Multi-target switching device

Abstract

The utility model discloses a multi-target switching device which is used for converting electron beams in an accelerator into X-rays and comprises a target seat and at least two different conversion targets, the target seat is slidably arranged relative to a beam axis of the accelerator, and at least two preset positions are arranged on a sliding path of the target seat; the conversion targets and the preset positions are arranged in a one-to-one correspondence mode, the at least two conversion targets are arranged on the target seat in the sliding direction of the target seat, and the target seat is configured in the mode that when the target seat slides to the preset position, the target seat can be switched to the corresponding conversion target and hit by the electron beam. According to the multi-target switching device provided by the invention, the at least two different conversion targets are simultaneously arranged on the target seat which is arranged in a sliding manner, and the target seat slides among different preset positions to realize switching among the different conversion targets, so that the accelerator can generate X-rays with different energies according to requirements, and the quality of the X-rays is improved. Meanwhile, the device can be compatible with various X-ray conversion target types of a vacuum inner target and a vacuum outer target.

Description

Technical Field

[0001] This application relates to the technical field of medical devices, and more particularly, to a multi-target switching device. Background Art

[0002] The energy of X-rays is determined by the energy of the incident electron beam and the material and thickness of the target. Generally, for electron beams with different energies, the optimal X-ray conversion targets are also different. In related technologies, electron linear accelerators mainly use monoenergetic electron beams and single-type X-ray conversion targets. Some dual-energy accelerators also use single-type X-ray conversion targets, but the energy span of such accelerators is small, and at the same time, a certain quality of X-rays is sacrificed. If an accelerator with three or more energy levels is used, such as from hundreds of kV to 10 MV, three or more different types of X-ray conversion targets are required to improve the ray quality, and the replacement is difficult. Summary of the Utility Model

[0003] An embodiment of this application provides a multi-target switching device.

[0004] A multi-target switching device according to an embodiment of this application is used to convert an electron beam into X-rays in an accelerator. The accelerator can generate an electron beam and includes:

[0005] A target seat, the target seat is slidably arranged relative to the beam axis of the accelerator, and at least two preset positions are arranged on the sliding path of the target seat;

[0006] At least two different conversion targets, the conversion targets are arranged in one-to-one correspondence with the preset positions, and at least two of the conversion targets are arranged on the target seat along the sliding direction of the target seat. The target seat is configured such that when the target seat slides to the preset position, it can be switched to the corresponding conversion target and the conversion target can be hit by the electron beam.

[0007] A multi-target switching device provided by this application can generate X-rays with different energies according to needs by simultaneously arranging at least two different conversion targets on a slidable target seat and realizing the switching between different conversion targets by sliding the target seat between different preset positions. At the same time, it can meet various types of targets suitable for different electron beam energies, which is beneficial to improving the quality of X-rays.

[0008] In some embodiments, the multi-target switching device further includes a driving assembly, which includes a motor, a sleeve, a nut, and a push rod. The motor has an output shaft, the axis direction of the output shaft is parallel to the sliding direction of the target seat, the output shaft is a lead screw, the sleeve is sleeved outside the output shaft and connected to the motor, the nut is slidably arranged inside the sleeve, the nut is threadedly connected to the output shaft, one end of the push rod is connected to the side of the nut away from the motor, and the other end of the push rod is connected to the target seat.

[0009] In this way, the sliding of the target seat can be controlled by the driving assembly to achieve automatic switching of the conversion target, which is beneficial to improving the operation convenience of the multi-target switching device.

[0010] In some embodiments, the multi-target switching device further includes a vacuum box, the vacuum box is connected to the sleeve, the target seat is slidably arranged inside the vacuum box, two openings are provided on the vacuum box, and the two openings are arranged on opposite side walls of the vacuum box. The electron beam can pass through one of the openings, pass through the vacuum box, hit the conversion target, and emit X-rays from the other opening.

[0011] In this way, a vacuum can be formed inside the vacuum box, which is convenient for the transmission of the electron beam and reduces the scattering of the electron beam. At the same time, the vacuum environment can reduce the energy loss of the electron beam.

[0012] In some embodiments, the multi-target switching device further includes a motor vacuum flange. One side of the motor vacuum flange is connected to the sleeve, and the other side of the motor vacuum flange is connected to the vacuum box.

[0013] In this way, setting the motor vacuum flange facilitates the disassembly and assembly between the sleeve and the vacuum box, which is beneficial to reducing the difficulty of maintenance and replacement.

[0014] In some embodiments, the multi-target switching device further includes a motor bellows, the motor bellows is sleeved on the push rod, one end of the motor bellows is connected to the motor vacuum flange, and the other end of the motor bellows is connected to the nut.

[0015] In this way, the vacuum box, the motor vacuum flange, the motor bellows, the nut, and the push rod enclose to form a vacuum cavity, which is beneficial to improving the heat dissipation efficiency. At the same time, the telescopic motor bellows can absorb the vibration generated when the nut moves, and can also make the translation of the nut more stable.

[0016] In some embodiments, the multi-target switching device further includes a connecting vacuum flange, the connecting vacuum flange is connected to the vacuum box and communicated with the opening.

[0017] In this way, setting the motor vacuum flange facilitates the disassembly and assembly between the multi-target switching device and the accelerator, which is beneficial to reducing the difficulty of maintenance and replacement of the multi-target switching device.

[0018] In some embodiments, cooling channels are formed inside the target seat. An inlet and an outlet are provided on one side of the target seat, and are respectively communicated with the cooling channels. The multi-target switching device further includes an inlet pipe and an outlet pipe. The inlet pipe and the outlet pipe penetrate through the vacuum chamber and are communicated with the outside. The inlet pipe is communicated with the inlet, and the outlet pipe is communicated with the outlet.

[0019] In this way, the inlet pipe and the outlet pipe are used to conduct cooling water to the cooling channels inside the target seat, thereby cooling the switching target, which is beneficial to protecting the switching target and prolonging its service life.

[0020] In some embodiments, the inlet pipe includes a connected inlet straight pipe and an inlet bellows. One end of the inlet bellows away from the inlet straight pipe is connected to the inlet, and one end of the inlet bellows close to the inlet straight pipe is connected to the inlet straight pipe. The outlet pipe includes a connected outlet straight pipe and an outlet bellows. One end of the outlet bellows away from the outlet straight pipe is connected to the outlet, and one end of the outlet bellows close to the outlet straight pipe is connected to the outlet straight pipe. The inlet straight pipe and the outlet straight pipe penetrate through the side wall of the vacuum chamber and are fixed on the side wall of the vacuum chamber.

[0021] In this way, the inlet pipe and the outlet pipe can be telescoped within a certain range, without sliding the inlet pipe and the outlet pipe inside and outside the vacuum chamber, thus facilitating the sealing of the vacuum chamber.

[0022] In some embodiments, a long slot is provided on the side wall of the sleeve along the axial direction of the output shaft. A limiting post is provided on the side of the nut, and the limiting post is strung in the long slot.

[0023] In this way, the limiting post and the long slot can limit the rotation of the nut, making it move in a stable straight line. At the same time, the long slot can also limit the stroke of the nut to avoid damage to the multi-target switching device.

[0024] In some embodiments, the multi-target switching device further includes at least two photoelectric switches, which are arranged in one-to-one correspondence with the preset positions. The photoelectric switches are arranged on the outer side wall of the sleeve. The photoelectric switches have two relatively arranged gratings. A shielding portion is provided at the end of the limiting post. When the target seat moves to the preset position, the shielding portion is located between the two gratings of the corresponding photoelectric switch, so that the photoelectric switch generates an electrical signal.

[0025] In this way, the photoelectric switch can monitor whether the target seat slides to the preset position and lock its position, and the generated electrical signal can be used to control the motor.

[0026] Additional aspects and advantages of embodiments of the present application will be given in part in the following description, become apparent in part from the following description, or be learned by practice of the embodiments of the present application. Description of the Drawings

[0027] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0028] Figure 1 is a partial structural schematic diagram of a multi-target switching device according to an embodiment of the present application;

[0029] Figure 2 is a cross-sectional view of a multi-target switching device according to an embodiment of the present application;

[0030] Figure 3 is a structural schematic diagram of a multi-target switching device according to an embodiment of the present application;

[0031] Figure 4 is a cross-sectional view of a target seat of a multi-target switching device according to an embodiment of the present application.

[0032] Main element symbol description: multi-target switching device 100, target seat 10, water inlet 11, water outlet 12, cooling channel 13, switching target 20, drive assembly 30, motor 31, output shaft 311, sleeve 32, long slot hole 321, photoelectric switch 322, grating 3221, nut 33, limit post 331, shielding portion 3311, push rod 34, vacuum box 40, opening window 41, motor vacuum flange 50, motor bellows 60, connecting vacuum flange 70, water inlet pipe 80, water inlet straight pipe 81, water inlet bellows 82, water outlet pipe 90, water outlet straight pipe 91, water outlet bellows 92. Detailed Embodiments

[0033] Embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where like or similar reference numerals denote like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary only for explaining the present application and should not be construed as limiting the present application. In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application. In the description of the present application, "a plurality of" means two or more unless otherwise specifically defined.

[0034] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection. It may be a mechanical connection or an electrical connection. It may be directly connected or indirectly connected through an intermediate medium, and may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0035] In the present application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than that of the second feature.

[0036] The disclosure of the present application provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and settings of specific examples are described herein. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0037] X-rays have important applications in the fields of medical, industrial and other production and scientific research. The most common X-rays are generated by the bremsstrahlung effect when electrons hit a target. The bremsstrahlung effect, also known as bremsstrahlung or braking radiation, refers to the radiation generated when high-speed electrons are suddenly decelerated. This effect can be more specifically described as the radiation generated when charged particles (especially electrons) are subjected to changes in acceleration in an electromagnetic field.

[0038] The energy of X-rays is determined by the energy of the incident electron beam and the material and thickness of the target. Usually, for electron beams of different energies, the corresponding optimal X-ray conversion targets are also different. In the related art, electron linear accelerators mainly use monoenergetic electron beams and single-type X-ray conversion targets. Some dual-energy accelerators also use single-type X-ray conversion targets, but the energy span of such accelerators is small, and at the same time, a certain X-ray quality is sacrificed. If a three-energy or more multi-energy accelerator is used, such as from hundreds of kV to 10 MV, three or more different types of X-ray conversion targets are required to improve the ray quality, and the replacement is difficult.

[0039] Please refer to Figure 1 , a multi-target switching device 100 according to an embodiment of the present application is used to convert an electron beam into X-rays in an accelerator. The accelerator can generate an electron beam and includes a target seat 10 and at least two different conversion targets 20. The target seat 10 is slidably arranged relative to the beam axis of the accelerator, and at least two preset positions are arranged on the sliding path of the target seat 10; the conversion targets 20 are arranged in one-to-one correspondence with the preset positions, and at least two conversion targets 20 are arranged on the target seat 10 along the sliding direction of the target seat 10. The target seat 10 is configured such that when the target seat 10 slides to a preset position, it can be switched to the corresponding conversion target 20 and the conversion target 20 can be hit by the electron beam.

[0040] A multi-target switching device 100 provided by the present application simultaneously sets at least two different conversion targets 20 on a slidably arranged target seat 10, and realizes the switching between different conversion targets 20 by sliding the target seat 10 between different preset positions, so that the accelerator can generate X-rays with different energies as needed. At the same time, it can meet various suitable types of targets corresponding to different electron beam energies, which is beneficial to improving the quality of X-rays.

[0041] Specifically, an accelerator is a device that uses physical principles, such as electric fields or magnetic fields, to accelerate charged particles. These particles can be electrons, protons, ions, etc., and are accelerated to a high-energy state for various research and applications. The principle of the accelerator is based on the action of electromagnetic fields on charged particles. The particles are acted upon by forces in the electric or magnetic fields, thereby changing their motion states and increasing their speeds. The electric field accelerator generates a strong electric field through high voltage, while the magnetic field accelerator uses the magnetic force to change the particle motion trajectory to achieve acceleration.

[0042] The conversion target 20 refers to a physical sample used to receive the bombardment of the particle beam. These particle beams may include electrons, protons, deuterons, alpha particles, etc. After being accelerated to a higher energy by the accelerator, they will interact with the conversion target 20. In the embodiments of the present application, the particles are electrons.

[0043] In the embodiments of the present application, the number of conversion targets 20 is four. Since the energy of the X-rays is determined by the energy of the incident electron beam and the material and thickness of the target, at least one of the materials and thicknesses between any two of the four conversion targets 20 is different. The four conversion targets 20 are all cylindrical, the centers of the top surfaces of the four conversion targets 20 are on the same straight line, and the straight line where the centers of the top surfaces of the four conversion targets 20 are located is parallel to the sliding direction of the target seat 10. Four mounting holes are provided on the target seat 10, and the conversion targets 20 are arranged in one-to-one correspondence with the mounting holes.

[0044] Please refer to Figure 2 , in some embodiments, the multi-target switching device 100 further includes a driving assembly 30. The driving assembly 30 includes a motor 31, a sleeve 32, a nut 33, and a push rod 34. The motor 31 has an output shaft 311. The axis direction of the output shaft 311 is parallel to the sliding direction of the target seat 10. The output shaft 311 is a lead screw. The sleeve 32 is sleeved outside the output shaft 311 and is connected to the motor 31. The nut 33 is slidably arranged in the sleeve 32. The nut 33 is threadedly connected to the output shaft 311. One end of the push rod 34 is connected to the side of the nut 33 away from the motor 31, and the other end of the push rod 34 is connected to the target seat 10.

[0045] In this way, the sliding of the target seat 10 can be controlled by the driving assembly 30 to realize the automatic switching of the conversion targets 20, which is beneficial to improving the operation convenience of the multi-target switching device 100.

[0046] Specifically, the housing of the motor 31 and the sleeve 32 are connected by bolts, or the housing of the motor 31 and the sleeve 32 are integrally welded into an integral structure. During operation, after the motor 31 is started, the output shaft 311 rotates. Since the output shaft 311 is threadedly connected to the nut 33, the rotating output shaft 311 can push the nut 33 to translate. It is easy to understand that the nut 33 is arranged in the sleeve 32 to be able to translate only axially and cannot rotate. Further, one end of the push rod 34 is hollow and connected to the nut 33, and then sleeved on the output shaft 311. The other end of the push rod 34 is connected to the target seat 10. Optionally, the connection manner between the push rod 34 and the target seat 10 is threaded connection, plug connection, mortise and tenon connection, riveting or welding.

[0047] In other embodiments, the driving assembly 30 can also be set as other linear driving assemblies 30 such as cylinders, hydraulic cylinders, linear motors, etc.

[0048] Please refer to Figure 2 , in some embodiments, the multi-target switching device 100 further includes a vacuum box 40. The vacuum box 40 is connected to the sleeve 32. The target seat 10 is slidably arranged in the vacuum box 40. Two openings 41 are formed on the vacuum box 40. The two openings 41 are arranged on opposite side walls of the vacuum box 40. The electron beam can pass through one opening 41 through the vacuum box 40 and hit the conversion target 20, and emit X-rays from the other opening 41.

[0049] In this way, a vacuum can be formed inside the vacuum box 40, which is convenient for the transmission of the electron beam and reduces the scattering of the electron beam. At the same time, the vacuum environment can reduce the energy loss of the electron beam.

[0050] Specifically, the vacuum box 40 refers to a specific vacuum chamber, which contains the conversion target 20, the target seat 10 and other related components inside. In order to ensure the normal operation of the conversion target 20 and the efficiency of particle acceleration, a very high vacuum degree needs to be maintained inside the vacuum box 40. This high-vacuum environment helps to reduce the collision between particles and gas molecules, thereby reducing energy loss and ensuring imaging quality. The main function of the vacuum box 40 of the conversion target 20 is to provide an environment without gas molecules or with a low gas molecule density, ensuring that the electron beam can bombard the surface of the conversion target 20 efficiently and stably, generating high-quality X-rays or particle beams. During the process of high-speed electrons bombarding the surface of the conversion target 20, secondary electrons and scattered X-rays will be generated. The high-vacuum environment inside the vacuum box 40 helps to reduce the interference of these secondary electrons and scattered X-rays to the inside of the device and the imaging quality. The vacuum box 40 of the conversion target 20 is usually made of high-strength, corrosion-resistant and high-temperature-resistant materials, such as stainless steel or special alloys. Its internal structure design needs to consider the transmission, heat dissipation of the electron beam and the prevention of interference from secondary electrons and scattered X-rays.

[0051] In the embodiment of the present application, the vacuum box 40 is used to connect to the vacuum tube of the accelerator, so as to form a vacuum internal target. The vacuum degree inside the vacuum box 40 is 1e-6 Pa~1e -7 Pa.

[0052] In other embodiments, the vacuum box 40 can also be removed. In this case, only the driving assembly 30 needs to be fixed so that the target seat 10 can drive the conversion target 20 to linearly move in the air, completing the switching process of the conversion target 20.

[0053] In some embodiments, the multi-target switching device 100 further includes a motor vacuum flange 50. One side of the motor vacuum flange 50 is connected to the sleeve 32, and the other side of the motor vacuum flange 50 is connected to the vacuum box 40.

[0054] In this way, setting the motor vacuum flange 50 facilitates the disassembly and assembly between the sleeve 32 and the vacuum box 40, which is beneficial to reducing the difficulty of maintenance and replacement.

[0055] Specifically, a vacuum flange is a kind of flange used to connect the inside and outside of a vacuum device, which has the advantages of tight connection, good sealing performance, gas isolation and flame retardance, high temperature resistance, strong pressure-bearing capacity, etc. The vacuum flange is an important part of the vacuum system, mainly used to ensure that the connection between the inside and outside of the vacuum device remains sealed. Since the inside of the vacuum box 40 needs to maintain a vacuum state, it is necessary to use the motor vacuum flange 50 with good sealing performance for connection.

[0056] The motor vacuum flange 50 includes a first motor flange and a second motor flange. The first motor flange is connected to the vacuum box 40, the second motor flange is connected to the sleeve 32, and then the first motor flange and the second motor flange are connected by fasteners.

[0057] Please refer to Figure 2 and Figure 3 , in some embodiments, the multi-target switching device 100 further includes a motor bellows 60. The motor bellows 60 is sleeved on the push rod 34. One end of the motor bellows 60 is connected to the motor vacuum flange 50, and the other end of the motor bellows 60 is connected to the nut 33.

[0058] In this way, the vacuum box 40, the motor vacuum flange 50, the motor bellows 60, the nut 33 and the push rod 34 enclose to form a vacuum chamber, which is beneficial to improving the heat dissipation efficiency. At the same time, the telescopic motor bellows 60 can absorb the vibration generated when the nut 33 moves, and can also make the translation of the nut 33 more stable.

[0059] Specifically, a bellows is a tubular structure formed by connecting multiple foldable corrugated sheets along the folding and telescoping direction, which has the characteristics of an elastic sensitive element. The bellows wall is relatively thin, with high sensitivity, and the measurement range is from dozens of pascals to dozens of megapascals. When in use, an auxiliary helical spring or reed may be used to increase the elasticity.

[0060] In the embodiment of the present application, since the push rod 34 needs to be inserted into the vacuum chamber 40 through the middle of the motor vacuum flange 50 to push the target seat 10, it is difficult to form a seal between the periphery of the push rod 34 and the motor vacuum flange 50. The motor bellows 60 is provided to extend the sealed space to the nut 33 and form a seal between the motor bellows 60 and the nut 33, so that the vacuum chamber 40, the motor vacuum flange 50, the motor bellows 60, the nut 33 and the push rod 34 form a complete sealed cavity, thereby ensuring the vacuum degree in the vacuum chamber 40.

[0061] Furthermore, since the space between the motor bellows 60 and the push rod 34 is communicated with the inside of the vacuum chamber 40, the vacuum degree here is the same as that in the vacuum chamber 40, both being 1e -6 Pa~1e -7 Pa.

[0062] In some embodiments, the multi-target switching device 100 further includes a connecting vacuum flange 70, and the connecting vacuum flange 70 is connected to the vacuum chamber 40 and communicated with the window 41.

[0063] In this way, setting the motor vacuum flange 50 facilitates the disassembly and assembly between the multi-target switching device 100 and the accelerator, and is beneficial to reducing the difficulty of maintenance and replacement of the multi-target switching device 100.

[0064] Specifically, in the embodiment of the present application, a connecting pipe is formed at a window 41 of the vacuum chamber 40, and the connecting pipe is perpendicular to the surface of the vacuum chamber 40 where it is located and communicated with the window 41.

[0065] Furthermore, the connecting vacuum flange 70 includes a first connecting flange and a second connecting flange. The first connecting flange is connected to the connecting pipe, and the second vacuum flange is connected to the vacuum pipe of the accelerator. The first connecting flange and the second connecting flange are detachably connected by fasteners, so as to realize the detachable connection between the vacuum chamber 40 and the accelerator.

[0066] Please refer to Figure 1 and Figure 4 , in some embodiments, a cooling channel 13 is formed inside the target seat 10, a water inlet 11 and a water outlet 12 respectively communicated with the cooling channel 13 are arranged on one side of the target seat 10, the multi-target switching device 100 further includes a water inlet pipe 80 and a water outlet pipe 90, the water inlet pipe 80 and the water outlet pipe 90 penetrate through the vacuum chamber 40 and are communicated with the outside, the water inlet pipe 80 is communicated with the water inlet 11, and the water outlet pipe 90 is communicated with the water outlet 12.

[0067] In this way, the water inlet pipe 80 and the water outlet pipe 90 are used to conduct cooling water to the cooling channel 13 inside the target seat 10, so as to cool the conversion target 20, which is beneficial to protecting the conversion target 20 and prolonging the service life of the conversion target 20.

[0068] Specifically, when using the multi-target switching device 100, electrons are accelerated by the accelerator and act on the conversion target 20, and a series of nuclear reaction processes will occur within the conversion target 20. Due to reasons such as ionization energy loss and nuclear energy loss, most of the beam energy will be deposited within the conversion target 20 during these processes, resulting in a continuous increase in the temperature of the conversion target 20. Only by effectively removing the heat generated by the energy deposition in a timely manner and cooling the conversion target 20 can the normal progress of experiments and applications be ensured. Therefore, the cooling system is crucial.

[0069] Using cooling water for cooling is an effective cooling method, which usually has higher cooling efficiency and lower consumption of cooling working medium. The cooling water flows through the cooling channel 13 within the target seat 10, and can absorb the heat generated by the conversion target 20, thereby reducing the temperature of the conversion target 20.

[0070] In the embodiment of the present application, both the water inlet pipe 80 and the water outlet pipe 90 are arranged in a straight line along the sliding direction of the target seat 10.

[0071] In other embodiments, when the vacuum box 40 is removed, it is necessary to fix the water inlet and the water outlet pipe 90 to avoid interference with the sliding of the target seat 10.

[0072] Please refer to Figure 1 , in some embodiments, the water inlet pipe 80 includes a water inlet straight pipe 81 and a water inlet bellows pipe 82 that are connected. One end of the water inlet bellows pipe 82 away from the water inlet straight pipe 81 is connected to the water inlet 11, and one end of the water inlet bellows pipe 82 close to the water inlet straight pipe 81 is connected to the water inlet straight pipe 81. The water outlet pipe 90 includes a water outlet straight pipe 91 and a water outlet bellows pipe 92 that are connected. One end of the water outlet bellows pipe 92 away from the water outlet straight pipe 91 is connected to the water outlet 12, and one end of the water outlet bellows pipe 92 close to the water outlet straight pipe 91 is connected to the water outlet straight pipe 91. The water inlet straight pipe 81 and the water outlet straight pipe 91 pass through the side wall of the vacuum box 40 and are fixed on the side wall of the vacuum box 40.

[0073] In this way, the water inlet pipe 80 and the water outlet pipe 90 can be telescoped within a certain range, without the need to slide the water inlet pipe 80 and the water outlet pipe 90 inside and outside the vacuum box 40, thus facilitating the sealing of the vacuum box 40.

[0074] Specifically, in the embodiment of the present application, the water inlet straight pipe 81 and the water outlet straight pipe 91 are used to pass through the vacuum box 40 and be connected to an external water source. The water inlet bellows pipe 82 and the water outlet bellows pipe 92 are arranged inside the vacuum box 40. When the target seat 10 moves towards the side of the motor 31, the water inlet bellows pipe 82 and the water outlet bellows pipe 92 can be stretched accordingly. When the target seat 10 moves towards the side away from the motor 31, the water inlet bellows pipe 82 and the water outlet bellows pipe 92 can be compressed accordingly, so as to ensure the circulation and supply of cooling water during the movement of the target seat 10.

[0075] Please refer to Figure 3, in some embodiments, a long slot 321 is axially formed in the side wall of the sleeve 32 along the axial direction of the output shaft 311, and a limiting post 331 is provided on the side surface of the nut 33. The limiting post 331 is strung in the corresponding long slot 321.

[0076] In this way, the limiting post 331 and the long slot 321 can limit the rotation of the nut 33, enabling it to move linearly stably. At the same time, the long slot 321 can also limit the stroke of the nut 33 to prevent damage to the multi-target switching device 100.

[0077] Specifically, the number of the long slots 321 is four, and the four long slots 321 are uniformly arranged on the side wall along the circumferential direction of the socket head. The number of the limiting posts 331 is four, and the four limiting posts 331 are arranged in one-to-one correspondence with the four long slots 321.

[0078] Further, a positioning pointer is provided on one of the limiting posts 331. Correspondingly, a positioning scale is provided at the edge of the corresponding long slot 321 on the sleeve 32. During use, the positioning of the internal curtain can be realized through the cooperation of the positioning pointer and the positioning scale, and then the positioning of the position of the target seat 10 can be realized, so as to realize the positioning of the position of the conversion target 20.

[0079] In some embodiments, the multi-target switching device 100 further includes at least two photoelectric switches 322. The photoelectric switches 322 are arranged in one-to-one correspondence with preset positions. The photoelectric switches 322 are arranged on the outer side wall of the sleeve 32. The photoelectric switches 322 have two relatively arranged gratings 3221. A shielding portion 3311 is provided at the end of the limiting post 331. When the target seat 10 moves to the preset position, the shielding portion 3311 is located between the two gratings 3221 of the corresponding photoelectric switch 322, so that the photoelectric switch 322 generates an electrical signal.

[0080] In this way, the photoelectric switch 322 can monitor whether the target seat 10 slides to the preset position and lock its position. The generated electrical signal can be used to control the motor 31.

[0081] Specifically, the photoelectric switch 322, also known as a photoelectric proximity switch, is a device that uses the photoelectric effect to detect the presence or absence of an object. The photoelectric switch 322 converts the input current into a light signal and emits it from the emitter, and the receiver then detects the target object according to the intensity or presence or absence of the received light. The working principle of the photoelectric switch 322 is based on the photoelectric effect, that is, when photons are incident on a semiconductor, they will be absorbed by the semiconductor and cause the emission of electrons on the semiconductor surface, thereby generating an electrical signal.

[0082] In the embodiments of the present application, the number of the photoelectric switches 322 is four (not all drawn in the figure for the sake of simplicity of the drawing). The four photoelectric switches 322 are arranged in one-to-one correspondence with the four conversion targets 20.

[0083] The multi-target switching device 100 is further provided with a control component, and the control component is electrically connected to the optoelectronic switch 322. When using the multi-target switching device 100, the opening and closing of the corresponding optoelectronic switch 322 can be controlled by the control component according to actual needs. When the required conversion target 20 is in place, the corresponding optoelectronic switch 322 will generate an electrical signal and return it to the control component. After receiving the electrical signal, the control component can control the motor 31 to stop rotating and lock it, so as to lock the position of the conversion target 20.

[0084] In the description of this specification, the descriptions referring to the terms "certain embodiments", "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0085] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the said features. In the description of the present application, "a plurality of" means at least two, such as two, three, unless otherwise specifically and clearly defined.

[0086] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A multi-target switching device for converting electron beams into X-rays in an accelerator, wherein the accelerator can generate electron beams, characterized in that: include: A target seat, the target seat is slidably arranged relative to the beam axis of the accelerator, and at least two preset positions are arranged on the sliding path of the target seat; At least two different conversion targets are arranged in one-to-one correspondence with the preset positions, and at least two of the conversion targets are arranged on the target base along the sliding direction of the target base. The target base is configured so that when the target base slides to the preset position, it can switch to the corresponding conversion target and make it hit by the electron beam.

2. The multi-target switching device according to claim 1, characterized in that: The multi-target switching device also includes a driving assembly, which includes a motor, a sleeve, a nut and a push rod. The motor has an output shaft, and the axial direction of the output shaft is parallel to the sliding direction of the target seat. The output shaft is a screw rod. The sleeve is sleeved outside the output shaft and connected to the motor. The nut can be slidably arranged in the sleeve. The nut is threadedly connected to the output shaft. One end of the push rod is connected to the side of the nut away from the motor, and the other end of the push rod is connected to the target seat.

3. The multi-target switching device according to claim 2, characterized in that: The multi-target switching device also includes a vacuum box, which is connected to the sleeve. The target seat is slidably arranged in the vacuum box. Two windows are provided on the vacuum box, and the two windows are arranged on two opposite side walls of the vacuum box. The electron beam can pass through the vacuum box through one of the windows and then hit the conversion target, and emit X-rays from the other window.

4. The multi-target switching device according to claim 3, characterized in that: The multi-target switching device further comprises a motor vacuum flange, one side of the motor vacuum flange is connected to the sleeve, and the other side of the motor vacuum flange is connected to the vacuum box.

5. The multi-target switching device according to claim 4, characterized in that: The multi-target switching device also includes a motor bellows, which is sleeved on the push rod, one end of the motor bellows is connected to the motor vacuum flange, and the other end of the motor bellows is connected to the nut.

6. The multi-target switching device according to claim 3, characterized in that: The multi-target switching device also includes a connecting vacuum flange, which is connected to the vacuum box and communicates with the open window.

7. The multi-target switching device according to claim 3, characterized in that: A cooling channel is formed inside the target base, and a water inlet and a water outlet respectively connected to the cooling channel are formed on one side of the target base. The multi-target switching device also includes a water inlet pipe and a water outlet pipe, and the water inlet pipe and the water outlet pipe pass through the vacuum box and are connected to the outside, the water inlet pipe is connected to the water inlet, and the water outlet pipe is connected to the water outlet.

8. The multi-target switching device according to claim 7, characterized in that: The water inlet pipe includes a connected water inlet straight pipe and a water inlet corrugated pipe, the end of the water inlet corrugated pipe away from the water inlet straight pipe is connected to the water inlet, and the end of the water inlet corrugated pipe close to the water inlet straight pipe is connected to the water inlet straight pipe, the water outlet pipe includes a connected water outlet straight pipe and a water outlet corrugated pipe, the end of the water outlet corrugated pipe away from the water outlet straight pipe is connected to the water outlet, and the end of the water outlet corrugated pipe close to the water outlet straight pipe is connected to the water outlet straight pipe, the water inlet straight pipe and the water outlet straight pipe pass through the side wall of the vacuum box and are fixed on the side wall of the vacuum box.

9. The multi-target switching device according to claim 2, characterized in that: The side wall of the sleeve is provided with a long slot hole along the axial direction of the output shaft, and the side surface of the nut is provided with a limiting column, and the limiting column is arranged in series in the long slot hole.

10. The multi-target switching device according to claim 9, characterized in that: The multi-target switching device also includes at least two photoelectric switches, which are arranged in a one-to-one correspondence with the preset positions. The photoelectric switches are arranged on the outer side wall of the sleeve. The photoelectric switch has two oppositely arranged gratings. A shielding part is provided at the end of the limit column. When the target seat moves to the preset position, the shielding part is located between the two gratings of the corresponding photoelectric switch, so that the photoelectric switch generates an electrical signal.

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