A beam profile measurement device

Abstract

This utility model discloses a beam profile measurement device, relating to the field of particle accelerator technology. The beam profile measurement device includes: a laser generation module, a beam splitting module, a first delay module, a second delay module, an electron stripping and collection module, and a main control module. The beam splitting module includes a beam splitter. The laser beam enters the beam splitter and is split into a first beam and a second beam propagating along a first direction and a second beam, respectively. The first beam and the second beam propagate through optical paths of first and second lengths through the first and second delay modules, respectively, and then converge at the beam convergence point, stripping electrons propagating along the first and second directions from the beam. The first and second lengths are different. The electron collection end of the electron stripping and collection module is located on the beam convergence point side. The measurement signal output end of the electron stripping and collection module is connected to the measurement signal input end of the main control module. This utility model improves the efficiency and accuracy of beam profile measurement.

Description

Technical Field

[0001] This utility model relates to the field of particle accelerator technology, and in particular to a beam profile measurement device. Background Technology

[0002] Negative hydrogen linear accelerators are a crucial component of modern high-current proton accelerators. Their efficient acceleration and high-quality injection require precise control over the beam quality, emittance, and distribution of the negative hydrogen beam, while minimizing beam losses along the path to reduce residual dose after linear accelerator element activation and shutdown. Therefore, beam transverse profile measurement has become a research hotspot in linear accelerator beam diagnostics. The beam transverse profile refers to the intensity distribution of the particle beam in a plane perpendicular to its propagation direction, typically represented by a two-dimensional function I(X, Y), where I represents the beam intensity, and X and Y are the horizontal and vertical coordinates, respectively.

[0003] To accurately assess the beam quality of a negative hydrogen linear accelerator and ensure its stable operation, a specialized beam diagnostic device is required to accurately characterize the lateral beam distribution. Traditional profile measurement methods for negative hydrogen beams include interception methods (fluorescent screen method and multi-wire scanning method) and non-interception methods (residual gas ionization method). The fluorescent screen method generates fluorescence through the interaction of the beam with a fluorescent material, and the two-dimensional intensity distribution of the beam is captured by an optical observation system and camera. The multi-wire scanning method bombards an array of parallel filaments with the beam and collects the generated secondary electron signals to reconstruct the two-dimensional beam profile. The residual gas ionization method generates electron-ion pairs through the ionization of the beam and residual gas, and collects the electron or ion distribution projection under an electric field to reconstruct the one-dimensional lateral profile distribution of the beam.

[0004] The fluorescent screen method and the multi-wire scanning method are based on the principle of direct interaction between the beam and the solid medium, which can intercept the beam, making it impossible to simultaneously ensure normal beam supply and profile measurement of the linear accelerator. They also have strict requirements on beam parameters and solid medium performance. The residual gas ionization method cannot simultaneously measure the horizontal and vertical profiles of the beam, resulting in a complex structure of the beam diagnostic device and low profile measurement efficiency. Utility Model Content

[0005] This invention provides a beam profile measurement device that enables simultaneous measurement of the horizontal and vertical profiles of a beam without the need for a solid medium, thereby improving the efficiency and accuracy of beam profile measurement.

[0006] The first aspect of this utility model provides a beam profile measurement device, which includes: a laser generation module, a beam splitting module, a first delay module, a second delay module, an electron stripping and collection module, and a main control module;

[0007] The laser generating module is used to provide a laser beam;

[0008] The beam splitting module includes a beam splitter; the beam splitter includes an incident surface, a first exiting surface, and a second exiting surface; the laser beam enters the beam splitter through the incident surface and is split by the beam splitter into a first beam propagating in a first direction and a second beam propagating in a second direction; the first beam exits through the first exiting surface, and the second beam exits through the second exiting surface;

[0009] The first delay module is disposed on the first light-emitting surface side; the second delay module is disposed on the second light-emitting surface side; after the first beam propagates a first length of optical path through the first delay module, it merges with the beam at the beam confluence point and strips out electrons propagating along the first direction in the beam; after the second beam propagates a second length of optical path through the second delay module, it merges with the beam at the beam confluence point and strips out electrons propagating along the second direction in the beam; wherein, the first length and the second length are different;

[0010] The electron collection end of the stripped electron collection module is located on the side of the beam confluence point;

[0011] The main control module includes at least a measurement signal input terminal; the measurement signal output terminal of the stripped electron collection module is connected to the measurement signal input terminal.

[0012] Optionally, the main control module further includes a laser control terminal; the laser control terminal is connected to the control terminal of the laser generating module.

[0013] Optionally, the beam splitting module further includes a first scanning mirror and a second scanning mirror;

[0014] The first beam, propagated by the first delay module, is reflected by the reflective surface of the first scanning mirror and then propagates to the beam confluence point;

[0015] The second beam transmitted by the second delay module is reflected by the reflective surface of the second scanning mirror and then propagates to the beam confluence point.

[0016] Optionally, the beam-splitting module further includes a first focusing lens and a second focusing lens;

[0017] The first focusing lens is disposed in the optical path between the first scanning mirror and the beam confluence point;

[0018] The second focusing mirror is disposed in the optical path between the second scanning mirror and the beam confluence point.

[0019] Optionally, the beam profile measurement device further includes: a scanning reflection driver;

[0020] The main control module also includes a scanning reflection control terminal; the scanning reflection control terminal is connected to the control terminal of the scanning reflection driver; the scanning reflection drive signal output terminal of the scanning reflection driver is connected to the control terminals of the first scanning reflector and the second scanning reflector, respectively.

[0021] Optionally, the beam profile measurement device further includes: a focusing driver;

[0022] The main control module also includes a focusing control terminal; the focusing control terminal is connected to the control terminal of the focusing driver; the focusing drive signal output terminal of the focusing driver is connected to the control terminal of the first focusing lens and the control terminal of the second focusing lens, respectively.

[0023] Optionally, the first delay module includes m first reflectors; the second delay module includes n second reflectors; where m > n.

[0024] Optionally, the first delay module includes a first reflector group and a second reflector group; both the first and second reflector groups include two first reflectors arranged along a first optical axis; along the propagation path of the first beam, the beam splitter and the first reflector group are arranged along the positive direction of the second optical axis, and the first and second reflector groups are arranged along the negative direction of the second optical axis; wherein the first optical axis intersects the second optical axis; the positive direction of the second optical axis and the negative direction of the second optical axis are opposite directions; and / or,

[0025] The second delay module includes a second reflector; in the propagation path of the second beam, the second reflector and the beam splitter are arranged along the first optical axis.

[0026] Optionally, the stripped electron collection module includes a fan-shaped deflecting magnet, a power supply, and a Faraday cylinder;

[0027] The power supply signal output terminal is connected to the power supply signal input terminal of the sector deflecting magnet.

[0028] The fan-shaped deflecting magnet is positioned on the propagation path of the stripped electrons collected by the electron collection end of the stripped electron collection module.

[0029] The Faraday cylinder is positioned on the propagation path of the stripped electrons after they have been deflected by the fan-shaped deflecting magnet.

[0030] Optionally, the beam profile measurement device further includes: a signal amplification module and a data acquisition module;

[0031] The signal amplification module and the data acquisition module are sequentially electrically connected between the measurement signal output terminal of the Faraday cylinder and the measurement signal input terminal of the main control module.

[0032] The technical solution of this utility model, by setting a laser generation module, a beam splitting delay module, a first delay module, a second delay module, an electron stripping collection module, and a main control module in the beam profile measurement device, and by providing a laser beam through the laser generation module, enables the interaction between the laser beam and the beam emitted by the accelerator in the vacuum cavity to generate stripped electrons, thus ensuring the stability of the laser beam propagation. Simultaneously, by setting a beam splitter including an incident surface, a first exit surface, and a second exit surface in the beam splitter module, the laser beam can enter the beam splitter from the incident surface and be split into a first beam propagating in a first direction and a second beam propagating in a second direction. The first beam can exit through the first exit surface, and the second beam can exit through the second exit surface. Furthermore, by placing the first delay module on the first light-emitting surface side and the second delay module on the second light-emitting surface side, the first beam, after propagating a first-length optical path through the first delay module, merges with the beam at the beam convergence point. Similarly, the second beam, after propagating a second-length optical path through the second delay module, merges with the beam at the beam convergence point. The first and second lengths are set differently to ensure that the first and second beams undergo photoelectric stripping reactions at the beam convergence point, resulting in time separation of stripped electrons. By placing the electron collection end of the stripped electron collection module on the beam convergence point side and connecting its measurement signal output end to the measurement signal input end of the main control module, the independent stripped electron measurement signals corresponding to the first and second beams can be determined. This allows for simultaneous measurement of the beam profile along both the first and second directions, achieving simultaneous measurement of the horizontal and vertical beam profiles without the need for a solid medium. This simplifies the structure of the beam profile measurement device and improves the efficiency and accuracy of beam profile measurement.

[0033] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of a beam profile measuring device provided in an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the laser generation module and beam splitting module in the beam profile measurement device provided in this embodiment of the utility model;

[0037] Figure 3 This is a schematic diagram of the structure of the first delay module and the second delay module in the beam profile measurement device provided in this embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of stripping electronic measurement signals according to an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the stripped electron collection module in the beam profile measurement device provided in this embodiment of the utility model. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0041] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0042] This solution is applicable to a beam profile measurement system, which includes hardware modules such as an accelerator, a vacuum chamber, and a beam profile measurement device. The accelerator, located within the vacuum chamber, emits a negative hydrogen beam. The vacuum chamber provides a low-pressure environment to maintain beam stability. The beam profile measurement device performs lateral profile measurements on the beam emitted by the accelerator to obtain parameters such as beam size, shape, and center position. Simultaneously, the vacuum chamber is equipped with a vacuum observation window to facilitate the interaction of the laser beam with the beam.

[0043] Figure 1 This is a schematic diagram of the structure of a beam profile measurement device provided in an embodiment of this utility model. Figure 1 As shown, the beam profile measurement device includes: a laser generation module 1, a beam splitting module 2, a first delay module 21, a second delay module 22, an electron stripping and collection module 3, and a main control module 4; the laser generation module 1 is used to provide a laser beam S; the beam splitting module 2 includes a beam splitter 23; the beam splitter 23 includes an incident surface 2301, a first exit surface 2302, and a second exit surface 2303; the laser beam S enters the beam splitter 23 through the incident surface 2301 and is split into a first beam propagating along a first direction X and a second beam propagating along a second direction Y; the first beam exits through the first exit surface 2302, and the second beam exits through the second exit surface 2303; the first delay module 21 is disposed on the side of the first exit surface 2302; the second delay module 22 is disposed on the side of the second exit surface 2303; after the first beam propagates a first length of optical path through the first delay module 21, it merges with the beam H at the beam convergence point A. - The beams converge and are separated into H streams. - Electrons e propagating along the first direction X - After the second beam propagates through the second delay module 22 for a second length of optical path, it merges with the beam at beam convergence point A. - The beams converge and are separated into H streams. - Electrons e propagating along the second direction Y - The first length is different from the second length; the electron collection end 301 of the stripped electron collection module 3 is located on the beam confluence point A side; the main control module 4 includes at least a measurement signal input end 401; the measurement signal output end 302 of the stripped electron collection module 3 is connected to the measurement signal input end 401.

[0044] The laser generating module 1 is used to emit a laser beam S through its laser output terminal 101, so that the laser beam S can interact with the beam H emitted by the accelerator. - The laser beam S interacts with the beam H at the beam convergence point A. - A laser ablation reaction can occur, so that the beam current H - Capable of absorbing laser photon energy and decomposing it into neutral hydrogen atoms (H). 0and stripping electrons e - Stripping electrons e - The quantity and spatial distribution of the beam H - The intensity of the transverse distribution is proportional to the electron density; therefore, it can be obtained by collecting and stripping electrons. - And by measuring the stripped electron e - The quantity and spatial distribution of the beam H were used to reconstruct its quantity and spatial distribution. - The horizontal and vertical cross-sections. It can be understood that the laser beam S and the beam H... - Beam profile measurement is achieved through a photoelectric stripping reaction, eliminating the need for a solid medium, such as a fluorescent screen or filament, in the beam profile measurement device, thus avoiding interference with the beam H. - The interception and material contamination reduced the impact on the beam H - This method fundamentally avoids interference, phenomena such as target material sputtering, shedding, or melting that may occur in traditional intercept beam profiling measurements. It effectively eliminates the risk of vacuum environment contamination, ensuring the cleanliness and long-term reliability of the accelerator vacuum system, and enabling the accelerator to emit beams normally. - Simultaneously, the beam profile is measured in real time, improving the accuracy of beam profile detection.

[0045] The beam splitter module 2 includes a beam splitter 23, which includes an incident surface 2301, a first exiting surface 2302, and a second exiting surface 2303. This allows the beam splitter module 2 to receive the laser beam S emitted by the laser generating module 1 through the incident surface 2301. The beam splitter module 2 splits the laser beam S into a first beam propagating along a first direction X and a second beam propagating along a second direction Y. The first beam is emitted through the first exiting surface 2302, and the second beam is emitted through the second exiting surface 2303. The first direction X and the second direction Y intersect. For example, the first direction X can be horizontal, and the second direction Y can be vertical; however, this invention does not specifically limit this.

[0046] The first delay module 21 is disposed on the side of the first light-emitting surface 2302, and the second delay module 22 is disposed on the side of the second light-emitting surface 2303. This allows the first beam, after being split by the beam splitter 23, to propagate a first length of optical path through the first delay module 21 and then converge with the beam at beam convergence point A. - The beams converge and are separated into H streams. - Electrons e propagating along the first direction X - After the second beam propagates through the second delay module 22 for a second length of optical path, it merges with the beam at beam convergence point A. - The beams converge and are separated into H streams. - Electrons e propagating along the second direction Y -For example, the first delay module 21 and the second delay module 22 may include total internal reflection lenses or prisms to achieve optical path reversal through the geometric arrangement of the total internal reflection lenses or prisms. Alternatively, the first delay module 21 and the second delay module 22 may use long optical fibers as optical path delay media to delay the first beam and the second beam. Since the first length and the second length are different, the time it takes for the first beam and the second beam to propagate to the beam convergence point A will be separated in the time domain. The time difference between the first beam and the second beam propagating to the beam convergence point A is related to the optical path lengths of the first delay module 21 and the second delay module 22.

[0047] It is understandable that the beam splitter module 2 achieves time separation of the propagation of the first beam and the second beam to the beam convergence point A, so that the first beam and the second beam are separated from the beam H. - A photoelectro-stripping reaction occurs, generating stripped electrons (e). - Time separation. The electron collection end 301 of the stripped electron collection module 3 is located on the beam confluence point A side. Therefore, the stripped electron collection module 3 collects stripped electrons through the electron collection end 301. - And by measuring the stripped electron e - In the stripping electron measurement signals generated by the quantity and spatial distribution, the stripping electron measurement signals corresponding to the first beam and the second beam are independent of each other, avoiding overlap of the stripping electron measurement signals, thus enabling simultaneous measurement of the beam H. - Measurements are performed along cross-sections in the first direction X and the second direction Y, simplifying the structure of the beam profile measurement device and improving the efficiency of the profile measurement. It can also be understood that the laser beam S can include pulsed lasers, such as nanosecond or picosecond lasers, so that the laser beam S is aligned with the beam H. - During the interaction, the laser beam S is in the beam H - The area near the waist of the beam can be visualized as a laser filament, causing the laser beam S to interact with the beam current H. - The small effective area improves the accuracy of beam profile measurement. Furthermore, after the laser beam S is split by the beam splitting module 2 and delayed by the first delay module 21 and the second delay module 22, it can be introduced into the vacuum cavity through the vacuum observation window to interact with the beam H. - The interaction between the laser beam S and the beam H during profile measurement eliminates the need for complex mechanical components within the vacuum chamber, simplifying the equipment structure, reducing installation and maintenance difficulties, and effectively minimizing the risk of system failures caused by mechanical devices. - The interaction time is extremely short, only on the order of picoseconds or nanoseconds, thus ensuring the beam H - The stability of propagation and the smoothness of accelerator operation.

[0048] The stripped electron collection module 3 collects the laser beam S and beam H through the electron collection end 301. - The stripped electrons generated by the interaction - And by measuring the stripped electron e - After determining the quantity and spatial distribution of the stripped electron measurement signal, the stripped electron measurement signal is output from the measurement signal output terminal 302 of the electron collection module 3 to the measurement signal input terminal 401 of the main control module 4, so that the main control module 4 can determine the beam current H based on the stripped electron measurement signal. - Cross-sections along the first direction X and the second direction Y. The stripping of the electronic measurement signal can be specifically understood as the laser beam S and the beam H... - Stripped electrons generated at the interaction sites - The strength of the stripped electrons - The intensity reflects the electron number density, and the electron number density is related to the beam current H. - The intensity at the interaction location is proportional. The main control module 4 may include a microprocessor, such as a central processing unit (CPU), and may also include other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The main control module 4 is used to determine the intensity of the laser beam S and the beam current H based on their interaction. - The beam profile is determined by the interaction positions of the laser beam S and the stripped electron measurement signal. Specifically, the main control module 4 can determine the beam profile by plotting the interaction between the laser beam S and the beam H. - The interaction positions and the two-dimensional relationship between the stripped electron measurement signals at those positions are used to determine the beam current H. - The cross-sections along the first direction X and the second direction Y enable simultaneous measurement of the beam current H without the need for a solid medium. - The horizontal and vertical profiles improve the efficiency and accuracy of beam profile measurement.

[0049] In this embodiment, a laser generation module, a beam splitting and delay module, a first delay module, a second delay module, an electron stripping and collection module, and a main control module are set up in the beam profile measurement device. The laser generation module provides a laser beam, which interacts with the beam emitted by the accelerator in the vacuum cavity to generate stripped electrons, ensuring the stability of the laser beam propagation. Simultaneously, a beam splitter including an incident surface, a first exit surface, and a second exit surface is provided in the beam splitter module. This allows the laser beam to enter the beam splitter from the incident surface and be split into a first beam propagating in a first direction and a second beam propagating in a second direction. The first beam exits through the first exit surface, and the second beam exits through the second exit surface. Furthermore, by placing the first delay module on the first light-emitting surface side and the second delay module on the second light-emitting surface side, the first beam, after propagating a first-length optical path through the first delay module, merges with the beam at the beam convergence point. Similarly, the second beam, after propagating a second-length optical path through the second delay module, merges with the beam at the beam convergence point. The first and second lengths are set differently to ensure that the first and second beams undergo photoelectric stripping reactions at the beam convergence point, resulting in time separation of stripped electrons. By placing the electron collection end of the stripped electron collection module on the beam convergence point side and connecting its measurement signal output end to the measurement signal input end of the main control module, the independent stripped electron measurement signals corresponding to the first and second beams can be determined. This allows for simultaneous measurement of the beam profile along both the first and second directions, achieving simultaneous measurement of the horizontal and vertical beam profiles without the need for a solid medium. This simplifies the structure of the beam profile measurement device and improves the efficiency and accuracy of beam profile measurement.

[0050] Optional, Figure 2 This is a schematic diagram of the laser generation module and beam splitting module in the beam profile measurement device provided in this embodiment of the utility model. Figure 2 As shown, the main control module 4 also includes a laser control terminal 402; the laser control terminal 402 is connected to the control terminal 102 of the laser generating module 1.

[0051] Specifically, the laser control terminal 402 of the main control module 4 is connected to the control terminal 102 of the laser generating module 1, so that the main control module 4 can control the scanning range, scanning speed, and scanning step size of the laser beam S emitted by the laser generating module 1 through the control signal output by the laser control terminal 402. For example, the laser generating module 1 may include a laser, which can be a 1064nm nanosecond laser to ensure a large reaction cross-section for laser ablation; for example, the maximum reaction cross-section corresponds to a laser wavelength of 830nm. By adjusting the laser single pulse energy to be greater than 100mJ, the laser focal spot size to be less than 1 / 5 of the RMS beam spot size, and the laser Rayleigh length to be greater than 3 times the RMS beam spot size, the laser beam S and the beam current H are synchronized. - The stripping probability within the interaction region reaches over 90%. Specifically, the RMS beam spot size can be understood as the beam current H... - The standard deviation of the lateral dimension; the Rayleigh length can be specifically understood as the range within which a Gaussian beam maintains approximately collimated propagation near the beam waist. Within this range, the wavefront curvature of the beam is small, and it can be considered as parallel light propagation. Furthermore, the laser beam S emitted by laser generation module 1 can be transmitted through atmospheric reflection via a mirror or through optical fiber.

[0052] Optional, continue to refer to Figure 2 The beam splitter module 2 also includes a first scanning mirror 241, a second scanning mirror 242, a first focusing mirror 251, and a second focusing mirror 252. The first beam propagated by the first delay module 21 is reflected by the reflecting surface of the first scanning mirror 241 and then propagates to the beam confluence point A. The second beam transmitted by the second delay module 22 is reflected by the reflecting surface of the second scanning mirror 242 and then propagates to the beam confluence point A. The first focusing mirror 251 is disposed in the optical path between the first scanning mirror 241 and the beam confluence point A. The second focusing mirror 252 is disposed in the optical path between the second scanning mirror 242 and the beam confluence point A.

[0053] The first scanning mirror 241 and the second scanning mirror 242 are used to precisely adjust the scanning position of the laser beam S so that the laser beam S can cover the beam H. - The first focusing mirror 251 and the second focusing mirror 252 are used to reduce the thickness of the laser beam S along the scanning direction to achieve higher resolution. Thus, the scanning trajectory of the first beam can be adjusted by the first scanning mirror 241 and the first focusing mirror 251, and the scanning trajectory of the second beam can be adjusted by the second scanning mirror 242 and the second focusing mirror 252.

[0054] Specifically, the first beam propagated by the first delay module 21 is reflected by the reflective surface of the first scanning mirror 241 and then propagates to the beam confluence point A. The first focusing mirror 251 is disposed in the optical path between the first scanning mirror 241 and the beam confluence point A. It can be understood that the first beam delayed by the first delay module 21 is adjusted by the first scanning mirror 241 to scan its position along the first direction X, and is focused by the first focusing mirror 251 to act on the beam H. - On the transverse cross section, thus enabling the first beam and beam H to pass through. - The stripping electrons generated during the laser stripping reaction - Reconstructed Beam H - The horizontal cross-section. The second beam transmitted by the second delay module 22 is reflected by the reflective surface of the second scanning mirror 242 and then propagates to the beam confluence point A. The second focusing mirror 252 is disposed in the optical path between the second scanning mirror 242 and the beam confluence point A. It can also be understood that the second beam adjusts its scanning position along the second direction Y by the second scanning mirror 242, and is focused by the second focusing mirror 252 and then acts on the beam H. - On the transverse cross section, thus enabling the second beam to pass through with the beam H - The stripping electrons generated during the laser stripping reaction - Reconstructed Beam H - The vertical cross-section.

[0055] Optional, continue to refer to Figure 2 The beam profile measurement device also includes a scanning reflection driver 26; the main control module 4 also includes a scanning reflection control terminal 403; the scanning reflection control terminal 403 is connected to the control terminal 261 of the scanning reflection driver 26; the scanning reflection drive signal output terminal 262 of the scanning reflection driver 26 is connected to the control terminal 2411 of the first scanning mirror 241 and the control terminal 2421 of the second scanning mirror 242 respectively.

[0056] Specifically, the scanning reflection control terminal 403 of the main control module 4 is connected to the control terminal 261 of the scanning reflection driver 26, so that the main control module 4 can control the scanning reflection driver 26 to control the angle and position of the first scanning reflector 241 and the second scanning reflector 242 through the control signal output by the scanning reflection control terminal 403.

[0057] Furthermore, the scanning reflection drive signal output terminal 262 of the scanning reflection driver 26 can also be connected to the control terminal 231 of the beam splitter 23, so that the beam splitter 23 can split the laser beam S into a first beam and a second beam according to the control signal output by the scanning reflection driver 26, and can output the first beam and the second beam through the first light-emitting surface 2102 and the second light-emitting surface 2103 respectively. The scanning reflection drive signal output terminal 262 of the scanning reflection driver 26 is connected to the control terminal 2411 of the first scanning mirror 241 and the control terminal 2421 of the second scanning mirror 242, so that the first scanning mirror 241 can adjust the scanning position of the first beam according to the control signal output by the scanning reflection driver 26, and the second scanning mirror 242 can adjust the scanning position of the second beam according to the control signal output by the scanning reflection driver 26.

[0058] Optional, continue to refer to Figure 2 The beam profile measurement device also includes a focus driver 27; the main control module 4 also includes a focus control terminal 404; the focus control terminal 404 is connected to the control terminal 271 of the focus driver 27; the focus drive signal output terminal 272 of the focus driver 27 is connected to the control terminal 2511 of the first focusing lens 251 and the control terminal 2521 of the second focusing lens 252, respectively.

[0059] Specifically, the focusing control terminal 404 of the main control module 4 is connected to the control terminal 271 of the focusing driver 27, so that the main control module 4 can control the focusing driver 27 to control the angle and position of the first focusing lens 251 and the second focusing lens 252 through the control signal output by the focusing control terminal 404.

[0060] The focusing drive signal output terminal 272 of the focusing driver 27 is connected to the control terminal 2511 of the first focusing lens 251 and the control terminal 2521 of the second focusing lens 252, so that the first focusing lens 251 can focus the first beam according to the control signal output by the focusing driver 27, and the second focusing lens 252 can focus the second beam according to the control signal output by the focusing driver 27.

[0061] Understandably, to ensure that the laser beam S can be transmitted stably and efficiently to the beam convergence point A, the laser transmission efficiency needs to be kept as high as possible, and it is necessary to ensure that the laser beam S and the beam H are in sync. - The interaction between them remains stable. Therefore, a high-reflectivity mirror can be used to precisely adjust the transmission path of the laser beam S, thereby effectively reducing the loss of the laser beam S during transmission. The angle and position of the first scanning mirror 241 and the second scanning mirror 242 are precisely controlled by the scanning reflection driver 26 to ensure that the jitter at the target position during the transmission of the laser beam S is less than 1 / 5 of the RMS spot size, thereby ensuring that the laser beam S and the beam H remain stable. -High-precision alignment. It is also understood that the scanning reflection driver 26 may include a high-precision stepper motor, enabling the main control module 4 to control the high-precision stepper motor of the scanning reflection driver 26 to drive the first scanning reflector 241 to scan along the first direction X, and drive the second scanning reflector 242 to scan along the second direction Y. The high-precision stepper motor of the scanning reflection driver 26 is equipped with a high-precision grating ruler to ensure that the displacement accuracy of the first scanning reflector 241 and the second scanning reflector 242 meets the detection requirements. The scanning reflection driver 26 may also include a high-stability displacement stage, the repeatability of which is required to be less than one order of magnitude lower than the focused spot of the laser beam S, typically set to less than or equal to 20 micrometers, to ensure that the laser beam S and the beam H are aligned. - Accurate adjustment of relative position.

[0062] For example, the main control module 4 can first set the scanning range (ΔX) of the first scanning mirror 241 along the first direction X. min ΔX max The scanning step size dx and the moving speed are set, and the scanning range (ΔY) of the second scanning mirror 242 along the second direction Y is set. min ΔY max ), scan step size dy, and movement speed. Where ΔX min Let ΔX be the starting position of the first scanning mirror 241 along the first direction X. max The scanning cutoff position of the first scanning mirror 241 along the first direction X, ΔY min The starting position of the second scanning mirror 242 along the second direction Y is ΔY. max dx is the scanning cutoff position of the second scanning mirror 242 along the second direction Y, dx is the preset scanning step size of the first scanning mirror 241 along the first direction X, and dy is the preset scanning step size of the second scanning mirror 242 along the second direction Y.

[0063] After determining the scanning range, scanning step size, and moving frequency of the first scanning mirror 241 and the second scanning mirror 242, the main control module 4 controls the high-precision stepper motor of the scanning reflection driver 26 to move the first scanning mirror 241, and simultaneously controls the focusing driver 27 to adjust the position of the first focusing mirror 251 along the laser optical axis, and records the stripped electrons collected by the stripped electron collection module 3 at different focusing positions. - The signal strength is such that the focusing position of the first focusing mirror 251 is maintained such that the stripped electrons are... - The largest number of positions ensure that the focal point of the first beam is at the beam H. - Center. The scanning positions of the first scanning mirror 241 along the first direction X are ΔX. i(i = 2, 3, 4, ..., M), M = (ΔX) max -ΔX min ) / dx, ΔX2 refers to the first scanning position of the first scanning mirror 241 along the first direction X. i≥2, M is a positive integer. The main control module 4 controls the high-precision stepper motor of the scanning reflection driver 26 to move the first scanning mirror 241 to each scanning position ΔX. i (i = 2, 3, 4, ... M), for subsequent acquisition of stripped electrons e through stripped electron collection module 3. - Measure the signal and use ΔX at each scan position. i (i = 2, 3, 4, ..., M) is the x-axis, and ΔX is the x-axis at each scan position. i The stripped electron e corresponding to (i = 2, 3, 4, ..., M) - Plot the beam H with signal strength as the ordinate. - The horizontal cross-section laid the foundation.

[0064] Simultaneously, the main control module 4 controls the high-precision stepper motor of the scanning reflection driver 26 to move the second scanning reflection mirror 242, and controls the focusing driver 27 to adjust the position of the second focusing mirror 252 along the laser optical axis, and records the stripped electrons collected by the stripped electron collection module 3 at different focusing positions. - The signal strength is such that the focusing position of the second focusing mirror 252 is maintained such that the stripped electrons are... - The position with the largest number of beams ensures that the focus of the second beam is at the beam H. - Center. The scanning positions of the second scanning mirror 242 along the second direction Y are ΔY. j (j=2,3,4,...N),N=(ΔY max -ΔY min ) / dx, ΔY2 refers to the first scanning position of the second scanning mirror 242 along the second direction Y. j≥2, N is a positive integer. The main control module 4 controls the high-precision stepper motor of the scanning reflection driver 26 to move the second scanning mirror 242 to each scanning position ΔY. j (j=2,3,4,...N), for subsequent acquisition of stripped electrons e through stripped electron collection module 3. - Measure the signal and output it at each scan position ΔY. j (j=2,3,4,...N) is the x-axis, and ΔY is the x-axis at each scan position. j The stripped electron e corresponding to (j=2,3,4,...N) - Plot the beam H with signal strength as the ordinate. - The vertical cross-section laid the foundation.

[0065] Furthermore, the laser pulse duration (half-width at half maximum) of the laser beam S emitted by laser generation module 1 can be on the order of 10 nanoseconds, and its repetition frequency can be adjusted, for example, from 1 Hz to 10 Hz. This is to achieve the desired effect between the laser beam S and the beam current H. - The temporal overlap requires precise control over the time it takes for the laser beam S to propagate to the beam convergence point A, for example, controlling the arrival time jitter to be less than 1 ns, in order to ensure the stability of the stripped electronic signal.

[0066] Optional, Figure 3 This is a schematic diagram of the structure of the first delay module and the second delay module in the beam profile measurement device provided in this embodiment of the utility model. Figure 3 As shown, the first delay module 21 includes m first reflectors 221; the second delay module 22 includes n second reflectors 222; where m > n.

[0067] Specifically, by setting m first reflectors 221 in the first delay module 21, the first beam can propagate sequentially through the m first reflectors 221 to the first scanning reflector 241, thereby delaying the first beam through the m first reflectors 221. By setting n second reflectors 222 in the second delay module 22, the second beam can propagate sequentially through the n second reflectors 222 to the second scanning reflector 242, thereby delaying the second beam through the n second reflectors 222.

[0068] Understandably, the number of first reflectors 221 in the first delay module 21 is greater than the number of second reflectors 222 in the second delay module 22, resulting in a difference in the length of the delay optical path between the first delay module 21 and the second delay module 22. Therefore, the time it takes for the first beam and the second beam to propagate to the beam convergence point A will be separated in the time domain, enabling simultaneous measurement of the beam H without the need for a solid medium. - The horizontal and vertical profiles improve the efficiency and accuracy of beam profile measurement. For example, the first reflector 221 and the second reflector 222 can be total internal reflection lenses.

[0069] Optional, continue to refer to Figure 3The first delay module 21 includes a first reflector group 01 and a second reflector group 02; both the first reflector group 01 and the second reflector group 02 include two first reflectors 221 arranged along the first optical axis L1; along the propagation path of the first beam, the beam splitter 23 and the first reflector group 01 are arranged along the positive direction of the second optical axis L2, and the first reflector group 01 and the second reflector group 02 are arranged along the negative direction of the second optical axis L2; ​​wherein the first optical axis L1 and the second optical axis L2 intersect; the positive direction of the second optical axis L2 and the negative direction of the second optical axis L2 are opposite directions; and / or, the second delay module 22 includes a second reflector 222; in the propagation path of the second beam, the second reflector 222 and the beam splitter 23 are arranged along the first optical axis L1.

[0070] Specifically, the first delay module 21 includes two first reflectors 221, each arranged along the first optical axis L1: a first reflector group 01 and a second reflector group 02. Along the propagation path of the first beam, the beam splitter 23 and the first reflector group 01 are arranged along the positive direction of the second optical axis L2, while the first reflector group 01 and the second reflector group 02 are arranged along the negative direction of the second optical axis L2. This allows for delaying the first beam using the first reflector group 01 and the second reflector group 02. The first optical axis L1 intersects the second optical axis L2, and the positive and negative directions of the second optical axis L2 are opposite. For example, the first optical axis L1 can be horizontal, and the second optical axis L2 can be vertical; however, this invention does not impose specific limitations on this. Therefore, the first beam can propagate from the first light-emitting surface 2302 of the beam splitter 23 along the positive direction of the second optical axis L2 to the first reflecting mirror group 01, and the propagation direction of the first beam can be changed by the first reflecting mirror group 01. The first reflecting mirror group 01 then propagates the first beam in the opposite direction of the second optical axis L2 to the second reflecting mirror group 02. After the propagation direction is changed again by the second reflecting mirror group 02, the first beam finally propagates to the first scanning reflecting mirror 241. Through the geometric arrangement of the first reflecting mirror group 01 and the second reflecting mirror group 02, the first beam can be refracted multiple times between the first light-emitting surface 2302 of the beam splitter 23 and the first scanning reflecting mirror 241, thereby achieving time delay of the first beam through the first reflecting mirror group 01 and the second reflecting mirror group 02.

[0071] Meanwhile, by setting a second reflector 222 in the second delay module 22, and arranging the second reflector 222 and the beam splitter 23 along the first optical axis L1 in the propagation path of the second beam, the second beam can propagate from the second light-emitting surface 2303 of the beam splitter 23 along the first optical axis L1 to the second reflector 222, and then propagate to the second scanning reflector 242 after the propagation direction is changed by the second reflector 222. This achieves delay of the second beam through the second reflector 222. It can be understood that the length of the delay optical path of the first delay module 21 is greater than the length of the delay optical path of the second delay module 22, so that the propagation time of the first beam and the second beam to the beam confluence point A is separated, so that the beam current H can be measured synchronously without the use of a solid medium. - The horizontal and vertical profiles improve the efficiency and accuracy of beam profile measurement.

[0072] It is also understandable that the difference between the length of the delay optical path of the first delay module 21 and the length of the delay optical path of the second delay module 22 can be greater than the product of the pulse duration and the speed of light of the laser beam S, so as to ensure that the first beam and the second beam are aligned with the beam current H. - A photoelectro-stripping reaction occurs, generating stripped electrons (e). - The time separation allows the stripped electron collection module 3 to measure the stripped electrons e - The quantity and spatial distribution produce, for example Figure 4 In the stripping electron measurement signals shown, the stripping electron measurement signals corresponding to the first beam and the second beam are independent of each other, avoiding overlap of the stripping electron measurement signals, thus enabling simultaneous measurement of the beam H. - Measurements are taken along the first direction X and the second direction Y, which simplifies the structure of the beam profile measurement device and improves the efficiency of profile measurement.

[0073] For example, the speed of light is 3 × 10⁻⁶. 8 When the pulse duration of the laser beam S is 20 ns, the difference between the length of the delay optical path of the first delay module 21 and the length of the delay optical path of the second delay module 22 can be set to be greater than 6 m. This ensures that the time interval between the propagation of the first beam and the second beam to the beam convergence point A is greater than 20 ns, thereby enabling beam H to be controlled without the need for a complex delay mechanical structure. - The simultaneous measurement of horizontal and vertical profiles simplifies the structure of the beam profile measurement device and improves the efficiency and accuracy of beam profile measurement.

[0074] Optional, Figure 5 This is a schematic diagram of the stripped electron collection module in the beam profile measurement device provided in this embodiment of the utility model. Figure 5As shown, the stripped electron collection module 3 includes a sector-shaped deflecting magnet 31, a power supply 32, and a Faraday cylinder 33; the power supply signal output terminal 321 of the power supply 32 is connected to the power supply signal input terminal 311 of the sector-shaped deflecting magnet 31; the sector-shaped deflecting magnet 31 is disposed on the stripped electrons collected by the electron collection terminal 301 of the stripped electron collection module 3. - On the propagation path; Faraday cylinder 33 is set at the stripping electron e - The propagation path after being deflected by the fan-shaped deflecting magnet 31.

[0075] Specifically, the power supply signal output terminal 321 of the power supply 32 is connected to the power supply signal input terminal 311 of the sector-shaped deflecting magnet 31, so that power can be supplied to the sector-shaped deflecting magnet 31 through the power supply 32, thereby generating a uniform magnetic field in the sector-shaped deflecting magnet 31. This is achieved by placing the sector-shaped deflecting magnet 31 at the electron collection terminal 301 of the stripped electron collection module 3 to collect stripped electrons. - In the propagation path, so as to strip electrons e - It can enter the sector-shaped deflecting magnet 31 and can strip electrons e through the magnetic field generated by the sector-shaped deflecting magnet 31. - Applying the Lorentz force to precisely guide the stripping of electrons e - Propagation follows a preset arc trajectory to the Faraday cylinder 33, avoiding damage to the stripped electrons. - Measurements were performed on the beam H - The resulting scattering or energy loss ensures the beam H - The stability of propagation and the smoothness of accelerator operation.

[0076] By setting the Faraday cylinder 33 to strip the electron e - After being deflected by the fan-shaped deflecting magnet 31, the propagation path allows the Faraday cylinder 33 to collect stripped electrons through a high-sensitivity electrode. - and generate and strip electrons e - The number of stripped electron measurement signals is proportional to the number of electrons removed, so that the measurement signal output terminal 302 of the electron collection module 3 can output the stripped electron measurement signals to the measurement signal input terminal 401 of the main control module 4, so as to facilitate the subsequent synchronous measurement of the beam current H by the main control module 4. - The horizontal and vertical profiles laid the foundation for improving the efficiency and accuracy of beam profile measurements.

[0077] It is also understandable that the laser beam S output by beam splitter 2 and the beam H - Stripped electrons generated by interactions within the vacuum cavity - The sector-shaped deflecting magnet 31 is generally placed outside the vacuum cavity and can generate a deflecting magnetic field inside the vacuum cavity, thereby deflecting the stripped electrons e inside the vacuum cavity. -The effect on the negative hydrogen beam is relatively small. The Faraday cylinder 33 is placed inside the vacuum chamber to allow for the stripping of electrons. - The magnetic field generated by the sector-shaped deflecting magnet 31 in the vacuum cavity can be precisely guided to propagate to the Faraday cylinder 33, thereby enabling the generation and stripping of electrons e through the Faraday cylinder 33. - The number of stripped electrons is proportional to the measurement signal. Placing the Faraday cylinder 33 inside a vacuum chamber prevents air molecules from affecting the stripped electrons. - Scattering and ionization, so as to retain stripped electrons e - The accuracy of the propagation trajectory improves the signal-to-noise ratio of the stripped electron measurement signal, thereby enhancing the accuracy of beam profile measurement.

[0078] Optional, continue to refer to Figure 5 The beam profile measurement device also includes a signal amplification module 34 and a data acquisition module 35; the signal amplification module 34 and the data acquisition module 35 are electrically connected in sequence between the measurement signal output terminal 331 of the Faraday cylinder 33 and the measurement signal input terminal 401 of the main control module 4.

[0079] Specifically, the measurement signal output terminal 331 of the Faraday cylinder 33 is connected to the measurement signal input terminal 341 of the signal amplification module 34, so that the signal amplification module 34 can receive the electrons generated by the Faraday cylinder 33 and the stripped electrons. - The number of stripped electron measurement signals is proportional to the quantity of the signal. These signals are weak electrical signals. The signal amplification module 34 amplifies the signal with high gain and filters out noise to generate a usable measurement signal. The amplified signal is then transmitted from the signal amplification module 34's measurement signal output terminal 342 to the measurement signal input terminal 351 of the data acquisition module 35, improving the accuracy of the beam profile measurement. After receiving the stripped electron measurement signal from the signal amplification module 34, the data acquisition module 35 performs analog-to-digital conversion to digitize the signal. This digital signal is then transmitted from the data acquisition module 35's measurement signal output terminal 352 to the measurement signal input terminal 401 of the main control module 4, facilitating subsequent synchronous measurement of the beam H by the main control module 4. - The horizontal and vertical sections laid the foundation.

[0080] Understandably, the main control module 4 can receive the stripped electron measurement signal processed by the signal amplification module 34 and the data acquisition module 35 through the measurement signal input terminal 401. The beam splitting module 2 achieves time separation of the first and second beams propagating to the beam convergence point A. Therefore, the stripped electron measurement signal corresponding to the first beam and the second beam are separated in the time domain, allowing the main control module 4 to determine the propagation direction of the laser beam S corresponding to the stripped electron measurement signal based on the arrival time of the stripped electron measurement signal. Simultaneously, the main control module 4 can also acquire the scanning position of the first scanning mirror 241 along the first direction X and the scanning position of the second scanning mirror 242 along the second direction Y in real time through the scanning reflection driver 26, thereby defining each scanning position of the first scanning mirror 241 along the first direction X as ΔX. i (i = 2, 3, 4, ..., M) and stripped electron e - The signal strength is correlated, and the scanning positions of the second scanning mirror 242 along the second direction Y are ΔY. j (j=2,3,4,...N) and stripped electron e - The signal strength is correlated. This allows the main control module 4 to control the signal strength at each scanning position ΔX. i (i = 2, 3, 4, ..., M) is the x-axis, and ΔX is the x-axis at each scan position. i The stripped electron e corresponding to (i = 2, 3, 4, ..., M) - Plot the beam H with signal strength as the ordinate. - A horizontal cross-section, and capable of scanning at various positions ΔY. j (j=2,3,4,...N) is the x-axis, and ΔY is the x-axis at each scan position. j The stripped electron e corresponding to (j=2,3,4,...N) - Plot the beam H with signal strength as the ordinate. - The vertical cross-section of the beam allows for simultaneous measurement of the beam current H without the need for a solid medium. - The horizontal and vertical profiles simplify the structure of the beam profile measurement device and improve the efficiency and accuracy of beam profile measurement.

[0081] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A beam profile measurement device, characterized by, include: The system includes a laser generating module, a beam splitting module, a first delay module, a second delay module, a stripping electron collection module, and a main control module. The laser generating module is used to provide a laser beam; The beam splitting module includes a beam splitter; the beam splitter includes an incident surface, a first exiting surface, and a second exiting surface; the laser beam enters the beam splitter through the incident surface and is split by the beam splitter into a first beam propagating in a first direction and a second beam propagating in a second direction; the first beam exits through the first exiting surface, and the second beam exits through the second exiting surface; The first delay module is disposed on the first light-emitting surface side; the second delay module is disposed on the second light-emitting surface side; after the first beam propagates a first length of optical path through the first delay module, it merges with the beam at the beam confluence point and strips out electrons propagating along the first direction in the beam; after the second beam propagates a second length of optical path through the second delay module, it merges with the beam at the beam confluence point and strips out electrons propagating along the second direction in the beam; wherein, the first length and the second length are different; The electron collection end of the stripped electron collection module is located on the side of the beam confluence point; The main control module includes at least a measurement signal input terminal; the measurement signal output terminal of the stripped electron collection module is connected to the measurement signal input terminal.

2. The beam profile measurement device of claim 1, wherein, The main control module also includes a laser control terminal; the laser control terminal is connected to the control terminal of the laser generating module.

3. The beam profile measuring device according to claim 1, characterized in that, The beam splitting module also includes a first scanning mirror and a second scanning mirror; The first beam, propagated by the first delay module, is reflected by the reflective surface of the first scanning mirror and then propagates to the beam confluence point; The second beam transmitted by the second delay module is reflected by the reflective surface of the second scanning mirror and then propagates to the beam confluence point.

4. The beam profile measuring device according to claim 3, characterized in that, The beam-splitting module also includes a first focusing lens and a second focusing lens; The first focusing lens is disposed in the optical path between the first scanning mirror and the beam confluence point; The second focusing mirror is disposed in the optical path between the second scanning mirror and the beam confluence point.

5. The beam profile measuring device according to claim 3, characterized in that, Also includes: Scan reflection driver; The main control module also includes a scanning reflection control terminal; the scanning reflection control terminal is connected to the control terminal of the scanning reflection driver; the scanning reflection drive signal output terminal of the scanning reflection driver is connected to the control terminals of the first scanning reflector and the second scanning reflector, respectively.

6. The beam profile measuring device according to claim 4, characterized in that, Also includes: Focused driver; The main control module also includes a focusing control terminal; the focusing control terminal is connected to the control terminal of the focusing driver; the focusing drive signal output terminal of the focusing driver is connected to the control terminal of the first focusing lens and the control terminal of the second focusing lens, respectively.

7. The beam profile measuring device according to claim 1, characterized in that, The first delay module includes m first reflectors; the second delay module includes n second reflectors; where m > n.

8. The beam profile measuring device according to claim 7, characterized in that, The first delay module includes a first reflector group and a second reflector group; each of the first and second reflector groups includes two first reflectors arranged along a first optical axis; along the propagation path of the first beam, the beam splitter and the first reflector group are arranged along the positive direction of the second optical axis, and the first reflector group and the second reflector group are arranged along the negative direction of the second optical axis; wherein the first optical axis intersects the second optical axis; the positive direction of the second optical axis and the negative direction of the second optical axis are opposite directions; and / or, The second delay module includes a second reflector; in the propagation path of the second beam, the second reflector and the beam splitter are arranged along the first optical axis.

9. The beam profile measuring device according to claim 1, characterized in that, The stripped electron collection module includes a fan-shaped deflecting magnet, a power supply, and a Faraday cylinder; The power supply signal output terminal is connected to the power supply signal input terminal of the sector deflecting magnet. The fan-shaped deflecting magnet is positioned on the propagation path of the stripped electrons collected by the electron collection end of the stripped electron collection module. The Faraday cylinder is positioned on the propagation path of the stripped electrons after they have been deflected by the fan-shaped deflecting magnet.

10. The beam profile measuring device according to claim 9, characterized in that, Also includes: Signal amplification module and data acquisition module; The signal amplification module and the data acquisition module are sequentially electrically connected between the measurement signal output terminal of the Faraday cylinder and the measurement signal input terminal of the main control module.

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