Method for realizing beam expansion and dispersion angle by quadrupole magnet and solenoid combination

Abstract

The application relates to a method for realizing beam expansion and divergence angle compression by a quadrupole magnet and a solenoid, which is used for controlling high-energy electron beams generated by an accelerator, eliminating the influence of the Coulomb force of the electron beams and weakening the divergence angle of the electron beams. The method realizes electron beam expansion and primary compression of the divergence angle by four fixed permanent quadrupole magnetic rings and one electric quadrupole magnetic ring, and realizes ultimate compression of the beam divergence angle by one composite solenoid electromagnet. The electron beam radius is expanded from the millimeter level to the centimeter level in a very short distance, the influence of the Coulomb force is reduced by 1-2 orders of magnitude, and the increment of the divergence angle is controlled in the 0.01 mrad level. The initial divergence angle of the electron beam is compressed from the 1 mrad level to the 0.1 mrad level, and theoretically, the beam spot can be compressed from the meter level to the 10 cm level when the electron beam is transmitted for 1 km, so that the transmission distance of the electron beam is greatly increased.

Description

Technical Field

[0001] This invention relates to a method for achieving beam amplification and dispersion angle by combining a quadrupole magnet and a solenoid, belonging to the field of particle beam technology. Background Technology

[0002] The emittance of a high-energy electron beam at the accelerator exit is typically mm·mrad, meaning the electron beam radius is on the order of millimeters and the divergence angle is on the order of milliradians. Beam expansion and divergence angle compression are required for long-distance transmission, which can then be applied to synchrotron radiation source generation or electron beam irradiation.

[0003] Because electron beams are negatively charged, the Coulomb force between the charges causes the electron beam cluster radius to expand rapidly. Analysis shows that if an electron beam with a radius on the order of millimeters is allowed to diffuse freely, the increase in its divergence angle due to the Coulomb force will reach several milliradians. This means that after traveling 1 km, the radius of the electron beam will increase to 1 meter. Generally, high-energy electron beams need to move continuously for extended periods within energy storage rings, which typically have a circumference of over 100 meters, and sometimes even on the order of kilometers. However, the radius of these energy storage rings is usually only tens of centimeters. Therefore, if the influence of the Coulomb force cannot be eliminated, the electron beam will hit the inner wall of the energy storage ring within a very short operating time, making it difficult to achieve further energy retention and hindering important applications such as synchrotron radiation source generation.

[0004] The emission intensity of the electron beam at the accelerator exit is typically mm·mrad, which means that the initial divergence angle corresponding to the beam spot radius on the order of millimeters is milliradians. If it is not compressed, the radius of the electron beam will increase to about 1 meter after it has traveled 1 km. The electron beam will also hit the inner wall of the energy storage ring in a very short running time, making it difficult to achieve further energy retention.

[0005] Of course, the above analysis assumes that there are no beam control devices on the energy storage ring. In practical applications, various magnets are used on the energy storage ring to control the electron beam, but the general requirement is that the divergence angle of the electrons entering the energy storage ring should be as small as possible, usually within 0.1 mrad. Furthermore, if the electron beam is used for outer space exploration, such as using it to generate X-rays for spacecraft imaging, the transmission distance of the electron beam in outer space typically reaches hundreds of kilometers. If the electron beam is not expanded and its divergence angle is not compressed, the beam spot reaching the target will be on the order of hundreds of meters, the electron flux density will decrease significantly, and the total integrated energy of the generated X-rays will be very weak, making target imaging difficult.

[0006] Increasing the electron beam radius from millimeters to centimeters over extremely short distances can reduce the influence of Coulomb force by 1 to 2 orders of magnitude, resulting in a divergence angle increment of only 0.01 mrad. Compressing the initial divergence angle of the electron beam from the 1 mrad level to the 0.1 mrad level theoretically allows the beam spot to be compressed from meters to 10 centimeters over a 1 km transmission distance, significantly increasing the transmission distance.

[0007] Currently, the most commonly used method for diffusion and compression divergence angle is the multi-magnet control method, which combines more than a dozen magnets for control. The length of the wire control device usually reaches more than ten meters, which is complex in structure, has low debugging efficiency, and is not conducive to system miniaturization. Summary of the Invention

[0008] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a method for beam amplification and divergence angle compression by combining a quadrupole magnet and a solenoid. This method achieves centimeter-level beam amplification and more than 10 times divergence angle compression within a length of meters, simplifies the existing beam amplification and divergence angle compression system, and lays the foundation for future space exploration applications of electron beams.

[0009] The technical solution of this invention is: a high-energy electron beam expansion and divergence angle compression system, comprising:

[0010] The permanent magnet module includes several permanent magnets, which are used to form a uniform magnetic field to expand the input electron beam in the positive and negative X and positive and negative Y directions and to compress the electron divergence angle; the X and Y directions are mutually perpendicular directions on the radial plane of the permanent magnet.

[0011] An electromagnet module is used to compress the divergence angle of an incident electron beam by controlling the magnitude of the current.

[0012] Furthermore, the permanent magnet module includes four annular permanent magnets; wherein,

[0013] The first ring-shaped permanent magnet forms a uniform magnetic field that causes the input electron beam to expand in the positive and negative X directions;

[0014] The second ring-shaped permanent magnet compresses the electron divergence angle in the X direction after beam expansion;

[0015] The third ring permanent magnet forms a uniform magnetic field that causes the electron beam to expand in the positive and negative Y directions;

[0016] The fourth ring permanent magnet compresses the electron divergence angle in the Y direction after beam expansion.

[0017] Furthermore, the electromagnet module includes a solenoid electromagnet, a controllable current source, and a toroidal electromagnet wound with a coil, used to compress the divergence angle of the electron beam in the X and Y directions.

[0018] Furthermore, the ring electromagnet is a ring multipole magnet controlled by an electric current.

[0019] Furthermore, the solenoid electromagnet includes a current source, a ring-shaped cylindrical permanent magnet, and an electric solenoid;

[0020] The excitation direction of the annular cylindrical permanent magnet is consistent with the beam transmission direction.

[0021] An electric solenoid is fitted around a ring-shaped cylindrical permanent magnet and connected to a current source to compress the divergence angle of the electron beam from the order of mrad to less than 0.1 mrad.

[0022] Furthermore, the end of the solenoid electromagnet along the beam transmission direction is provided with a ring-shaped current intensity test coil conformally designed with the solenoid electromagnet, which is used to test the current of the incident electron beam.

[0023] A method for beam amplification and divergence angle compression using the aforementioned high-energy electron beam expanding and divergence angle compression system includes:

[0024] Select a fixed mounting plane and set up a ring current detector for measuring the beam expansion radius and beam expansion uniformity; install a fluorescent target at a distance from the accelerator exit and measure the divergence angle of the electron beam through the fluorescent target;

[0025] Install the permanent magnet in place: Adjust the angle of the annular permanent magnet and the spacing between adjacent permanent magnets around the central axis so that the electron beam expansion in the X and Y directions reaches the first preset level;

[0026] Install the electromagnet module in place: Adjust and correct the magnetic field size of the electromagnet module, the angle around the central axis, and the distance between it and the permanent magnet. Modulate the divergence angle of the electron beam in the X and Y directions to be consistent and compress it to the second preset level.

[0027] The positions of the fixed permanent magnet and electromagnet modules are used to form an electron beam expansion and divergence angle compression system. At the same time, the electron beam expansion and divergence angle compression system is placed in a magnetically shielded environment and connected to the accelerator.

[0028] Furthermore, a ring-shaped current intensity test coil, conformally designed with the solenoid electromagnet module, is provided at the end of the electromagnet module along the beam transmission direction to test the current of the incident electron beam.

[0029] Furthermore, the first preset level is a number of mrad, and the second preset level is below 0.1 mrad.

[0030] Furthermore, the installation of the electromagnet module into place includes:

[0031] Install the ring electromagnet module in place: adjust and correct the magnitude of the electromagnet's magnetic field, the angle around the central axis, and the distance from the adjacent permanent magnets, modulate the divergence angle of the electron beam in the X and Y directions to be consistent, and compress the beam divergence angle to 1 mrad for the second time.

[0032] Install the solenoid electromagnet in place: Adjust and correct the magnetic field strength of the solenoid electromagnet, the angle around the central axis, and the distance from the ring electromagnet to compress the divergence angle of the electron beam in the X and Y directions to below 0.1 mrad.

[0033] The advantages of this invention compared to the prior art are:

[0034] (1) The currently commonly used diffusion and divergence angle compression method is the multi-magnet control method, which combines more than a dozen magnets for control. The length of the beam control device usually reaches more than ten meters, which is complex in structure, has low debugging efficiency, and is not conducive to system miniaturization. The quadrupole magnet and solenoid combination system proposed in this invention can achieve centimeter-level beam expansion and more than 10 times divergence angle compression within a length of meter. It has a simple structure, reliable operation, and features miniaturization, light weight, and high debugging efficiency.

[0035] (2) This invention is the first to apply solenoid electromagnets to the compression treatment after the divergence angle of the electron beam, which has the advantages of high redundancy, large adjustment range and relaxed requirements for electron beam energy dispersion.

[0036] (3) This invention proposes for the first time an integrated design of composite permanent magnet solenoid, electric solenoid and beam current Liu Qiang test, which greatly reduces the power consumption, weight and size of solenoid electromagnet, and can monitor the electron beam current through the electron beam expansion and compression divergence angle system in real time.

[0037] (4) This invention uses the X / Y direction beam integrated correction electromagnet module and electromagnetic solenoid to jointly control the size of the electron beam divergence angle, which can be remotely corrected and adjusted, laying the technical foundation for the future space application of electron beam equipment. Attached Figure Description

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0039] Figure 1 This is a schematic diagram of the beam amplification and dispersion angle system achieved by combining a quadrupole magnet and a solenoid according to the present invention;

[0040] Figure 2A schematic diagram of the beam phase space spectrum illustrating the implementation process of the method for beam amplification and dispersion angle adjustment using a combination of a quadrupole magnet and a solenoid according to the present invention.

[0041] Figure 3 This is a schematic diagram of the solenoid electromagnet structure involved in the present invention;

[0042] Figure 4 This is a schematic diagram of the fluorescent target used in the measuring device involved in the invention. Detailed Implementation

[0043] To better understand the above technical solutions, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0044] The following description, in conjunction with the accompanying drawings, provides a more detailed explanation of a method for achieving beam amplification and dispersion angle using a combination of a quadrupole magnet and a solenoid, as provided in the embodiments of this application. Specific implementation methods may include (e.g.) Figure 1 As shown):

[0045] A high-energy electron beam beam expansion and divergence angle compression system includes an X-direction beam expanding permanent magnet and an X-direction beam correction permanent magnet module, a Y-direction beam expanding permanent magnet and a Y-direction beam correction permanent magnet module, an X / Y direction beam integrated correction electromagnet module, and a divergence angle compression solenoid electromagnet module, etc.

[0046] The X-direction beam expanding permanent magnet and the X-direction beam correction permanent magnet module consist of two ring-shaped permanent magnets. The first ring-shaped permanent magnet forms a uniform magnetic field that expands the electron beam in the positive and negative X directions. At this time, the electron divergence angle rapidly increases from the initial mrad level to the hundreds of mrad level. After an axial drift of tens of centimeters, the X-direction electron beam radius expands to the cm level. The second permanent magnet rapidly compresses the X-direction electron divergence angle after beam expansion, reducing the divergence angle from the hundreds of mrad level to the several mrad level.

[0047] The Y-direction beam expanding permanent magnet and the Y-direction beam correction permanent magnet module consist of two ring-shaped permanent magnets. The first ring-shaped permanent magnet forms a uniform magnetic field that expands the electron beam in the positive and negative Y directions. At this time, the electron divergence angle rapidly expands from the initial mrad level to the hundreds of mrad level. After an axial drift of tens of centimeters, the radius of the Y-direction electron beam expands to the cm level. The second permanent magnet rapidly compresses the Y-direction electron divergence angle after beam expansion, reducing the divergence angle from the hundreds of mrad level to the several mrad level.

[0048] The X / Y direction beam current integration and correction electromagnet module consists of a precision controllable current source and a toroidal electromagnet wound with coils. The electron beam undergoes X-direction beam expansion via an X-direction beam expanding permanent magnet and an X-direction beam current correction permanent magnet module, and then Y-direction beam expansion via a Y-direction beam expanding permanent magnet and a Y-direction beam current correction permanent magnet module. After this, the beam radius increases from the millimeter level to the centimeter level, and the divergence angle can theoretically be compressed to the 0.1 mrad level. However, due to manufacturing and assembly errors, it is difficult to control the electron beam divergence angle to within 1 mrad over a distance of tens of centimeters. In reality, the divergence angle of the electron beam after expansion usually reaches several mrad levels. Therefore, the X / Y direction beam current integration and correction electromagnet module is needed to further compress the electron beam divergence angle to the mrad level.

[0049] The compressed divergence angle solenoid electromagnet module consists of a precision current source with a power of tens to hundreds of W, a ring-shaped cylindrical solenoid, an electric solenoid, and a current intensity testing coil. A ring-shaped cylindrical permanent magnet is embedded inside the solenoid electromagnet, with its excitation direction aligned with the beam transmission direction. This permanent magnet bears most of the magnetic field strength of the solenoid electromagnet. Metal wire is uniformly wound around the outside of the permanent magnet, forming a set of electric solenoids. By controlling the amplitude of the excitation current, the magnetic field strength can be precisely adjusted to obtain the designed magnetic field type. The current intensity testing coil is located at the end of the solenoid electromagnet, with a separate coil wound around its outside. Through the principle of electromagnetic induction, it can accurately measure the current intensity of the incident electron beam. As mentioned earlier, after beam expansion, the divergence angle of the electron beam is usually on the order of several mrad. Using the X / Y direction beam current comprehensive correction electromagnet module to further compress the divergence angle of the electron beam to the order of mrad, it still cannot meet the needs of practical applications. The function of the divergence angle compression solenoid electromagnet module is to compress the divergence angle of the electron beam from the order of mrad to within 0.1 mrad. In engineering, it can be up to 0.05 mrad at meter-level distances.

[0050] The method for achieving beam amplification and dispersion angle by combining a quadrupole magnet with a solenoid involves the following steps:

[0051] (1) Select a fixed installation plane and set up a ring current detector at a distance of 2 meters. The resolution can reach the millimeter level. It can be considered that the detector is composed of a series of mutually insulated metal rings from the inside out. Each metal ring is divided into four parts: up and down (Y direction), left and right (X direction). The four parts are mutually insulated. That is to say, the current magnitude in the four directions of positive X, negative X, positive Y, and negative Y can be obtained through a ring surface. Through a set of ring surfaces, the beam expansion radius of the electron beam in the X and Y directions can be measured. At the same time, by comparing the current magnitudes of different ring surfaces, the beam expansion uniformity of the electron beam can be analyzed. The main function of the fluorescent target is to measure the beam expansion radius and the beam expansion uniformity.

[0052] (2) Select the same fixed installation plane as the above-mentioned ring current detector and install a fluorescent target 10 meters away from the accelerator exit. The resolution of the fluorescent target can reach the order of 0.1 mm. The divergence angle of the electron beam is measured through the fluorescent target.

[0053] (3) Install the X-direction beam expanding permanent magnet in place, with its central axis coaxial with the accelerator electron beam exit. Adjust the angle of the annular beam expanding permanent magnet (around the central axis) to expand the X-direction electron beam to the order of cm; install the X-direction beam correction permanent magnet in place, with its central axis coaxial with the accelerator electron beam exit, and adjust the angle of the X-direction correction permanent magnet (around the central axis) and the distance between it and the X-direction beam expanding permanent magnet to compress the X-direction electron beam divergence angle to the order of several mrad;

[0054] (4) Install the Y-direction beam expanding permanent magnet in place, with its central axis coaxial with the accelerator electron beam exit. Adjust the angle of the annular beam expanding permanent magnet (around the central axis) and the distance between it and the X-direction correcting permanent magnet in front, so that the Y-direction electron beam expansion reaches the order of cm; install the Y-direction beam correcting permanent magnet in place, with its central axis coaxial with the accelerator electron beam exit, and adjust the angle of the Y-direction correcting permanent magnet (around the central axis) and the distance between it and the Y-direction beam expanding permanent magnet in front, so that the Y-direction electron beam expansion divergence angle is compressed to the order of several mrad;

[0055] (5) Install the X / Y direction beam integration correction electromagnet module in place, with its central axis coaxial with the accelerator electron beam exit. Adjust the magnitude and angle of the correction electromagnet's magnetic field (around the central axis) and the distance between it and the Y direction correction permanent magnet to compress the X / Y direction electron beam divergence angle to the order of mrad;

[0056] (6) Install the compressed divergence angle solenoid electromagnet module into place, with its central axis coaxial with the accelerator electron beam exit. Adjust the magnetic field magnitude, angle (around the central axis), and spacing of the correction solenoid with the X / Y direction beam current integration correction electromagnet to compress the X / Y direction electron beam divergence angle to below 0.1 mrad.

[0057] (7) After all the magnet groups are adjusted to their positions, fix their positions and place the entire beam expansion and divergence angle compression device in a magnetic shielding environment. Connect the system to the accelerator to achieve beam expansion at the cm level and divergence angle compression of more than 10 times.

[0058] In the solution provided in this application embodiment, the present invention addresses the problems of small beam spot diameter and large initial divergence angle at the exit of current high-energy electron beam accelerators. Based on in-depth research on existing electron beam expansion and divergence angle compression technologies, it proposes a new method for beam expansion and divergence angle compression by combining a fixed ring magnet group with a solenoid electromagnet: X-direction electron beam expansion and divergence angle correction are achieved through a set of X-direction beam expanding permanent magnets and X-direction beam current correction permanent magnets; Y-direction electron beam expansion and divergence angle correction are achieved through a set of Y-direction beam expanding permanent magnets and Y-direction beam current correction permanent magnets; the electron beam divergence angle is further compressed through an X / Y direction beam current integrated correction electromagnet module; and finally, the divergence angle of the electron beam is compressed to the order of 0.1 mrad through the solenoid electromagnet.

[0059] like Figure 1 As shown, this invention proposes a high-energy electron beam beam expansion and divergence angle compression system, including an X-direction beam expanding permanent magnet and an X-direction beam correction permanent magnet module, a Y-direction beam expanding permanent magnet and a Y-direction beam correction permanent magnet module, an X / Y direction beam integrated correction electromagnet module, and a divergence angle compression solenoid module, etc.

[0060] 1) X-direction beam expanding permanent magnet and X-direction beam correction permanent magnet module

[0061] This module is divided into two parts: an X-direction beam-expanding permanent magnet and an X-direction beam-correcting permanent magnet. The X-direction beam-expanding permanent magnet is placed at the front end of the entire system to expand the electron beam in the X direction, increasing the electron beam spot size from the millimeter level to the centimeter level. The X-direction beam-correcting permanent magnet is placed at the rear end of the X-direction beam-expanding permanent magnet to compress and correct the large divergence angle of the electron beam from the hundreds of mrad level to the several mrad level.

[0062] 2) Y-direction beam expanding permanent magnet and Y-direction beam correcting permanent magnet module

[0063] This module consists of two parts: a Y-direction beam-expanding permanent magnet and a Y-direction beam-correcting permanent magnet. The Y-direction beam-expanding permanent magnet is placed behind the X-direction beam-correcting permanent magnet to expand the electron beam in the Y direction, increasing the electron beam spot size from the millimeter level to the centimeter level. The Y-direction beam-correcting permanent magnet is placed behind the Y-direction beam-expanding permanent magnet to compress and correct the large divergence angle of the electron beam, reducing the divergence angle in the Y direction from the hundreds of mrad level to the several mrad level.

[0064] 3) X / Y direction beam current integrated correction electromagnet module

[0065] The X / Y direction beam current integrated correction electromagnet module consists of a precision controllable current source and a toroidal electromagnet wound with coils. This module is located at the rear end of the Y direction beam current correction permanent magnet. The electron beam undergoes X-direction beam expansion and divergence angle compression after passing through the X-direction beam expanding permanent magnet and the X-direction beam current correction permanent magnet module, and then undergoes Y-direction beam expansion and divergence angle compression after passing through the Y-direction beam expanding permanent magnet and the Y-direction beam current correction permanent magnet module. Due to manufacturing and assembly errors, the divergence angle of the electron beam typically reaches several mrads within a distance of tens of centimeters. The X / Y direction beam current integrated correction electromagnet module further compresses the divergence angle of the electron beam to the mrad level.

[0066] 4) Compression divergence angle solenoid electromagnet module

[0067] The compressed divergence angle solenoid electromagnet module consists of a precision current source with a power of several hundred watts, a ring-shaped cylindrical permanent magnet, an electric solenoid, and a current intensity testing coil. The ring-shaped cylindrical permanent magnet is embedded inside the solenoid electromagnet, and its outer wall is uniformly wound with metal wire. This module is located at the rear end of the X / Y direction beam current integration and correction electromagnet module. Its function is to compress the divergence angle of the electron beam from the mrad range to within 0.1 mrad, and in engineering, it can achieve an optimal 0.05 mrad at meter-level distances. An independent wound coil is configured at the end of the solenoid electromagnet; through the principle of electromagnetic coupling, accurate testing of the incident electron beam current intensity can be achieved.

[0068] like Figure 2 As shown, a method for beam amplification and dispersion angle using a combination of a quadrupole magnet and a solenoid is described, and the implementation steps are as follows:

[0069] (1) Select a fixed installation surface and set up a ring current detector at a distance of 2 meters. Figure 3 The main function of this detector is to measure the beam expansion radius and the uniformity of the beam expansion; a fluorescent target is installed 10 meters away from the accelerator exit. Figure 4 The divergence angle of the electron beam is measured using a fluorescent target.

[0070] (2) Install the X-direction beam expanding permanent magnet in place. Adjust the angle of the annular beam expanding permanent magnet (around the central axis) to expand the X-direction electron beam to the order of cm; install the X-direction beam correcting permanent magnet in place. Adjust the angle of the X-direction correcting permanent magnet (around the central axis) and the distance between it and the preceding X-direction beam expanding permanent magnet to compress the X-direction electron beam divergence angle to the order of several mrad;

[0071] (3) Install the Y-direction beam expanding permanent magnet in place. Adjust the angle of the annular beam expanding permanent magnet (around the central axis) and the distance between it and the preceding X-direction correcting permanent magnet to expand the Y-direction electron beam to the order of cm; Install the Y-direction beam correcting permanent magnet in place. Adjust the angle of the Y-direction correcting permanent magnet (around the central axis) and the distance between it and the preceding Y-direction beam expanding permanent magnet to compress the Y-direction electron beam divergence angle to the order of several mrad;

[0072] (4) Install the X / Y direction beam integration correction electromagnet module into place. Adjust the magnitude and angle of the correction electromagnet's magnetic field (around the central axis) and the distance between it and the Y direction correction permanent magnet to compress the X / Y direction electron beam divergence angle to the order of mrad;

[0073] (6) Install the compressed divergence angle solenoid electromagnet module into place. Adjust the magnetic field strength, angle (around the central axis) of the correcting solenoid electromagnet and the distance between it and the X / Y direction beam current integration correcting electromagnet to compress the X / Y direction electron beam expansion divergence angle to below 0.1 mrad;

[0074] (7) After all the magnet groups are adjusted to their positions, fix their positions and place the entire beam expansion and compression divergence angle device in a magnetically shielded environment. Connect the system to the accelerator to enable the system to work normally.

[0075] This invention relates to a method for expanding and compressing the divergence angle of a high-energy electron beam, used to control high-energy electron beams generated by accelerators, eliminate the influence of the electron beam's own Coulomb force, and reduce the divergence angle of the electron beam. Expanding the electron beam radius from the millimeter level to the centimeter level over an extremely short distance can reduce the influence of the Coulomb force by 1-2 orders of magnitude, resulting in a divergence angle increment controlled to the order of 0.01 mrad. Compressing the initial divergence angle of the electron beam from the order of 1 mrad to the order of 0.1 mrad theoretically allows the beam spot to be compressed from the meter level to the 10 cm level when the electron beam travels 1 km, significantly increasing the transmission distance. Electron beam space communication and X-ray imaging are important future applications; this method shortens the total length of traditional beam expanding and divergence angle compressing devices from the order of 10 meters to the order of meters.

[0076] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0077] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

[0078] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A high-energy electron beam expanding and divergence angle compression system, characterized in that, include: The permanent magnet module includes several permanent magnets, which are used to form a uniform magnetic field to expand the input electron beam in the positive and negative X and positive and negative Y directions and to compress the electron divergence angle; the X and Y directions are mutually perpendicular directions on the radial plane of the permanent magnet. An electromagnet module is used to compress the divergence angle of an incident electron beam by controlling the magnitude of the current. The electromagnet module includes a solenoid electromagnet, a controllable current source, and a toroidal electromagnet wound with coils, used to compress the divergence angle of the electron beam in the X and Y directions. The solenoid electromagnet includes a current source, a ring-shaped cylindrical permanent magnet, and an electric solenoid. The excitation direction of the annular cylindrical permanent magnet is consistent with the beam transmission direction. An electric solenoid is fitted around a ring-shaped cylindrical permanent magnet and connected to a current source to compress the divergence angle of the electron beam from the order of mrad to less than 0.1 mrad.

2. The high-energy electron beam expanding and divergence angle compression system according to claim 1, characterized in that, The permanent magnet module includes four ring-shaped permanent magnets; wherein... The first ring-shaped permanent magnet forms a uniform magnetic field that causes the input electron beam to expand in the positive and negative X directions; The second ring-shaped permanent magnet compresses the electron divergence angle in the X direction after beam expansion; The third ring permanent magnet forms a uniform magnetic field that causes the electron beam to expand in the positive and negative Y directions; The fourth ring permanent magnet compresses the electron divergence angle in the Y direction after beam expansion.

3. The high-energy electron beam expanding and divergence angle compression system according to claim 1, characterized in that, The ring electromagnet is a ring-shaped multipole magnet controlled by an electric current.

4. The high-energy electron beam expanding and divergence angle compression system according to claim 1, characterized in that, The end of the solenoid electromagnet along the beam transmission direction is provided with a ring-shaped current intensity test coil that is conformally designed with the solenoid electromagnet, which is used to test the current of the incident electron beam.

5. A method for beam amplification and divergence angle compression using the high-energy electron beam expanding and divergence angle compression system described in claim 1, characterized in that, include: Select a fixed mounting plane and set up a ring current detector for measuring the beam expansion radius and the uniformity of the beam expansion; A fluorescent target is installed at a distance from the accelerator exit, and the divergence angle of the electron beam is measured through the fluorescent target; Install the permanent magnet in place: Adjust the angle of the annular permanent magnet and the spacing between adjacent permanent magnets around the central axis so that the electron beam expansion in the X and Y directions reaches the first preset level; Install the electromagnet module in place: Adjust and correct the magnetic field size of the electromagnet module, the angle around the central axis, and the distance between it and the permanent magnet. Modulate the divergence angle of the electron beam in the X and Y directions to be consistent and compress it to the second preset level. The positions of the fixed permanent magnet and electromagnet modules are used to form an electron beam expansion and divergence angle compression system. At the same time, the electron beam expansion and divergence angle compression system is placed in a magnetically shielded environment and connected to the accelerator. The process of installing the electromagnet module in place includes: Install the ring electromagnet module in place: adjust and correct the magnitude of the electromagnet's magnetic field, the angle around the central axis, and the distance from the adjacent permanent magnets, modulate the divergence angle of the electron beam in the X and Y directions to be consistent, and compress the beam divergence angle to 1 mrad for the second time. Install the solenoid electromagnet in place: Adjust and correct the magnetic field strength of the solenoid electromagnet, the angle around the central axis, and the distance from the ring electromagnet to compress the divergence angle of the electron beam in the X and Y directions to below 0.1 mrad.

6. The method according to claim 5, characterized in that, A ring-shaped current intensity test coil, conformally designed with the solenoid electromagnet module, is provided at the end of the electromagnet module along the beam transmission direction to test the current of the incident electron beam.

7. The method according to claim 5, characterized in that, The first preset level is several mrad, and the second preset level is below 0.1 mrad.

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