A method and product for obtaining initial parameters of source region particles based on observation position characteristics

Abstract

The invention discloses a method and product for obtaining the initial parameters of particles in a source region according to the characteristics of an observed position. The method is implemented based on a uniform magnetic field and comprises: receiving a particle to be studied emitted by a transmitting device, establishing an orthogonal rectangular coordinate system with a starting point of the particle as the origin of the coordinate system, and obtaining the coordinates of the terminal position reached by the particle; calculating the maximum gyration radius of the particle, and judging whether the particle initial parameters are present according to whether the distance between the projection of the terminal in an XY plane and the origin is greater than the maximum gyration radius; when the particle initial parameters are present, calculating the minimum number of cycles for the particle to reach the terminal, taking different numbers of cycles exceeding the minimum number of cycles to obtain a group of particle initial parameters, and screening the particle initial parameters that meet the requirements; calculating the motion trajectory of the emitted particle with each initial parameter of the particle to obtain a group of particle motion trajectories, and calculating the deviation with the minimum distance between the trajectory and the coordinates of the terminal position; and taking the particle initial parameter corresponding to the minimum deviation as the final result.

Description

Technical Field

[0001] The present invention belongs to the technical field of space particle transmission, and in particular relates to a method and a product for obtaining initial parameters of particles in a source region according to observation position characteristics. Background Art

[0002] Geospace particle transport technology is gaining increasing attention. Based on the particle characteristics at the observation location, the initial parameters of the source particles are given so that the particles starting from the source can accurately reach the destination. The difficulty of this technology lies in the fact that the magnetic field in geospace is non-uniform and the trajectory of the particles is non-analytical, so it is very difficult to find accurate initial parameters of the source particles. To solve this problem, a common strategy is to exhaustively enumerate all possible initial parameters of the source particles. This strategy will bring huge computational complexity and computing time. There is an urgent need for a method to evaluate the initial parameters of the source particles in a uniform field and to perform preliminary screening for iterating the optimal initial parameters. This method can greatly reduce the amount of computation and save computing time. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and propose a calculation method for evaluating the initial parameters of source region particles according to the characteristics of the observed position.

[0004] In order to achieve the above object, the present invention proposes a method for obtaining the initial parameters of particles in the source region according to the characteristics of the observation position, which is implemented based on a uniform magnetic field and includes:

[0005] Step 1) receiving the particle to be studied emitted by the emission device, establishing an orthogonal rectangular coordinate system with the starting point of the particle to be studied as the origin of the coordinate system, and obtaining the coordinates of the terminal position of the particle to be studied;

[0006] Step 2) Calculate the maximum gyration radius of the particle, and determine whether the particle has initial parameters according to whether the distance between the projection of the end point in the XY plane and the origin is greater than the maximum gyration radius;

[0007] Step 3) When the particle initial parameters are obtained, the minimum number of cycles for the particle to reach the end point is calculated, different numbers of cycles exceeding the minimum number of cycles are taken to obtain a set of particle initial parameters, and the particle initial parameters that meet the requirements are selected;

[0008] Step 4) Calculate the motion trajectory of the emitted particles with the initial parameters of each particle, obtain a set of particle motion trajectories, and calculate the deviation with the minimum distance between the end position coordinates; traverse the deviations, and take the particle initial parameters corresponding to the minimum deviation as the final result.

[0009] Preferably, the step 1) comprises:

[0010] Receive the particle to be studied emitted by the launch device, set the starting point of the particle to be studied as the origin of the coordinate system, set the direction of the uniform magnetic field to be the Z axis of the coordinate system, and the X and Y directions are perpendicular to the Z axis. The coordinates of the final position of the particle to be studied are obtained as (x end ,y end ,z end ).

[0011] Preferably, in step 2), the maximum radius of gyration R of the particles b for:

[0012]

[0013] Among them, q is the charge of the particle, m0 is the mass of the particle, c is the speed of light, B is the size of the uniform magnetic field, and E is the energy of the particle;

[0014] when If the end point is not within the reach of the electron, there are no initial particle parameters; otherwise, there are initial particle parameters.

[0015] Preferably, in step 3), the minimum number of cycles N for the particle to reach the end point is min for:

[0016]

[0017] Among them, [] is a rounding operation.

[0018] Preferably, the step 3) takes different cycle numbers exceeding the minimum cycle number to obtain a set of particle initial parameters, including:

[0019] Take more than the minimum number of cycles N min Different cycle numbers N can be obtained according to the following formula function:

[0020]

[0021] Among them, when x end ≥0 hours Take the + sign, otherwise Take the - sign and find the angle between the projection of the particle emission direction in the XY plane and the X axis when the function takes the minimum value

[0022] Different cycle numbers N and corresponding Substitute into the following formulas to obtain the angle θ between the particle emission direction and the Z axis:

[0023]

[0024] Thus, we get a set of initial particle parameters

[0025] Substitute into the following formulas to calculate the theoretical end point y coordinate:

[0026]

[0027] Among them, sign() is used to determine the sign of a given integer, returning 1 for a positive number and -1 for a negative number;

[0028] Determine the calculated y and sign(y end ) are equal, the result will be judged to be consistent with the initial parameters of the particle Leave.

[0029] In another aspect, the present invention provides a computer program product, comprising a computer program / instruction, which implements the steps of the above method when executed by a processor.

[0030] Compared with the prior art, the advantages of the present invention are:

[0031] 1. Because the present application adopts the method of equating the particle trajectory equation with the end point and deriving the equation f(φ)=0 on this basis, finding the numerical solution of this equation and further screening out the optimal initial particle parameters, this method brings the beneficial effect of reducing the amount of calculation and improving the calculation efficiency.

[0032] 2. The present invention proposes for the first time how to calculate the initial parameters (θ0, φ0) of a particle passing through two points in a uniform magnetic field. The initial parameters of the particle can minimize the deviation between the particle trajectory and the end point. Compared with the exhaustive method, this calculation scheme can greatly reduce the amount of calculation and improve the calculation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of initial parameters of particles of the present invention;

[0034] Figure 2 It is a flow chart of the method for evaluating the initial parameters of particles in the source region according to the characteristics of the observation position of the present invention. DETAILED DESCRIPTION

[0035] This application aims to provide a calculation scheme for evaluating the initial parameters of source region particles based on the observation position characteristics of two points in a uniform field. Figure 1 Shown is a schematic diagram of the initial parameters of the particles.

[0036] It is known that the particle energy is E, the uniform magnetic field strength is B, and the starting and ending coordinates of the particle are (0,0,0) and (x end ,y end ,z end ). If the distance between the projection of the end point in the XY plane and the origin is greater than the maximum gyration radius of the particle, that is The end point is not within the reachable range of the particle, and the particle initial parameters do not exist; otherwise, the particle initial parameters (θ0, φ0) of the particle are calculated according to the technical solution process, where θ0 is the angle between the emission direction and the Z axis, and φ0 is the angle between the projection of the emission direction in the XY plane and the X axis.

[0037] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0038] Example 1

[0039] like Figure 2 As shown, the embodiment of the present invention proposes a method for obtaining the initial parameters of the source region particles according to the observation position characteristics. The specific scheme is as follows:

[0040] (1) Establish an orthogonal rectangular coordinate system, set the starting point of the particle as the origin of the coordinate system, set the direction of the uniform magnetic field to the Z axis of the coordinate system, and set the X and Y directions to be perpendicular to the Z axis. The magnitude of the uniform magnetic field is known to be B, the energy of the particle is E, and the end point it passes is (x end ,y end ,z end ).

[0041] (2) Calculate the maximum gyration radius of the particle Where q is the charge of the particle, m0 is the mass of the particle, and c is the speed of light. If the distance between the projection of the end point in the XY plane and the origin is greater than the maximum gyration radius of the particle, that is If the end point is not within the reachable range of the particle, there is no initial particle parameter. Otherwise, the initial particle parameter calculation will proceed.

[0042] (3) Using the formula The [] sign is a rounding operation, which calculates the minimum number of turns (cycles) that the particle must go through to reach the end point. The value range of N is greater than N min .

[0043] (4) The initial parameters of the particles are To express, θ is the angle between the aiming direction and the Z axis, is the angle between the projection of the aiming direction in the XY plane and the X axis. Calculate the corresponding angle when N takes different values function

[0044]

[0045] When x end When ≥0, take the + sign, otherwise take the - sign. Find the corresponding value that makes the function reach the minimum value.

[0046] (5) Substitute the N and Substituting into the θ expression, we get the corresponding θ

[0047]

[0048] (6) The series of particle initial parameters calculated above are Substituting into the equation

[0049]

[0050] The sign function is used to determine the sign of a given integer. It returns 1 for positive integers and -1 for negative integers. Filter out.

[0051] (7) Calculate the initial particle parameters obtained above The emitted particle trajectory and the minimum distance between the particle trajectory and the target point are used as the deviation.

[0052] (8) Find the initial particle parameters corresponding to the minimum deviation and mark them as

[0053] Example 2

[0054] The embodiment of the present invention may also provide a computer program product, including a computer program / instruction. When the computer program / instruction is executed by a processor, each step in the above method embodiment can be implemented.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention and should be included in the scope of the claims of the present invention.

Claims

1. A method for obtaining the initial parameters of source region particles according to the characteristics of the observation position, based on a uniform magnetic field, comprising: Step 1) receiving the particle to be studied emitted by the emission device, establishing an orthogonal rectangular coordinate system with the starting point of the particle to be studied as the origin of the coordinate system, and obtaining the coordinates of the terminal position of the particle to be studied; Step 2) Calculate the maximum gyration radius of the particle, and determine whether the particle has initial parameters according to whether the distance between the projection of the end point in the XY plane and the origin is greater than the maximum gyration radius; Step 3) When the particle initial parameters are obtained, the minimum number of cycles for the particle to reach the end point is calculated, different numbers of cycles exceeding the minimum number of cycles are taken to obtain a set of particle initial parameters, and the particle initial parameters that meet the requirements are selected; Step 4) Calculate the motion trajectory of the emitted particles with the initial parameters of each particle, obtain a set of particle motion trajectories, and calculate the deviation with the minimum distance between the end position coordinates; traverse the deviations, and take the particle initial parameters corresponding to the minimum deviation as the final result.

2. The method for obtaining the initial parameters of source region particles according to the observation position characteristics according to claim 1, characterized in that: The step 1) comprises: Receive the particle to be studied emitted by the launch device, set the starting point of the particle to be studied as the origin of the coordinate system, set the direction of the uniform magnetic field to be the Z axis of the coordinate system, and the X and Y directions are perpendicular to the Z axis. The coordinates of the final position of the particle to be studied are obtained as (x end ,y end ,z end ).

3. The method for obtaining the initial parameters of source region particles according to the observation position characteristics according to claim 2, characterized in that: The maximum gyration radius R of the particle in step 2) b for: Among them, q is the charge of the particle, m0 is the mass of the particle, c is the speed of light, B is the size of the uniform magnetic field, and E is the energy of the particle; when If the end point is not within the reach of the electron, there are no initial particle parameters; otherwise, there are initial particle parameters.

4. The method for obtaining the initial parameters of source region particles according to the observation position characteristics according to claim 3, characterized in that: Step 3) The minimum number of cycles N that the particle can reach the end point min for: Among them, [] is a rounding operation.

5. The method for obtaining the initial parameters of source region particles according to the observation position characteristics according to claim 4, characterized in that: The step 3) takes different cycle numbers exceeding the minimum cycle number to obtain a set of particle initial parameters, including: Take more than the minimum number of cycles N min Different cycle numbers N can be obtained according to the following formula function: Among them, when x end ≥0 hours Take the + sign, otherwise Take the - sign and find the angle between the projection of the particle emission direction in the XY plane and the X axis when the function takes the minimum value Different cycle numbers N and corresponding Substitute into the following formulas to obtain the angle θ between the particle emission direction and the Z axis: Thus, we get a set of initial particle parameters Substitute into the following formulas to calculate the theoretical end point y coordinate: Among them, sign() is used to determine the sign of a given integer, returning 1 for a positive number and -1 for a negative number; Determine the calculated y and sign(y end ) are equal, the result will be judged to be consistent with the initial parameters of the particle Leave.

6. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to claim 1 are implemented.

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