Superconducting quadrupole magnet structure for particle accelerator

Abstract

The invention relates to a superconducting quadrupole magnet structure for a particle accelerator, which comprises four superconducting quadrupole coils formed by winding superconducting cables, each superconducting quadrupole coil provides four magnetic poles, and the coils jointly form a particle beam channel; each coil is composed of a plurality of flush winding turns, each winding turn is of a bent square structure and comprises two straight edge sections and two end arc sections, the two straight edge sections are located on two planes or curved surfaces forming angles, and the end arc sections are connected with the two straight edge sections to form a closed loop; the straight edge sections of the two adjacent coils on the same plane or curved surface are kept flush, and the end arc sections of the two adjacent coils on the same plane or curved surface are kept flush. The superconducting quadrupole magnet structure for the particle accelerator is formed by winding the superconducting cable, the magnetic field gradient is high, only a refrigerating machine needs to maintain a low-temperature environment, energy consumption is low, an iron core can be added or not added, and the size and the weight are remarkably reduced.

Description

Technical Field

[0001] The present invention relates to an accelerator, and more particularly to a superconducting quadrupole magnet structure for a particle accelerator. Background Art

[0002] In the field of particle accelerators, achieving precise control of the beam is crucial. With the continuous advancement of technology, the demand for particle accelerators with higher energy and brightness is increasing. This growing demand has prompted scientists to seek more advanced magnet technology to meet the performance requirements of the next generation of particle accelerators. While traditional electromagnetic quadrupole magnets can achieve beam focusing and control to a certain extent, they have certain limitations in terms of magnetic field strength and stability. Specifically, the magnetic field gradient generated by traditional electromagnetic quadrupole magnets under certain spatial dimensions is relatively small, which limits their application in high-energy and high-brightness particle accelerators. Moreover, traditional electromagnetic quadrupole magnets are wound with copper coils, require an iron core on the outside, and have a water cooling system, resulting in large size and weight, and high energy consumption. Summary of the Invention

[0003] In order to solve the problems of low magnetic field gradient, large size and weight in the above-mentioned prior art, the present invention aims to provide a superconducting quadrupole magnet structure for a particle accelerator.

[0004] The superconducting quadrupole magnet structure for a particle accelerator according to the present invention includes four superconducting quadrupole coils formed by winding superconducting cables, each providing four magnetic poles, and these coils together constitute a particle beam channel; each coil is composed of multiple flush winding turns, each winding turn is a bent U-shaped structure, including two straight side segments and two end arc segments, wherein the two straight side segments are located on two angled planes or curved surfaces, and the end arc segments connect the two straight side segments to form a closed loop; the straight side segments of two adjacent coils located on the same plane or curved surface remain flush, and the end arc segments of two adjacent coils located on the same plane or curved surface remain flush.

[0005] In a preferred embodiment, in two adjacent coils located on the same plane or curved surface, the end arc segment of one coil is superimposed on the end arc segment of the other coil.

[0006] In a preferred embodiment, the end arc segments of the same coil located on the same plane or curved surface are tilted relative to the straight edge segments.

[0007] In a preferred embodiment, the superconducting cables are wound in grooves on the surface of the frame.

[0008] In a preferred embodiment, the material of the skeleton is G10 glass fiber, nano-ceramics, aluminum alloy, stainless steel, PEEK or PEI.

[0009] In a preferred embodiment, the superconducting cable is a superconducting wire, a superconducting tape, or a superconducting cable formed by twisting multiple strands.

[0010] In a preferred embodiment, the cross-sectional shape of the particle beam channel is rectangular, square, circular or elliptical.

[0011] In a preferred embodiment, the superconducting quadrupole magnet is a linear or curved quadrupole coil.

[0012] In a preferred embodiment, the superconducting quadrupole magnet structure further includes an iron core located outside the superconducting quadrupole magnet to enhance the coil excitation efficiency and shield the coil leakage magnetic field.

[0013] In a preferred embodiment, the superconducting quadrupole magnet structure further includes a superconducting dipole deflection magnet, which is nested with the superconducting quadrupole magnet to form a combined functional magnet.

[0014] The superconducting quadrupole magnet structure for a particle accelerator according to the present invention is wound with superconducting cables, has a high magnetic field gradient, requires only a refrigerator to maintain a low-temperature environment, has low energy consumption, can be added with or without an iron core, and significantly reduces size and weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 3 is a schematic structural diagram of a quadrupole magnet structure according to a first embodiment of the present invention.

[0016] Figure 2 4 is a schematic structural diagram of a quadrupole magnet structure according to a second embodiment of the present invention.

[0017] Figure 3 3 is a schematic structural diagram of a quadrupole magnet structure according to a third embodiment of the present invention.

[0018] Figure 4 yes Figure 3 sectional view of .

[0019] Figure 5 4 is a schematic structural diagram of a quadrupole magnet structure according to a fourth embodiment of the present invention.

[0020] Figure 6 4 is a schematic structural diagram of a quadrupole magnet structure according to a fifth embodiment of the present invention.

[0021] Figure 7 yes Figure 6 sectional view of .

[0022] Figure 8 4 is a schematic structural diagram of a quadrupole magnet structure according to a sixth embodiment of the present invention.

[0023] Figure 94 is a schematic structural diagram of a quadrupole magnet structure according to a seventh embodiment of the present invention.

[0024] Figure 10 4 is a schematic structural diagram of a quadrupole magnet structure according to an eighth embodiment of the present invention.

[0025] Figure 11 yes Figure 10 sectional view of . DETAILED DESCRIPTION

[0026] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings and described in detail.

[0027] like Figures 1-11 As shown, the superconducting quadrupole magnet structure for a particle accelerator according to the present invention is formed by winding a superconducting cable 100 to form a superconducting quadrupole magnet. Superconducting cable 100 has zero resistance at low temperatures. The superconducting quadrupole magnet formed thereby can generate a high current density, thereby generating an extremely strong magnetic field, and can achieve a higher magnetic field gradient within the same space compared to conventional magnets.

[0028] In this way, the present invention can provide stronger focusing capabilities within a more compact space, effectively reducing the size of the magnet. The superconducting quadrupole magnet of the present invention can be used not only in accelerator beam transport lines but also in accelerator rotating gantries, meeting the high-performance magnet requirements of high-energy and high-brightness particle accelerators. By using superconducting quadrupole magnets, particle accelerators can achieve higher magnetic field gradients and better focusing within a smaller footprint, making the accelerator magnet system more compact.

[0029] In the present invention, the superconducting cable 100 can be a superconducting wire, a superconducting tape, or a superconducting cable made of multiple twisted strands. Typically, a low-temperature superconducting quadrupole coil is wound using a low-temperature superconducting wire or a superconducting cable, while a high-temperature superconducting quadrupole coil is wound using a superconducting tape.

[0030] In the traditional manufacturing process of quadrupole magnets, copper tubes are typically wound directly onto a mold, followed by curing to form the final magnet structure. However, in the present invention, the winding process for the superconducting cable 100 is different. The superconducting cable 100 is wound into a prefabricated wire groove on the surface of a bobbin to ensure precise positioning and securement of the superconducting cable. After winding, the bobbin and superconducting cable 100 undergo a curing process to ensure the structural stability and mechanical strength of the coil. The bobbin materials used in the present invention can be diverse, including but not limited to non-metallic materials such as G10 glass fiber and nanoceramics, or metallic materials such as aluminum alloy and stainless steel. These materials can be machined into the desired bobbin shape. Furthermore, high-performance plastic materials such as PEEK (polyetheretherketone) or PEI (polyetherimide) can also be formed into the bobbin through injection molding.

[0031] In the present invention, to ensure that the superconducting cable 100 reaches and maintains its superconducting state, various cooling methods can be used to achieve the low-temperature environment required for superconducting magnet operation. For example, liquid helium immersion cooling involves directly immersing the superconducting magnet in liquid helium, utilizing the low-temperature properties of liquid helium to cool the magnet. Another example is conduction cooling, where a refrigerator is in contact with the magnet surface to conduct heat away from the magnet, achieving a cooling effect.

[0032] like Figure 1 As shown, the quadrupole magnet structure according to the first embodiment of the present invention includes a first coil 1, a second coil 2, a third coil 3 and a fourth coil 4, each providing four magnetic poles. These coils 1, 2, 3, 4 together constitute a particle beam channel 5, along which the particle beam moves.

[0033] Each coil 1, 2, 3, 4 is located at a corner of the magnet structure and consists of two flush turns (i.e., two turns). Each turn is a curved U-shaped structure, consisting of two straight segments 11 and two end arc segments 12. The straight segments 11 lie on two perpendicular planes, while the end arc segments 12 connect the straight segments 11 on these two planes, forming a closed loop.

[0034] Specifically, the two straight-side segments 11 of the first coil 1 are respectively located on the right side of the top surface and the top side of the right surface, the two straight-side segments 11 of the second coil 2 are respectively located on the bottom side of the right surface and the right side of the bottom surface, the two straight-side segments 11 of the third coil 3 are respectively located on the left side of the bottom surface and the bottom side of the left surface, and the two straight-side segments 11 of the fourth coil 4 are respectively located on the top side of the left surface and the left side of the top surface.

[0035] The straight side segment 11 of the first coil 1 located on the top surface and the straight side segment 11 of the fourth coil 4 located on the top surface are located on the same plane, the straight side segment 11 of the first coil 1 located on the right surface and the straight side segment 11 of the second coil 2 located on the right surface are located on the same plane, the straight side segment 11 of the third coil 3 located on the bottom surface and the straight side segment 11 of the second coil 2 located on the bottom surface are located on the same plane, and the straight side segment 11 of the third coil 3 located on the left surface and the straight side segment 11 of the fourth coil 4 located on the left surface are located on the same plane.

[0036] The end arc segment 12 of the first coil 1 located on the top surface and the end arc segment 12 of the fourth coil 4 located on the top surface are located on the same plane, the end arc segment 12 of the first coil 1 located on the right surface and the end arc segment 12 of the second coil 2 located on the right surface are located on the same plane, the end arc segment 12 of the third coil 3 located on the bottom surface and the end arc segment 12 of the second coil 2 located on the bottom surface are located on the same plane, and the end arc segment 12 of the third coil 3 located on the left surface and the end arc segment 12 of the fourth coil 4 located on the left surface are located on the same plane.

[0037] Obviously, the size of the inner winding turns of each coil 1, 2, 3, 4 is smaller than the size of the outer winding turns. The further inward, the smaller the bending radius at the connection between the straight edge segment 11 and the end arc segment 12. If the bending radius is less than the minimum bending radius during the winding process, the superconducting cable 100 will be damaged. Therefore, in the embodiment shown in the figure, each coil 1, 2, 3, 4 can only be arranged with 2 turns.

[0038] like Figure 2 As shown, the quadrupole magnet structure according to the second embodiment of the present invention includes a first coil 10, a second coil 20, a third coil 30 and a fourth coil 40, which respectively provide four magnetic poles. These coils 10, 20, 30, 40 together constitute a particle beam channel 50, along which the particle beam moves.

[0039] Unlike the first embodiment, each coil 10, 20, 30, 40 in this embodiment is not located at a corner of the coil structure, but instead spans a larger area. Furthermore, each coil 10, 20, 30, 40 consists of three flush winding turns (i.e., three turns). Similar to the first embodiment, each winding turn has a curved U-shaped structure, consisting of two straight segments 110 and two end arc segments 120. The straight segments 110 are located on two perpendicular planes, while the end arc segments 120 connect the straight segments 110 on these two planes, forming a closed loop.

[0040] Specifically, the two straight-side segments 110 of the first coil 10 are respectively located on the left side of the top surface and the bottom side of the right surface, the two straight-side segments 110 of the second coil 20 are respectively located on the top side of the right surface and the left side of the bottom surface, the two straight-side segments 110 of the third coil 30 are respectively located on the right side of the bottom surface and the top side of the left surface, and the two straight-side segments 110 of the fourth coil 40 are respectively located on the bottom side of the left surface and the right side of the top surface.

[0041] The straight side segment 110 on the top surface of the first coil 10 and the straight side segment 110 on the top surface of the fourth coil 40 are located on the same plane, the straight side segment 110 on the right surface of the first coil 10 and the straight side segment 110 on the right surface of the second coil 20 are located on the same plane, the straight side segment 110 on the bottom surface of the third coil 30 and the straight side segment 110 on the bottom surface of the second coil 20 are located on the same plane, and the straight side segment 110 on the left surface of the third coil 30 and the straight side segment 11 on the left surface of the fourth coil 40 are located on the same plane.

[0042] The arc segment 120 at the top of the first coil 10 is positioned above the arc segment 120 at the top of the fourth coil 40. Specifically, the arc segment 120 at the top of the fourth coil 40 and the straight edge segment 110 at the top of the fourth coil 40 are located on the same plane. The arc segment 120 at the top of the first coil 10 is tilted outward relative to the straight edge segment 110 at the top of the first coil 10, thereby allowing the arc segment 120 at the top of the first coil 10 to extend rightward over the arc segment 120 at the top of the fourth coil 40. It should be understood that the fact that the arc segment 120 at the top of the fourth coil 40 and the straight edge segment 110 at the top of the fourth coil 40 are located on the same plane is merely an example and not a limitation. It is also feasible to have the arc segment 120 at the top of the fourth coil 40 be recessed inward relative to the straight edge segment 110 at the top of the fourth coil 40. Similarly, the end arc segment 120 of the first coil 10 located on the right is stacked above the end arc segment 120 of the second coil 20 located on the right, the end arc segment 120 of the third coil 30 located on the bottom is stacked above the end arc segment 120 of the second coil 20 located on the bottom, and the end arc segment 120 of the third coil 30 located on the left is stacked above the end arc segment 120 of the fourth coil 40 located on the left.

[0043] Obviously, by spanning a larger area, the bending radius at the junction of the straight-side segment 110 and the end arc segment 120 of each coil 10, 20, 30, 40 located in the interior of the winding turn is kept at a relatively small increase. Therefore, in the embodiment shown in the figure, each coil 10, 20, 30, 40 can be arranged with three turns. In this way, by optimizing the winding form, this embodiment not only avoids bending damage to the superconducting cable 100 in a small space, but also allows for more turns per magnetic pole in the same space, improving space utilization and magnetic field gradient, further enhancing the uniformity and stability of the magnetic field, and making the application of the quadrupole magnet structure in particle accelerators more flexible and efficient.

[0044] like Figure 3-Figure 4 As shown, the quadrupole magnet structure according to the third embodiment of the present invention is a linear quadrupole coil, used to focus and control a particle beam moving in a straight line. Its cross-section is a rectangle bounded by four straight sidewalls, top, bottom, left, and right. These sidewalls are wound with closely packed superconducting cables 100 according to the method of the second embodiment. The coil is centrally symmetrical, and the current distribution across the coil cross-section is centrally symmetrical. The currents at the top and bottom flow in the same direction, while the currents at the sides flow in opposite directions. This can generate the quadrupole magnetic field required for a circular good field. In this embodiment, each coil can have eight turns. It should be understood that the rectangular cross-section here is merely an example and not a limitation. A square cross-section is also feasible, and the aspect ratio can be flexibly adjusted to meet the requirements of the magnet's good field. It should be understood that the end turn spacing (the distance between adjacent end arc segments 120 of the quadrupole coil) can be appropriately adjusted to achieve higher magnetic field quality. In this embodiment, the cross-section of the superconducting cable 100 is circular. It should be understood that this circular cross-section is merely an example and not a limitation. For example, the cross-section of the superconducting cable 100 in the first and second embodiments is rectangular.

[0045] like Figure 5 As shown, the quadrupole magnet structure according to the fourth embodiment of the present invention includes a window-shaped iron core 200 located on the outside in addition to the pure coil form in the third embodiment. By providing the iron core 200, the coil excitation efficiency can be enhanced and the coil leakage magnetic field can be shielded. The iron core can be in the form of a cold iron core or a warm iron core. The material of the iron core can be electrical pure iron, silicon steel sheet, or ferrite. It should be understood that the iron core 200 is only an optional option in the present invention, and the third embodiment without adding the iron core is a relatively more preferred solution because it has a relatively smaller size and mass.

[0046] like Figure 6-Figure 7As shown, the quadrupole magnet structure according to the fifth embodiment of the present invention is a linear quadrupole coil used to focus and control a particle beam moving in a straight line. Its cross-section is a circle formed by four arc-shaped sidewalls, one above, one below, and one below, respectively. These sidewalls are wound using closely packed superconducting cables 100 according to the second embodiment. The coil is centrally symmetrical, and the current distribution across the coil cross-section is centrally symmetrical. The currents at the top and bottom flow in the same direction, while the currents at the sides flow in opposite directions. This generates the quadrupole magnetic field required for a circular good field. In this embodiment, each coil can have nine turns. It should be understood that the circular cross-section is provided here by way of example only and not limitation; variations such as elliptical shapes are also feasible. The diameter-to-length ratio can be flexibly adjusted based on the requirements for the magnet's good field. It should be understood that the end turn spacing (the distance between adjacent end arc segments 120 of the quadrupole coil) can be appropriately adjusted to achieve higher magnetic field quality.

[0047] like Figure 8 As shown, the magnet form of the quadrupole magnet structure according to the sixth embodiment of the present invention is a curved quadrupole coil, which is used to focus and control the particle beam in a curved path. Its cross-section is a rectangle surrounded by four straight side walls on the top, bottom, left and right sides. These side walls are wound by closely arranged superconducting cables 100 according to the method of the second embodiment. The coil is symmetrical along the midplane to obtain a higher integrated gradient uniformity. The current distribution of the corresponding coil cross section is symmetrical in the upper and lower directions. The current at the top and bottom flows in the same direction, and the current direction on the side is opposite. In this embodiment, according to the quality of the magnetic field, the number of turns or the turn spacing of the inner and outer coils can be flexibly adjusted to obtain the required uniformity. The number of turns of the inner and outer coils can be set to be the same or different.

[0048] like Figure 9 As shown, the quadrupole magnet structure according to the seventh embodiment of the present invention includes, in addition to the pure coil form in the sixth embodiment, an external iron core 200. The iron core 200 can enhance the coil excitation efficiency and shield the coil leakage magnetic field.

[0049] like Figure 10-11 As shown, the quadrupole magnet structure according to the eighth embodiment of the present invention includes, in addition to the iron core-enclosed coil structure of the seventh embodiment, a dipole coil 300. The dipole coil 300 is a curved superconducting dipole deflection magnet located outside the quadrupole coil. The two are nested together to form a combined functional magnet, possessing both a dipole magnetic field and a quadrupole magnetic field without having to convert the magnet into two or three magnets. This further reduces the space and size of the particle accelerator magnet, achieving miniaturization and compactness. It should be understood that the dipole coil 300 can also be located inside the quadrupole coil.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Various modifications are possible. In other words, any simple, equivalent changes and modifications made in accordance with the claims and the description of the present invention fall within the scope of protection of the present invention. Anything not fully described in this invention constitutes conventional technology.

Claims

1. A superconducting quadrupole magnet structure for a particle accelerator, characterized in that: The superconducting quadrupole magnet structure includes four superconducting quadrupole coils wound by superconducting cables, each providing four magnetic poles. These coils together constitute a particle beam channel. Each coil is composed of multiple flush winding turns, and each winding turn is a bent U-shaped structure, including two straight edge segments and two end arc segments, wherein the two straight edge segments are located on two angled planes or curved surfaces, and the end arc segment connects the two straight edge segments to form a closed loop. The straight edge segments of two adjacent coils located on the same plane or curved surface remain flush, and the end arc segments of two adjacent coils located on the same plane or curved surface remain flush.

2. The superconducting quadrupole magnet structure according to claim 1, characterized in that: In two adjacent coils located on the same plane or curved surface, the end arc segment of one coil is superimposed on the end arc segment of the other coil.

3. The superconducting quadrupole magnet structure according to claim 2, characterized in that: The end arc segments of the same coil located on the same plane or curved surface are tilted relative to the straight edge segments.

4. The superconducting quadrupole magnet structure according to claim 1, characterized in that: The superconducting cables are wound in the grooves on the surface of the frame.

5. The superconducting quadrupole magnet structure according to claim 4, characterized in that: The material of the skeleton is G10 glass fiber, nano ceramics, aluminum alloy, stainless steel, PEEK or PEI.

6. The superconducting quadrupole magnet structure according to claim 1, characterized in that: Superconducting cables are superconducting wires, superconducting tapes or cables made of twisted multiple strands.

7. The superconducting quadrupole magnet structure according to claim 1, characterized in that: The cross-sectional shape of the particle beam channel is rectangular, square, circular or elliptical.

8. The superconducting quadrupole magnet structure according to claim 1, characterized in that: The superconducting quadrupole magnet is a linear or curved quadrupole coil.

9. The superconducting quadrupole magnet structure according to claim 1, characterized in that: The superconducting quadrupole magnet structure further includes an iron core, which is located outside the superconducting quadrupole coil to enhance the coil excitation efficiency and shield the coil leakage magnetic field.

10. The superconducting quadrupole magnet structure according to claim 1, characterized in that: The superconducting quadrupole magnet structure further includes a superconducting dipole deflection magnet, which is nested with the superconducting quadrupole magnet to form a combined functional magnet.

Images