A cyclotron stripping and extraction method

Abstract

The present invention discloses a cyclotron stripping extraction method: determining a target position outside the accelerator to which a beam is extracted, and using a single particle tracking method to simulate the motion trajectory of the beam in the accelerator to obtain the trajectory of the beam when it is accelerated to the extraction energy; calculating the vertical distribution of the beam on the trajectory when it reaches the target position, and adjusting the front and rear positions of a stripping target, which are positions where the vertical direction meets the distribution requirements when the beam reaches the target position; calculating the horizontal distribution of the beam on the trajectory when it reaches the target position, and adjusting the angle between the stripping target and the beam, which is the angle where the horizontal direction meets the distribution requirements when the beam reaches the target position; the present invention adopts a method of first determining the stripping target position and then determining the angle between the stripping target and the beam, thereby solving the problems of the prior art that the horizontal focusing of the beam can only be improved but the vertical focusing cannot be improved, and the beam quality can only be partially improved but not fully improved.

Description

Technical Field

[0001] The invention belongs to the technical field of cyclotron stripping and extraction, and in particular relates to a cyclotron stripping and extraction method. Background Art

[0002] When accelerating a negative ion beam in a cyclotron, a stripping extraction method can be used: a stripping target is installed along the beam's trajectory. When the negative ions pass through a thin film, electrons are stripped away, becoming positive ions. The curvature of the trajectory is reversed, and the ions are extracted from the accelerator. Stripping extraction has the advantages of simple structure, low cost, and high extraction efficiency, making it widely used in cyclotrons.

[0003] Existing ablation extraction technologies are primarily designed for weak beam extraction at the microamp level of 100 μA or less. The beam quality requirements for weak beam extraction are relatively low. This is because the microamp level of 100 μA differs tenfold from the high mA level. Even if particles are lost due to divergence, the loss is only one-tenth of that for the high mA level. Consequently, for a long time, there has been no dedicated research or practice on the installation position and orientation of ablation targets for weak beam extraction. Target installation is typically based on the principle of mounting the target on a circle with a certain radius that meets the extraction energy requirements, and the target is installed wherever mechanical mounting is suitable.

[0004] While the aforementioned stripping extraction method is convenient, the extracted beam quality is relatively poor. Accelerators with high requirements for extracted beam quality generally use other extraction methods. For applications where beam quality is less demanding, beam extraction is sufficient only to a specific location. For example, common small medical cyclotrons operate at low energy and intensity, requiring only that the beam reach the isotope production target. Even partial beam loss poses no significant risk. Therefore, most cyclotrons currently employing stripping extraction do not place such high demands on extracted beam quality, and stripping extraction is a relatively low priority.

[0005] As accelerator technology advances, accelerator flux increases. A beam loss of the same proportion will produce a higher radiation dose, potentially affecting accelerator operation. Therefore, the present invention is needed to improve the quality of the extracted beam and reduce the loss of the extracted beam.

[0006] To improve the quality of beam extraction, prior art application number 201811027056.0, entitled "Extraction Method and System for Improving the Quality of Cyclotron Beam Extraction," proposes a technical solution for "forming an angle between the stripping film in the cyclotron and the beam normal." This solution enhances the radial focusing of the beam by changing the angle between the stripping film and the beam normal, but does not enhance the axial focusing of the beam. As stated in its specification: "When the stripping film forms a certain angle with the beam normal (i.e., perpendicular to the direction of beam movement), ignoring higher-order terms, the angle between the stripping film and the direction perpendicular to the beam movement can be used to focus / defocus in the horizontal direction, but has no effect in the vertical direction."

[0007] The shortcoming of this technical solution is that its principle dictates that it can only change horizontal focusing / defocusing, not vertical focusing / defocusing. Improving beam quality requires focusing not only horizontally but also vertically, requiring both vertical and horizontal focusing. Therefore, existing technologies for stripping and extraction can only partially improve beam quality, not fully. Summary of the Invention

[0008] In order to solve the problems existing in the prior art, the present invention proposes a cyclotron stripping and extraction method, which aims to solve the problem that the prior art can only improve horizontal focusing but not vertical focusing, and can only partially improve beam quality but not fully improve beam quality.

[0009] The present invention proposes the following technical solutions to solve the technical problems:

[0010] A design method for cyclotron stripping extraction is characterized by comprising the following steps:

[0011] Step 1: Determine the target location outside the accelerator to which the beam is to be extracted, and use the single particle tracking method to simulate the motion trajectory of the beam in the accelerator to obtain the trajectory of the beam when it is accelerated to the extraction energy; the target location outside the accelerator to which the beam is to be extracted includes but is not limited to the location of the beam line entrance outside the accelerator and the location where the isotope production target is arranged; the target location is any location within a set radius outside the accelerator;

[0012] Step 2: Calculate the vertical distribution of the beam on the trajectory reaching the target position, and compare whether the vertical distribution meets the vertical allowable range of the target position;

[0013] Step 3: Adjust the front and rear position of the stripping target, which is the position that meets the distribution requirements in the vertical direction when the beam reaches the target position; the adjustment of the front and rear position of the stripping target is to adjust the front and rear position of the stripping target on the beam trajectory;

[0014] Step 4: Calculate the horizontal distribution of the beam on the trajectory reaching the target position, and compare whether the distribution meets the horizontal allowable range of the target position;

[0015] Step 5: Adjust the angle between the stripping target and the beam so that the beam reaches the target position and meets the distribution requirements in the horizontal direction.

[0016] Step 6: After obtaining the front-back position of the stripping target and the angle between the stripping target and the beam from Steps 3 and 5, calculate the horizontal and vertical distribution of the beam on the stripping target, determine the size of the stripping film based on the beam spot size, and determine the installation orientation of the stripping target based on the front-back position of the stripping target and the angle between the stripping target and the beam;

[0017] Step 7: After obtaining the front and rear positions of the stripping target and the angle between the stripping target and the beam in steps 3 and 5, calculate the trajectory and beam envelope of the beam when it passes through the magnetic yoke. The trajectory determines the position of the extraction channel, and the beam envelope determines the size of the extraction channel.

[0018] Furthermore, the specific process of adjusting the front and rear positions of the stripping target in step three is as follows:

[0019] 1) determining all candidate intervals of the stripping target on the trajectory, wherein all candidate intervals include intervals with large curvature of the beam trajectory at each magnetic pole on the trajectory or intervals on the trajectory that are convenient for mechanical installation;

[0020] 2) installing the stripping target on the candidate interval corresponding to the target position among all the candidate intervals;

[0021] 3) adjusting the front and rear positions of the stripping target in the candidate interval corresponding to the target position;

[0022] 4) Observe the vertical distribution of the beam reaching the target position at different front and rear positions of the stripping target;

[0023] 5) Whether the current vertical beam distribution meets the requirements; if not, return to step 3); if so, continue to step 6);

[0024] 6) The front and rear positions of the current stripping target in the candidate interval are used as the positions of the stripping target that meet the requirements.

[0025] Furthermore, the adjustment of the angle between the stripping target and the beam in step 5 is as follows:

[0026] 1) The line connecting the head and tail of the stripping target forms an angle with the beam forward direction;

[0027] 2) The head of the stripping target is fixed and the tail of the stripping target is adjusted;

[0028] 3) Observe the horizontal distribution of the beam when it reaches the target position at different angles;

[0029] 4) Whether the current horizontal distribution meets the requirements, if not, return to step 2), if yes, continue to step 5)

[0030] 5) The angle between the current stripping target and the beam is used as the angle that the stripping target meets the requirements.

[0031] Furthermore, when the front and rear positions of the stripping target are changed, the axial focus and radial focus of the beam reaching the target position will change simultaneously. When the axial focus is enhanced, the radial focus is weakened, or when the axial focus is weakened, the radial focus is enhanced; when the angle between the stripping target and the beam is changed, the radial focus of the beam reaching the target position will change but the axial focus will not change.

[0032] Furthermore, when adjusting the front and rear positions of the stripping target on the trajectory, only whether the vertical distribution of the beam meets the requirements when it reaches the target position is considered, without considering whether the horizontal distribution meets the requirements.

[0033] Furthermore, when calculating the horizontal distribution of the beam on the trajectory reaching the target position, the change in the horizontal distribution is caused by adjusting the change in the vertical distribution of the beam.

[0034] Advantages and effects of the present invention

[0035] 1. The present invention adopts a method of first determining the position of the stripping target and then determining the angle between the stripping target and the beam; first calculating the vertical distribution of the beam when it reaches the target position and then calculating the horizontal distribution of the beam when it reaches the target position. This solves the problem that the existing technology can only improve the horizontal focusing of the beam but not the vertical focusing, and can only partially improve the beam quality but not completely improve the beam quality.

[0036] 2. The present invention organically combines the adjustment of the front and rear positions of the stripping target and the adjustment of the angle between the stripping target and the beam, thereby solving the long-standing problem of poor quality of the beam extracted by the stripping target: the organic combination involves adjusting the front and rear positions of the stripping target while also adjusting the angle between the stripping target and the beam, otherwise it would be like only focusing on one aspect and ignoring the other. Before adjusting the angle between the stripping target and the beam, the front and rear positions of the stripping target must be adjusted first, otherwise it would be like water without a source and a tree without roots. The organic combination of the two and their mutual dependence achieves an effect after the combination, which is much superior to the sum of the individual effects before the combination.

[0037] 3. The present invention cleverly utilizes the characteristics of adjusting the position and posture sequence of the stripping target to solve the long-standing problem of poor beam quality extracted from the stripping target, and realizes the extraction of high-quality flux at a low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of a cyclotron stripping and extraction method according to the present invention;

[0039] Figure 2 This is a process flow chart of a cyclotron stripping and extraction method according to the present invention;

[0040] 1: Magnetic pole; 2: Magnetic yoke; 3: Extraction channel; 4: Stripping target; 5: Target position; 6: Beam trajectory before stripping; 7: Beam trajectory after stripping. DETAILED DESCRIPTION

[0041] Design principle of the present invention

[0042] 1. Innovation of the present invention: For the first time, a design method for cyclotron stripping extraction based on adjusting the stripping target posture is proposed. This method first calculates the posture of the stripping target and then calculates the position and size of the extraction channel opening. The posture of the stripping target is determined according to the requirements of axial focusing and radial focusing when the beam reaches the target position. In previous extraction designs, only step 1 of the present invention, "determining the interval of alternative positions for the stripping target", was used. The purpose of "determining the interval of alternative positions for the stripping target" is to determine the extraction channel. The position of the extraction channel is first calculated and then the position of the stripping target is calculated. The position of the stripping target is designed according to the principle that the beam passes through the extraction channel after extraction. Therefore, the quality of the previous extracted beam is not high enough. Although there have been studies related to the quality of the extracted beam before, there is no method that combines radial focusing and axial focusing for an overall design. The characteristics of the present invention are to first determine the position of the stripping target and then determine the angle between the stripping target and the beam, and to first determine the position of the stripping target and the angle between the stripping target and the beam and then determine the position of the extraction channel.

[0043] 2. Design difficulties of the present invention: The difficulty lies in that changing the vertical distribution of the beam depends on the change of the magnetic field. Since the direction of the magnetic field is vertical, the vertical distribution of the beam is changed by changing the magnetic field. Although the direction of the magnetic field is vertical, the change of the magnetic field will simultaneously bring about changes in the vertical and horizontal distributions of the beam. The present invention adjusts the vertical distribution of the beam by adjusting the front and rear positions of the stripping target, and also changes the horizontal distribution of the beam. The reasons are as follows: (The free oscillation frequency calculation formula is an existing conclusion, combined with the cyclotron magnetic field analysis. There has been no published research on the influence of the stripping target position on the focusing ability, but it is a conclusion that is not difficult to obtain)

[0044] Magnetic drop index:

[0045]

[0046] The focusing ability of the magnetic field is related to the magnetic drop index, the horizontal and vertical free oscillation frequencies:

[0047]

[0048] ν r is radial focusing, ν z Axial focusing. A higher free oscillation frequency indicates stronger focusing capability. The magnetic field at the pole tail decreases rapidly with radius. Considering the reversed beam rotation direction after stripping, the magnetic drop index is a large negative number, resulting in strong horizontal focusing and vertical defocusing. When the stripping target is located at the pole entrance, the extracted beam passes through the pole tail. When the stripping target is located at the pole exit, the extracted beam does not pass through the pole tail, causing the stripping target position to affect both horizontal and vertical focusing.

[0049] 3. The key points of the present invention: ① The order of step three and step five cannot be interchanged, because: adjusting the position of the stripping target in step three will change the focus in the horizontal and vertical directions at the same time, and adjusting the angle between the stripping target and the beam in step five will only change the focus in the horizontal direction. Therefore, it is necessary to perform step three first, so that the vertical beam distribution meets the requirements, and then perform step five to make the horizontal distribution meet the requirements. This is one of the key points of the present invention. ② The order of step two and step four cannot be interchanged. Because the horizontal distribution of the beam arriving at the target position calculated in step four is caused by adjusting the vertical distribution of the beam. If the order is reversed, the horizontal distribution is calculated first and then the vertical distribution is calculated, then after the vertical distribution is calculated, the horizontal distribution needs to be calculated again, so the horizontal distribution must be calculated twice. If the horizontal distribution is only calculated once and before the vertical distribution is calculated, the horizontal distribution calculation is inaccurate.

[0050] 4. In the present invention, the beam center is used as the origin and is divided into longitudinal, horizontal, and vertical directions. The longitudinal direction refers to the direction of the beam, the vertical direction is the direction of the magnetic field, and the horizontal direction is perpendicular to the beam and magnetic fields.

[0051] Based on the above principles, the present invention designs a cyclotron stripping extraction method as follows Figure 1 As shown, its characteristics are: comprising the following steps:

[0052] Step 1: Determine a target location 5 outside the accelerator to which the beam is extracted, and use a single particle tracking method to simulate the motion trajectory of the beam in the accelerator to obtain a trajectory 6 of the beam when accelerated to an extraction energy; the target location 5 outside the accelerator to which the beam is extracted includes but is not limited to a location outside the accelerator where the beam is extracted and a location where an isotope production target is arranged; the target location 5 is any location within a set radius outside the accelerator;

[0053] Supplementary Note 1:

[0054] 1. The target position 5 is not fixed. It can be anywhere on a circle with a certain radius.

[0055] 2. The beam trajectory 6 before stripping is the trajectory of the beam when it is accelerated to the extraction energy;

[0056] 3. Tracking the trajectory of the bunch midpoint is called the single-particle tracking method. Using the single-particle tracking method, the tracked particle is a reference particle designed for the accelerator, and its initial coordinates are the coordinates of the accelerator injection point or the coordinates of the static equilibrium orbit in the low-energy range. The static equilibrium orbit is a closed orbit of the particle in the central plane, determined by the magnetic field of the main magnet, and can reflect the basic orbital characteristics of the particle under the influence of the magnetic field. In the absence of electric field acceleration, the particle can move along the static equilibrium orbit. Using the magnetic field calculated by the main magnet design and the electric field calculated by the high-frequency cavity design as initial conditions, the reference particle is tracked to the extraction region.

[0057] Step 2: Calculate the vertical distribution of the beam on the trajectory 6 when it reaches the target position 5, and compare whether the vertical distribution meets the vertical allowable range of the target position;

[0058] Supplementary Note 2:

[0059] 1. The vertical distribution of the beam arriving at the target position 5 is related to the axial focusing. The better the axial focusing, the smaller the axial divergence of the beam and the smaller the vertical distribution. The worse the axial focusing, the greater the axial divergence of the beam and the greater the vertical distribution.

[0060] 2. Steps 2 to 7 use a multi-particle tracking method with a certain distribution centered on a reference particle; this distribution is provided by the accelerator injection system design or estimated based on the pole 1 gap of the main magnet; these particles are tracked to the stripping target to obtain the particle distribution on the stripping target; the particle distribution on the stripping target is used as the initial condition, the charge number of the particle is changed, and the particles are tracked again to obtain the particle trajectory and distribution after stripping.

[0061] Step 3: Adjust the front-to-back position of the stripping target 4, which is the position that meets the distribution requirements in the vertical direction when the beam reaches the target position 5; the adjustment of the front-to-back position of the stripping target 4 is to adjust the front-to-back position of the stripping target 4 on the beam trajectory 6;

[0062] Supplementary Note 3:

[0063] The stripping target 4 can be installed at any position on the track 6 to achieve extraction at a given energy. The alternative interval of the stripping target 4 position is determined according to the situation. For example, Figure 1For the four pairs of magnetic poles 1 shown, only the results within the 1 / 4 interval need to be considered; the same results can be obtained for other locations due to the symmetry of the accelerator. For example, in many cyclotron accelerators, the stripping target is generally mounted on magnetic pole 1 due to the large curvature of the beam trajectory at magnetic pole 1 and the mechanical structure of the stripping target.

[0064] Step 4: Calculate the horizontal distribution of the beam on the trajectory 6 reaching the target position 5, and compare whether the distribution meets the horizontal allowable range of the target position;

[0065] Supplementary Note 4

[0066] The horizontal distribution of the beam arriving at the target position 5 is related to the radial focusing. The better the radial focusing, the smaller the radial divergence of the beam and the smaller the horizontal distribution. The worse the radial focusing, the greater the radial divergence of the beam and the greater the horizontal distribution.

[0067] Step 5: Adjust the angle between the stripping target and the beam so that the beam reaches the target position and meets the distribution requirements in the horizontal direction.

[0068] Supplementary Note 5

[0069] The angle between the stripping target and the beam is the angle between the stripping target and the direction of the beam. When the angle is 90 degrees, the stripping target is perpendicular to the direction of the beam.

[0070] Step 6: After obtaining the front-back position of the stripping target and the angle between the stripping target and the beam from Steps 3 and 5, calculate the horizontal and vertical distribution of the beam on the stripping target, determine the size of the stripping film based on the beam spot size, and determine the installation orientation of the stripping target based on the front-back position of the stripping target and the angle between the stripping target and the beam;

[0071] Supplementary Note 6

[0072] The beam spot size mentioned in step 6 refers to the size of the beam in the horizontal and vertical directions. The size of the stripping film should have a margin of more than 50% based on the beam spot size.

[0073] Step 7: After obtaining the front and rear positions of the stripping target and the angle between the stripping target and the beam in steps 3 and 5, calculate the trajectory and beam envelope of the beam when it passes through the magnetic yoke 2. The trajectory determines the position of the extraction channel 3, and the beam envelope determines the size of the extraction channel 3.

[0074] Supplementary Note 7

[0075] The beam trajectory in step 7 refers to the trajectory at the center of the tracked particle, and the beam envelope refers to the envelope formed by the particle in the horizontal and vertical directions, which continuously changes as the beam advances. The size of the extraction channel 3 should reserve a margin of more than 50% based on the maximum value of the beam envelope.

[0076] Furthermore, the specific process of adjusting the front and rear positions of the stripping target in step three is as follows:

[0077] 1) determining all candidate intervals of the stripping target on the trajectory, wherein all candidate intervals include intervals with large curvature of the beam trajectory at each magnetic pole 1 on the trajectory or intervals on the trajectory that are convenient for mechanical installation;

[0078] 2) installing the stripping target on the candidate interval corresponding to the target position among all the candidate intervals;

[0079] 3) adjusting the front and rear positions of the stripping target in the candidate interval corresponding to the target position;

[0080] 4) Observe the vertical distribution of the beam reaching the target position at different front and rear positions of the stripping target;

[0081] 5) Whether the current vertical beam distribution meets the requirements; if not, return to step 3); if so, continue to step 6);

[0082] 6) The front and rear positions of the current stripping target in the candidate interval are used as the positions of the stripping target that meet the requirements.

[0083] Furthermore, the adjustment of the angle between the stripping target and the beam in step 5 is as follows:

[0084] 1) The line connecting the head and tail of the stripping target forms an angle with the beam forward direction;

[0085] 2) The head of the stripping target is fixed and the tail of the stripping target is adjusted;

[0086] 3) Observe the horizontal distribution of the beam when it reaches the target position at different angles;

[0087] 4) Whether the current horizontal distribution meets the requirements, if not, return to step 2), if yes, continue to step 5)

[0088] 5) The angle between the current stripping target and the beam is used as the angle that the stripping target meets the requirements.

[0089] Furthermore, when the front and rear positions of the stripping target are changed, the axial focus and radial focus of the beam reaching the target position will change simultaneously. When the axial focus is enhanced, the radial focus is weakened, or when the axial focus is weakened, the radial focus is enhanced; when the angle between the stripping target and the beam is changed, the radial focus of the beam reaching the target position will change but the axial focus will not change.

[0090] Furthermore, when adjusting the front and rear positions of the stripping target on the trajectory, only whether the vertical distribution of the beam meets the requirements when it reaches the target position is considered, without considering the impact of the vertical distribution change on the horizontal distribution change.

[0091] Furthermore, when calculating the horizontal distribution of the beam on the trajectory reaching the target position, the change in the horizontal distribution is caused by adjusting the change in the vertical distribution of the beam.

[0092] It should be emphasized that the above specific embodiments are merely explanations of the present invention and are not limitations of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the above embodiments as needed, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A cyclotron stripping and extraction method, characterized in that: The following steps are involved: Step 1: Determine the target location outside the accelerator to which the beam is to be extracted, and use the single particle tracking method to simulate the motion trajectory of the beam in the accelerator to obtain the trajectory of the beam when it is accelerated to the extraction energy; the target location outside the accelerator to which the beam is to be extracted includes but is not limited to the location of the beam line entrance outside the accelerator and the location where the isotope production target is arranged; the target location is any location within a set radius outside the accelerator; Step 2: Calculate the vertical distribution of the beam on the trajectory reaching the target position, and compare whether the vertical distribution meets the vertical allowable range of the target position; Step 3: Adjust the front and rear position of the stripping target, which is the position that meets the distribution requirements in the vertical direction when the beam reaches the target position; the adjustment of the front and rear position of the stripping target is to adjust the front and rear position of the stripping target on the beam trajectory; Step 4: Calculate the horizontal distribution of the beam on the trajectory reaching the target position, and compare whether the distribution meets the horizontal allowable range of the target position; Step 5: Adjust the angle between the stripping target and the beam so that the beam reaches the target position and meets the distribution requirements in the horizontal direction. Step 6: After obtaining the front-back position of the stripping target and the angle between the stripping target and the beam from Steps 3 and 5, calculate the horizontal and vertical distribution of the beam on the stripping target, determine the size of the stripping film based on the beam spot size, and determine the installation orientation of the stripping target based on the front-back position of the stripping target and the angle between the stripping target and the beam; Step 7: After obtaining the front and rear positions of the stripping target and the angle between the stripping target and the beam in steps 3 and 5, calculate the trajectory and beam envelope of the beam when it passes through the magnetic yoke. The trajectory determines the position of the extraction channel, and the beam envelope determines the size of the extraction channel.

2. The cyclotron stripping and extraction method according to claim 1, characterized in that: The specific process of adjusting the front and rear positions of the peeling target in step 3 is as follows: 1) determining all candidate intervals of the stripping target on the trajectory, wherein all candidate intervals include intervals with large curvature of the beam trajectory at each magnetic pole on the trajectory or intervals on the trajectory that are convenient for mechanical installation; 2) installing the stripping target on the candidate interval corresponding to the target position among all the candidate intervals; 3) adjusting the front and rear positions of the stripping target in the candidate interval corresponding to the target position; 4) Observe the vertical distribution of the beam reaching the target position at different front and rear positions of the stripping target; 5) Whether the current beam vertical distribution meets the requirements; if not, return to step 3); if so, continue to step 6); 6) The front and rear positions of the current stripping target in the candidate interval are used as the positions of the stripping target that meet the requirements.

3. The cyclotron stripping and extraction method according to claim 1, characterized in that: The adjustment of the angle between the stripping target and the beam in step 5 is as follows: 1) The line connecting the head and tail of the stripping target forms an angle with the beam forward direction; 2) The head of the stripping target is fixed and the tail of the stripping target is adjusted; 3) Observe the horizontal distribution of the beam when it reaches the target position at different angles; 4) Whether the current horizontal distribution meets the requirements, if not, return to step 2), if yes, continue to step 5) 5) The angle between the current stripping target and the beam is used as the angle that the stripping target meets the requirements.

4. The cyclotron stripping and extraction method according to claim 1, characterized in that: When the front and rear positions of the stripping target are changed, the axial focus and radial focus of the beam reaching the target position will change at the same time. When the axial focus is enhanced, the radial focus is weakened, or when the axial focus is weakened, the radial focus is enhanced. When the angle between the stripping target and the beam is changed, the radial focus of the beam reaching the target position will change, but the axial focus will not change.

5. The cyclotron stripping and extraction method according to claim 4, characterized in that: When adjusting the front and rear positions of the stripping target on the trajectory, only whether the vertical distribution of the beam meets the requirements when it reaches the target position is considered, without considering the impact of the vertical distribution change on the horizontal distribution change.

6. The cyclotron stripping and extraction method according to claim 1, characterized in that: When calculating the horizontal distribution of the beam on the trajectory reaching the target position, the change in the horizontal distribution is caused by adjusting the change in the vertical distribution of the beam.

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