Magnetic pole optimization method and isotope separation device

Abstract

The invention relates to the technical field of electromagnetic separation, and provides a magnetic pole optimization method and an isotope separation device.The optimization method comprises the steps that a shimmed finite element model is established; setting characteristic parameters of the section shape of the finite element model; the characteristic parameters are used for simulation calculation of particle beam transport, and a simulation result is obtained; and determining the characteristic parameters according to the simulation result. According to the optimization method provided by the embodiment of the invention, the design time of the magnetic pole can be shortened, and the mechanical design difficulty is reduced.

Description

Technical Field

[0001] The present application relates to the field of electromagnetic separation technology, and in particular to a magnetic pole optimization method and an isotope separation device. Background Art

[0002] This section is intended to provide a background or context for the embodiments of the present application. No description herein is admitted to be prior art by virtue of its inclusion in this section.

[0003] Stable isotopes have been widely used in defense, military, medicine, communications, nuclear batteries and other fields. For example, the precursor materials of radionuclides Yb176 and sr88 for diagnosis and treatment of cancer, the atomic clock with rubidium 87 as the core has been used in the Beidou satellite navigation system, and the nickel 63 isotope has also been used in the research and development of micro-nuclear batteries. However, the abundance of stable isotopes in nature is not very high, and if stable isotopes are to be used accordingly, they must be separated and prepared by various methods to increase their abundance.

[0004] Electromagnetic separation is the most versatile method for separating stable isotopes. The advancement of the technology is directly related to whether stable isotopes with sufficient abundance and yield can be produced. Today, Russia, the United States and other countries use this method to produce large quantities of stable isotopes and sell them internationally. The implementation of the electromagnetic separation method requires an isotope separation device. In the design of the isotope separation device, the quality of the magnetic field directly affects the transport trajectory of the particle beam, thereby affecting the separation effect. Therefore, it is necessary to form a corresponding magnetic field strength and magnetic field pattern (i.e., magnetic field lines). In order to achieve the corresponding magnetic field, the corresponding magnetic pole design is required, that is, the magnetic field pattern of the physical design is ultimately realized through mechanical design.

[0005] In the related technology, designing magnetic field patterns is time-consuming and difficult, and even some magnetic field patterns cannot reproduce the corresponding magnetic poles through mechanical design. Summary of the invention

[0006] In view of this, the embodiments of the present application hope to provide a magnetic pole optimization method and an isotope separation device, which can shorten the design time of the magnetic pole and reduce the difficulty of mechanical design.

[0007] In a first aspect, an embodiment of the present application provides a method for optimizing a magnetic pole, wherein the magnetic pole is used for isotope separation of a particle beam, wherein the magnetic pole comprises a base and a shim, wherein the shim is arranged on one side of the base along a thickness direction, and a surface of the shim away from the base along the thickness direction is a pole surface, comprising:

[0008] Establishing a finite element model of the shim;

[0009] Setting characteristic parameters of the cross-sectional shape of the finite element model;

[0010] Using the characteristic parameters for simulation calculation of particle beam transport and obtaining simulation results;

[0011] The characteristic parameter is determined according to the simulation result.

[0012] In some embodiments, the cross-sectional shape includes a first side line and a second side line opposite to each other along a thickness direction, the first side line is connected to the polar surface, the first side line divides a plurality of nodes, and the characteristic parameter includes a thickness dimension between each of the nodes and the second side line.

[0013] In some embodiments, setting characteristic parameters of the cross-sectional shape of the finite element model includes:

[0014] The thickness size of each node is adjusted according to the step size.

[0015] In some embodiments, the number of steps is not less than ten.

[0016] In some embodiments, the number of nodes is not less than 2.

[0017] In some embodiments, at least two of the nodes are evenly spaced apart along the first edge.

[0018] In some embodiments, the characteristic parameters are used for simulation calculation of particle beam transport, including:

[0019] The characteristic parameters are substituted into beam transport simulation software to perform simulation calculation of particle beam.

[0020] In some embodiments, determining the characteristic parameter according to the simulation result includes:

[0021] The simulation results are compared to determine whether the simulation results meet the set results, and the characteristic parameters corresponding to the set results are determined as target parameters.

[0022] In some embodiments, the simulation result includes a target image width of the particle beam, and the setting result includes that the target image width reaches a minimum value, and the target image width refers to the width of the particle beam at the receiving end of the magnetic pole.

[0023] In some embodiments, the simulation result includes a target image width, where the target image width refers to a width of the particle beam at a receiving end of the magnetic pole.

[0024] A second aspect of an embodiment of the present application provides an isotope separation device, comprising:

[0025] A magnetic yoke is formed with an electromagnetic cavity;

[0026] Two magnetic poles are generated by any of the optimization methods described above, and the two magnetic poles are arranged in the electromagnetic cavity at intervals along the thickness direction. The pole faces of the two magnetic poles jointly define a transport channel, and the transport channel is used to circulate the particle beam.

[0027] The embodiment of the present application provides an optimization method for a magnetic pole. Compared with the related art, on the one hand, by establishing a finite element model of padding, it is not necessary to model and analyze the magnetic pole as a whole, and then the magnetic field pattern can be changed by adjusting the characteristic parameters, and the magnetic field pattern does not need to be designed separately, which simplifies the design process and reduces the design difficulty. On the other hand, the association between the particle beam and the magnetic field pattern can be converted into the association between the particle beam and the characteristic parameters, thereby shortening the design time of the magnetic pole. On the other hand, by simulating the transport of the particle beam, the feasibility and optimal solution of the simulation results are guaranteed, that is, an isotope electromagnetic separator can be manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of the assembly of a yoke and two magnetic poles provided in some embodiments of the present application;

[0029] Figure 2 A schematic diagram of a flow chart of an optimization method provided for some embodiments of the present application;

[0030] Figure 3 A schematic diagram of the structure of a magnetic pole provided in some embodiments of the present application;

[0031] Figure 4 A schematic diagram of the structure of magnetic poles provided in other embodiments of the present application;

[0032] Figure 5 A schematic diagram of the structure of magnetic poles provided in other embodiments of the present application;

[0033] Figure 6 A schematic diagram of a particle beam of two isotopes in a non-uniform magnetic field provided in some embodiments of the present application;

[0034] Figure 7 for Figure 6 Enlarged view of point A in the middle.

[0035] Description of Reference Numerals

[0036] Magnetic yoke 10; Electromagnetic cavity 10a;

[0037] Magnetic pole 20; transport channel 20a; transmitting end 20b; receiving end 20c;

[0038] base 21;

[0039] Shimming 22; polar surface 22a; first side line 22b; second side line 22c;

[0040] The coil 30 is energized. DETAILED DESCRIPTION

[0041] The following is a further detailed description of the implementation of the present application in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but cannot be used to limit the scope of the present application.

[0042] The various specific technical features and embodiments described in the specific implementation methods can be combined in any suitable manner without contradiction. For example, different implementation methods can be formed by combining different specific technical features / embodiments. In order to avoid unnecessary repetition, the various possible combinations of the specific technical features / embodiments in this application are no longer described separately. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. The application is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0043] To facilitate understanding of the optimization method provided in the embodiment of the present application, the isotope separation device provided in the embodiment of the present application is first described:

[0044] See also Figure 1 An embodiment of the present application provides an isotope separation device, including a magnetic yoke 10 and two magnetic poles 20. The magnetic yoke 10 forms an electromagnetic cavity 10a. The magnetic poles 20 are generated by the optimization method in any embodiment of the present application. The two magnetic poles 20 are arranged in the electromagnetic cavity 10a at intervals along the thickness direction. The pole surfaces 22a of the two magnetic poles 20 jointly define a transport channel 20a, and the transport channel 20a is used to circulate a particle beam.

[0045] An isotope separation device refers to a device that uses electromagnetic separation to separate isotopes.

[0046] The magnetic yoke 10 refers to a soft magnetic structure that does not generate a magnetic field itself and only transmits magnetic flux lines in the magnetic circuit. Two magnetic poles 20 are arranged in the electromagnetic cavity 10a. On the one hand, the two magnetic poles 20 are fixed by the magnetic yoke 10, and the electromagnetic cavity 10a plays a limiting role on the two magnetic poles 20, which can improve the structural stability of the isotope separation device. On the other hand, the magnetic flux lines generated by the two magnetic poles 20 can be constrained in the electromagnetic cavity 10a to improve the magnetic field strength.

[0047] For example, one of the two magnetic poles 20 may be an N pole (North Pole), and the other may be an S pole (South Pole). The magnetic flux lines of the two magnetic poles 20 form a magnetic field in the transport channel 20a. Figures 3 to 5 The emission end 20b of the magnetic pole 20 is provided with an ion source, which is used to ionize the isotopes to make them become charged particles that are deflected and move in the magnetic field of the transport channel 20a to form a particle beam.

[0048] The specific material of the magnetic pole 20 is not limited. For example, the magnetic pole 20 can be made of DT4 (steel with an iron content of more than 99.5%), No. 10 steel and other materials, which have high magnetic permeability and are beneficial to isotope separation.

[0049] In the related art, the manufacturing process of the isotope separation device usually includes magnetic field pattern design and mechanical design. The magnetic field pattern design is carried out first, and then the mechanical design is carried out according to the magnetic field pattern. In this way, on the one hand, the two independent design processes are time-consuming. On the other hand, it is difficult to carry out mechanical design according to the magnetic field pattern, and even some magnetic field patterns cannot be reproduced through mechanical design, which affects the operating performance of the isotope separation device and leads to insufficient abundance and output of isotopes.

[0050] See also Figure 2 The embodiment of the present application provides an optimization method for a magnetic pole 20, the magnetic pole 20 is used for isotope separation of a particle beam, the magnetic pole 20 comprises a base 21 and a shim 22, the shim 22 is arranged on one side of the base 21 along the thickness direction, and the surface of the shim 22 away from the base 21 along the thickness direction is a pole surface 22a, comprising:

[0051] Step S10, establishing a finite element model of the shim 22;

[0052] Finite element analysis (FEA) is a method of simulating a real physical system using mathematical approximation methods, and solving the real physical system through simple and interacting units and mathematical solutions based on a limited number of units. Finite element analysis requires less computing time, has high computational accuracy and is applicable to complex structures. Exemplarily, the finite element model of the shim 22 includes a three-dimensional model, a simplified model and a finite element solution model. The three-dimensional model of the shim 22 can be established at a preset ratio through finite element analysis software, etc. After the three-dimensional model is converted into a simplified model through simplification processing, the simplified model is then divided to obtain a meshed finite element solution model.

[0053] The shim 22 can be used to adjust the magnetic field pattern. By establishing a finite element model of the shim 22, it is not necessary to perform modeling analysis on the entire magnetic pole 20, which simplifies the design process and shortens the design time.

[0054] Step S20, setting characteristic parameters of the cross-sectional shape of the finite element model;

[0055] That is to say, the cross-sectional shape of the finite element model can be adjusted through the characteristic parameters, thereby changing the shape of the finite element model, that is, changing the magnetic field pattern. In this way, there is no need to design the magnetic field pattern separately, and the magnetic field pattern can be changed by adjusting the characteristic parameters, which is convenient and quick.

[0056] Step S30, using the characteristic parameters for simulation calculation of particle beam transport, and obtaining simulation results;

[0057] That is to say, the calculation conditions of beam transport include characteristic parameters, and different simulation results of beam transport can be calculated by adjusting the characteristic parameters, so that, on the one hand, the relationship between the particle beam and the magnetic field pattern can be converted into the relationship between the particle beam and the characteristic parameters, thereby shortening the design time of the magnetic pole 20. On the other hand, by simulating the transport of the particle beam, the feasibility and optimal solution of the simulation results are guaranteed, that is, the isotope electromagnetic separator can be manufactured.

[0058] Step S40: determining the characteristic parameters according to the simulation results.

[0059] For example, when the simulation results need to be optimized, the characteristic parameters are adjusted until the simulation results take into account both feasibility and the separation effect on isotopes, and the current characteristic parameters are determined as the mechanical design parameters of the isotope ionization device. In this way, compared with the related art, it can avoid that the isotope separation device cannot reproduce the magnetic field pattern.

[0060] The embodiment of the present application provides an optimization method for the magnetic pole 20. Compared with the related art, on the one hand, by establishing a finite element model of the shim 22, it is not necessary to model and analyze the magnetic pole 20 as a whole, and then the magnetic field pattern can be changed by adjusting the characteristic parameters, and the magnetic field pattern does not need to be designed separately, which simplifies the design process and reduces the design difficulty. On the other hand, the association between the particle beam and the magnetic field pattern can be converted into the association between the particle beam and the characteristic parameters, thereby shortening the design time of the magnetic pole 20. On the other hand, by performing transport simulation on the particle beam, the feasibility and optimal solution of the simulation results are guaranteed, that is, an isotope electromagnetic separator can be manufactured.

[0061] It should be noted that the magnetic pole 20 generated by the optimization method of the embodiment of the present application can be used not only in isotope separators, but also in devices that need to accelerate charged particles, such as cyclotrons.

[0062] For some examples, see Figures 3 to 5 The cross-sectional shape includes a first side line 22b and a second side line 22c that are opposite to each other along the thickness direction, the first side line 22b is connected to the pole surface 22a, the first side line 22b divides a plurality of nodes, and the characteristic parameters include the thickness dimension between each node and the second side line 22c.

[0063] It should be noted that the magnetic field pattern is roughly the same as the shape of the pole surface 22a. For example, see Figure 4 and Figure 5 , Figure 4 The shape of the mid-pole surface 22a is roughly wavy, that is, the magnetic field pattern is roughly wavy. Figure 5 The shape of the middle pole surface 22a is roughly semicircular, that is, the magnetic field pattern is roughly semicircular. By adjusting the size thickness between the node and the second edge line 22c, the shape of the pole surface 22a can be adjusted, thereby changing the magnetic field pattern, which is easy to operate.

[0064] Please continue reading Figures 3 to 5 , the connection surfaces between the shim 22 and the base 21 are fitted together, the second sideline 22c is connected to the surface of the shim 22 connected to the base 21, and the surface of the shim 22 facing the base 21 does not change. In this way, the shape of the second sideline 22c can be basically unchanged, which can reduce the difficulty of manufacturing the isotope separation device.

[0065] In one embodiment, the nodes can be set in a linear difference manner, which is convenient for operation and helps to reduce the error of the simulation results.

[0066] In one embodiment, the first edge line 22b is stretched along a preset direction and / or rotated along a preset rotation axis to form the polar surface 22a. In this way, after adjusting the characteristic parameters, it is convenient to reconstruct the finite element model of the shim 22.

[0067] In some embodiments, the thickness is between 0 mm (millimeter) and 30 mm, for example, 0 mm, 5 mm, 10 mm, 15 mm, 25 mm or 30 mm.

[0068] In some embodiments, setting characteristic parameters of the cross-sectional shape of the finite element model includes:

[0069] Step S21, adjusting the thickness of each node according to the step size.

[0070] The step size refers to the value of the thickness dimension increase in each calculation in repeated simulation calculations. In this way, by adjusting the step size multiple times, the number of simulation calculations can be increased, thereby improving the accuracy of the simulation results. In addition, the step size is a fixed value, which can clearly understand the structural size of the shim 22, and can take into account the operating performance and manufacturing difficulty of the isotope separation device during the design process.

[0071] It should be noted that, in the present application, multiple times refers to a number including twice or more.

[0072] In some embodiments, the number of steps is not less than 10. That is, the thickness dimension is adjusted no less than 10 times. For example, it may be 10 times, 15 times, 20 times or 25 times, etc. By setting a suitable number, the accuracy of the simulation results can be improved.

[0073] In some embodiments, the number of nodes is not less than 2. For example, it may be 2 nodes, 4 nodes, 8 nodes, or 10 nodes, etc. By setting a suitable number, the accuracy of the simulation results can be further improved.

[0074] Take 10 steps and 10 nodes as an example, that is, each node can be adjusted 10 times in step, so that the padding 22 has 10 to the power of 10 cross-sectional shapes.

[0075] In some embodiments, at least two nodes are evenly spaced and distributed along the first edge line 22b. In this way, it is not only easy to set the nodes, but also the calculation error caused by uneven node distribution can be reduced, thereby improving the accuracy of the simulation results. At the same time, the evenly spaced nodes are beneficial to reducing the manufacturing difficulty of the shim 22, that is, reducing the manufacturing difficulty of the isotope separation device.

[0076] In some embodiments, the characteristic parameters are used for simulation calculation of particle beam transport, including:

[0077] Step S31, substituting the characteristic parameters into beam transport simulation software to perform particle beam simulation calculation.

[0078] For example, the characteristic parameters can be brought into the finite element analysis software to perform simulation calculations of the particle beam, which can shorten the simulation calculation time and improve the accuracy of the simulation results.

[0079] In some embodiments, determining the characteristic parameter according to the simulation result includes:

[0080] Step S41, comparing the simulation results, determining whether the simulation results meet the set results, and determining the characteristic parameters corresponding to the set results as target parameters.

[0081] In this way, by adjusting the characteristic parameters, continuous optimization can be carried out before the isotope separation device is produced, thereby assisting designers to improve to obtain the target parameters and manufacture the isotope separation device based on the target parameters. On the basis of shortening the R&D cycle, it can also improve the operating performance of the isotope separation device.

[0082] In some embodiments, the simulation result includes a target image width of the particle beam, and the setting result includes the target image width reaching a minimum value, where the target image width refers to the width of the particle beam at the receiving end 20 c of the magnetic pole 20 .

[0083] Exemplarily, a receiver is provided at the receiving end 20c of the magnetic pole 20, and the receiver is used to receive the isotopes separated by the magnetic field. In this way, when the target image width reaches the minimum value, it is convenient for the receiver to collect isotopes, thereby improving the isotope abundance and yield.

[0084] Exemplarily, the number of characteristic parameters is set, the current characteristic parameters are substituted into the beam transport simulation software, the particle beam simulation calculation is performed, and the current target image width is obtained, the current target image width is compared with the previous target image width, and the characteristic parameters corresponding to the relatively smaller one are retained. For example, if the current target image width is smaller than the previous target image width, the characteristic parameters corresponding to the current target image width are retained; if the previous target image width is smaller than the current target image width, the characteristic parameters corresponding to the previous target image width are retained; the characteristic parameters are adjusted and substituted into the beam transport simulation software again, and the next target image width is obtained. Repeat the above steps until all characteristic parameters are simulated, obtain the characteristic parameters corresponding to the minimum target image width, that is, the simulation result meets the set result, determine the corresponding characteristic parameters as the target parameters, and manufacture the isotope separation device based on the target parameters.

[0085] In one embodiment, please refer to Figure 6 and Figure 7 The magnetic pole 20 generated by the optimization method provided in the present application forms a non-uniform magnetic field pattern in the transport channel 20a. At the receiving end 20c of the magnetic pole 20, the separation effect of the particle beams of the two isotopes is obvious, and the target image width reaches the minimum value, which is convenient for the receiver to collect the two isotopes.

[0086] In some embodiments, the simulation results include the target image width, which refers to the width of the particle beam at the receiving end 20c of the magnetic pole 20. Thus, by adjusting the characteristic parameters, the target image width can be changed to facilitate the collection of isotopes by the receiver.

[0087] For some examples, see Figure 1 The magnetic pole 20 includes two energized coils 30, which are respectively arranged on the circumferential surfaces of the two magnetic poles 20. The energized coils 30 can enhance the magnetic field strength and improve the isotope abundance and yield.

[0088] In some embodiments, taking a plane perpendicular to the thickness direction as a projection plane, the projection range of the shim 22 is within the projection range of the base 21. That is, the shim 22 does not protrude from the base 21, which facilitates the assembly of the shim 22 and the base 21.

[0089] In some embodiments, the shim 22 and the base 21 are detachably connected, so that the shim 22 and the base 21 can be manufactured separately, reducing the difficulty of manufacturing the isotope separation device. In addition, when the shim 22 needs to be maintained or replaced, the shim 22 and the base 21 can be easily assembled and disassembled.

[0090] In the description of this specification, the description with reference to the terms "an embodiment", "some embodiments", "other embodiments" and "exemplary" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0091] The various embodiments / implementations provided in this application can be combined with each other without causing any contradiction. The above description is only a preferred embodiment of this application and is not intended to limit this application. For those skilled in the art, this application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the protection scope of this application.

Claims

1. A method for optimizing magnetic poles, characterized in that: The magnetic pole is used for isotope separation of a particle beam, and comprises a base and a shim, wherein the shim is arranged on one side of the base along the thickness direction, and the surface of the shim away from the base along the thickness direction is a pole surface, and comprises: Establishing a finite element model of the shim; Setting characteristic parameters of the cross-sectional shape of the finite element model; Using the characteristic parameters for simulation calculation of particle beam transport and obtaining simulation results; The characteristic parameter is determined according to the simulation result.

2. The optimization method according to claim 1, characterized in that: The cross-sectional shape includes a first sideline and a second sideline that are opposite to each other along a thickness direction, the first sideline is connected to the polar surface, the first sideline divides a plurality of nodes, and the characteristic parameter includes a thickness dimension between each of the nodes and the second sideline.

3. The optimization method according to claim 2, characterized in that: Setting characteristic parameters of the cross-sectional shape of the finite element model includes: The thickness size of each node is adjusted according to the step size.

4. The optimization method according to claim 3, characterized in that: The number of steps is not less than 10.

5. The optimization method according to claim 2, characterized in that: The number of the nodes is not less than 2.

6. The optimization method according to claim 5, characterized in that: At least two of the nodes are evenly spaced apart along the first edge.

7. The optimization method according to claim 1, characterized in that: The characteristic parameters are used for simulation calculation of particle beam transport, including: The characteristic parameters are substituted into beam transport simulation software to perform simulation calculation of particle beam.

8. The optimization method according to any one of claims 1 to 7, characterized in that: Determining the characteristic parameter according to the simulation result includes: The simulation results are compared to determine whether the simulation results meet the set results, and the characteristic parameters corresponding to the set results are determined as target parameters.

9. The optimization method according to claim 8, characterized in that: The simulation result includes a target image width of the particle beam, and the setting result includes that the target image width reaches a minimum value, wherein the target image width refers to a width of the particle beam at a receiving end of the magnetic pole.

10. The optimization method according to any one of claims 1 to 7, characterized in that: The simulation result includes a target image width, where the target image width refers to a width of the particle beam at a receiving end of the magnetic pole.

11. An isotope separation device, characterized in that: include: A magnetic yoke is formed with an electromagnetic cavity; Two magnetic poles, the magnetic poles are generated by the optimization method described in any one of claims 1 to 10, the two magnetic poles are arranged in the electromagnetic cavity at intervals along the thickness direction, and the pole faces of the two magnetic poles jointly define a transport channel, and the transport channel is used to circulate a particle beam.

Images