cavity. Therefore, on the one hand, the atomic number of the bremsstrahlung target is large, and the intensity of the generated X-rays is high, so the X-ray conversion efficiency is high and the conversion effect is good. On the other hand, by setting the shielding device, it is possible to limit the range of the generated X-ray radiation field as needed while shielding the leakage rays, so that the X-ray conversion effect can be better. In addition, the electron inlet is located on one side of the shielding device along the first direction, and the X-ray outlet is located on one side of the shielding device along the second direction, the opening of the electron inlet faces the target body, and the opening of the X-ray outlet faces the target body. Therefore, it is convenient for high-energy electrons emitted from the electron accelerator to enter the accommodating cavity from the electron inlet and hit the target body, and the X-rays generated by the target body are emitted from the accommodating cavity through the X-ray outlet, thereby realizing the establishment of the X-ray radiation field, which can achieve a better X-ray conversion effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural schematic diagram of an under-beam X-ray conversion device according to an embodiment of the present application; the figure shows a limiting device for limiting the position of an electron accelerator;

[0030] Figure 2 for Figure 1 A partial enlarged view of the middle A;

[0031] Figure 3 for Figure 1 A partial enlarged view of point B in the middle;

[0032] Figure 4 for Figure 1 A schematic diagram of the structure of the first chassis;

[0033] Figure 5 for Figure 4 A schematic diagram of the structure of the first base frame after the lifting bracket is hidden;

[0034] Figure 6 for Figure 1 Schematic diagram of the coordination relationship among the bremsstrahlung target, shielding device and driving assembly;

[0035] Figure 7 for Figure 6 Schematic diagram of the structure of the middle drive assembly;

[0036] Figure 8 for Figure 6 Middle CC section view;

[0037] Fig. 9 for Figure 8 Schematic diagram of the coordination between the Bremsstrahlung target and the cooling coil;

[0038] Fig.10 for Figure 6 Cross-sectional view of the shielding aperture.

[0039] Description of Reference Numerals

[0040] 10. Bremsstrahlung target; 11. target body; 12. target shell; 20. shielding device; 20a. electron incident port; 20b. accommodating cavity; 20c. X-ray exit port; 21. shielding shell; 211. shielding room; 212. lead brick; 22. shielding aperture; 22a. beam limiting hole; 30. driving assembly; 40. cooling coil; 50. first base frame; 51. supporting frame; 52. lifting bracket; 53. screw lift; 60. second base frame; 70. ionization chamber clamping device; 80. limiting device. DETAILED DESCRIPTION

[0041] In this application, the orientation or position relationship of "first direction" and "second direction" is based on the attached Figure 6 It should be understood that these directional terms are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application.

[0042] An embodiment of the present application provides a beam-down X-ray conversion device, see Figure 1 , Figure 2 and Figure 8 The under-beam X-ray conversion device includes a bremsstrahlung target 10 and a shielding device 20 .

[0043] See also Figure 6 and Figure 8 The bremsstrahlung target 10 includes a target body 11, and the shielding device 20 has an electron inlet 20a, a accommodating cavity 20b and an X-ray outlet 20c. The electron inlet 20a and the X-ray outlet 20c are respectively connected to the accommodating cavity 20b, and the bremsstrahlung target 10 is located in the accommodating cavity 20b; the electron inlet 20a is located on one side of the shielding device 20 along the first direction, and the X-ray outlet 20c is located on one side of the shielding device 20 along the second direction; wherein the first direction is perpendicular to the second direction.

[0044] The opening of the electron incident port 20 a faces the target body 11 , so that the electrons entering the containing cavity 20 b from the electron incident port 20 a can bombard the target body 11 .

[0045] The opening of the X-ray emission port 20C faces the target 11 so that the X-rays generated by the target 11 can be emitted from the accommodating cavity 20 b.

[0046] Specifically, the under-beam X-ray conversion device of the present application can generate various types of X-rays. For ease of description, the present application takes the example of the under-beam X-ray conversion device receiving high-energy electrons from an electron accelerator and then generating high-energy X-rays. Among them, high-energy X-rays refer to X-rays at the MeV energy level.

[0047] When irradiating products with high density, large thickness or large volume, different high-energy X-rays are required. Higher energy X-rays can be obtained by hitting heavy metal targets with higher energy electrons. Therefore, the key to producing higher energy X-rays is to increase the energy of electrons. Since electron accelerators can increase the energy of electrons to more than ten MeV, referring to the structure of X-ray machines, high-energy electrons generated after being accelerated by electron accelerators are used to bombard the target material to generate high-energy X-rays through bremsstrahlung. The generated X-rays have higher penetrating power and can be used to irradiate products with higher density, greater thickness and larger volume. They can be widely used in irradiation processing, container inspection and calibration inspection.

[0048] The target body 11 of the Bremsstrahlung target 10 is used to generate X-rays, and the target material is a heavy element material with a high atomic number and a high melting point. This is because the larger the atomic number, the higher the intensity of the generated X-rays, and the higher the conversion efficiency of the target body 11. Since most of the electron beam power is reflected in the form of ionization energy loss, the target body 11 heats up severely, and the overall X-ray conversion efficiency will be low, so the target material is required to have high temperature resistance.

[0049] For example, the target body 11 is a tungsten target, and the material of the tungsten target is a tungsten alloy. Since the melting point of tungsten (W) is 3140°C, which is higher than the melting point of tantalum (Ta) (2996°C) and the melting point of lead (Pb) (327°C), etc., the tungsten target is selected as the bremsstrahlung target 10, which can further improve the conversion efficiency.

[0050] The specific element composition of the tungsten alloy can be determined according to actual conditions, such as the composition of the tungsten alloy is 95% tungsten, 3.5% nickel and 1.5% Fe.

[0051] The shielding device 20 is used to install the bremsstrahlung target 10 so as to provide a shielding effect when the bremsstrahlung target 10 generates X-rays and to limit the range of the generated radiation field.

[0052] The electron entrance port 20a of the shielding device 20 is used to receive high-energy electrons from the electron accelerator. It should be noted that the type of electron accelerator that cooperates with the under-beam X-ray conversion device is not limited, such as the DZ-12 / 4 multi-energy-level electron linear accelerator.

[0053] The accommodating cavity 20 b is used to accommodate the bremsstrahlung target 10 , and the X-ray emission port 20C is used to allow high-energy X-rays generated by the bremsstrahlung target 10 to emit out of the accommodating cavity 20 b .

[0054] The electron inlet 20a and the X-ray outlet 20C are not arranged on opposite sides of the shielding device 20 in the same direction. In fact, one of the electron inlet 20a and the X-ray outlet 20C is arranged on one side of the shielding device 20 in the height direction, and the other is arranged on one side of the shielding device 20 in the horizontal direction. Thus, it is better to facilitate the high-energy electrons to bombard the target 11 and the high-energy X-rays generated by the target 11 to be emitted.

[0055] In the beam X-ray conversion device of the embodiment of the present application, on the one hand, the atomic number of the bremsstrahlung target 10 is large, and the intensity of the generated X-rays is high, so the X-ray conversion efficiency is high and the conversion effect is good. On the other hand, by setting the shielding device 20, it is possible to limit the range of the generated X-ray radiation field as needed while shielding the leakage rays, so that the X-ray conversion effect can be better. In addition, the electron entrance port 20a is located on one side of the shielding device 20 along the first direction, and the X-ray exit port 20C is located on one side of the shielding device 20 along the second direction. The opening of the electron entrance port 20a faces the target body 11, and the opening of the X-ray exit port 20C faces the target body 11. As a result, it is convenient for high-energy electrons emitted from the electron accelerator to enter the accommodating cavity 20b from the electron entrance port 20a and hit the target body 11, and the X-rays generated by the target body 11 are emitted from the accommodating cavity 20b through the X-ray exit port 20C, thereby realizing the establishment of the X-ray radiation field, which can achieve a better X-ray conversion effect.

[0056] It can be seen that the beam-down X-ray conversion device of the embodiment of the present application generates high-energy X-rays based on the method of generating high-energy electron target shooting by electron accelerator, which can be used to establish a higher-energy X-ray radiation field. An X-ray radiation field with MeV energy can be established to facilitate the study of its dosimetric characteristics, and then a standard X-ray radiation field with MeV energy can be established and relevant standards can be improved. The establishment of a high-energy pulse X-ray radiation field can not only improve the reference standard of the X-ray radiation field at the MeV energy level, but also provide support for nuclear industry metrology, calibration, and radiation metrology testing technologies such as high-energy X-ray irradiation processing and container inspection.

[0057] In one embodiment, please refer to Figure 8 The bremsstrahlung target 10 includes a target shell 12, which is inclined relative to the plane where the electron incident port 20a and the plane where the X-ray outlet 20c are located. The target shell 12 has an installation cavity on one side close to the electron incident port 20a and the X-ray outlet 20c, and the target body 11 is arranged in the installation cavity.

[0058] That is, the target shell 12 is tilted relative to the side of the shielding device 20 having the electron inlet 20a and the X-ray outlet 20C. By tilting the target shell 12, the electron inlet 20a and the X-ray outlet 20C can be better oriented toward the target body 11, so that high-energy electrons bombard the target material to generate high-energy X-rays.

[0059] The specific shape of the target shell 12 can be set according to actual conditions. For example, the target shell 12 is in the shape of a disk with a diameter of 10 cm and a thickness of 5 mm.

[0060] The material of the target shell 12 can also be set according to actual conditions, for example, the target shell 12 is an aluminum shell. The use of aluminum alloy material can facilitate heat transfer of the target shell 12, and then facilitate heat dissipation of the target material.

[0061] In one embodiment, please refer to Figures 6 to 8 The bremsstrahlung target 10 is rotatably disposed in the accommodating cavity 20b, and the under-beam X-ray conversion device further comprises a driving assembly 30, at least a portion of which is located in the accommodating cavity 20b and is drivingly connected to the bremsstrahlung target 10 to drive the bremsstrahlung target 10 to rotate. Thus, the angle of the bremsstrahlung target 10 can be adjusted, which can further improve the conversion efficiency.

[0062] Specifically, when the positions of the electron inlet 20a and the X-ray outlet 20c are determined, the bremsstrahlung target 10 is installed at the best position in the accommodating cavity 20b, which can make the conversion efficiency of high-energy X-rays higher. At the same time, for different bremsstrahlung targets 10 and different X-ray radiation field establishment requirements, the bremsstrahlung target 10 can be driven to rotate by the driving assembly 30 to adjust the specific position of the bremsstrahlung target 10 to meet actual needs.

[0063] The specific configuration of the bremsstrahlung target 10 is not limited.

[0064] Exemplarily, the bremsstrahlung target 10 has an initial state at the installation position. When the bremsstrahlung target 10 is at the installation position, the bremsstrahlung target 10 is tilted relative to the plane where the electron inlet 20a and the plane where the X-ray outlet 20c are located. The driving assembly 30 can drive the bremsstrahlung target 10 to rotate along a first rotation direction and a second rotation direction; wherein the first rotation direction and the second rotation direction are opposite. Therefore, after the bremsstrahlung target 10 is installed in the accommodating cavity 20b, it can be rotated in different directions as needed to adjust the specific position of the bremsstrahlung target 10.

[0065] That is, the bremsstrahlung target 10 has a fixed initial installation position after being installed in the accommodation cavity 20 b , in which the driving assembly 30 can drive the bremsstrahlung target 10 to rotate in both positive and negative directions (i.e., the first rotation direction and the second rotation direction), thereby better realizing the angle adjustment of the bremsstrahlung target 10 .

[0066] It should be noted that the specific rotation angle of the bremsstrahlung target 10 can be determined according to actual conditions.

[0067] For example, the rotation range of the bremsstrahlung target 10 along the first rotation direction is greater than 0° and less than or equal to 45°. That is, along the first rotation direction, the bremsstrahlung target 10 can rotate within a rotation range of 0° to 45°. According to actual conditions, the bremsstrahlung target 10 can rotate and stay at a position corresponding to any angle. Among them, the rotation accuracy of the bremsstrahlung target 10 can be set according to actual conditions, for example, the rotation accuracy of the bremsstrahlung target 10 is ±1°.

[0068] For another example, the rotation range of the bremsstrahlung target 10 along the second rotation direction is greater than 0° and less than or equal to 45°. Along the second rotation direction, the bremsstrahlung target 10 can rotate within a rotation range of 0° to 45°. According to actual conditions, the bremsstrahlung target 10 can rotate and stay at a position corresponding to any angle. Among them, the rotation accuracy of the bremsstrahlung target 10 can be set according to actual conditions, for example, the rotation accuracy of the bremsstrahlung target 10 is ±1°.

[0069] In one embodiment, the specific structure of the driving assembly 30 is not limited.

[0070] Exemplarily, the driving assembly 30 includes a driving motor and a target axis motor seat, the shielding device 20 has a communication port on one side along the horizontal direction, the body of the driving motor is located outside the shielding device 20, and the driving shaft of the driving motor passes through the communication port and extends into the accommodating cavity 20b to be driven and connected with the bremsstrahlung target 10. The body of the driving motor and the shielding device 20 are arranged at intervals, and the target axis motor seat is arranged at the interval and is connected to the body of the driving motor and the shielding device 20, respectively.

[0071] The specific shape of the target axis motor seat is not limited. For example, the target axis motor seat includes a first connecting plate, a second connecting plate and a supporting plate. The first connecting plate is fitted with the body of the drive motor, the second connecting plate is fitted with the outer wall of the shielding device 20, the supporting plate is located between the first connecting plate and the second connecting plate, and the opposite ends of the supporting plate are respectively connected to the bottom ends of the first connecting plate and the second connecting plate. In this way, the connection effect of the supporting plate to the first connecting plate and the second connecting plate can be greatly improved, and the connection between the body of the drive motor and the shielding device 20 can be made more stable.

[0072] In one embodiment, please refer to Fig. 9The bremsstrahlung target 10 includes a target shell 12, a target body 11 is arranged on the target shell 12, and the under-beam X-ray conversion device includes a cooling coil 40, the cooling coil 40 has a cooling water channel, and the cooling coil 40 is arranged on the side of the target shell 12 away from the target body 11. In this way, the heat dissipation effect of the target body 11 can be further improved to prevent the temperature of the target body 11 from being too high, which affects the conversion effect and structure.

[0073] Specifically, the cooling coil 40 is a spiral cooling pipe structure wound on the side of the target shell 12 away from the target body 11. There is a cooling water channel inside it. In fact, one end of the cooling coil 40 is a water inlet, which is used for cooling water to enter the cooling coil 40 and flow along the cooling water channel, thereby achieving the purpose of cooling the bremsstrahlung target 10. The other end of the cooling coil 40 is a water outlet, which is used for cooling water to flow out, thereby taking away the heat emitted by the target body 11.

[0074] It should be noted that the cooling coil 40 needs to cooperate with an external cooling device. For example, the water inlet of the cooling coil 40 is connected to an external chiller to provide cooling water through the chiller.

[0075] In a specific embodiment, the external chiller can keep the tungsten target temperature below 50 degrees when the electron beam power is highest and the heat generation power is 420W. The cooling power of the water chiller is greater than 2500W, the cooling capacity is 2.8kW, and the input power is 1.1kW.

[0076] In one embodiment, please refer to Figures 6 to 8 The shielding device 20 includes a shielding shell 21, which includes a shielding chamber 211 and a plurality of lead bricks 212. The shielding chamber 211 has an electron inlet 20a, a receiving cavity 20b and an X-ray outlet 20C, and lead bricks 212 are respectively arranged on the outer peripheral side of the shielding chamber 211. Thus, a better shielding effect can be achieved, and the scattered X-rays generated after the high-energy electrons bombard the target body 11 can be shielded.

[0077] Specifically, the material of the shielding room 211 is not limited. For example, the shielding room 211 may be a fixed frame structure made of stainless steel.

[0078] Lead bricks 212 are arranged around the shielding room 211, thereby achieving a better shielding effect.

[0079] The specific shape of the shielding room 211 is not limited.

[0080] For example, the box structure of the shielding room 211 is a hollow cube, the size of the internal accommodating cavity 20b is 20cm×20cm×20cm, the thickness of the lead brick 212 is 7cm, and the electron incident port 20a is a cylindrical opening with a diameter of 5cm.

[0081] In one embodiment, the opening cross section of the X-ray outlet 20C gradually increases toward the outside of the accommodating cavity 20b, and the inclination angle of the inner wall surface of the X-ray outlet 20C relative to the central axis is greater than or equal to 4° and less than or equal to 12°. Thus, it is possible to facilitate the emission of X-rays to better establish an X-ray radiation field.

[0082] Specifically, since the X-rays generated by the target 11 are not all emitted horizontally, but are mostly at a certain angle to the horizontal direction, the X-ray emission port 20C with a gradually increasing opening cross section can better facilitate the X-ray emission from the accommodating cavity 20b.

[0083] The inclination angle of the inner wall surface of the X-ray outlet 20C relative to the central axis refers to the angle between the edge line of the inner wall surface of the X-ray outlet 20C and the horizontal direction along the height direction, which ranges from 4° to 12°, for example, 4°, 6°, 8° or 12°.

[0084] The X-ray emission port 20C may be in a cone shape or a truncated cone shape.

[0085] The specific size of the X-ray outlet 20C is not limited. For example, the radius of the X-ray outlet 20C close to the accommodating cavity 20b is 2.35 cm, and the radius of the X-ray outlet 20C away from the accommodating cavity 20b is 3.09 cm.

[0086] In one embodiment, please refer to Figure 6 and Fig.10 The shielding device 20 includes a shielding aperture 22, which is arranged on a side of the accommodating cavity 20b close to the X-ray exit port 20C. The shielding aperture 22 has a beam limiting hole 22a, which is correspondingly connected to the X-ray exit port 20C. The opening cross section of the beam limiting hole 22a gradually increases toward the side away from the X-ray exit port 20C, and the inclination angle of the inner wall surface of the beam limiting hole 22a relative to the central axis is greater than or equal to 4° and less than or equal to 12°. Therefore, it can correspond to the X-ray exit port 20C, and can better facilitate the establishment of the X-ray radiation field.

[0087] Specifically, the shielding aperture 22 is designed as a truncated cone hollowed out from a cylinder, and its specific material is not limited. For example, the material of the shielding aperture 22 is tungsten alloy.

[0088] The shielding aperture 22 may include multiple aperture structures. For example, the shielding aperture 22 includes 6 aperture structures. From the side close to the X-ray exit port 20C to the side far from the X-ray exit port 20C, the upper and lower bottom surface radii of each aperture structure are 1.79cm and 2.00cm, 2.00cm and 2.21cm, 2.21cm and 2.42cm, 2.42cm and 2.63cm, 2.63cm and 2.84cm, and 2.84cm and 3.05cm, respectively.

[0089] The opening center line of the shielding aperture 22 is collinear with the center line of the X-ray emission port 20C.

[0090] In one embodiment, please refer to Figure 1 and Figure 4 The under-beam X-ray conversion device further comprises a first base frame 50, which comprises a support frame 51 and a lifting support frame 52 disposed on the support frame 51, and the shielding device 20 is disposed on the lifting support frame 52, and the lifting support frame 52 can move in the height direction relative to the support frame 51. Thus, the shielding device 20 can be lifted and lowered in the height direction to meet the height requirements of the shielding device 20 under different experimental conditions.

[0091] It should be noted that the connection method between the lifting bracket 52 and the support frame 51 is not limited, and the lifting bracket 52 and the support frame 51 may be detachably connected to facilitate the disassembly of the lifting bracket 52 and the support frame 51.

[0092] In addition to supporting the lifting bracket 52 and the shielding device 20 , the support frame 51 also needs to cooperate with the electron accelerator.

[0093] For example, the electron accelerator includes a conveyor belt plane, and the support frame 51 is erected on the conveyor belt plane.

[0094] For example, the conveyor belt plane is 780mm high, 1240mm wide, 640mm away from the wall on both sides, the inner reducer is 200mm away from the wall, and the height from the X-ray outlet 20C is 470mm. The support frame 51 can bear 450kg, and the table height of the support frame 51 is 920mm and the width is 1500mm.

[0095] The specific manner in which the lifting bracket 52 can move relative to the supporting frame 51 is not limited.

[0096] For example, the first base frame 50 further includes a screw lift 53 , and the support frame 51 and the lifting bracket 52 are slidably connected via the screw lift 53 .

[0097] The first base frame 50 further includes a hand wheel, which is disposed on one side of the lifting bracket 52 and is drivingly connected to the screw lift 53. The hand wheel drives the screw lift 53 to move so as to slide the lifting bracket 52 in the height direction. Thus, the user can rotate the hand wheel to slide the lifting bracket 52 relative to the support frame 51 under the transmission action of the screw lift 53, thereby realizing the lifting and lowering of the shielding device 20 in the height direction.

[0098] It should be noted that the first base frame 50 may include only one screw lift 53 or may include a plurality of screw lifts 53 .

[0099] In addition, the lifting stroke of the lifting bracket 52 is not limited, such as the lifting stroke is 0-120 mm.

[0100] In a specific embodiment, the support frame 51 is made of rectangular tubes welded together, the structure is firm and reliable, the top is welded with steel plates, and the whole is painted. The lifting bracket 52 is detachable and can be raised and lowered manually.

[0101] In one embodiment, please refer to Figure 1 , Figure 4 and Figure 5 The first base frame 50 also includes a screw lift 53, and the support frame 51 and the lifting bracket 52 are slidably connected through the screw lift 53; the first base frame 50 also includes a commutator, which cooperates with the screw lift 53 to switch the lifting bracket 52 between rising and falling.

[0102] Specifically, the commutator is used to cooperate with the screw lift 53. By setting the commutator, the lifting bracket 52 can be switched from the rising state to the falling state, and the lifting bracket 52 can also be switched from the falling state to the rising state.

[0103] In one embodiment, please refer to Figure 1 and Figure 3 The under-beam X-ray conversion device also includes a second base frame 60 and an ionization chamber clamping device 70 , and the ionization chamber clamping device 70 is arranged on the second base frame 60 .

[0104] One of the ionization chamber clamping device 70 and the second base frame 60 has a slide groove, and the other has a slide rail, the slide rail extends in a horizontal direction, and the extension direction is perpendicular to the direction of the X-ray outlet 20C, and the slide groove and the slide rail are slidably matched, so that the ionization chamber clamping device 70 can slide relative to the second base frame 60. In this way, the position of the ionization chamber clamping device 70 can be adjusted, so as to adjust the specific position of the ionization chamber.

[0105] Specifically, the ionization chamber clamping device 70 is used to hold the ionization chamber.

[0106] According to actual conditions, the ionization chamber clamping device 70 may have a slide groove, and the second base frame 60 may have a slide rail. Alternatively, the ionization chamber clamping device 70 may have a slide rail, and the second base frame 60 may have a slide groove.

[0107] Thus, by inserting the slide rail into the slide groove, the sliding cooperation between the ionization chamber clamping device 70 and the second base frame 60 can be achieved, thereby facilitating the adjustment of the specific position of the ionization chamber along the horizontal direction.

[0108] In a specific embodiment, the second chassis 60 is designed to avoid the plane of the conveyor belt. The second chassis 60 is made of overlapped aluminum profiles, with a Forma caster at the bottom and an ionization chamber clamping device 70 at the top, which can be moved by electric control in the horizontal plane and in the direction perpendicular to the beam of rays. The moving range is the entire conveyor belt width, the stroke is 0-1240mm, the moving accuracy is ±1mm, and the repeat positioning accuracy is 0.1mm.

[0109] In one embodiment, the under-beam X-ray conversion device further comprises a processor, a drive assembly 30 and a drive device, wherein the drive assembly 30 is drive-connected to the bremsstrahlung target 10, and the drive device is drive-connected to the ionization chamber clamping device 70. The processor is signal-connected to the drive assembly 30 and the drive device respectively.

[0110] In fact, the processor includes a device information display component and a device control component, wherein the device information display component can display the target angle of the current bremsstrahlung target 10 and the horizontal position of the ionization chamber clamping device 70. The device control component can control the horizontal position of the ionization chamber clamping device 70 and the target angle of the bremsstrahlung target 10. Thus, remote control of the X-ray conversion process can be achieved.

[0111] For example, the rotation angle range of the bremsstrahlung target 10 is 0-45°, the adjustable precision is 1°, the movement range of the ionization chamber support is 0-1000 mm, the movement precision is 0.1 mm. The specific positions of the bremsstrahlung target 10 and the ionization chamber clamping device 70 can be controlled by the processor.

[0112] In some embodiments, the ionization chamber clamping device 70 includes a guide column and a clamping assembly. The guide column extends in a height direction. The clamping assembly is slidably disposed on the guide column. The clamping assembly is used to clamp the ionization chamber.

[0113] In the description of the present application, the description with reference to the terms "in one embodiment", "in some embodiments", "in a specific embodiment", or "exemplary" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the present application, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0114] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A beam-down X-ray conversion device, characterized in that: include: A bremsstrahlung target, the bremsstrahlung target comprising a target body; A shielding device, the shielding device having an electron inlet, a containing cavity and an X-ray outlet, the electron inlet and the X-ray outlet are respectively connected to the containing cavity, and the bremsstrahlung target is located in the containing cavity; the electron inlet is located on one side of the shielding device along a first direction, and the X-ray outlet is located on one side of the shielding device along a second direction; wherein the first direction is perpendicular to the second direction; The opening of the electron incident port faces the target body, so that the electrons entering the containing cavity from the electron incident port bombard the target body; The opening of the X-ray outlet faces the target body, so that the X-rays generated by the target body can be emitted out of the accommodating cavity.

2. The under-beam X-ray conversion device according to claim 1, characterized in that: The bremsstrahlung target comprises a target shell, which is inclined relative to the plane where the electron entrance port and the plane where the X-ray exit port are located. The target shell has an installation cavity on one side close to the electron entrance port and the X-ray exit port, and the target body is arranged in the installation cavity.

3. The under-beam X-ray conversion device according to claim 2, characterized in that: The target body is a tungsten target, and the material of the tungsten target is a tungsten alloy; and / or, The target shell is an aluminum shell.

4. The under-beam X-ray conversion device according to any one of claims 1 to 3, characterized in that: The bremsstrahlung target is rotatably disposed in the accommodating cavity. The under-beam X-ray conversion device further comprises a driving component, at least a portion of which is located in the accommodating cavity and is drivingly connected to the bremsstrahlung target to drive the bremsstrahlung target to rotate.

5. The under-beam X-ray conversion device according to claim 4, characterized in that: The bremsstrahlung target has an initial state of being located at an installation position. When the bremsstrahlung target is at the installation position, the bremsstrahlung target is tilted relative to a plane where the electron entrance port is located and a plane where the X-ray exit port is located. The driving assembly can drive the bremsstrahlung target to rotate along a first rotation direction and a second rotation direction; wherein the first rotation direction is opposite to the second rotation direction; The rotation range of the bremsstrahlung target along the first rotation direction is greater than 0° and less than or equal to 45°; and / or, A rotation range of the bremsstrahlung target along the second rotation direction is greater than 0° and less than or equal to 45°.

6. The under-beam X-ray conversion device according to claim 1, characterized in that: The bremsstrahlung target comprises a target shell, the target body is arranged on the target shell, the under-beam X-ray conversion device comprises a cooling coil, the cooling coil has a cooling water channel, and the cooling coil is arranged on a side of the target shell away from the target body.

7. The under-beam X-ray conversion device according to any one of claims 1 to 3, characterized in that: The shielding device comprises a shielding shell, the shielding shell comprises a shielding room and a plurality of lead bricks, the shielding room has the electron entrance port, the accommodating cavity and the X-ray exit port, and the lead bricks are respectively arranged on the outer peripheral sides of the shielding room; and / or, Towards the outside of the accommodating cavity, the opening cross-section of the X-ray outlet gradually increases, and the inclination angle of the inner wall surface of the X-ray outlet relative to the central axis is greater than or equal to 4° and less than or equal to 12°; and / or, The shielding device includes a shielding aperture, which is arranged on a side of the accommodating cavity close to the X-ray exit port. The shielding aperture has a beam limiting hole, which is correspondingly connected to the X-ray exit port. The opening cross-section of the beam limiting hole gradually increases toward the side away from the X-ray exit port, and the inclination angle of the inner wall surface of the beam limiting hole relative to the central axis is greater than or equal to 4° and less than or equal to 12°.

8. The under-beam X-ray conversion device according to any one of claims 1 to 3, characterized in that: The under-beam X-ray conversion device also includes a first base frame, which includes a support frame and a lifting bracket arranged on the support frame. The shielding device is arranged on the lifting bracket, and the lifting bracket can move in the height direction relative to the support frame.

9. The under-beam X-ray conversion device according to claim 8, characterized in that: The first base frame further includes a screw lift, and the support frame and the lifting bracket are slidably connected through the screw lift; The first base frame further includes a hand wheel, which is arranged on one side of the lifting bracket and is drivingly connected to the screw lifter, and the hand wheel drives the screw lifter to move so that the lifting bracket slides along the height direction; and / or, The first base frame also includes a commutator, and the commutator cooperates with the screw lifter to switch the lifting bracket between rising and falling.

10. The under-beam X-ray conversion device according to any one of claims 1 to 3, characterized in that: The under-beam X-ray conversion device further comprises a second base frame and an ionization chamber clamping device, wherein the ionization chamber clamping device is arranged on the second base frame; One of the ionization chamber clamping device and the second base frame has a slide groove, and the other has a slide rail, which extends in a horizontal direction and is perpendicular to the direction of the X-ray outlet. The slide groove slidably cooperates with the slide rail so that the ionization chamber clamping device can slide relative to the second base frame.

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