A high-energy proton space transmission control method based on bayesian optimization

Abstract

The application relates to a high-energy proton space transmission control method based on Bayesian optimization. The method comprises the following steps: constructing a single-particle motion model by comprehensively considering the influence of the magnetic field force, the relativistic effect and the bremsstrahlung emitted by the high-energy proton itself on the motion trajectory of the high-energy proton in a proton transmission space model; obtaining a candidate exit angle of a Gaussian proton through a Bayesian optimization algorithm on the basis of the single-particle motion model; controlling the high-energy proton to exit through the candidate exit angle; controlling the high-energy proton to transmit from an initial point to a target point through the single-particle motion model to obtain a proton transmission path; finally, selecting a transmission path with the minimum energy loss as an optimal path, and selecting a candidate exit angle corresponding to the optimal path as an optimal exit angle. The method can realize accurate control of high-energy protons in space transmission.

Description

Technical Field

[0001] This application relates to the field of proton space transport technology, and in particular to a high-energy proton space transport control method based on Bayesian optimization. Background Technology

[0002] In recent years, the emission of charged particles has been widely used in radiation protection, space debris removal and other fields. In the research conducted at home and abroad, most researchers have focused on electron transport due to the fact that the mass of electrons is much smaller than that of ions. There is relatively little research on high-energy protons. However, the transport of high-energy protons plays an important role in the research of space weapons. Therefore, it is necessary to study the precise control of high-energy proton transport in space.

[0003] Although existing research on electron transport can be applied to proton transport to some extent, the transport of high-energy protons in space is closely related to factors such as the strength and direction of the Earth's magnetic field and their own energy. Existing research has not fully considered the deflection and radiation of high-energy protons by the Earth's magnetic field, as well as the influence of relativistic factors on the transport of high-energy protons. As a result, the space transport of high-energy protons still faces technical problems such as low control precision and great difficulty in engineering applications. Summary of the Invention

[0004] Therefore, it is necessary to provide a Bayesian optimization-based high-energy proton space transport control method to address the aforementioned technical problems and achieve precise control of high-energy proton space transport.

[0005] A high-energy proton space transport control method based on Bayesian optimization, the method comprising:

[0006] A space model for proton transport is constructed, and the space model of the proton transport environment is a geomagnetic field model in near-Earth space.

[0007] High-energy protons are injected into the proton transport space model. The trajectory of the high-energy protons is constrained by the magnetic field force, relativistic effects and bremsstrahlung emitted by the high-energy protons in the proton transport space model. A single-particle motion model of the high-energy protons in the proton transport space model is then constructed.

[0008] The initial and target points of high-energy protons in the proton transport space model are obtained. The emission angle of high-energy protons at the initial point is optimized according to the Bayesian optimization algorithm, and the emission angle with the closest distance to the target point after emission is less than the set distance is selected as the candidate emission angle.

[0009] The high-energy protons are controlled to exit from the initial point based on the selected exit angle, and then transported from the initial point to the target point based on the single-particle motion model. The transmission path of the high-energy protons is obtained, and the transmission path with the least energy loss is selected as the optimal path of the high-energy protons in the proton transmission space model. The selected exit angle corresponding to the optimal path is then selected as the optimal exit angle.

[0010] In one embodiment, the proton transport space model is represented as follows:

[0011]

[0012] Where μ0 is the free permeability. This represents a vector coordinate in a (x, y, z) coordinate system constructed with the Earth's center as the origin. The x-axis points to the equator and intersects the Earth's surface at the 0° meridian, and the z-axis points towards the Earth's North Pole. It is a unit vector along the x-axis. It is a unit vector along the y-axis. It is a unit vector along the z-axis. The vector represents the unit vector of the coordinate system, r represents the distance between the coordinate system and the origin, and M is the magnitude of the Earth's magnetic moment. The magnetic moment of the Earth is antiparallel to the z-axis.

[0013] In one embodiment, the trajectory of the high-energy proton is constrained by the magnetic field force in the proton transport space model, as expressed as:

[0014]

[0015] Where m0 represents the rest mass of the high-energy proton, q represents the charge of the high-energy proton, v represents the velocity of the high-energy proton, E(r) = 0 represents the electric field strength, dt represents the time step, v represents the velocity vector of the high-energy proton, and B(r) represents the magnetic induction intensity in the proton transport space model.

[0016] In one embodiment, the trajectory of the high-energy proton is constrained according to relativistic effects, as expressed as:

[0017]

[0018] in, This represents the mass of a high-energy proton, where γ is the relativistic factor, γ = (1 - v 2 / c 2 )-(1 / 2), where c represents the speed of light.

[0019] In one embodiment, the power of bremsstrahlung emitted by high-energy protons in the proton transport space model is expressed as:

[0020]

[0021] Where q represents the charge of the high-energy proton, and v represents the velocity of the high-energy proton. Let ε0 be the first derivative of velocity with respect to time, ε0 be the vacuum conductivity, and c be the speed of light.

[0022] In one embodiment, the initial point and target point of the high-energy proton in the proton transport space model are obtained. The emission angle of the high-energy proton at the initial point is optimized according to the Bayesian optimization algorithm, and the emission angle with the closest distance to the target point after emission being less than a set distance is selected as the candidate emission angle, expressed as:

[0023] The initial and target points of high-energy protons in the proton transport space model are obtained. The radial and angular angles of the high-energy protons at the initial point are optimized using the Bayesian optimization algorithm. The exit angle with the closest distance to the target point after exiting is less than a set distance is selected as the candidate exit angle. The set distance is 10 meters.

[0024] The aforementioned Bayesian optimization-based high-energy proton space transport control method comprehensively considers the influence of magnetic field forces, relativistic effects, and bremsstrahlung emitted by the high-energy protons on their trajectories in the proton transport space model. A single-particle motion model is constructed based on this model. Then, a Bayesian optimization algorithm is used to obtain candidate emission angles for Gaussian protons. These candidate emission angles are then used to control the high-energy proton emission, and the single-particle motion model is used to control the high-energy protons' transport from the initial point to the target point, obtaining the proton transport path. Finally, the transport path with the minimum energy loss is selected as the optimal path, and the corresponding candidate emission angle is chosen as the optimal emission angle. This method enables precise control of high-energy protons during space transport. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating a high-energy proton space transport control method based on Bayesian optimization in one embodiment.

[0026] Figure 2 This is a schematic diagram comparing the magnetic field strength calculated based on the proton transport space model with the actual geomagnetic field strength in one embodiment.

[0027] Figure 3 This is a schematic diagram of the trajectory of a high-energy proton under the constraint of a magnetic field in a proton transport space model in one embodiment.

[0028] Figure 4 This is a schematic diagram comparing the trajectories of high-energy protons with and without considering relativistic effects in one embodiment.

[0029] Figure 5This is a schematic diagram comparing the trajectories of high-energy protons with and without considering bremsstrahlung in one embodiment;

[0030] Figure 6 This is a schematic diagram illustrating the relationship between the closest distance between a high-energy proton and the target point and the emission angle in one embodiment.

[0031] Figure 7 This is a schematic diagram illustrating the motion of high-energy protons in one embodiment; wherein, Figure 7 (a) is a schematic diagram showing three scenarios of a high-energy proton moving from the initial point to the target point. Figure 7 (b) is a schematic diagram illustrating three scenarios in which a high-energy proton cannot move from the initial point to the target point. Figure 7 (c) is a schematic diagram showing the thermodynamic relationship between the minimum distance and the launch angle when the initial point and the target point are at the same height. Figure 7 (d) is a schematic diagram of the thermodynamic relationship between the minimum distance and the launch angle when the initial point is 1 km higher than the target point. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0033] In one embodiment, such as Figure 1 As shown, a high-energy proton space transport control method based on Bayesian optimization is provided, including the following steps:

[0034] Step S1: Construct a proton transport space model. The proton transport environment space model is a geomagnetic field model in near-Earth space.

[0035] Near-Earth space refers to the spatial region extending from the Earth's center within a radius of 1.015 to 6.6 Earth radii.

[0036] Step S2: Inject high-energy protons into the proton transport space model. Constrain the trajectory of the high-energy protons based on the magnetic field force, relativistic effects, and bremsstrahlung emitted by the high-energy protons in the proton transport space model. Construct a single-particle motion model of the high-energy protons in the proton transport space model.

[0037] It is understandable that the Earth's magnetic field, relativity, and bremsstrahlung can affect the speed and direction of high-energy protons, thus influencing their trajectory. Therefore, when constructing a single-particle motion model, considering the constraints of the Earth's magnetic field, relativity, and bremsstrahlung effectively improves the accuracy of the single-particle motion model in simulating the trajectory of high-energy protons.

[0038] Step S3: Obtain the initial point and target point of the high-energy proton in the proton transport space model. Optimize the emission angle of the high-energy proton at the initial point according to the Bayesian optimization algorithm, and select the emission angle whose closest distance to the target point after emission is less than a set distance as the candidate emission angle.

[0039] Bayesian optimization is a method for finding the optimal solution of a function through surrogate optimization. The true objective function is generally unknown, so a surrogate function is used to replace the objective function. The surrogate function can first sample some points and then fit the objective function using the obtained points. Based on the constructed surrogate function, more points can be collected near the optimal solution points or in the unsampled region. By using more points to update the surrogate function, it can be made to more closely approximate the shape of the true objective function. The sampling process can be represented by constructing a sampling function, that is, knowing the shape of the current surrogate function, selecting the next point to maximize the benefit, and repeating the above process to finally obtain an approximate optimal solution of the function.

[0040] Step S4: Control the high-energy protons to be emitted from the initial point according to the selected emission angle, and control the high-energy protons to be transmitted from the initial point to the target point according to the single-particle motion model. Obtain the transmission path of the high-energy protons, select the transmission path with the least energy loss as the optimal path of the high-energy protons in the proton transmission space model, and select the selected emission angle corresponding to the optimal path as the optimal emission angle.

[0041] In one embodiment, the proton transport space model is represented as follows:

[0042]

[0043] Where μ0 is the free permeability. This represents a vector coordinate in a (x, y, z) coordinate system constructed with the Earth's center as the origin. The x-axis points to the equator and intersects the Earth's surface at the 0° meridian, and the z-axis points towards the Earth's North Pole. It is a unit vector along the x-axis. It is a unit vector along the y-axis. It is a unit vector along the z-axis. The vector represents the unit vector of the coordinate system, r represents the distance between the coordinate system and the origin, and M is the magnitude of the Earth's magnetic moment. The magnetic moment of the Earth is antiparallel to the z-axis.

[0044] Where x = R at the Earth's equator e (R e (where is the Earth's radius), y = z = 0, and the Earth's magnetic field strength is approximately B0 = 3.07 × 10⁻⁶. -5 T, Therefore, the expression for the proton transport space model at this point is:

[0045]

[0046] like Figure 2 As shown, this application compares the magnetic field strength calculated based on the proton transport space model with the actual geomagnetic field strength obtained from the International Geomagnetic Reference Field (IGRF). The goodness of fit of the magnetic field strength calculated based on the proton transport space model is calculated to be R. 2 =0.9739, which is a good result, indicating that the proton transport space model can be used to replace the actual geomagnetic field.

[0047] In one embodiment, the trajectory of the high-energy proton is constrained by the magnetic field force in the proton transport space model, as expressed as:

[0048]

[0049] Where m0 represents the rest mass of the high-energy proton, q represents the charge of the high-energy proton, v represents the velocity of the high-energy proton, E(r) = 0 represents the electric field strength, dt represents the time step, v represents the velocity vector of the high-energy proton, and B(r) represents the magnetic induction intensity in the proton transport space model.

[0050] Specifically, after constraining the trajectory of high-energy protons based on the magnetic field force in the proton transport space model, the trajectory of high-energy protons is as follows: Figure 3 As shown.

[0051] In one embodiment, the trajectory of the high-energy proton is constrained according to relativistic effects, as expressed as:

[0052]

[0053] in, This represents the mass of a high-energy proton, where γ is the relativistic factor, γ = (1 - v 2 / c 2 )-(1 / 2), where c represents the speed of light.

[0054] It is understandable that when a particle's energy is greater than 1 / 10 of its rest energy, the effects of relativistic effects on the particle's velocity, mass, etc., should be considered. Specifically, given a high-energy proton energy of 100 MeV and an ejection sphere coordinate of... The launch angle is At that time, should we consider the relativistic effects on the trajectory of high-energy protons, for example? Figure 4 As shown, by Figure 4It can be seen that whether or not relativistic effects are considered has little impact on the general direction of motion of high-energy protons, but has a significant impact on their precise position. Calculations show that the maximum distance between the two curves at the same moment can reach more than 20,000 m. Relativism has a significant impact on whether high-energy protons can be transported to the target point. Therefore, the constraints of relativistic effects need to be considered when constructing motion models.

[0055] In one embodiment, the power of bremsstrahlung emitted by high-energy protons in the proton transport space model is expressed as:

[0056]

[0057] Where q represents the charge of the high-energy proton, and v represents the velocity of the high-energy proton. Let ε0 be the first derivative of velocity with respect to time, ε0 be the vacuum conductivity, and c be the speed of light.

[0058] Bremsstrahlung is understandable; it refers to the radiation produced by the sudden deceleration of high-speed particles. High-energy protons moving in a magnetic field are not only deflected by the Lorentz force, but also undergo bremsstrahlung. While emitting bremsstrahlung, high-energy protons lose energy, affecting the Lorentz deflection radius and thus their trajectory. Specifically, given a high-energy proton with an energy of 100 MeV and an exit sphere coordinate of... The launch angle is At that time, should the trajectory of the high-energy protons in bremsstrahlung be considered, for example... Figure 5 As shown, by Figure 5 It can be observed that the effect of bremsstrahlung on the trajectory of high-energy protons is similar to the effect of relativity. Figure 5 The distance between the two curves at the same moment can be more than 80,000m, so the constraint of phase bremsstrahlung needs to be considered when constructing the motion model.

[0059] In one embodiment, the trajectory of the high-energy proton is constrained based on the magnetic field force, relativistic effects, and bremsstrahlung emitted by the high-energy proton in the proton transport space model, and a single-particle motion model of the high-energy proton in the proton transport space model is constructed as follows:

[0060]

[0061] In this context, the velocity v of the high-energy proton is determined by the given proton energy, and the other parameters are consistent with the above description.

[0062] In one embodiment, the initial point and target point of the high-energy proton in the proton transport space model are obtained. The emission angle of the high-energy proton at the initial point is optimized according to the Bayesian optimization algorithm, and the emission angle with the closest distance to the target point after emission being less than a set distance is selected as the candidate emission angle, expressed as:

[0063] The initial and target points of high-energy protons in the proton transport space model are obtained. The radial and angular angles of the high-energy protons at the initial point are optimized using the Bayesian optimization algorithm. The exit angle with the closest distance to the target point after exiting is less than a set distance is selected as the candidate exit angle. The set distance is 10 meters.

[0064] Specifically, firstly, a spherical coordinate system is established within the proton transport space model as follows: Obtain the initial and target coordinates of the high-energy proton in spherical coordinates. By changing the proton's emission angle, discretize the proton's motion over time, with dt = 10. -8 S is a time step. The Lorentz force is calculated once every dt, and the acceleration is changed. A total of N steps are taken, and the coordinates at each moment are recorded. Finally, a 3*N dimensional coordinate matrix of the particle's motion is obtained. This matrix can be used to calculate the distance to the target point at each moment, ultimately determining the minimum distance. Here, r represents the distance from a point in the coordinate system to the origin, and θ represents the zenith angle between a point in the coordinate system and the positive z-axis. This represents the azimuth angle between the projection of the line connecting a point in the coordinate system to the origin onto the xy-plane and the positive x-axis. Then, the radial and angular directions of the high-energy proton's exit angle at the initial point are optimized using a Bayesian optimization algorithm.

[0065] In one specific embodiment, firstly, given a high-energy proton energy of 100 MeV, the initial point coordinates in spherical coordinates are... The coordinates of the target point are When a high-energy proton is emitted, the relationship between the closest distance to the target point and the emission angle is as follows: Figure 6 As shown. Then, based on the Bayesian optimization algorithm, the radial angle v of the high-energy proton's exit angle at the initial point is calculated. θ and angle to angle v φ Optimize to obtain, for example Figure 7 (a) shows the three candidate emission angles, and the radial angle v of the candidate emission angle. θ and angle to angle v φThe values ​​are represented as (1.4965, 2.07654), (1.73651, 2.06042), and (1.10425, 1.7201), respectively. The closest distances to the target point after launch are approximately 5.55m, 1.15m, and 6.56m, respectively, all meeting the requirement of a minimum distance to the target point of less than 10m. The high-energy protons are then controlled by three candidate launch angles, and their transmission from the initial point to the target point is controlled using a single-particle motion model. The transmission paths of the protons are obtained, with the third direction showing the lowest energy loss. Figure 7 The third case in (a) has the lowest energy loss; therefore, the transmission path with the lowest energy loss is selected as the optimal path, and the candidate emission angle corresponding to the optimal path is selected as the optimal emission angle. Furthermore, this application... Figure 7 (b) Demonstrates three scenarios where a high-energy proton cannot reach the target point from its initial point. In all three scenarios, the minimum distance between the high-energy proton's trajectory and the target point is greater than 10m. Furthermore, the radial and angular angles of the Gaussian proton's candidate emission angles are (2.8, 2.1), (1.6, 2), and (1.1, 1.8), respectively, with minimum distances to the target point of approximately 81711m, 86844m, and 25786m, respectively. This application... Figure 7 (c) A thermodynamic diagram showing the minimum distance versus the launch angle at the same heights of the initial and target points is presented, and... Figure 7 (d) presents a thermodynamic diagram showing the minimum distance versus the launch angle when the initial point is 1 km higher than the target point. It can be observed that the range of minimum distances less than 10 m exhibits a quasi-elliptical stacked distribution, and the range of angles satisfying the conditions is only 10 m. -4 The range is on the order of rads. The control of the launch angle needs to be very precise. After the launch height increases, the range is still a quasi-elliptical stacked distribution. The launch angle increases compared to the same height, but the number of quasi-elliptical shapes decreases and the range decreases.

[0066] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A high-energy proton space transport control method based on Bayesian optimization, characterized in that, The method includes: A proton transport space model is constructed, wherein the proton transport environment space model is a geomagnetic field model in near-Earth space; High-energy protons are injected into the proton transport space model. The trajectory of the high-energy protons is constrained by the magnetic field force, relativistic effects and bremsstrahlung emitted by the high-energy protons in the proton transport space model. A single-particle motion model of the high-energy protons in the proton transport space model is then constructed. The initial point and target point of the high-energy proton in the proton transport space model are obtained. The emission angle of the high-energy proton at the initial point is optimized according to the Bayesian optimization algorithm, and the emission angle with the closest distance to the target point after emission is less than a set distance is selected as the candidate emission angle. The high-energy protons are controlled to exit from the initial point according to the selected exit angle, and the high-energy protons are controlled to be transmitted from the initial point to the target point according to the single-particle motion model. The transmission path of the high-energy protons is obtained, and the transmission path with the least energy loss is selected as the optimal path of the high-energy protons in the proton transmission space model. The selected exit angle corresponding to the optimal path is selected as the optimal exit angle.

2. The method according to claim 1, characterized in that, The proton transport space model is represented as follows: Where μ0 is the free permeability. This represents a vector coordinate in a (x, y, z) coordinate system constructed with the Earth's center as the origin. The x-axis points to the equator and intersects the Earth's surface at the 0° meridian, and the z-axis points towards the Earth's North Pole. It is a unit vector along the x-axis. It is a unit vector along the y-axis. It is a unit vector along the z-axis. The vector represents the unit vector of the coordinate system, r represents the distance between the coordinate system and the origin, and M is the magnitude of the Earth's magnetic moment. The magnetic moment of the Earth is antiparallel to the z-axis.

3. The method according to claim 1, characterized in that, The trajectory of high-energy protons is constrained by the magnetic field force in the proton transport space model, as expressed in: Where m0 represents the rest mass of the high-energy proton, q represents the charge of the high-energy proton, v represents the velocity of the high-energy proton, E(r) = 0 represents the electric field strength, dt represents the time step, v represents the velocity vector of the high-energy proton, and B(r) represents the magnetic induction intensity in the proton transport space model.

4. The method according to claim 3, characterized in that, The trajectory of a high-energy proton is constrained by relativistic effects, expressed as follows: in, This represents the mass of a high-energy proton, where γ is the relativistic factor, γ = (1 - v 2 / c 2 )-(1 / 2), where c represents the speed of light.

5. The method according to claim 4, characterized in that, The power of the bremsstrahlung emitted by high-energy protons in the proton transport space model is expressed as: Where q represents the charge of the high-energy proton, and v represents the velocity of the high-energy proton. Let ε0 be the first derivative of velocity with respect to time, ε0 be the vacuum conductivity, and c be the speed of light.

6. The method according to claim 1, characterized in that, The initial and target points of the high-energy protons within the proton transport space model are obtained. The emission angle of the high-energy protons at the initial point is optimized using a Bayesian optimization algorithm. The emission angle with the closest distance to the target point after emission being less than a set distance is selected as the candidate emission angle, expressed as: The initial point and target point of the high-energy proton in the proton transport space model are obtained. The radial angle and angular angle of the high-energy proton at the initial point are optimized according to the Bayesian optimization algorithm. The emission angle with the closest distance to the target point after emission is less than a set distance is selected as the candidate emission angle. The set distance is 10 meters.

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