A current-limiting and energy-reducing device for a particle beam and a method of using the same

Abstract

The application discloses a current-limiting and energy-reducing device for a particle beam and a use method thereof. The current-limiting and energy-reducing device comprises a vacuum cavity, a current limiter and a plurality of energy reducers, and the current limiter and the energy reducers are arranged in parallel in the vacuum cavity. Two energy-reducing blocks with adjustable positions are arranged in each energy reducer, each energy-reducing block is in a wedge-shaped plate structure, the two energy-reducing blocks are arranged in parallel and move relatively during the adjustment process. The use method is that the current limiter and the energy reducers are independently operated, when only the flow intensity needs to be adjusted, the current limiter is adjusted to the required position, when only the energy needs to be adjusted, the energy reducers are adjusted or a single energy reducer is selectively adjusted, the thickness of each energy-reducing block through which the beam passes is added to reach the thickness value of the required energy-reducing material, and when the flow intensity and the energy need to be adjusted simultaneously, the current limiter and the energy reducers are adjusted simultaneously, so that the beam passes through the current limiter and the energy reducers in sequence. In the application, the thickness of the energy reducer is continuously adjustable, and the application is flexible and convenient.

Description

Technical Field

[0001] This invention relates to the field of high-energy accelerator technology, and in particular to a current-limiting and energy-reducing device for particle beams and its usage method. Background Technology

[0002] The Associated Proton Beam Experiment Platform (APEP) is a device that utilizes a proton beam of a certain energy generated by the China Spallation Neutron Source (CSNS) linear accelerator for proton irradiation experiments. The CSNS linear accelerator accelerates negative hydrogen ions to an energy of 80 MeV. During transport, the negative hydrogen ions interact with residual gas molecules in the vacuum tube, and a small portion of the negative hydrogen ions are converted into protons. Finally, under the filtering action of the diode magnet at the end of the linear accelerator, the negative hydrogen ions are injected into the fast-cycle synchrotron, while the protons enter the APEP experimental platform for proton irradiation research, such as the irradiation effects on integrated circuits and electronic devices, irradiation damage assessment and modification of materials, proton beam activation analysis, and proton detector calibration.

[0003] Generally, a current limiting and energy reduction device consists of two parts: a current limiter and an energy reducer, which are used to adjust the current intensity and energy of the particle beam to meet different experimental requirements.

[0004] The de-energizer adjusts the beam energy by changing the thickness of the material acting on the particle beam. Traditional de-energizers often use multiple layers of material to change the thickness. Before the irradiation experiment, the required thickness of the de-energizer material combination is assessed, and then the operation is performed manually or electrically. The thickness of the de-energizer material in a multi-layered structure is the sum of the thicknesses of the various layers, and can only take discrete values. This is inconvenient in practical applications, as the de-energizer material thickness adjustment can only be the sum of the thicknesses of multiple materials, making it difficult to achieve more precise values; and the adjustable range is very small when the beam size is large and the thickness adjustment range is wide. In addition, APEP beamline equipment usually requires a compact layout, with both the de-energizer and current limiter located within a shield. Larger beam sizes require a more compact de-energizer with a wider adjustment range.

[0005] Furthermore, in dedicated accelerator ion irradiation facilities, the intensity of the particle beam can be controlled through various methods, such as ion source modulation, slit scattering, target scattering, and electrostatic deflection rejection. The APEP experimental platform is a proton beam experimental platform based on the proton beam generated during the negative hydrogen ion transport process of the CSNS linear accelerator. The proton beam intensity can only be modulated within the APEP beamline. Due to space limitations and the compact layout of the beamline equipment, other current-limiting schemes are difficult to adapt to this environment. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a current limiting and energy reduction device for particle beams. The thickness of the energy reducer in this current limiting and energy reduction device is continuously adjustable, making it flexible and convenient to use. The overall structure of the current limiting and energy reduction device is compact and can be well applied to the APEP experimental platform.

[0007] Another object of the present invention is to provide a method of using the aforementioned current limiting and energy reduction device for particle beams.

[0008] The technical solution of this invention is as follows: a current-limiting and energy-reducing device for particle beams, comprising a vacuum cavity, a current limiter, and multiple energy reducers, wherein the current limiter and each energy reducer are respectively disposed within the vacuum cavity; each energy reducer contains two adjustable energy-reducing blocks, each energy-reducing block having a wedge-shaped plate structure, the two energy-reducing blocks being arranged parallel to each other and undergoing relative movement towards or in opposite directions during adjustment. The energy reducer primarily regulates the energy of the particle beam through the blocking and slowing effect of the material; the current limiter primarily regulates the current intensity of the particle beam.

[0009] As a preferred embodiment, there are two energy degraders, namely a first energy degrader and a second energy degrader. The first energy degrader has two first energy degrading blocks in the shape of wedge plates, and the second energy degrader has two second energy degrading blocks in the shape of wedge plates. The wedge angle of the first energy degrader is smaller than that of the second energy degrader, and the maximum thickness of the first energy degrader is greater than that of the minimum thickness of the second energy degrader.

[0010] The wedge angle of the first de-current block is 0.5°–3°, and the wedge angle of the second de-current block is 5°–10°. To accommodate larger beam sizes and while ensuring the thinnest material in the de-current device can be relatively small, the wedge angle of the first de-current block can be set as small as possible, with 0.5°–3° being the ideal range. To achieve the required material thickness to completely block the beam, the thickest material in the de-current device needs to be relatively thick; therefore, the wedge angle of the second de-current block can be larger. However, to reduce the overall lateral dimensions of the de-current device, the wedge angle of the second de-current block cannot be too large; thus, 5°–10° is the ideal range. Furthermore, the maximum thickness of the first de-current block is greater than the minimum thickness of the second de-current block, allowing the overall de-current material thickness to be continuously adjustable across the entire range from the minimum thickness of the first de-current block to the maximum thickness of the second de-current block.

[0011] The first energy reducer includes a first motor, a first coupling, a first positive and negative double helical screw, a first screw nut, a first linear guide, a first slider, a first mounting base, and a first energy reduction block. The power output shaft of the first motor is connected to one end of the first positive and negative double helical screw through the first coupling. The first positive and negative double helical screw includes a first upper thread and a first lower thread with opposite helical directions. The first upper thread and the first lower thread are respectively provided with matching first screw nuts. Parallel first linear guides are provided on both sides of the first positive and negative double helical screw, and matching first sliders are provided on each first linear guide. The first energy reduction block is fixed on the first mounting base. One end of the first mounting base is connected to the first screw nut, and the other end of the first mounting base is connected to the first slider. During adjustment, the first motor drives the first positive and negative double helical screw to rotate, which in turn drives the two first screw nuts to rotate in opposite directions, causing the two first energy-reducing blocks to move linearly in opposite directions. During the movement, they are guided along their respective first linear guides by the corresponding first sliders. When the two first energy-reducing blocks move to the point where their thickness superposition value reaches the required thickness of the energy-reducing material, the first motor is turned off to stop the movement.

[0012] In the first energy reducer, the first energy reducer block includes a main frame, a wedge-shaped energy reducer plate, and a pressure plate. The bottom of the main frame is fixed to a first mounting base. The wedge-shaped energy reducer plate is installed in the main frame, and a pressure plate is provided on one side. The pressure plate is locked and fixed to the main frame by bolts. This ensures that the wedge-shaped energy reducer plate is pressed and fixed in the main frame, forming a stable overall structure of the energy reducer block.

[0013] Furthermore, in the first energy reducer, one end of the first energy reducer block is connected to the first mounting base, and the other end of the first energy reducer block is also connected to an auxiliary slider, which cooperates with the corresponding first linear guide rail. During the adjustment of the first energy reducer block, both ends have the guiding effect of the slider and the guide rail, which on the one hand makes its operation more stable and avoids the first energy reducer block from deflecting or shaking due to excessive length, and on the other hand, improves its adjustment accuracy.

[0014] The second energy reducer includes a second motor, a second coupling, a second positive and negative double helical screw, a second screw nut, a second linear guide, a second slider, a second mounting base, and a second energy reduction block. The power output shaft of the second motor is connected to one end of the second positive and negative double helical screw via the second coupling. The second positive and negative double helical screw includes a second upper thread and a second lower thread with opposite helical directions. The second upper thread and the second lower thread are respectively provided with matching second screw nuts. Parallel second linear guides are provided on both sides of the second positive and negative double helical screw, and matching second sliders are provided on each second linear guide. The second energy reduction block is fixed on the second mounting base. One end of the second mounting base is connected to the second screw nut, and the other end of the second mounting base is connected to the second slider. During adjustment, the principle is the same as that of the first energy reducer. The second motor drives the second positive and negative double helical screws to rotate, which in turn drives the two second screw nuts to rotate synchronously in opposite directions, causing the two second energy reducer blocks to move linearly in opposite directions. During the movement, they are guided along their respective second linear guides by their corresponding second sliders. When the combined thickness of the two second energy reducer blocks reaches the required thickness of the energy reducer material, the second motor is turned off to stop the movement. Alternatively, the first and second energy reducers can be used in conjunction to adjust the material until the combined thickness of the first and second energy reducer blocks reaches the required thickness of the energy reducer material.

[0015] The current limiter includes a third motor, a third coupling, a one-way screw, a third screw nut, a third linear guide, a third slider, a third mounting base, and a current limiting component. The power output shaft of the third motor is connected to one end of the one-way screw via the third coupling. A matching third screw nut is provided on the one-way screw. Third linear guides are provided on both sides of the one-way screw, and matching third sliders are provided on each of the third linear guides. The current limiting component is fixed to the third mounting base, with the middle of the third mounting base connected to the third screw nut, and the two sides of the third mounting base connected to the third sliders. During adjustment, the third motor drives the one-way screw to rotate, thereby driving the third screw nut to rotate, causing the current limiting component to move linearly. During this movement, the third linear guides and third sliders on both sides of the one-way screw provide guidance. When the current limiting component moves to the desired position, the drive of the third motor is stopped.

[0016] The current limiter includes a fixed base, a Y-axis rotating plate, and an X-axis rotating plate. The bottom of the fixed base is connected to a third mounting base. The Y-axis rotating plate is mounted on the fixed base, and the X-axis rotating plate is mounted on the Y-axis rotating plate. Multiple current limiters are mounted on the X-axis rotating plate, and the current limiters have different orifice distribution densities (different orifice densities represent different current limiting intensity levels; when the current limiter can completely deviate from the beam envelope, it has no obstruction effect on the particle beam). The fixed base serves as... The base, which connects to the third mounting base, has a Y-axis rotating plate that can rotate relative to the fixed substrate around the Y-axis to achieve fine adjustment of the current limiting plate in the Y-axis direction. Similarly, the X-axis rotating plate can rotate relative to the Y-axis rotating plate around the X-axis to achieve fine adjustment of the current limiting plate in the X-axis direction, thus ensuring that the axis of each current limiting hole on the current limiting plate remains parallel to the beam center axis of the particle beam. Each current limiting plate is locked and fixed to the corresponding through hole on the X-axis rotating plate by mounting pressure plates and mounting screws. The current limiting plates can be switched according to the actual needs of the experiment.

[0017] One side of the fixed base plate is provided with a rotation axis around the Y-axis, and the other side of the fixed base plate is provided with a first locking threaded hole. One side of the rotation plate around the Y-axis is provided with a rotation through hole around the Y-axis that mates with the rotation axis around the Y-axis. The other side of the rotation plate around the Y-axis is provided with a first adjusting elongated hole and a first locking screw that mate with the first locking threaded hole. A Y-axis adjusting screw is also provided on the side of the rotation plate around the Y-axis. The Y-axis adjusting screws on the side of the rotation plate around the Y-axis are arranged in pairs, with at least one pair. The corresponding side of the fixed base plate is embedded between two Y-axis adjusting screws. When adjustment is required, the Y-axis adjusting screw is rotated, and the Y-axis adjusting screw pushes the rotation plate around the rotation axis around the Y-axis to rotate. After reaching the desired position, the two are locked and fixed by the first locking screw at the first adjusting elongated hole and the first locking threaded hole.

[0018] The upper end of the Y-axis rotating plate is provided with an X-axis rotating shaft, and the lower end of the Y-axis rotating plate is provided with an X-axis adjusting screw. A second locking threaded hole is located in the middle of the Y-axis rotating plate. The upper end of the X-axis rotating plate is provided with an X-axis rotating through hole that mates with the X-axis rotating shaft. The lower end of the X-axis rotating plate is fitted between two X-axis adjusting screws at the lower end of the Y-axis rotating plate. A second adjusting elongated hole and a second locking screw are located in the middle of the X-axis rotating plate, mates with the second locking threaded hole. The two X-axis adjusting screws at the lower end of the Y-axis rotating plate are symmetrically arranged, and the lower end of the X-axis rotating plate is fitted between them. When adjustment is needed, rotating the X-axis adjusting screw pushes the X-axis rotating plate to rotate around the X-axis rotating shaft. After reaching the desired position, the second locking screw locks both the plate in place at the second adjusting elongated hole and the second locking threaded hole.

[0019] In the current limiting and energy reduction device described above, due to the structural design of the current limiter and each energy reduction device, the structure inside the vacuum cavity is more compact than that of a traditional current limiting and energy reduction device. Therefore, the size of the vacuum cavity is smaller than that of a traditional current limiting and energy reduction device, especially in the length along the beam direction. The vacuum cavity of this current limiting and energy reduction device is thinner. However, the structural form of the vacuum cavity in the current limiting and energy reduction device is the same as that of the vacuum cavity in a traditional current limiting and energy reduction device. A shielding block is provided on the top of the inner side of the vacuum cavity. The shielding block covers the current limiting component in the current limiter and the energy reduction block in each energy reduction device. The motor of the current limiter, the motor of each energy reduction device (i.e., the first motor, the second motor, and the third motor mentioned above) and the corresponding couplings (i.e., the first coupling, the second coupling, and the third coupling mentioned above) are respectively installed on the outside of the vacuum cavity. However, a magnetic fluid vacuum transmission device is also provided at the connection with the vacuum cavity to achieve a good sealing effect inside the vacuum cavity. Flanges are also provided on both sides of the vacuum cavity. When the particle beam enters the vacuum cavity, it passes through the flanges on both sides in sequence and passes through the current limiter and each energy reduction device. In addition, several limit switches can be installed in the vacuum chamber as needed.

[0020] The principle of this current limiting and energy reduction device is as follows:

[0021] In each energy degrader, two energy degrading blocks (i.e., the first energy degrading block or the second energy degrading block mentioned above) move in opposite directions or in opposite directions along the corresponding linear guide rails with the horizontal plane where the beam center axis is located as the plane of symmetry. Correspondingly, within the range through which the beam passes, the thickness of the energy degrading material acting on the beam can also change continuously, ultimately achieving continuous adjustment of the beam energy. In the first and second de-energizers, two sets of de-energizer blocks with different wedge angles are used. The first set of de-energizer blocks has a smaller wedge angle, which can accommodate thinner de-energizer material thicknesses. The second set of de-energizer blocks has a larger wedge angle, which can accommodate thicker de-energizer material thicknesses. The de-energizer material thickness acting on the beam by the two sets of de-energizer blocks can be continuous, that is, the thickest part of the first set of de-energizer blocks is greater than the thinnest part of the second set of de-energizer blocks. The total thickness of the de-energizer material acting on the beam can be obtained by adjusting a single set of de-energizer blocks, or by adjusting and combining both sets of de-energizer blocks simultaneously. The de-energizer material thickness formed by the superposition of the thickest parts of the two sets of de-energizer blocks is greater than the de-energizer material thickness required for the beam to be completely stopped or completely shielded. Moreover, the two sets of de-energizer blocks can be completely deviated from the envelope of the beam's lateral boundary. At this time, the particle beam can pass freely without being blocked by any material. Therefore, each de-energizer also functions as a beam switch. Depending on factors such as the type of particle beam and the particle energy, different energy reduction blocks can be made of materials such as graphite, aluminum, copper, beryllium, titanium, and boron carbide.

[0022] In the current limiter, the current limiting plate takes the form of a micro-perforated plate. When particles pass through the micro-perforated area, they are not blocked by the material and can pass freely. When particles pass through other areas outside the micro-perforated area, they are blocked by the current limiting plate material and cannot pass normally, thus reducing the beam intensity. In the current limiter of this current limiting and energy reduction device, multiple micro-perforated current limiting plates with different beam aperture distribution densities are arranged on the same adjustable support. By strictly controlling the processing accuracy of the support, the multiple current limiting plates are ensured to be parallel to each other. The support can rotate around the X and Y axes, thereby adjusting the micro-perforation axis of the micro-perforated plate to be parallel to the beam center axis. Particles that meet specific conditions can pass through the micro-perforations without being blocked. Among them, rotating the plate around the X-axis can widen the plate, and during installation and testing, the test data will be more sensitive to small angle adjustments. During use, the current limiter can also be completely deviated from the envelope of the beam's lateral boundary. In this case, the particle beam can pass freely without being blocked by any material.

[0023] The present invention provides a method for using the current limiting and energy reduction device for the above-mentioned particle beam, specifically: the current limiter and each energy reduction device operate independently of each other; in the associated proton beam experiment, the current limiter and each energy reduction device are arranged sequentially along the beam direction.

[0024] When the beam current of the particle beam needs to be adjusted, simply adjust the current limiter to the desired position.

[0025] When the energy of the particle beam needs to be adjusted, multiple energy de-energizers can be adjusted simultaneously or a single energy de-energizer can be selected and adjusted until the sum of the thicknesses of the energy de-energizers through which the beam passes reaches the required thickness value of the energy de-energizer material.

[0026] When the beam intensity and energy of a particle beam need to be adjusted simultaneously, the current limiter and a single or multiple energy depletors are adjusted at the same time so that the beam passes through the current limiter and energy depletors in sequence.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] In this current-limiting energy reduction device for particle beams, each energy reducer is formed into a rectangle by using pairs of wedge-shaped energy reduction blocks. By adjusting the staggered spacing between the energy reduction blocks, the thickness of the beam energy reduction material can be continuously changed. Different energy reduction material thicknesses achieve different particle beam energy reduction effects, making it more flexible and convenient to use. Its thickness adjustment range is wider, and the overall structure of the current-limiting energy reduction device is more compact, making it well-suited for APEP experimental platforms.

[0029] In the current-limiting energy reduction device used for this particle beam, the first and second energy reducers each employ two sets of energy reduction blocks with different wedge angles. This allows for a wider range of adjustment for the thickness of the energy reduction material and effectively reduces the overall thickness of the current-limiting energy reduction device, resulting in a smaller overall size and a more compact structure. Furthermore, the two energy reduction blocks in each energy reducer are synchronously driven by positive and negative double helical screws, effectively ensuring the stability of their mutual motion relationship. Moreover, only a single motor is required for drive, resulting in a simple overall structure and improved reliability and stability of the equipment operation.

[0030] In the current limiting and energy reduction device used for this particle beam, multiple current limiting plates with different current limiting orifice distribution densities can be used in the current limiter to correspond to different beam current intensities. While adjusting the beam current intensity, the maximum energy of the beam is not changed.

[0031] In this particle beam current limiting and energy reduction device, the current limiter and each energy reducer operate independently. They can be selected individually or used in combination according to the actual experimental needs, offering flexibility and convenience. Furthermore, both the energy reducer blocks and the current limiting components can be completely deviated from the particle beam, allowing the beam to pass through the vacuum cavity without obstruction and without changing its intensity or energy. When the maximum thickness of the energy reducer blocks in each energy reducer is superimposed, the beam can be completely blocked, thus the energy reducer can also be used as a beam switch.

[0032] In the current limiting and energy reduction device used for this particle beam, the current limiter and the energy reducer are placed in the same equipment vacuum cavity. Combined with the specific structural design of the current limiter and each energy reducer, space in the beam length direction can be effectively saved, and the radiation protection shielding of the equipment can be saved. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the current limiting and energy reduction device used for this particle beam.

[0034] Figure 2 for Figure 1 A schematic diagram of the structure of the second energy reducer after removing the second motor and the second coupling.

[0035] Figure 3 for Figure 2 A-direction view.

[0036] Figure 4 This is a schematic diagram of the second energy reduction block.

[0037] Figure 5 This is a schematic diagram illustrating the principle of the first and second energy degraders in use.

[0038] Figure 6 for Figure 1 A schematic diagram of the structure of the current limiter after removing the third motor and the third coupling.

[0039] Figure 7 for Figure 6 View from direction B.

[0040] Figure 8 This is a schematic diagram of the current limiting component.

[0041] The components indicated by the reference numerals in the above figures are as follows:

[0042] 1 is a vacuum chamber, 2 is a flow limiter, 3 is a first energy depletion device, 4 is a second energy depletion device, 5 is a shielding block, 6 is a magnetic fluid vacuum transmission device, 7 is a flange, and 8 is a limit switch.

[0043] 2-1 is the current limiting component, 2-2 is the third motor, 2-3 is the third coupling, 2-4 is the one-way screw, 2-5 is the third screw nut, 2-6 is the third linear guide, 2-7 is the third slider, and 2-8 is the third mounting base.

[0044] 2-1-1 is a fixed base plate, 2-1-2 is a plate rotating around the Y-axis, 2-1-3 is a plate rotating around the X-axis, 2-1-4 is a rotating shaft around the Y-axis, 2-1-5 is a first locking threaded hole, 2-1-6 is a rotating through hole around the Y-axis, 2-1-7 is a first adjusting elongated hole, 2-1-8 is a first locking screw, 2-1-9 is an adjusting screw around the Y-axis, 2-1-10 is a rotating shaft around the X-axis, 2-1-11 is an adjusting screw around the X-axis, 2-1-12 is a second locking threaded hole, 2-1-13 is a rotating through hole around the X-axis, 2-1-14 is a second adjusting elongated hole, 2-1-15 is a second locking screw, 2-1-16 is a flow limiting plate, 2-1-17 is a mounting pressure plate, and 2-1-18 is a mounting screw;

[0045] 3-1 is the first energy reduction block, 3-2 is the first motor, 3-3 is the first coupling, 3-4 is the first positive and negative double helical screw, 3-5 is the first linear guide rail, and 3-6 is the first mounting base;

[0046] 4-1 is the second energy reduction block, 4-2 is the second motor, 4-3 is the second coupling, 4-4 is the second positive and negative double helical screw, 4-5 is the second screw nut, 4-6 is the second linear guide, 4-7 is the second slider, and 4-8 is the second mounting base.

[0047] 4-1-1 is the main frame, 4-1-2 is the wedge-shaped energy reduction plate, 4-1-3 is the pressure plate, and 4-1-4 is the bolt;

[0048] a represents the wedge angle of the first de-energizing block, b represents the wedge angle of the second de-energizing block, and c represents the transverse boundary of the beam. Detailed Implementation

[0049] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0050] Example 1

[0051] This embodiment provides a current-limiting and energy-reducing device for particle beams, such as... Figure 1 As shown, the device includes a vacuum chamber 1, a flow limiter 2, and multiple energy depletion devices (in this embodiment, a first energy depletion device 3 and a second energy depletion device 4). The flow limiter and each energy depletion device are respectively disposed within the vacuum chamber. Each energy depletion device contains two adjustable energy depletion blocks, each energy depletion block having a wedge-shaped plate structure. The two energy depletion blocks are arranged parallel to each other and undergo relative movement towards or in opposite directions during adjustment. The energy depletion device mainly regulates the energy of the particle beam through the blocking and slowing effect of the material; the flow limiter mainly regulates the current intensity of the particle beam. In this current-limiting and energy-reducing device, due to the structural design of the current limiter and each energy reducer, the structure inside the vacuum chamber is more compact than that of a traditional current-limiting and energy-reducing device. Therefore, the size of the vacuum chamber is smaller than that of a traditional current-limiting and energy-reducing device, especially in terms of thickness in the beam direction. The vacuum chamber of this current-limiting and energy-reducing device is thinner. However, the structural form of the vacuum chamber in the current-limiting and energy-reducing device is the same as that of the vacuum chamber in a traditional current-limiting and energy-reducing device. A shielding block 5 is provided on the top of the inner side of the vacuum chamber. The shielding block covers the current-limiting components in the current limiter and the energy-reducing blocks in each energy reducer. The motors of the current limiter, the motors of each energy reducer (i.e., the first motor, the second motor, and the third motor below) and the corresponding couplings (i.e., the first coupling, the second coupling, and the third coupling below) are respectively installed on the outside of the vacuum chamber. However, a magnetic fluid vacuum transmission device 6 (a common device for vacuum chambers) is also provided at the connection with the vacuum chamber to achieve a good sealing effect inside the vacuum chamber. Flanges 7 are also provided on both sides of the vacuum chamber. The particle beam passes through the flanges on both sides (its direction is as follows). Figure 1 As indicated by the arrows in the diagram, when entering the vacuum chamber, it can pass through the flow limiter and each energy depletion device in sequence. In addition, several limit switches 8 can be installed in the vacuum chamber as needed.

[0052] In this embodiment, there are two energy depressors, such as... Figure 1 As shown, the first and second energy degraders are respectively, and their main structures are identical. The first energy degrader contains two wedge-shaped first energy degrading blocks 3-1, and the second energy degrader contains two wedge-shaped second energy degrading blocks 4-1. The wedge angle of the first energy degrading blocks is smaller than that of the second energy degrading blocks, and the maximum thickness of the first energy degrading block is greater than the minimum thickness of the second energy degrading block. Figure 5As shown, the wedge angle 'a' of the first de-energizer is 0.5° to 3°, and the wedge angle 'b' of the second de-energizer is 5° to 10°. To accommodate larger beam sizes and while ensuring the thinnest material of the de-energizer can be relatively small, the wedge angle of the first de-energizer can be set as small as possible, with 0.5° to 3° being the ideal range. To achieve the required material thickness to completely block the beam, the thickest material of the de-energizer needs to be relatively thick; therefore, the wedge angle of the second de-energizer can be larger. However, to reduce the overall lateral dimension of the de-energizer, the wedge angle of the second de-energizer cannot be too large; thus, 5° to 10° is the ideal range. Furthermore, the maximum thickness of the first de-energizer is greater than the minimum thickness of the second de-energizer, allowing the overall de-energizing material thickness to be continuously adjustable across the entire range from the minimum thickness of the first de-energizer to the maximum thickness of the second de-energizer.

[0053] like Figure 1 As shown, the first energy reducer includes a first motor 3-2, a first coupling 3-3, a first positive and negative double helical screw 3-4, a first screw nut (not shown in the figure), a first linear guide rail 3-5, a first slider (not shown in the figure), a first mounting base 3-6, and a first energy reduction block 3-1. The power output shaft of the first motor is connected to one end of the first positive and negative double helical screw through the first coupling. The first positive and negative double helical screw includes a first upper thread and a first lower thread with opposite helical directions. The first upper thread and the first lower thread are respectively provided with matching first screw nuts. Parallel first linear guide rails are provided on both sides of the first positive and negative double helical screw. Matching first sliders are provided on each first linear guide rail. The first energy reduction block is fixed on the first mounting base. One end of the first mounting base is connected to the first screw nut, and the other end of the first mounting base is connected to the first slider. During adjustment, the first motor drives the first positive and negative double helical screw to rotate, which in turn drives the two first screw nuts to rotate synchronously in opposite directions, causing the two first energy-reducing blocks to move linearly in opposite directions. During the movement, they are guided along their respective first linear guides by their corresponding first sliders. When the two first energy-reducing blocks have moved to the point where their combined thickness reaches the required thickness of the energy-reducing material, the first motor is turned off to stop the movement. In the first energy reducer, the first energy-reducing block includes a main frame, a wedge-shaped energy-reducing plate, and a pressure plate. The bottom of the main frame is fixed to the first mounting base, the wedge-shaped energy-reducing plate is installed in the main frame, and a pressure plate is set on one side. The pressure plate is locked and fixed to the main frame by bolts. This ensures that the wedge-shaped energy-reducing plate is pressed and fixed in the main frame, forming a stable overall structure of the energy-reducing block.

[0054] like Figure 1 , Figure 2 or Figure 3As shown, the second energy reducer includes a second motor 4-2, a second coupling 4-3, a second positive and negative double helical screw 4-4, a second screw nut 4-5, a second linear guide rail 4-6, a second slider 4-7, a second mounting base 4-8, and a second energy reducer block 4-1. The power output shaft of the second motor is connected to one end of the second positive and negative double helical screw through the second coupling. The second positive and negative double helical screw includes a second upper thread and a second lower thread with opposite helical directions. The second upper thread and the second lower thread are respectively provided with matching second screw nuts. Parallel second linear guide rails are provided on both sides of the second positive and negative double helical screw, and matching second sliders are provided on each second linear guide rail. The second energy reducer block is fixed on the second mounting base. One end of the second mounting base is connected to the second screw nut, and the other end of the second mounting base is connected to the second slider. During adjustment, the principle is the same as that of the first energy reducer. The second motor drives the second positive and negative double helical screws to rotate, which in turn drives the two second screw nuts to rotate synchronously in opposite directions, causing the two second energy reducer blocks to move linearly in opposite directions. During the movement, they are guided along their respective second linear guides by their corresponding second sliders. When the combined thickness of the two second energy reducer blocks reaches the required thickness of the energy reducer material, the second motor is turned off to stop the movement. In this adjustment process, the first and second energy reducers can also be used in conjunction to adjust the material until the combined thickness of the first and second energy reducer blocks reaches the required thickness of the energy reducer material. Figure 4 As shown, in the second energy reducer, the second energy reducer block includes a main frame 4-1-1, a wedge-shaped energy reducer plate 4-1-2, and a pressure plate 4-1-3. The bottom of the main frame is fixed to the second mounting base. The wedge-shaped energy reducer plate is installed in the main frame, and a pressure plate is provided on one side. The pressure plate is locked and fixed to the main frame by bolts 4-1-4. This ensures that the wedge-shaped energy reducer plate is pressed and fixed in the main frame, forming a stable overall structure of the energy reducer block.

[0055] like Figure 1 , Figure 6 or Figure 7As shown, the current limiter includes a third motor 2-2, a third coupling 2-3, a one-way screw 2-4, a third screw nut 2-5, a third linear guide 2-6, a third slider 2-7, a third mounting base 2-8, and a current limiting component 2-1. The power output shaft of the third motor is connected to one end of the one-way screw via the third coupling. A matching third screw nut is provided on the one-way screw. Third linear guides are provided on both sides of the one-way screw, and matching third sliders are provided on each of the third linear guides. The current limiting component is fixed to the third mounting base, with the middle of the third mounting base connected to the third screw nut, and the two sides of the third mounting base connected to the third sliders. During adjustment, the third motor drives the one-way screw to rotate, thereby driving the third screw nut to move, causing the current limiting component to move linearly. During the movement, the third linear guides and third sliders on both sides of the one-way screw provide guidance. When the current limiting component moves to the desired position, the drive of the third motor is stopped.

[0056] like Figure 8 As shown, in the current limiter, the current limiting component includes a fixed substrate 2-1-1, a rotating plate around the Y-axis 2-1-2, and a rotating plate around the X-axis 2-1-3. The bottom of the fixed substrate is connected to a third mounting base. The rotating plate around the Y-axis is mounted on the fixed substrate, and the rotating plate around the X-axis is mounted on the rotating plate around the Y-axis. Multiple current limiting plates are mounted on the rotating plate around the X-axis, and the distribution density of the current limiting holes on each current limiting plate is different (the current limiting plates with different hole densities represent different current limiting intensity levels; when the current limiter can completely deviate from the beam envelope, it has no obstruction effect on the particle beam). The fixed substrate serves as... The base connected to the third mounting base has a Y-axis rotating plate that can rotate relative to the fixed substrate around the Y-axis to achieve fine adjustment of the current limiting plate in the Y-axis direction. The X-axis rotating plate can rotate relative to the Y-axis rotating plate around the X-axis to achieve fine adjustment of the current limiting plate in the X-axis direction, thereby ensuring that the axis of each current limiting hole on the current limiting plate remains parallel to the beam center axis of the particle beam. Each current limiting plate 2-1-16 is locked and fixed to the corresponding through hole on the X-axis rotating plate by mounting pressure plate 2-1-17 and mounting screw 2-1-18. Each current limiting plate can be switched according to the actual needs of the experiment.

[0057] One side of the fixed base plate is provided with a Y-axis rotation axis 2-1-4, and the other side of the fixed base plate is provided with a first locking threaded hole 2-1-5. One side of the Y-axis rotating plate is provided with a Y-axis rotation through hole 2-1-6 that mates with the Y-axis rotation axis, and the other side of the Y-axis rotating plate is provided with a first adjusting elongated hole 2-1-7 that mates with the first locking threaded hole and a first locking screw 2-1-8. A Y-axis adjusting screw 2-1-9 is also provided on the side of the Y-axis rotating plate. The Y-axis adjusting screws on the side of the Y-axis rotating plate are arranged in pairs, with at least one pair. The corresponding side of the fixed base plate is embedded between two Y-axis adjusting screws. When the equipment is aligned and installed, the Y-axis adjusting screw is rotated, and the Y-axis adjusting screw pushes the Y-axis rotating plate to rotate around the Y-axis rotation axis. After reaching the desired position, the two are locked and fixed by the first locking screw at the first adjusting elongated hole and the first locking threaded hole.

[0058] The upper end of the plate rotating around the Y-axis is provided with a rotating shaft around the X-axis 2-1-10, the lower end of the plate rotating around the Y-axis is provided with an adjusting screw around the X-axis 2-1-11, the middle part of the plate rotating around the Y-axis is provided with a second locking threaded hole 2-1-12, the upper end of the plate rotating around the X-axis is provided with a rotating through hole around the X-axis 2-1-13 that mates with the rotating shaft around the X-axis, the lower end of the plate rotating around the X-axis is embedded between the two adjusting screws around the X-axis at the lower end of the plate rotating around the Y-axis, and the middle part of the plate rotating around the X-axis is provided with a second adjusting elongated hole 2-1-14 that mates with the second locking threaded hole and a second locking screw 2-1-15. The two X-axis adjusting screws at the lower end of the Y-axis rotating plate are symmetrically arranged. The lower end of the X-axis rotating plate is embedded between the two X-axis adjusting screws. When the equipment is aligned and installed, the X-axis adjusting screws are rotated, and the X-axis adjusting screws push the X-axis rotating plate to rotate around the X-axis rotating axis. After reaching the desired position, the two are locked and fixed by the second locking screw at the second adjusting elongated hole and the second locking threaded hole.

[0059] The principle of this current limiting and energy reduction device is as follows:

[0060] In each de-energizer, two de-energizing blocks (i.e., the first de-energizing block or the second de-energizing block mentioned above) move in opposite directions or in opposite directions along the corresponding linear guide rails with the horizontal plane where the beam center axis is located as the plane of symmetry. Correspondingly, within the range through which the beam passes, the thickness of the de-energizing material acting on the beam can also change continuously, ultimately achieving continuous adjustment of the beam capability. In the first and second de-energizers, two sets of de-energizer blocks with different wedge angles are used. The first set of de-energizer blocks has a smaller wedge angle, which is mainly compatible with thinner de-energizer material thicknesses. The second set of de-energizer blocks has a larger wedge angle, which is mainly compatible with thicker de-energizer material thicknesses. The de-energizer material thickness acting on the beam by the two sets of de-energizer blocks can be continuous, that is, the thickest part of the first set of de-energizer blocks is greater than the thinnest part of the second set of de-energizer blocks. The total thickness of the de-energizer material acting on the beam can be obtained by adjusting a single set of de-energizer blocks, or by adjusting and combining both sets of de-energizer blocks simultaneously. The de-energizer material thickness formed by the superposition of the thickest parts of the two sets of de-energizer blocks is greater than the de-energizer material thickness required for the beam to be completely stopped or completely shielded. Moreover, the two sets of de-energizer blocks can be completely deviated from the envelope of the beam's transverse boundary c. At this time, the particle beam can pass freely without being blocked by any material. Therefore, each de-energizer also functions as a beam switch. Depending on factors such as the type of particle beam and the particle energy, different energy reduction blocks can be made of materials such as graphite, aluminum, copper, beryllium, titanium, and boron carbide.

[0061] In the current limiter, the current limiting plate takes the form of a micro-perforated plate. When particles pass through the micro-perforated area, they are not blocked by the material and can pass freely. When particles pass through other areas outside the micro-perforated area, they are blocked by the current limiting plate material and cannot pass normally, thus reducing the beam intensity. In the current limiter of this current limiting and energy reduction device, multiple micro-perforated current limiting plates with different beam aperture distribution densities are arranged on the same adjustable support. By strictly controlling the processing accuracy of the support, the multiple current limiting plates are ensured to be parallel to each other. The support can rotate around the X and Y axes, so during the collimation installation process, the micro-perforation axis of the micro-perforated plate can be adjusted to be parallel to the beam center axis. Particles that meet specific conditions can pass through the micro-perforations without being blocked. Among them, rotating the plate around the X-axis can widen the plate, and the test data will be more sensitive to small angle adjustments during collimation calibration. During use, the current limiter can also be completely deviated from the envelope of the beam's lateral boundary. In this case, the particle beam can pass freely without being blocked by any material.

[0062] The method of using the current limiting and energy reduction device for the particle beam described in this embodiment is as follows: the current limiter and each energy reduction device operate independently of each other. In the associated proton beam experiment, the current limiter and each energy reduction device are arranged sequentially along the beam direction.

[0063] When the beam current of the particle beam needs to be adjusted, simply switch the current limiter to the desired position.

[0064] When the energy of the particle beam needs to be adjusted, multiple energy de-energizers can be adjusted simultaneously or a single energy de-energizer can be selected and adjusted until the sum of the thicknesses of the energy de-energizers through which the beam passes reaches the required thickness value of the energy de-energizer material.

[0065] When the beam intensity and energy of a particle beam need to be adjusted simultaneously, the current limiter and a single or multiple energy depletors are adjusted at the same time so that the beam passes through the current limiter and energy depletors in sequence.

[0066] Example 2

[0067] This embodiment provides a current-limiting and energy-reducing device for particle beams. Compared with Embodiment 1, the difference lies in the following:

[0068] An auxiliary slider is further provided in the first energy degrader. One end of the first energy degrader is connected to the first mounting base, and the other end of the first energy degrader is also connected to the auxiliary slider. The auxiliary slider cooperates with the corresponding first linear guide rail. During the adjustment of the first energy degrader, both ends of it have the guiding effect of the slider and the guide rail. On the one hand, this makes its operation more stable and avoids the first energy degrader from deflecting or shaking due to its excessive length. On the other hand, it also improves the accuracy of its adjustment.

[0069] Similarly, an auxiliary slider is set in the second energy reducer. One end of the second energy reducer is connected to the second mounting base, and the other end of the second energy reducer is also connected to the auxiliary slider, which cooperates with the corresponding second linear guide rail. During the adjustment of the second energy reducer, both ends are guided by the slider and the guide rail. This makes its operation more stable and prevents the second energy reducer from deflecting or shaking due to its excessive length. It also improves the accuracy of its adjustment.

[0070] As described above, the present invention can be well implemented. The above embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention; that is, all equivalent changes and modifications made in accordance with the content of the present invention are covered by the scope of protection claimed in the claims of the present invention.

Claims

1. A current limiting and energy degrading device for a particle beam, characterized in that The energy reducer comprises a vacuum cavity, a flow restrictor and a plurality of energy reducers, the flow restrictor and the energy reducers are arranged in the vacuum cavity respectively; two energy-reducing blocks with adjustable positions are arranged in each energy reducer, the energy-reducing blocks are in wedge-shaped plate structure, and the two energy-reducing blocks are arranged in parallel and move towards or reversely in the adjusting process. The energy reducer comprises two energy reducers, which are a first energy reducer and a second energy reducer, the first energy reducer is provided with two first energy-reducing blocks in wedge-shaped plate structure; the second energy reducer is provided with two second energy-reducing blocks in wedge-shaped plate structure, the wedge angle of the first energy-reducing block is smaller than the wedge angle of the second energy-reducing block, and the maximum thickness of the first energy-reducing block is greater than the minimum thickness of the second energy-reducing block; the wedge angle of the first energy-reducing block is 0.5°-3°, and the wedge angle of the second energy-reducing block is 5°-10°. The first energy reducer comprises a first motor, a first coupling, a first positive and negative double helix screw rod, a first screw nut, a first linear guide rail, a first sliding block, a first mounting base and a first energy-reducing block; the power output shaft of the first motor is connected with one end of the first positive and negative double helix screw rod through the first coupling; the first positive and negative double helix screw rod comprises a first upper segment thread and a first lower end thread with opposite helix directions, and the first upper segment thread and the first lower end thread are respectively provided with a first screw nut matched thereon; the first positive and negative double helix screw rod is provided with a first linear guide rail in parallel on each side, and each first linear guide rail is provided with a first sliding block matched thereon; the first energy-reducing block is fixed on the first mounting base, one end of the first mounting base is connected with the first screw nut, and the other end of the first mounting base is connected with the first sliding block. In the first energy reducer, the first energy-reducing block comprises a main frame, a wedge-shaped energy-reducing plate and a pressing plate, the main frame is fixed on the first mounting base at the bottom, the wedge-shaped energy-reducing plate is installed in the main frame and is provided with the pressing plate on one side, and the pressing plate is locked and fixed with the main frame through bolts. The flow restrictor comprises a flow-restricting assembly, the flow-restricting assembly comprises a fixed base plate, a Y-axis rotating plate and an X-axis rotating plate, the fixed base plate is connected with the third mounting base at the bottom, the Y-axis rotating plate is installed on the fixed base plate, the X-axis rotating plate is installed on the Y-axis rotating plate, and a plurality of flow-restricting plates are installed on the X-axis rotating plate, and the flow-restricting holes on each flow-restricting plate have different distribution densities.

2. The current limiting and energy degrading device for particle beams according to claim 1, characterized in that In the first energy reducer, one end of the first energy-reducing block is connected with the first mounting base, and the other end of the first energy-reducing block is further connected with an auxiliary sliding block, and the auxiliary sliding block is matched with the corresponding first linear guide rail.

3. The current limiting and energy degrading device for particle beams according to claim 1, characterized in that The second energy reducer comprises a second motor, a second coupling, a second positive and negative double helix screw rod, a second screw nut, a second linear guide rail, a second sliding block, a second mounting base and a second energy reduction block; the power output shaft of the second motor is connected with one end of the second positive and negative double helix screw rod through the second coupling; the second positive and negative double helix screw rod comprises a second upper segment thread and a second lower end thread with opposite screw directions, and the second upper segment thread and the second lower end thread are respectively provided with a second screw nut matched therewith; the two sides of the second positive and negative double helix screw rod are respectively provided with a second linear guide rail in parallel, and each second linear guide rail is provided with a second sliding block matched therewith; the second energy reduction block is fixed on the second mounting base, one end of the second mounting base is connected with the second screw nut, and the other end of the second mounting base is connected with the second sliding block.

4. The current limiting and energy degrading device for particle beams according to claim 1, characterized in that The flow limiter comprises a third motor, a third coupling, a one-way screw rod, a third screw nut, a third linear guide rail, a third sliding block, a third mounting base and a flow limiting assembly; the power output shaft of the third motor is connected with one end of the one-way screw rod through the third coupling; the one-way screw rod is provided with a third screw nut matched therewith; the two sides of the one-way screw rod are respectively provided with a third linear guide rail, and each third linear guide rail is provided with a third sliding block matched therewith; the flow limiting assembly is fixed on the third mounting base, the middle part of the third mounting base is connected with the third screw nut, and the two sides of the third mounting base are respectively connected with the third sliding block.

5. The current limiting and energy degrading device for particle beams according to claim 1, characterized in that One side of the fixed base plate is provided with a Y-axis rotating shaft, the other side of the fixed base plate is provided with a first locking threaded hole, one side of the Y-axis rotating plate is provided with a Y-axis rotating through hole matched with the Y-axis rotating shaft, the other side of the Y-axis rotating plate is provided with a first adjusting long hole and a first locking screw matched with the first locking threaded hole, and a Y-axis adjusting screw is further arranged on the side edge of the Y-axis rotating plate; The upper end of the Y-axis rotating plate is provided with an X-axis rotating shaft, the lower end of the Y-axis rotating plate is provided with an X-axis adjusting screw, the middle part of the Y-axis rotating plate is provided with a second locking threaded hole, the upper end of the X-axis rotating plate is provided with an X-axis rotating through hole matched with the X-axis rotating shaft, the lower end of the X-axis rotating plate is embedded between the two X-axis adjusting screws at the lower end of the Y-axis rotating plate, and the middle part of the X-axis rotating plate is provided with a second adjusting long hole and a second locking screw matched with the second locking threaded hole.

6. A method of using the current limiting and energy degrading device for a particle beam according to any one of claims 1 to 5, characterized in that, The flow limiter and each energy reducer are independently operated, and in the associated proton beam experiment, the flow limiter and each energy reducer are arranged in sequence along the beam direction. When the beam flow of the particle beam needs to be adjusted, the flow limiter can be adjusted to the required position. When the beam flow of the particle beam needs to be adjusted in energy, a plurality of energy reducers are adjusted at the same time or a single energy reducer is adjusted, and the thickness of each energy reduction block through which the beam flows is added to reach the thickness value of the required energy reduction material. When the beam flow of the particle beam needs to be adjusted in both flow and energy, the flow limiter and a single energy reducer or a plurality of energy reducers are adjusted at the same time, and the beam flow passes through the flow limiter and the energy reducer in sequence.

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