Injection system and smearing method of high-current proton accelerator

Abstract

The invention discloses an injection system of a high-current proton accelerator and a smearing method. The injection system comprises a horizontal smearing convex rail and a vertical smearing convex rail. The horizontal smearing convex rail comprises four horizontal scanning magnets; the horizontal scanning convex rail set has the functions of a horizontal fixed convex rail and a horizontal position smearing convex rail, and position smearing and angle smearing of beams in the horizontal direction can be achieved at the same time. The vertical smearing convex rail comprises four vertical scanning magnets; the vertical scanning magnet is used for achieving vertical position smearing. The vertical scanning magnets are located on the two sides of the horizontal smearing protruding rail and are symmetrically arranged relative to the central axis of the horizontal smearing protruding rail. According to the technical scheme, the problem that the peak temperature of a main stripping film is too high due to a traditional convex rail smearing mode can be solved, and the peak temperature of the film is greatly reduced; correlation smearing and anti-correlation smearing can be considered, and free switching of smearing modes is achieved; the layout and the structure of the injection region are simplified; the key difficulty of waste beam collection caused by traditional injection beam angle scanning is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of proton acceleration, and in particular to an injection system and a coating method for a high-current proton accelerator. Background Art

[0002] Currently, high-intensity proton accelerators are widely used in scientific research, industrial applications, medical technology, energy development, and national defense security. They are particularly important in studying material properties using neutron beams produced by spallation neutron sources. Due to the high injected beam power and high particle number density, high-intensity proton accelerators experience significant space charge effects, leading to frequency shifts at the operating point and significant increases in emittance, which in turn cause significant beam losses and severe radiation doses.

[0003] To reduce the impact of space charge effects, the phase space smearing injection method is commonly used, which can effectively alleviate the impact of space charge effects on beam injection and beam accumulation. Phase space smearing methods are generally divided into correlated smearing and anticorrelated smearing, and the specific implementation methods are divided into: bump track and sweep angle. The first phase accelerator of the China Spallation Neutron Source (CSNS) uses a fixed bump track phase space smearing injection method. However, the fixed bump track phase space smearing injection method has several serious problems: the peak temperature of the stripping film is too high; a single fixed smearing method may not be consistent with the actual beam state of future machines; and the fixed bump track magnet has a significant edge focusing effect, which has a significant adverse impact. Summary of the Invention

[0004] The present invention provides an injection system and smearing method for a high-current proton accelerator, and proposes a new design scheme for the injection zone of a synchrotron accelerator. A horizontal fixed cam and a horizontal position scanning cam are combined into a set of cams, and beam smearing is achieved by simultaneously using position and angle scanning in the horizontal direction, thereby improving the smearing uniformity of the beam. The system can significantly reduce the peak temperature of the stripping film, solving the problem of excessively high peak temperature of the stripping film caused by the traditional cam-track smearing method. The system can take into account both correlated and anti-correlated smearing, realizing free switching between different smearing methods. A small cutting pulse magnet is used to compensate for the angle, solving the key difficulty of waste beam collection caused by angle scanning of the injection beam. The system saves a set of cam magnets and a power supply, and simplifies the injection zone structure of the high-current proton accelerator.

[0005] The present invention provides an injection system for a high-current proton accelerator, comprising:

[0006] A horizontal smearing convex rail includes four convex rail scanning magnets; the horizontal scanning magnets are used to realize position scanning and angular scanning of the beam in the horizontal direction; the horizontal smearing convex rail includes a first horizontal scanning magnet, a second horizontal scanning magnet, a third horizontal scanning magnet, and a fourth horizontal scanning magnet arranged in sequence;

[0007] A vertical smearing cam includes four vertical scanning magnets; the vertical magnets are used to achieve smearing of the beam in the vertical direction;

[0008] In which, the vertical scanning magnets are located on both sides of the horizontal smearing convex rail and are symmetrically arranged about the central axis of the horizontal smearing convex rail; the vertical smearing convex rail located at the first horizontal scanning magnet away from the central axis includes a first vertical scanning magnet and a second vertical scanning magnet arranged in sequence; the vertical smearing convex rail located at the fourth horizontal scanning magnet away from the central axis includes a third vertical scanning magnet and a fourth vertical scanning magnet arranged in sequence.

[0009] Optionally, the injection system of the high-current proton accelerator also includes:

[0010] A main stripping film is located between the second horizontal scanning magnet and the third horizontal scanning magnet; the main stripping film is used to strip the injected beam into a circulating beam.

[0011] Optionally, the injection system of the high-current proton accelerator also includes:

[0012] The first DC cutting magnet is located on the side of the first DC cutting magnet facing away from the second horizontal scanning magnet; in a direction parallel to the plane where the second vertical scanning magnet is located, the first DC cutting magnet is located on the side of the second vertical scanning magnet close to the injection beam entry; the first DC cutting magnet is used to cut the injection beam into the small vacuum tube of the yoke of the first horizontal scanning magnet.

[0013] Optionally, the injection system of the high-current proton accelerator also includes:

[0014] The secondary stripping film is located between the third horizontal scanning magnet and the fourth horizontal scanning magnet; the secondary stripping film is used to strip the uncharged particles remaining after the primary stripping film is stripped into waste charged particles.

[0015] Optionally, the high-current proton accelerator injection system also includes:

[0016] The second DC cutting magnet is located between the third vertical scanning magnet and the fourth vertical scanning magnet; the second DC cutting magnet is used to guide the waste charged particles into the waste beam station.

[0017] Optionally, the injection system of the high-current proton accelerator also includes:

[0018] The horizontal cutting pulse magnet is located between the fourth horizontal scanning magnet and the third vertical scanning magnet; the horizontal cutting pulse magnet is used to compensate for the angular dispersion of the waste charged particles.

[0019] Optionally, the injection system of the high-current proton accelerator also includes:

[0020] A horizontal cutting pulse power supply is electrically connected to the horizontal cutting pulse magnet; the horizontal cutting pulse power supply is used to provide a pulse electrical signal to the horizontal cutting pulse magnet, and the horizontal cutting pulse magnet provides a changing magnetic field under the action of the horizontal cutting pulse electrical signal.

[0021] Optionally, the injection system of the high-current proton accelerator also includes: six pulse power supplies;

[0022] The pulse power supply includes four horizontal pulse power supplies and two vertical pulse power supplies; the four horizontal pulse power supplies are electrically connected to the four horizontal scanning magnets respectively; the four horizontal pulse power supplies are used to provide horizontal pulse electrical signals to the four horizontal scanning magnets, and the four horizontal scanning magnets provide a changing magnetic field under the action of the horizontal pulse electrical signals;

[0023] One vertical pulse power supply is electrically connected to two vertical scanning magnets; the two vertical pulse power supplies are used to provide vertical pulse electrical signals to the four vertical scanning magnets, and the four vertical scanning magnets provide changing magnetic fields under the action of the vertical pulse electrical signals.

[0024] Optionally, the pulse electrical signals provided by the pulse power supplies are different.

[0025] In a second aspect, the present invention further provides a coating method for a high-current proton accelerator, which is performed using the injection system for the high-current proton accelerator described in the first aspect. The coating method for the high-current proton accelerator comprises:

[0026] When the high-current proton accelerator is in the related smearing mode, the four horizontal pulse electrical signals received by the four horizontal scanning magnets are in the first mode M1;

[0027] When the high-current proton accelerator is in the anti-correlation smearing mode, the four horizontal pulse electrical signals received by the four horizontal scanning magnets are in the second mode M2;

[0028] The first mode M1 and the second mode M2 ​​are different.

[0029] The technical solution provided by the present invention, by setting a horizontal smearing cam and a vertical smearing cam, allows the beam entering the injection system of the high-current proton accelerator to be smeared in the horizontal and vertical directions, thereby improving the smearing uniformity of the beam. The horizontal smearing cam includes four horizontal scanning magnets. The horizontal smearing cam combines the functions of the fixed cam and the position scanning cam, and can perform horizontal angle scanning smearing and horizontal position smearing on the beam. Using a set of horizontal smearing cams, angle scanning smearing and position scanning smearing in the horizontal direction can be achieved, which greatly increases the contact area between the beam and the stripping film, thereby greatly reducing the peak temperature of the stripping film. It can take into account both correlated and anti-correlated smearing at the same time, realize free switching between different smearing methods, reduce the number of cam magnets set in the injection system of the high-current proton accelerator, and can increase the injection area space of the high-current proton accelerator injection system, which is conducive to optimizing the injection area layout of the high-current proton accelerator and simplifying the structure of the high-current proton accelerator injection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic structural diagram of an injection system for a high-current proton accelerator provided in an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of the change in the position of the RCS reception ellipse during a related smearing process provided by an embodiment of the present invention;

[0032] Figure 3 A schematic diagram of the change in the position of the RCS reception ellipse during an anti-correlation smearing process provided by an embodiment of the present invention;

[0033] Figure 4 A schematic structural diagram of another high-current proton accelerator injection system provided by an embodiment of the present invention;

[0034] Figure 5 A schematic structural diagram of an injection system for a high-current proton accelerator according to another embodiment of the present invention;

[0035] Figure 6 A schematic diagram of a beam flow provided by an embodiment of the invention;

[0036] Figure 7 A schematic diagram of anti-correlation smearing of a beam provided by an embodiment of the present invention;

[0037] Figure 8 A schematic diagram of the peak temperature change of the main peeling film provided by an embodiment of the present invention;

[0038] Figure 9 A schematic diagram of a beam emittance growth curve provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0040] Figure 1 A structural diagram of an injection system for a high-current proton accelerator provided in an embodiment of the present invention is shown in FIG. Figure 1 As shown, the injection system of the high-current proton accelerator includes a horizontal smearing cam 1 and a vertical smearing cam 2: the horizontal smearing cam 1 includes four horizontal scanning magnets BCH, and the horizontal smearing cam is used to achieve position scanning and angle scanning smearing of the beam in the horizontal direction. The horizontal smearing cam 1 includes a first horizontal scanning magnet BCH1, a second horizontal scanning magnet BCH2, a third horizontal scanning magnet BCH3, and a fourth horizontal scanning magnet BCH4 arranged in sequence. The vertical smearing cam 2 includes four vertical scanning magnets BV; the vertical smearing cam is used to achieve smearing of the beam in the vertical direction.

[0041] The vertical scanning magnets BV are located on both sides of the horizontal smearing convex rail 1 and are symmetrically arranged with respect to the central axis OO' of the horizontal smearing convex rail 1 .

[0042] Specifically, the vertical smearing cam 2 can scan the position of the circulating beam in the vertical direction to achieve smearing of the circulating beam in the vertical direction. The horizontal scanning magnet BCH combines the functions of the fixed cam BC and the position scanning cam BH. The horizontal scanning magnet BCH can scan the horizontal angle of the injected beam. At the same time, the horizontal track of the injected beam will also have a small position scan, that is, the horizontal angle and horizontal position of the injected beam will change, and the angle scanning smearing and position scanning smearing of the beam in the horizontal direction can be achieved. By setting the horizontal smearing cam 1 and the vertical smearing cam 2, the horizontal position and vertical position of the circulating beam can be scanned, that is, the horizontal position and vertical position of the circulating beam will change to achieve uniform smearing in the horizontal and vertical directions. Compared to the existing fixed bump track (BC) and position scanning bump track (BH), the horizontal scanning magnet (BCH) in this solution combines the advantages of both. This significantly increases the contact area between the beam and the stripping film, thereby significantly reducing the peak temperature of the stripping film. It can simultaneously take into account both correlated and anticorrelated smearing, enabling free switching between different smearing methods. This reduces the number of bump track magnets required in the injection system of a high-current proton accelerator and simplifies the structure of the hadron proton accelerator injection system. Furthermore, compared to the fixed bump track solution, the horizontal smearing bump track significantly shortens its operating time and significantly reduces the edge focusing effect of the bump track magnet.

[0043] The technical solution provided by the present invention, by setting a horizontal smearing cam and a vertical smearing cam, allows the beam entering the injection system of the high-current proton accelerator to be smeared in the horizontal and vertical directions, thereby improving the uniformity of the beam smearing. The horizontal smearing cam includes four horizontal scanning magnets. The horizontal smearing cam combines the functions of the fixed cam and the position scanning cam, and can perform horizontal angle scanning smearing and horizontal position smearing on the beam. Using a set of horizontal smearing cams, the angle scanning smearing and position scanning smearing in the horizontal direction can be achieved, which greatly increases the contact area between the injected beam and the stripping film, thereby greatly reducing the peak temperature of the stripping film. It can take into account both correlated and anti-correlated smearing at the same time, realize free switching between different smearing methods, reduce the number of cam magnets set in the high-current proton accelerator, make the injection system space of the high-current proton accelerator more spacious, and is conducive to optimizing the injection area layout of the high-current proton accelerator, simplifying the structure of the high-current proton accelerator, and making the high-current proton accelerator easier to achieve lightweight.

[0044] Optional, reference Figure 1 The injection system of the high-current proton accelerator also includes a main stripping film Str-1, which is located between the second horizontal scanning magnet BCH2 and the third horizontal scanning magnet BCH3; the main stripping film Str-1 is used to strip the injection beam into a circulating beam.

[0045] The particle types of the injection beam and the circulating beam can be set according to actual needs. In an exemplary embodiment, the injection beam is negative hydrogen particles and the circulating beam is protons. The main stripping film Str-1 can be used to remove H particles from the injection beam. - The protons are then injected into the ring accelerator. When the injected beam passes through the main stripping membrane Str-1, the H - It will undergo multiple reactions with the carbon ions on the main stripping membrane Str-1, and then be stripped of two electrons, becoming protons.

[0046] Specifically, the interaction between the particles injected into the beam and the carbon ions in the main stripping film Str-1 will increase the temperature of the main stripping film Str-1. At the same time, during the injection process, the circulating beam will repeatedly pass through the main stripping film and interact with the carbon ions, thereby increasing the temperature of the stripping film. Since the horizontal smearing cam 1 can take into account the horizontal angle scanning, the contact area between the beam and the stripping film is greatly increased. At the same time, the horizontal smearing cam 1 and the vertical smearing cam 2 can increase the uniformity of the beam smearing, significantly reducing the average number of times the beam passes through the main stripping film Str-1, thereby significantly reducing the peak temperature of the main stripping film Str-1 during operation, increasing the service life of the main stripping film Str-1, and ensuring the safe and stable operation of the high-current proton accelerator.

[0047] It should be noted that the existing horizontal smearing method using the original smearing cam leads to excessively high peak temperatures of the main stripping film Str-1, causing it to melt at high temperatures and produce numerous holes. For the China Spallation Neutron Source (CSNS) Phase I project, the current peak temperature of the stripping film is approximately 1600K, and its service life is approximately 3-4 weeks, not more than a month. After reaching the end of its service life, it becomes unusable and requires replacement with a new main stripping film Str-1. This process takes approximately two weeks, severely impacting the stable operation of the high-current proton accelerator. For the CSNS Phase II project, the injected beam energy increased by nearly 4 times, the beam intensity increased by 5 times, and the beam power increased by 20 times. Simulations show a peak temperature of nearly 3000K, exceeding the melting point of the stripping film material and rendering the film unusable. This solution adopts a horizontal smearing cam, which comprehensively absorbs the advantages of a fixed cam and a position scanning cam. It can take into account both correlated smearing and anti-correlated smearing, and realize the free switching of different smearing methods. At the same time, it can increase the contact area between the beam and the stripping film, greatly reduce the peak temperature of the main stripping film Str-1, reduce the risk of damage to the main stripping film Str-1, and extend the service life of the main stripping film Str-1.

[0048] For the correlation smearing and anti-correlation smearing, the pulse current drop curve is used for smearing or sweeping in both the horizontal and vertical directions. Figure 2 A schematic diagram of the change in the position of the RCS reception ellipse during a related smearing process provided by an embodiment of the present invention, Figure 3 A schematic diagram of the change in the position of the RCS reception ellipse during an anti-correlation smearing process provided by an embodiment of the present invention is shown as follows: Figure 2 and Figure 3 As shown in Figure 2, for correlated smearing, smearing is from the center to the edge in both the horizontal and vertical directions. For anti-correlated smearing, smearing is from the edge to the center in the horizontal direction and from the center to the edge in the vertical direction.

[0049] Optional, reference Figure 1 The injection system of the high-current proton accelerator also includes a first DC cutting magnet SEP1, which is located on the side of the first horizontal scanning magnet BCH1 away from the second horizontal scanning magnet BCH2. In a direction parallel to the plane where the second vertical scanning magnet BV2 is located, the first DC cutting magnet SEP1 is located on the side of the second vertical scanning magnet BV2 close to the injection beam entry; the first DC cutting magnet SEP1 is used to cut the injection beam into the small vacuum tube of the yoke of the first horizontal scanning magnet BCH1.

[0050] Specifically, the first DC cutting magnet SEP1 can generate an electromagnetic field under the action of an electrical signal. When the injection beam passes through the electromagnetic field in the first DC cutting magnet SEP1, the angle and position of the injection beam will change under the action of the magnetic field, so that the adjusted injection beam can smoothly enter the small vacuum tube of the yoke of the first horizontal scanning magnet BCH1, thereby improving the reliability of the injection beam and reducing the beam loss of the injection beam.

[0051] It should be noted that with existing beam angle scanning, different particles have different angles, and particles scatter during their forward motion. To reduce beam losses, the aperture of the equipment on the injection beam transport line typically needs to be large. However, the present invention places the injection beam scanning magnet BCH2 very close to the injection point, that is, at the junction of the injection beam transport line and the ring. This eliminates the need for a large aperture on the transport line equipment and prevents significant injection beam losses. Therefore, this solution also solves the problem of angle scanning requiring a large aperture at the injection port of the transport line.

[0052] Optional, reference Figure 1 The injection system of the high-current proton accelerator also includes a secondary stripping film Str-2, which is located between the third horizontal scanning magnet BCH3 and the fourth horizontal scanning magnet BCH4; the secondary stripping film Str-2 is used to strip the uncharged particles remaining after the main stripping film is stripped into discarded charged particles.

[0053] Among them, the uncharged particle H 0 Particles, etc., discarded charged particles include protons, etc., which can be set according to actual needs and are not specifically limited here.

[0054] Specifically, after the injected beam passes through the primary stripping film Str-1, most of the injected beam's negative hydrogen ions are stripped of two electrons, becoming protons (a circulating beam). However, in actual applications, some injected beams may fail to convert into a circulating beam, becoming uncharged particles after passing through the primary stripping film Str-1. By placing a secondary stripping film Str-2 between the third horizontal scanning magnet BCH3 and the fourth horizontal scanning magnet BCH4, the uncharged particles are completely stripped into waste charged particles. The waste charged particles are then collected in a waste beam station by the fourth horizontal scanning magnet BCH4 and other magnets on the waste beam line.

[0055] Optional, Figure 4 A structural diagram of another high-current proton accelerator injection system provided in an embodiment of the present invention is shown in FIG. Figure 4 As shown, the injection system of the high-current proton accelerator further includes a horizontal cutting pulse magnet LRBD and a horizontal cutting pulse power supply 50. The horizontal cutting pulse magnet LRBD is located between the fourth horizontal scanning magnet BCH3 and the third vertical scanning magnet BCH4.

[0056] The horizontally cut pulsed magnet (LRBD) is used to compensate for the angular dispersion of the waste charged particles, facilitating their subsequent collection at the waste beam station. Angular dispersion refers to the angular spread of all the waste charged particles.

[0057] Specifically, the horizontal cutting pulse power supply 50 is electrically connected to the horizontal cutting pulse magnet LRBD, so that the horizontal cutting pulse electrical signal provided by the horizontal cutting pulse power supply 50 can be transmitted to the horizontal cutting pulse magnet LRBD. The horizontal cutting pulse magnet provides a changing magnetic field under the action of the horizontal cutting pulse electrical signal. The angular dispersion of the waste charged particles is 0 under the action of the changing magnet, preventing the waste charged particles from diffusing everywhere due to different angular dispersions, thereby improving the accuracy and recovery rate of the collection of the waste charged particles.

[0058] Optional, reference Figure 1 The vertical smearing cam located away from the central axis of the first horizontal scanning magnet BCH1 includes a first vertical scanning magnet BV1 and a second vertical scanning magnet BV2, which are arranged in sequence. The vertical smearing cam located away from the central axis of the fourth horizontal scanning magnet BCH4 includes a third vertical scanning magnet BV3 and a fourth vertical scanning magnet BV4, which are arranged in sequence. The injection system of the high-current proton accelerator also includes a second DC cutting magnet SEP2, which is located between the third vertical scanning magnet BV3 and the fourth vertical scanning magnet BV4. The second DC cutting magnet SEP2 is used to guide waste charged particles into the waste beam station.

[0059] Specifically, after the secondary stripping film Str-2 strips the uncharged particles into waste charged particles, the waste charged particles sequentially pass through the fourth horizontal scanning magnet BCH4 and other magnets on the waste beam line. Because the injected beam is angularly scanned, the waste charged particles drawn from the injection region exhibit an angular distribution over time. Therefore, by installing a horizontal cutting pulse magnet LRBD behind the fourth horizontal scanning magnet BCH4 to compensate for the angle, and then using the second DC cutting magnet SEP2 to guide the waste charged particles into the waste beam station, beam losses during transmission can be significantly reduced, reducing the waste charged particles remaining in the high-current proton accelerator and the resulting radiation dose, thereby improving the personal safety of subsequent inspection and maintenance personnel.

[0060] Optional, Figure 5 A structural diagram of an injection system of a high-current proton accelerator provided in an embodiment of the present invention is shown in FIG. Figure 5As shown, the high-current proton accelerator injection system also includes six pulse power supplies, including four horizontal pulse power supplies 30 and two vertical pulse power supplies 40. The four horizontal pulse power supplies 30 are electrically connected to the four horizontal scanning magnets BCH, respectively, and are used to provide horizontal pulse electrical signals to the four horizontal scanning magnets BCH. The horizontal scanning magnets BCH provide a varying magnetic field under the action of the horizontal pulse electrical signals.

[0061] Specifically, by setting up four horizontal pulse power supplies 30, and each horizontal pulse power supply 30 provides a different pulse electrical signal, each horizontal scanning magnet BCH can generate a different changing magnetic field under the action of the pulse electrical signal, thereby generating four different deflection angles, further improving the uniformity of the beam in the horizontal direction.

[0062] It should be noted that, under the action of different pulse power supplies providing different pulse electrical signals, the magnetic fields generated by the horizontal scanning magnets BCH are different. Figure 6 A schematic diagram of a beam flow provided by an embodiment of the invention, referring to Figure 6 At the beginning of injection, the injection beam and the circulation beam are located on the same line. At this time, the smearing is from the center to the edge in the horizontal direction and from the center to the edge in the vertical direction, so it is a correlated smearing. Figure 7 A schematic diagram of anti-correlation smearing of a beam provided by an embodiment of the present invention, with reference to Figure 7 At the beginning of injection, the purple line represents the injection beam. The injection beam and the circulation beam are not on the same line. At this time, the beam is smeared from the edge to the center in the horizontal direction and from the center to the edge in the vertical direction, so it is anti-correlated smearing. In addition, if Figure 6 and Figure 7 As shown in the figure, the horizontal smearing bump track BCH can be adjusted to an irregular shape under different pulse electrical signals, which can avoid interference between the waste beam extraction tube and the circulating beam vacuum box, and can control the overall movement of the waste beam toward the outside of the ring, greatly reducing the injection beam loss.

[0063] Continue to refer Figure 5 A vertical pulse power supply 40 is electrically connected to two vertical scanning magnets BV. The first vertical scanning magnet BV1 and the fourth vertical scanning magnet BV4 are electrically connected to one vertical pulse power supply 40, while the second vertical scanning magnet BV2 and the third vertical scanning magnet BV3 are electrically connected to another vertical pulse power supply 40.

[0064] Among them, each vertical pulse power supply 40 is used to provide a changing vertical pulse electrical signal. The vertical pulse electrical signal includes a pulse voltage signal or a pulse current signal, which can be selected according to actual needs and is not specifically limited here.

[0065] Specifically, each vertical pulse power supply 40 provides a different pulse electrical signal, so that each vertical scanning magnet BV generates a different changing magnetic field under the action of the pulse electrical signal, thereby generating a different position offset, further improving the uniformity of the beam in the vertical direction.

[0066] Optional, reference Figure 1 When the high-current proton accelerator is in the correlated smearing mode, the four horizontal pulse electrical signals received by the four horizontal scanning magnets BCH1-4 are in the first mode 1; when the high-current proton accelerator beam injection is in the anti-correlated smearing mode, the four horizontal pulse electrical signals received by the four horizontal scanning magnets BCH1-4 are in the second mode M2.

[0067] The first mode M1 and the second mode M2 ​​are different.

[0068] Specifically, the smearing mode of the high-current proton accelerator can be adjusted by adjusting the pulse electrical signals provided to the four horizontal scanning magnets BCH1-4 and adjusting the deflection angle of the first DC cutting magnet SEP1 or other parameters. This can complete the switching between the correlated smearing mode and the anti-correlated smearing mode, realize the free switching of different smearing modes, and improve the flexibility of beam injection of the high-current proton accelerator.

[0069] It should be noted that the reference Figure 1 、 Figure 4 or Figure 5 The injection system of the high-current proton accelerator also includes four DC bump magnets INBA1-4, which are distributed in the LRBT part of the injection system and are used to provide a vertical fixed bump amount during the injection stage so that the correlation and anti-correlation smearing methods can be achieved using the falling edge of the pulse power supply. When the main stripping membrane Str-1 is at a smaller βx and βy, it is beneficial to reduce the injection beam size, reduce the injection beam vacuum box control and optimize the phase space smearing. After the injection system design is completed in a free straight section, the injection system minimizes the impact of the magnetic focusing structure of the RCS, and also reduces the impact of the Lattice parameter changes on the smearing injection. The vast majority of the injection beam that cannot be stripped into protons at the main stripping membrane Str-1 is H 0 , and a very low proportion of H － . H 0 After passing through the secondary stripping membrane Str-2, the beam is almost completely stripped into protons and transported to the waste beam station. － The beam will be absorbed by the copper collimator stopper Col near the secondary stripping film Str-2. The electrons generated by the injected beam passing through the primary stripping film will be deflected by the combined leakage field of the second horizontal scanning magnet and the third scanning magnet, and then collected by a dedicated electron collector.

[0070] This scheme was simulated using Py-ORBIT and ANSYS, with a focus on the influence of space charge effects. To address future adjustments and improvements to the RCS machine mode, three typical operating point modes were focused on: the nominal CSNS operating point (4.86, 4.80), the current operating point of the CSNS (4.80, 4.87), and the operating point that significantly reduces beam instabilities (4.33, 5.30). The simulation results are shown in Table 1.

[0071] Table 1

[0072]

[0073] Compared with the traditional position smearing convex track scheme, although the angle scanning of the beam in this scheme causes the average number of times the particles pass through the stripping film to increase, the area where the injected beam passes through the stripping film is greatly increased. After combining these two factors, the peak temperature of the main stripping film Str-1 is greatly reduced. Figure 8 Schematic diagram of the peak temperature change of the main stripping film provided in an embodiment of the present invention. The left figure shows the horizontal position scanning of the beam using a traditional position smearing cam, and the right figure shows the angle and position smearing of the beam performed by this scheme. It can be seen from the figure that the peak temperature of the main stripping film Str-1 is greatly reduced. Figure 9 A schematic diagram of the beam emittance growth curve provided by an embodiment of the present invention. The left figure shows a conventional fixed-bump scheme, while the right figure shows the beam position smearing performed by this scheme. The figure shows a significant reduction in the edge focusing effect of the injection bump magnet. Simulation results also indicate that the high-current proton accelerator provided by the present invention can implement both correlated and anticorrelated smearing. The high-current proton accelerator can switch smearing modes based on the actual beam state after construction, avoiding numerous failures caused by selecting an inappropriate smearing mode during initial design.

[0074] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations, and substitutions are possible for those skilled in the art without departing from the scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. An injection system for a high-current proton accelerator, characterized in that: include: A horizontal smearing convex rail includes four horizontal scanning magnets; the horizontal scanning magnets are used to realize position scanning and angle scanning of the beam in the horizontal direction; the horizontal smearing convex rail includes a first horizontal scanning magnet, a second horizontal scanning magnet, a third horizontal scanning magnet, and a fourth horizontal scanning magnet arranged in sequence; A vertical smearing cam includes four vertical scanning magnets; the vertical scanning magnets are used to achieve smearing of the beam in the vertical direction; In which, the vertical scanning magnets are located on both sides of the horizontal smearing convex rail and are symmetrically arranged about the central axis of the horizontal smearing convex rail; the vertical smearing convex rail located at the first horizontal scanning magnet away from the central axis includes a first vertical scanning magnet and a second vertical scanning magnet arranged in sequence; the vertical smearing convex rail located at the fourth horizontal scanning magnet away from the central axis includes a third vertical scanning magnet and a fourth vertical scanning magnet arranged in sequence.

2. The injection system of the high-current proton accelerator according to claim 1, characterized in that: Also includes: a main peeling film, located between the second horizontal scanning magnet and the third horizontal scanning magnet; The main stripping film is used to strip the injected beam into a circulating beam.

3. The injection system of the high-current proton accelerator according to claim 1, characterized in that: Also includes: a first DC cutting magnet, located on a side of the first horizontal scanning magnet facing away from the second horizontal scanning magnet; In a direction parallel to the plane where the second vertical scanning magnet is located, the first DC cutting magnet is located on the side of the second vertical scanning magnet close to the injection beam entry; the first DC cutting magnet is used to cut the injection beam into the small vacuum tube of the first horizontal scanning magnet yoke.

4. The injection system of the high-current proton accelerator according to claim 2, characterized in that: Also includes: a secondary peeling film located between the third horizontal scanning magnet and the fourth horizontal scanning magnet; The secondary stripping film is used to strip the uncharged particles remaining after the primary stripping film is stripped to form waste charged particles.

5. The injection system of the high-current proton accelerator according to claim 4, characterized in that: Also includes: a second DC cutting magnet, located between the third vertical scanning magnet and the fourth vertical scanning magnet; The second DC cutting magnet is used to guide the waste charged particles into the waste beam station.

6. The injection system of the high-current proton accelerator according to claim 4, characterized in that: Also includes: a horizontal cutting pulse magnet, located between the fourth horizontal scanning magnet and the third vertical scanning magnet; The horizontal cutting pulse magnet is used to compensate for the angular dispersion of the waste charged particles.

7. The injection system of the high-current proton accelerator according to claim 6, characterized in that: Also includes: a horizontal cutting pulse power supply electrically connected to the horizontal cutting pulse magnet; The horizontal cutting pulse power supply is used to provide a horizontal cutting pulse electrical signal to the horizontal cutting pulse magnet, and the horizontal cutting pulse magnet provides a changing magnetic field under the action of the horizontal cutting pulse electrical signal.

8. The injection system of the high-current proton accelerator according to claim 1, characterized in that: Also includes: Six pulse power supplies; The pulse power supply includes four horizontal pulse power supplies and two vertical pulse power supplies; The four horizontal pulse power supplies are electrically connected to the four horizontal scanning magnets respectively; The four horizontal pulse power supplies are used to provide horizontal pulse electrical signals to the four horizontal scanning magnets, and the horizontal scanning magnets provide a changing magnetic field under the action of the horizontal pulse electrical signals; One of the vertical pulse power supplies is electrically connected to the two vertical scanning magnets; The two vertical pulse power supplies are used to provide vertical pulse electrical signals to the four vertical scanning magnets, and the four vertical scanning magnets provide changing magnetic fields under the action of the vertical pulse electrical signals.

9. The injection system of the high-current proton accelerator according to claim 8, characterized in that: The pulse electrical signals provided by the pulse power supplies are different.

10. A coating method for a high-current proton accelerator, performed using the injection system for a high-current proton accelerator according to any one of claims 1 to 9, characterized in that: The coating method of the high-current proton accelerator includes: When the high-current proton accelerator is in the related smearing mode, the four horizontal pulse electrical signals received by the four horizontal scanning magnets are in the first mode M1; When the high-current proton accelerator is in the anti-correlation smearing mode, the four horizontal pulse electrical signals received by the four horizontal scanning magnets are in the second mode M2; The first mode M1 and the second mode M2 ​​are different.

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