Multilayer composite solenoid system for beam control

Abstract

The invention discloses a beam-controlled multi-layer composite solenoid system which comprises a plurality of layers of tubular magnets arranged on a beam line, the plurality of layers of tubular magnets comprise tubular magnets and tubular solenoids, and the tubular magnets and the tubular solenoids jointly form a composite solenoid group. The tubular magnet can be a permanent magnet, an electromagnet and / or an electromagnet, and the tubular solenoid is an electromagnetic solenoid. The invention provides a multi-layer composite solenoid system. The technical problems that in the prior art, a beam expanding magnet set guarantees regulation and control flexibility, meanwhile, magnet miniaturization design is completed, and the beam expanding magnet set guarantees the same magnetic flux density, and meanwhile the weight and the size are smaller are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of accelerator physical beam spot expansion, relates to a composite solenoid, and in particular to a beam-controlled multi-layer composite solenoid system. Background Art

[0002] Electron beam technology is a general term for technologies that use electromagnetic means to accelerate electrons to obtain higher energy, and use high-energy electrons to explore the structure of matter or other applications. Because of this, this technology also has very important and extensive applications in industrial and agricultural production, medical and health care, science and technology, and national defense construction. In some large electron accelerators, electron beams need to be transported over long distances, and the beams tend to diverge from their beam center, resulting in an increase in the envelope radius of the target beam spot, a decrease in flux density, and a significant reduction in work efficiency.

[0003] In order to solve this problem, an electron beam expander is usually added at the accelerator exit to compress the divergence angle of the incident electron beam. The current beam expansion magnet group generally uses pure permanent magnets or electromagnetic solenoids, but both have great defects. For a single permanent magnet, once it is made, the relevant parameters cannot be changed, and its magnetic field distribution is fixed. After the key parameters of the high-energy electron beam change, it cannot be adjusted accordingly. Although a single electromagnetic solenoid can be adjusted to a certain extent by controlling the size of the winding current, to achieve the same size of magnetic field, the volume and weight of a single electromagnetic solenoid is much larger than that of a permanent magnet. A single electromagnetic solenoid cannot be used in scenarios where there are requirements for the weight and volume of the equipment itself. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a multi-layer composite solenoid system for beam control, so as to solve the technical problem that the beam expansion magnet group in the prior art is difficult to balance the control flexibility and magnet miniaturization.

[0005] Another object of the present invention is to provide a multi-layer composite solenoid system for beam control, so as to solve the technical problem that the beam expansion magnet group in the prior art is difficult to balance the magnetic flux density and the miniaturization of the magnet.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0007] A beam-controlled multilayer composite solenoid system includes a multilayer tubular magnet arranged on a beam line, wherein the multilayer tubular magnet includes a tubular magnet and a tubular solenoid, and the tubular magnet and a common interlayer with the tubular solenoid form a composite solenoid group.

[0008] The present invention also has the following technical features:

[0009] The tubular magnet is a permanent magnet, an electromagnet and / or an electromagnet; the tubular solenoid is an electromagnetic solenoid.

[0010] The permanent magnet is made of samarium cobalt material or neodymium iron boron material.

[0011] The angle between the magnetic moment orientation of the permanent magnet and the axis is 0° to 90°.

[0012] The calculation formula of the permanent magnet is:

[0013]

[0014] Where:

[0015] B m It represents the magnetic flux density of the permanent magnet on the axis;

[0016] B r Indicates the residual magnetic density of permanent magnetic materials;

[0017] z represents the z coordinate of the field point;

[0018] R o represents the outer diameter of the permanent magnet;

[0019] R i represents the inner diameter of the permanent magnet;

[0020] L represents the length of the permanent magnet.

[0021] The cross-sectional structure of the winding of the electromagnetic solenoid is hollow or contains a vacuum inside a good conductor.

[0022] The electromagnetic solenoid is wound in a conventional manner perpendicular to the axis of the solenoid, parallel to the axis and / or at a certain angle to the axis.

[0023] The winding angle of the electromagnetic solenoid is 0° to 180°.

[0024] The spacing between the windings of the electromagnetic solenoid is equal or unequal.

[0025] The winding of the electromagnetic solenoid is straight line winding, curved line winding and / or wavy line winding.

[0026] The calculation formula of the electromagnetic solenoid is:

[0027]

[0028] Where:

[0029] B s It represents the magnetic flux density of the electromagnetic solenoid;

[0030] μ0 represents the vacuum magnetic permeability;

[0031] I represents the current intensity in the electromagnetic solenoid winding;

[0032] R o Indicates the outer diameter of the electromagnetic solenoid;

[0033] R i Indicates the inner diameter of the corresponding electromagnetic solenoid;

[0034] L represents the length of the electromagnetic solenoid;

[0035] z represents the coordinates of the field point;

[0036] z' represents the z coordinate of the center position of the electromagnetic solenoid;

[0037] d represents the diameter of the winding.

[0038] The number of layers of the composite solenoid group is not less than 2.

[0039] Compared with the prior art, the present invention has the following technical effects:

[0040] Compared with the beam control system of the traditional beam expansion magnet group, the multilayer composite solenoid system for beam control proposed in the present invention can complete the miniaturized design of the magnet while ensuring the flexibility of regulation, and achieve the same magnetic flux density while consuming smaller volume, lower power, smaller weight, and lower magnet electrical indicators, which greatly increases the advantages in lightweight and simplified magnet power supply design. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of a multi-layer solenoid assembly device.

[0042] Figure 2 This is an example diagram of the magnetic moment orientation and density inside a permanent magnet.

[0043] Figure 3 A cross-sectional diagram of an electromagnetic solenoid.

[0044] Figure 4 Schematic diagram of the winding of the electromagnetic solenoid.

[0045] Figure 5 Schematic diagram of the distribution of the thermal insulation layer and the thermal conductive structure.

[0046] Figure 6 This is a simulation model diagram of a double-layer composite solenoid group.

[0047] Figure 7 Phase diagram at the inlet and outlet of the double-layer composite solenoid group.

[0048] The specific contents of the present invention are further described in detail below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0049] It should be noted that, unless otherwise specified, all components and devices in the present invention are components and devices known in the prior art.

[0050] In accordance with the above technical scheme, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical scheme of this application fall within the protection scope of the present invention.

[0051] Example:

[0052] This embodiment provides a multi-layer composite solenoid system for beam control, such as Figure 1 As shown, it includes a multi-layer tubular magnet arranged on the beam line, the multi-layer tubular magnet includes a tubular magnet and a tubular solenoid, and the tubular magnet and the tubular solenoid have a common interlayer to form a composite solenoid group.

[0053] Specifically, the tubular magnet is a permanent magnet, an electromagnet and / or an electromagnet; and the tubular solenoid is an electromagnetic solenoid. Figure 1 As shown, the inner diameters of different layers of magnets are (R 1i , R 2i ……R ni ); the outer diameters are (R 1o , R 2o ……R no ), the lengths are (L1, L2...L n ), the center positions are (z1, z2...z n ), the angles between the magnets in different layers and the axis are (θ1, θ2…θ n ). Among them, the number of layers of the composite solenoid group is not less than 2, and the interval between the two layers of magnets can be 0, that is, R 1o Can be equal to R 2i .

[0054] Specifically, the permanent magnet is made of samarium cobalt material or neodymium iron boron material.

[0055] Specifically, Figure 2 As shown, the angle between the permanent magnet magnetic moment orientation and the axis is 0° to 90°; the permanent magnet has multiple magnetic moment orientations; and the magnetic flux density moduli at multiple magnetic moment orientations of the permanent magnet are the same or different.

[0056] Specifically, the calculation formula of the permanent magnet is:

[0057]

[0058] Where:

[0059] B m It represents the magnetic flux density of the permanent magnet on the axis;

[0060] B r Indicates the residual magnetic density of permanent magnetic materials;

[0061] z represents the z coordinate of the field point;

[0062] R o Represents the outer diameter of the permanent magnet;

[0063] R i represents the inner diameter of the permanent magnet;

[0064] L represents the length of the permanent magnet.

[0065] Specifically, the material of the electromagnet coil is a good conductor material.

[0066] Specifically, Figure 3 As shown, the cross-sectional structure of the winding of the electromagnetic solenoid is a hollow core or a good conductor enclosing a vacuum, a semiconductor, an insulator material, etc.

[0067] Specifically, Figure 4 As shown, the winding method of the electromagnetic solenoid is conventional winding perpendicular to the axis of the solenoid, winding parallel to the axis and / or winding at a certain angle to the axis; the winding angle of the electromagnetic solenoid is 0° to 180°; the spacing between the windings of the electromagnetic solenoid is equal or unequal; the winding of the electromagnetic solenoid is straight line winding, curved line winding and / or wavy line winding.

[0068] Specifically, the calculation formula of the electromagnetic solenoid is:

[0069]

[0070] Where:

[0071] B s It represents the magnetic flux density of the electromagnetic solenoid;

[0072] μ0 represents the vacuum magnetic permeability;

[0073] I represents the current intensity in the electromagnetic solenoid winding;

[0074] R o Indicates the outer diameter of the electromagnetic solenoid;

[0075] R i Indicates the inner diameter of the corresponding electromagnetic solenoid;

[0076] L represents the length of the electromagnetic solenoid (representing the radial distance of the electromagnetic solenoid wire microelement);

[0077] z represents the coordinates of the field point;

[0078] z' represents the z coordinate of the center position of the electromagnetic solenoid;

[0079] d represents the diameter of the winding (Note: if the winding cross-section is an irregular pattern, the distance to the point with the largest circumference is used).

[0080] Specifically, in the calculation process of the electromagnet, for windings with non-square cross-sections, the calculation adopts the square cross-section approximation method. For example, if the winding cross-section is a solid circle, d 2 Alternative approximate.

[0081] Specifically, Figure 5 As shown, in order to eliminate the influence of electromagnetic solenoid heating on the permanent magnet, a heat insulation layer and a heat conductive structure can be added between the electromagnet and the permanent magnet. There are two ways to deal with this. One is to place the heat insulation layer adjacent to the permanent magnet and the heat conductive structure adjacent to the electromagnet. In this case, the electromagnet heats up too much, and heat conduction is the main method, supplemented by heat insulation. The other is to place the heat insulation layer adjacent to the electromagnet and the heat conductive structure adjacent to the permanent magnet. In this case, the electromagnet heats up negligibly, and the absolute temperature control of the permanent magnet is emphasized. The specific situation is as follows Figure 5 As shown in the figure, the blue layer is the electromagnetic solenoid, the yellow layer is the heat-conducting structure, the white layer is the heat-insulating material, and the black layer is the permanent magnet. The left side shows the situation where the heat generation of the electromagnetic solenoid cannot be ignored, and the right side shows the situation where the heat generation can be ignored.

[0082] Specifically, this embodiment provides a design method for a variable beam control magnet group based on the transmission theory of beam optical permanent magnets and electromagnetic solenoids and basic electromagnetic theory: first, the transverse state vector of the final state particle is given according to the beam optical transmission theory, and then the axial magnetic field analytical distribution of the energized solenoid is obtained by taking a certain approximation according to the classical electromagnetic theory, and the existing analytical solution is combined with the existing data group for calculation and analysis, and compared with the simulation to verify the correctness of the theoretical model, and the model is continuously modified when the deviation is large to obtain a relatively close mathematical model, and the optimization analysis is performed based on this model to obtain the optimal parameter group for magnet design, and finally the simulation verification and comparison of the design results are performed. The magnet group designed by this method can ensure the characteristics of relative stability and precision in the regulation of the longitudinal magnetic field, so that a single set of designs can meet relatively complex regulation conditions, and temporary adjustments can be made in the case of deviations in actual transmission to provide the most ideal transmission results.

[0083] As a preferred solution of this embodiment, specifically, Figure 6As shown, the present invention provides a double-layer composite solenoid group consisting of a layer of cylindrical permanent magnet wound around a cylindrical electromagnetic solenoid. No heat insulation material and heat conduction structure are temporarily arranged between the inner permanent magnet and the outer electromagnetic solenoid, and only basic simulation is performed.

[0084] The inner permanent magnet is made of samarium cobalt material, the outer electromagnetic solenoid winding is made of copper, and the beam integration object uses the beam distribution parameters after beam expansion. The phase space [x, x'] and [y, y'] are calculated according to the electromagnetic solenoid transmission matrix described by beam optics, and the phase space result after a certain distance through the electromagnetic solenoid is obtained. It is compared with the phase space distribution required by the target, and the equation group is given from the parameter restrictions such as beam spot size and divergence angle. The possible combination range of parameters such as the length, inner diameter, outer diameter, number of turns of electromagnetic solenoid winding, radius of the energized wire, and current of each layer of the composite solenoid group is obtained in reverse. After selecting the preliminary combination, simulation is carried out and the results are statistically analyzed, mainly the percentage of particles with divergence angles in a certain range of the total number of particles. Since the smaller the divergence angle, the closer the phase diagram is to the horizontal axis, and the stronger the magnetic field is, the phase diagram will be turned to the first and third quadrants. The input current is continuously adjusted according to the phase diagram to achieve the phase diagram of the exit beam completely close to the horizontal axis of the coordinate, such as Figure 7 shown.

[0085] By comparison, the double-layer composite solenoid group has the same beam deflection capability as the pure electromagnetic solenoid, but has greatly improved in terms of mass, volume and energy consumption. The density of the samarium cobalt material is 7600kg·m -3 , the density of copper winding is 8960kg·m -3 , the total mass of the above-mentioned double-layer composite solenoid group is about 16.8kg; if all electromagnetic solenoids are used, the copper mass will exceed 17.16kg under the same volume, and the magnetic field strength is much smaller than the magnetic field of the double-layer composite solenoid group; the simulation results confirm that if the part of the double-layer composite solenoid group that was originally a permanent magnet is replaced with an electromagnetic solenoid, and the other parameters remain unchanged, the magnetic flux density at the center position is 0.0041T, while the double-layer composite solenoid group reaches 0.0951T, which is more than 20 times that of the part of the same volume of permanent magnets replaced by electromagnetic solenoids. The resistance of the part of the same volume of permanent magnets replaced by electromagnetic solenoids is 590Ω higher than that of the double-layer composite solenoid group, which means that the energy loss per second is 3.481×10 more than that of the double-layer composite solenoid group at the same 1A current. 5 J, which is a very large energy loss. According to this embodiment, it can be seen that the advantages of the double-layer composite solenoid group are very obvious.

Claims

1. A multilayer composite solenoid system for beam control, comprising a multilayer tubular magnet arranged on a beam line, characterized in that: The multi-layer tubular magnet comprises a tubular magnet and a tubular solenoid, and the tubular magnet and a common interlayer with the tubular solenoid form a composite solenoid group.

2. The multilayer composite solenoid system for beam control according to claim 1, characterized in that: The tubular magnet is a permanent magnet, an electromagnet and / or an electromagnet; the tubular solenoid is an electromagnetic solenoid.

3. The multilayer composite solenoid system for beam control according to claim 2, characterized in that: The permanent magnet is made of samarium cobalt material or neodymium iron boron material.

4. The multilayer composite solenoid system for beam control according to claim 2, characterized in that: The angle between the magnetic moment orientation of the permanent magnet and the axis is 0° to 90°.

5. The multi-layer composite solenoid system for beam control according to claim 2, characterized in that: The calculation formula of the permanent magnet is: Where: B m It represents the magnetic flux density of the permanent magnet on the axis; B r Indicates the residual magnetic density of permanent magnetic materials; z represents the z coordinate of the field point; R o represents the outer diameter of the permanent magnet; R i represents the inner diameter of the permanent magnet; L represents the length of the permanent magnet.

6. The multilayer composite solenoid system for beam control according to claim 2, characterized in that: The cross-sectional structure of the winding of the electromagnetic solenoid is hollow or contains a vacuum inside a good conductor.

7. The multi-layer composite solenoid system for beam control according to claim 2, characterized in that: The electromagnetic solenoid is wound in a manner perpendicular to the axis of the solenoid, parallel to the axis and / or at a certain angle to the axis. The winding angle of the electromagnetic solenoid is 0° to 180°; The spacing between the windings of the electromagnetic solenoid is equal or unequal; The winding of the electromagnetic solenoid is straight line winding, curved line winding and / or wavy line winding.

8. The multi-layer composite solenoid system for beam control according to claim 2, characterized in that: The calculation formula of the electromagnetic solenoid is: Where: B s It represents the magnetic flux density of the electromagnetic solenoid; μ0 represents the vacuum magnetic permeability; I represents the current intensity in the electromagnetic solenoid winding; R o Indicates the outer diameter of the electromagnetic solenoid; R i Indicates the inner diameter of the corresponding electromagnetic solenoid; L represents the length of the electromagnetic solenoid; z represents the coordinates of the field point; z' represents the z coordinate of the center position of the electromagnetic solenoid; d represents the diameter of the winding.

9. The multi-layer composite solenoid system for beam control according to claim 1, characterized in that: The number of layers of the composite solenoid group is not less than 2.

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