Superconducting second-order gradient coil structure, method of manufacture and superconducting quantum interference gradiometer

Abstract

The application provides a superconducting second-order gradient coil structure, a manufacturing method and a superconducting quantum interference gradiometer, and relates to the field of superconducting quantum interference devices. The superconducting second-order gradient coil structure comprises a second-order gradient coil support and six second-order gradient coil groups. The second-order gradient coil support comprises a center support and four compensation supports. Each of the six second-order gradient coil groups comprises a center point coil and two symmetrical coils connected to the center point coil. The center point coil of each group is arranged at the center support, and the two symmetrical coils of each group are arranged on the opposite two compensation supports. The six second-order gradient coil groups are used for responding to Gzy, Gxy, Gyy, Gzx, Gyx and Gxx magnetic field gradient components. The superconducting second-order gradient coil structure provided by the application takes the center support as an efficient detection point, can realize efficient signal detection in a local space, and the second-order gradient coil support effectively reduces the height of the liquid surface and is suitable for detecting a local near-source target body.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of superconducting quantum interference devices, and particularly relates to a superconducting second-order gradient coil structure, a manufacturing method and a superconducting quantum interference gradient meter. BACKGROUND

[0002] A superconducting quantum interference device (SQUID) is a kind of magnetic detector with extremely high sensitivity, which is widely used in the fields of weak magnetic detection such as biomagnetism, extremely low field nuclear magnetic resonance, geophysics and magnetic anomaly detection, and has shown good application potential.

[0003] In actual detection, one of the main challenges faced by SQUID weak magnetic detection is to suppress the strong environmental magnetic field and improve the detection sensitivity. Taking biomagnetic signals as an example, the typical intensity of cardiac magnetism and brain magnetism is in the order of tens of pT and hundreds of fT, while the environmental magnetic field is very strong, such as the typical intensity of the earth's magnetic field is 30-50 μT, and the change of the urban environmental magnetic field also reaches hundreds of nT. In order to effectively suppress the environmental magnetic field, a high-performance magnetic shielding room is usually used. In addition to the magnetic shielding room, the SQUID gradient meter technology capable of improving the detection sensitivity and noise suppression performance of the SQUID has been widely used.

[0004] The SQUID gradient meter mainly consists of a core SQUID chip and a gradient receiving coil, wherein the gradient receiving coil is a sensitive unit of external signals, which receives signals through the gradient coil and transmits them to the SQUID chip to realize signal readout.

[0005] At present, the common gradient measurement structure is single gradient to three gradient mode. Although this method is simple, the efficiency of the detected signal is reduced, especially for the target signal of a specific area. Therefore, how to design an optimized gradient coil structure has important value for signal measurement. SUMMARY

[0006] In order to overcome the deficiencies in the prior art, the present application provides a superconducting second-order gradient coil structure, a manufacturing method and a superconducting quantum interference gradient meter.

[0007] The application provides a superconducting second-order gradient coil structure, which comprises a second-order gradient coil support and six second-order gradient coil groups.

[0008] In a possible implementation, the center point coil in each second-order gradient coil group is a 2-turn coil and is wound in the same direction, and the two symmetric coils in each second-order gradient coil group are single-turn coils and are wound in the same direction and in the opposite direction of the winding direction of the corresponding center point coil.

[0009] In a possible implementation, the area of the center point coil is equal to that of the symmetric coil in each second-order gradient coil group.

[0010] In a possible implementation, the two symmetric coils in each second-order gradient coil group are symmetric about the corresponding center point coil.

[0011] In a possible implementation, the four compensation supports are a first compensation support, a second compensation support, a third compensation support and a fourth compensation support, the first compensation support and the third compensation support are oppositely arranged on two sides of the center support, the second compensation support and the fourth compensation support are oppositely arranged on the other two sides of the center support, the line connecting the first compensation support and the third compensation support is perpendicular to the line connecting the second compensation support and the fourth compensation support, the x-axis direction is parallel to the line connecting the center support and the second compensation support, and the y-axis direction is parallel to the line connecting the center support and the first compensation support.

[0012] In a possible implementation, the center support, the first compensation support, the second compensation support, the third compensation support and the fourth compensation support are integrally formed.

[0013] In a possible implementation, the six groups of the second-order gradient coils are respectively a first group of second-order gradient coils for responding to a Gzy magnetic field gradient component, a second group of second-order gradient coils for responding to a Gxy magnetic field gradient component, a third group of second-order gradient coils for responding to a Gyy magnetic field gradient component, a fourth group of second-order gradient coils for responding to a Gzx magnetic field gradient component, a fifth group of second-order gradient coils for responding to a Gyx magnetic field gradient component, and a sixth group of second-order gradient coils for responding to a Gxx magnetic field gradient component.

[0014] In a possible implementation, in the first group of second-order gradient coils, the normal directions of the center point coil and the symmetric coils are parallel to the z-axis direction, one of the symmetric coils is arranged on the first compensation support, and the other is arranged on the third compensation support, and the line connecting the center point coil and the two symmetric coils is parallel to the y-axis, thereby realizing the response to the Gzy magnetic field gradient component.

[0015] In the second group of second-order gradient coils, the normal directions of the center point coil and the symmetric coils are parallel to the x-axis direction, one of the symmetric coils is arranged on the first compensation support, and the other is arranged on the third compensation support, and the line connecting the center point coil and the two symmetric coils is parallel to the y-axis, thereby realizing the response to the Gxy magnetic field gradient component.

[0016] In the third group of second-order gradient coils, the normal directions of the center point coil and the symmetric coils are parallel to the y-axis direction, one of the symmetric coils is arranged on the first compensation support, and the other is arranged on the third compensation support, and the line connecting the center point coil and the two symmetric coils is parallel to the y-axis, thereby realizing the response to the Gyy magnetic field gradient component.

[0017] In the fourth group of second-order gradient coils, the normal directions of the center point coil and the symmetric coils are parallel to the z-axis direction, one of the symmetric coils is arranged on the second compensation support, and the other is arranged on the fourth compensation support, and the line connecting the center point coil and the two symmetric coils is parallel to the x-axis, thereby realizing the response to the Gzx magnetic field gradient component.

[0018] In the fifth group of second-order gradient coils, the normal directions of the center point coil and the symmetric coils are parallel to the y-axis direction, one of the symmetric coils is arranged on the second compensation support, and the other is arranged on the fourth compensation support, and the line connecting the center point coil and the two symmetric coils is parallel to the x-axis, thereby realizing the response to the Gyx magnetic field gradient component.

[0019] In the sixth second-order gradient coil set, normal directions of the center point coil and the symmetric coils are parallel to the x-axis direction, one of the symmetric coils is arranged on the second compensation support, and the other is arranged on the fourth compensation support, and a line connecting the center point coil and the two symmetric coils is parallel to the x-axis, thereby realizing the response of the Gxx magnetic field gradient component.

[0020] The application also provides:

[0021] A manufacturing method for manufacturing the superconducting second-order gradient coil structure, the manufacturing method comprising the following steps:

[0022] providing the second-order gradient coil support;

[0023] winding six groups of the second-order gradient coil sets respectively;

[0024] connecting the coils in each of the second-order gradient coil sets.

[0025] In addition, the application also provides a superconducting quantum interference gradiometer comprising a SQUID chip and the superconducting second-order gradient coil structure, wherein the superconducting second-order gradient coil structure is connected to the SQUID chip.

[0026] Compared with the prior art, the application has the following beneficial effects:

[0027] The application provides a superconducting second-order gradient coil structure, a manufacturing method and a superconducting quantum interference gradiometer, wherein the superconducting second-order gradient coil structure adopts a horizontal-vertical type detection structure, takes the center support as an efficient detection point, can realize efficient signal detection in a local space, has good comprehensive detection performance, can effectively capture target signals, integrates three-axis vector detection, and has richer information; the second-order gradient coil support adopts a horizontal structure, mainly occupies a horizontal space, and effectively reduces the height of a liquid surface in a Dewar; without increasing the effective liquid surface, the magnetic field detection efficiency of the center point is greatly improved, and the superconducting second-order gradient coil structure is suitable for detection of a local near-source target body. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0029] Figure 1 Fig. 1 shows a structure schematic diagram of a superconducting second-order gradient coil structure according to an embodiment of the application;

[0030] Figure 2A structure diagram of a superconducting second-order gradient coil structure is shown. Figure 1 A structure diagram of a superconducting second-order gradient coil structure is shown.

[0031] Figure 3 A structure diagram of a superconducting second-order gradient coil structure is shown.

[0032] Figure 4 A structure diagram of a superconducting second-order gradient coil structure is shown.

[0033] Main element symbol explanation:

[0034] 100 - superconducting second-order gradient coil structure; 10 - second-order gradient coil support; 11 - center support; 12 - compensation support; 121 - first compensation support; 122 - second compensation support; 123 - third compensation support; 124 - fourth compensation support; 20 - second-order gradient coil group; 201 - center point coil; 202 - symmetric coil; 21 - first second-order gradient coil group; 22 - second second-order gradient coil group; 23 - third second-order gradient coil group; 24 - fourth second-order gradient coil group; 25 - fifth second-order gradient coil group; 26 - sixth second-order gradient coil group. DETAILED DESCRIPTION

[0035] Embodiments of the present application are described in detail below with reference to the accompanying drawings, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0036] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0037] In addition, the terms "first", "second", etc. are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an ordered sequence. Thus, features referring to "first", "second" etc. can include one or more of the features, explicitly or implicitly.

[0038] In the present application, unless specifically defined otherwise, the terms "mounting", "connecting", "connecting", "fixing" and the like should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature. It can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0040] Embodiment one

[0041] Please refer to Figure 1 An embodiment of the present application provides a superconducting second-order gradient coil structure 100. The superconducting second-order gradient coil structure 100 is used in a superconducting quantum interference gradient meter to receive external signals and realize detection of magnetic field strength.

[0042] The superconducting second-order gradient coil structure 100 includes a second-order gradient coil support 10 and six second-order gradient coil groups 20. The six second-order gradient coil groups 20 are respectively arranged around the second-order gradient coil support 10. The center line direction or normal direction of the six second-order gradient coil groups 20 is different, so as to measure different magnetic field gradient components at the target source and realize efficient detection of the horizontal gradient component at the target source.

[0043] The second-order gradient coil support 10 is generally cross-shaped. The second-order gradient coil support 10 includes a center support 11 and four compensation supports 12. The four compensation supports 12 are arranged on the center support 11 in pairs opposite to each other and perpendicular to each other.

[0044] The six groups of the second-order gradient coils 20 are respectively a first second-order gradient coil group 21, a second second-order gradient coil group 22, a third second-order gradient coil group 23, a fourth second-order gradient coil group 24, a fifth second-order gradient coil group 25, and a sixth second-order gradient coil group 26. The first second-order gradient coil group 21, the second second-order gradient coil group 22, the third second-order gradient coil group 23, the fourth second-order gradient coil group 24, the fifth second-order gradient coil group 25, and the sixth second-order gradient coil group 26 each include a center point coil 201 and two symmetrical coils 202 connected to the center point coil 201.

[0045] The center support 11 is a target source of the superconducting second-order gradient coil structure 100. The center point coil 201 of each group is arranged at the center support 11, and the center point coil 201 is a detection coil for receiving a signal at the center support 11. The two symmetrical coils 202 of each group are symmetrically arranged on the opposite compensation supports 12, and the symmetrical coils 202 are compensation coils for detecting a corresponding background magnetic field.

[0046] Specifically, four compensation supports 12 are defined as a first compensation support 121, a second compensation support 122, a third compensation support 123, and a fourth compensation support 124. The first compensation support 121 and the third compensation support 123 are arranged on the two sides of the center support 11. The second compensation support 122 and the fourth compensation support 124 are arranged on the other two sides of the center support 11, and the line connecting the first compensation support 121 and the third compensation support 123 is perpendicular to the line connecting the second compensation support 122 and the fourth compensation support 124.

[0047] Please refer to Figure 1 , a Cartesian coordinate system is established, and the z-axis direction is defined as the direction perpendicular to the connection between the center support 11 and the four compensation supports 12, that is, the thickness direction of the second-order gradient coil support 10; the x-axis direction is defined as the direction parallel to the line connecting the center support 11 and the second compensation support 122, that is, the length direction of the second-order gradient coil support 10; and the y-axis direction is defined as the direction parallel to the line connecting the center support 11 and the first compensation support 121, that is, the width direction of the second-order gradient coil support 10. It can be understood that the above definitions are only for the purpose of understanding the relative positional relationship of each component in the superconducting second-order gradient coil structure 100, and should not be construed as a limitation on the present application.

[0048] The first second-order gradient coil set 21 is used to respond to the Gzy magnetic field gradient component, the second second-order gradient coil set 22 is used to respond to the Gxy magnetic field gradient component, the third second-order gradient coil set 23 is used to respond to the Gyy magnetic field gradient component, the fourth second-order gradient coil set 24 is used to respond to the Gzx magnetic field gradient component, the fifth second-order gradient coil set 25 is used to respond to the Gyx magnetic field gradient component, and the sixth second-order gradient coil set 26 is used to respond to the Gxx magnetic field gradient component.

[0049] Please refer to Figure 2 In the first second-order gradient coil set 21, the normal directions of the center point coil 201 and the symmetric coils 202 are parallel to the z-axis direction. The center point coil 201 is arranged at the center support 11, one of the symmetric coils 202 is arranged on the first compensation support 121, and the other is arranged on the third compensation support 123. The two symmetric coils 202 are symmetric about the center point coil 201, and the connecting line of the center point coil 201 and the symmetric coils 202 is parallel to the y-axis. Thus, the response of the Gzy magnetic field gradient component is realized.

[0050] In the second second-order gradient coil set 22, the normal directions of the center point coil 201 and the symmetric coils 202 are parallel to the x-axis direction. The center point coil 201 is arranged at the center support 11, one of the symmetric coils 202 is arranged on the first compensation support 121, and the other is arranged on the third compensation support 123. The two symmetric coils 202 are symmetric about the center point coil 201, and the connecting line of the center point coil 201 and the symmetric coils 202 is parallel to the y-axis. Thus, the response of the Gxy magnetic field gradient component is realized.

[0051] In the third second-order gradient coil set 23, the normal directions of the center point coil 201 and the symmetric coils 202 are parallel to the y-axis direction. The center point coil 201 is arranged at the center support 11, one of the symmetric coils 202 is arranged on the first compensation support 121, and the other is arranged on the third compensation support 123. The two symmetric coils 202 are symmetric about the center point coil 201, and the connecting line of the center point coil 201 and the symmetric coils 202 is parallel to the y-axis. Thus, the response of the Gyy magnetic field gradient component is realized.

[0052] In the fourth second-order gradient coil set 24, the normal directions of the center point coil 201 and the symmetric coils 202 are parallel to the z-axis direction. The center point coil 201 is arranged at the center support 11, one of the symmetric coils 202 is arranged on the second compensation support 122, and the other is arranged on the fourth compensation support 124. The two symmetric coils 202 are symmetric about the center point coil 201, and the line connecting the center point coil 201 and the symmetric coils 202 is parallel to the x-axis. Thus, the response of the Gzx magnetic field gradient component is realized.

[0053] In the fifth second-order gradient coil set 25, the normal directions of the center point coil 201 and the symmetric coils 202 are parallel to the y-axis direction. The center point coil 201 is arranged at the center support 11, one of the symmetric coils 202 is arranged on the second compensation support 122, and the other is arranged on the fourth compensation support 124. The two symmetric coils 202 are symmetric about the center point coil 201, and the line connecting the center point coil 201 and the symmetric coils 202 is parallel to the x-axis. Thus, the response of the Gyx magnetic field gradient component is realized.

[0054] In the sixth second-order gradient coil set 26, the normal directions of the center point coil 201 and the symmetric coils 202 are parallel to the x-axis direction. The center point coil 201 is arranged at the center support 11, one of the symmetric coils 202 is arranged on the second compensation support 122, and the other is arranged on the fourth compensation support 124. The two symmetric coils 202 are symmetric about the center point coil 201, and the line connecting the center point coil 201 and the symmetric coils 202 is parallel to the x-axis. Thus, the response of the Gxx magnetic field gradient component is realized.

[0055] In the embodiment, the center point coil 201 in each second-order gradient coil set 20 is a 2-turn coil and is wound in the same direction to improve the detection efficiency; the two symmetric coils 202 in each set are single-turn coils and are wound in the same direction and opposite to the winding direction of the corresponding center point coil 201.

[0056] However, the ratio of the number of turns of the center point coil 201 to the two symmetric coils 202 in each set can also be 2n-n-n (n=2, 3, …) in other embodiments.

[0057] In the embodiment, the areas of the center point coil 201 and the symmetric coils 202 in each set are equal.

[0058] However, the area of the center point coil 201 can also be greater than that of the symmetric coils 202 in other embodiments for signal enhancement.

[0059] In this embodiment, the second-order gradient coil set 20 takes the center support 11 as the target source, and the magnetic field response of the second-order gradient coil set 20 can be represented as B = 2*B0-B1-B2, wherein B0 is the corresponding magnetic field of the center point coil 201, B1 is the corresponding magnetic field of one of the symmetric coils 202, and B2 is the corresponding magnetic field of the other symmetric coil 202. When the two symmetric coils 202 are symmetric about the center point coil 201, B1≈B2, at this time, the magnetic field response of the second-order gradient coil set 20 can be equivalent to a first-order gradient coil with 2 turns, that is, B≈2*(B0-B1), and the signal strength is much larger than that of the traditional second-order abstract gradient structure, that is, B=B1-2*B0+B2.

[0060] In this embodiment, the second-order gradient coil support 10 is an integral structure, that is, the center support 11, the first compensation support 121, the second compensation support 122, the third compensation support 123, and the fourth compensation support 124 are an integral whole. However, it is not limited to this, and it can be understood that in other embodiments, the second-order gradient coil support 10 can also be formed by combining multiple sub-supports, such as five small supports with similar structures, one of which is placed in the middle as the center support 11, and the remaining four are placed according to the four edges of the cross-shaped support and are connected to the center support 11.

[0061] The superconducting second-order gradient coil structure 100 adopts a horizontal-vertical type detection structure, takes the center support 11 as an efficient detection point, can realize efficient signal detection in a local space, has good comprehensive detection performance, can effectively capture target signals, integrates three-axis vector detection, and has richer information; the second-order gradient coil support 10 adopts a horizontal structure, mainly occupies horizontal space, and effectively reduces the height of the liquid surface in the Dewar; without increasing the effective liquid surface, the magnetic field detection efficiency of the center point is greatly improved, and it is suitable for detection of local near-source target bodies.

[0062] Embodiment Two

[0063] Please refer to Figure 3 The superconducting second-order gradient coil structure 100 provided in this embodiment can be used in a superconducting quantum interference gradiometer. This embodiment is an improvement based on the above-mentioned embodiment one, and the difference compared with the above-mentioned embodiment one is that:

[0064] In embodiment one, the six groups of second-order gradient coil sets 20 are located on the same surface of the second-order gradient coil support 10, and at the center support 11, the first second-order gradient coil set 21 and the fourth second-order gradient coil set 24 need to be set in a staggered manner because the normal directions are the same.

[0065] In the second embodiment, the first second-order gradient coil set 21, the second second-order gradient coil set 22, the third second-order gradient coil set 23, the fifth second-order gradient coil set 25, and the sixth second-order gradient coil set 26 are located on the same surface of the second-order gradient coil support 10. The fourth second-order gradient coil set 24 is located on the other surface of the second-order gradient coil support 10, thereby avoiding interference with the first second-order gradient coil set 21.

[0066] It can be understood that, since the fourth second-order gradient coil set 24 needs to be arranged on the other surface of the second-order gradient coil support 10, the length of the second-order gradient coil support 10 along the z-axis direction, i.e., the thickness of the second-order gradient coil support 10, needs to be as small as possible to ensure the consistency of the detection points as much as possible.

[0067] It can be understood that, when the second-order gradient coil support 10 is formed by combining a plurality of sub-supports, the center point coil 201 and the symmetric coil 202 of each of the six second-order gradient coil sets 20 can be arranged on different surfaces of the corresponding sub-supports. For example, when five regular hexahedrons are used as sub-supports, the corresponding center point coil 201 and symmetric coil 202 of each set can be formed on the surface of the corresponding sub-support, and the corresponding center point coil 201 and symmetric coil 202 are connected by a connecting wire. This can facilitate the arrangement of the coils and facilitate the processing and connection.

[0068] Embodiment three

[0069] Please refer to Figure 4 The embodiment also provides a manufacturing method of the superconducting second-order gradient coil structure, which can be used to manufacture the superconducting second-order gradient coil structure 100. The manufacturing method comprises the following steps:

[0070] S101: providing a second-order gradient coil support 10.

[0071] Specifically, the second-order gradient coil support 10 of the superconducting second-order gradient coil structure 100 is designed according to the inner diameter of the Dewar.

[0072] In the embodiment, the second-order gradient coil support 10 is integrally designed and manufactured. However, this is not limited, and in other embodiments, a plurality of sub-supports can be separately manufactured, and the plurality of sub-supports are connected to each other by a rigid connecting rod or other connecting member to form the second-order gradient coil support 10.

[0073] S102: winding six second-order gradient coil sets 20 respectively.

[0074] Specifically, the six second-order gradient coil sets 20 are wound according to the arrangement of the center point coil 201 and the symmetric coil 202 of each set. Figure 1 and Figure 2The middle coordinate system structure, according to the conventional second-order gradient mode, sequentially winds 6 groups of the second-order gradient coil groups 20. Among them, 2 turns of the center point coil 201 are wound in the same direction at the center support 11; 1 turn of the symmetrical coil 202 is wound in the same direction on the symmetrical two compensation supports 12, and is opposite to the center point coil 201.

[0075] S103: The center point coil 201 and the symmetrical coil 202 in each group of the second-order gradient coil group 20 are connected.

[0076] Specifically, the center point coil 201 and the corresponding symmetrical coil 202 in the six groups of the second-order gradient coil group 20 are sequentially connected, that is, the superconducting second-order gradient coil structure 100 is constructed.

[0077] Embodiment Four

[0078] Please refer to Figures 1 to 3 The superconducting quantum interference gradiometer provided in the embodiment can be used for detecting the magnetic field strength.

[0079] The superconducting quantum interference gradiometer includes a SQUID chip and the superconducting second-order gradient coil structure 100 as described in embodiments one to two. The superconducting second-order gradient coil structure 100 is connected with the SQUID chip.

[0080] The superconducting second-order gradient coil structure 100 is arranged along the horizontal direction, used for receiving external signals, and outputs voltage to the SQUID chip. The SQUID chip is used for processing the received voltage, so as to obtain the detected signal.

[0081] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0082] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A superconducting second-order gradient coil structure, characterized in that, The system includes a second-order gradient coil support and six sets of second-order gradient coils. The second-order gradient coil support includes a central support and four compensation supports. The four compensation supports are arranged opposite each other and perpendicularly on the central support. Each of the six sets of second-order gradient coils includes a central point coil and two symmetrical coils connected to the central point coil. The central point coil of each set of second-order gradient coils is located on the central support, and the two symmetrical coils of each set are respectively located on two opposite compensation supports. The six sets of second-order gradient coils are used to respond to the magnetic field gradient components Gzy, Gxy, Gyy, Gzx, Gyx, and Gxx. The x-axis and y-axis are perpendicular to each other and parallel to the line connecting the central support and one of the compensation supports, respectively. The z-axis is perpendicular to both the x-axis and the y-axis.

2. The superconducting second-order gradient coil structure according to claim 1, characterized in that, The center point coil in each group of second-order gradient coils is a 2-turn coil wound in the same direction. The two symmetrical coils in each group of second-order gradient coils are each a single-turn coil wound in the same direction, opposite to the winding direction of the corresponding center point coil.

3. The superconducting second-order gradient coil structure according to claim 1, characterized in that, The areas of the center point coil and the symmetrical coil in each group of second-order gradient coils are equal.

4. The superconducting second-order gradient coil structure according to claim 1, characterized in that, The two symmetrical coils in each group of second-order gradient coils are symmetrical about the corresponding center point coil.

5. The superconducting second-order gradient coil structure according to claim 1, characterized in that, The four compensation brackets are designated as a first compensation bracket, a second compensation bracket, a third compensation bracket, and a fourth compensation bracket. The first and third compensation brackets are positioned opposite each other on both sides of the central bracket, while the second and fourth compensation brackets are positioned opposite each other on the other two sides of the central bracket. The line connecting the first and third compensation brackets is perpendicular to the line connecting the second and fourth compensation brackets. The x-axis direction is parallel to the line connecting the central bracket and the second compensation bracket, and the y-axis direction is parallel to the line connecting the central bracket and the first compensation bracket.

6. The superconducting second-order gradient coil structure according to claim 5, characterized in that, The central support, the first compensation support, the second compensation support, the third compensation support, and the fourth compensation support are integrally formed.

7. The superconducting second-order gradient coil structure according to claim 5, characterized in that, The six groups of second-order gradient coils are respectively the first second-order gradient coil group for responding to the Gzy magnetic field gradient component, the second second-order gradient coil group for responding to the Gxy magnetic field gradient component, the third second-order gradient coil group for responding to the Gyy magnetic field gradient component, the fourth second-order gradient coil group for responding to the Gzx magnetic field gradient component, the fifth second-order gradient coil group for responding to the Gyx magnetic field gradient component, and the sixth second-order gradient coil group for responding to the Gxx magnetic field gradient component.

8. The superconducting second-order gradient coil structure according to claim 7, characterized in that, In the first second-order gradient coil group, the normal directions of the center point coil and the symmetrical coil are both parallel to the z-axis direction. One of the symmetrical coils is disposed on the first compensation bracket and the other is disposed on the third compensation bracket. The line connecting the center point coil and the two symmetrical coils is parallel to the y-axis, thereby realizing the response of the Gzy magnetic field gradient component. In the second second-order gradient coil group, the normal directions of the center point coil and the symmetrical coil are both parallel to the x-axis direction. One of the symmetrical coils is set on the first compensation bracket, and the other is set on the third compensation bracket. The line connecting the center point coil and the two symmetrical coils is parallel to the y-axis, thereby realizing the response of the Gxy magnetic field gradient component. In the third second-order gradient coil group, the normal directions of the center point coil and the symmetrical coil are both parallel to the y-axis direction. One of the symmetrical coils is disposed on the first compensation bracket, and the other is disposed on the third compensation bracket. The line connecting the center point coil and the two symmetrical coils is parallel to the y-axis, thereby realizing the response of the Gyy magnetic field gradient component. In the fourth second-order gradient coil group, the normal directions of the center point coil and the symmetrical coil are both parallel to the z-axis direction. One of the symmetrical coils is set on the second compensation bracket, and the other is set on the fourth compensation bracket. The line connecting the center point coil and the two symmetrical coils is parallel to the x-axis, thereby realizing the response of the Gzx magnetic field gradient component. In the fifth second-order gradient coil group, the normal directions of the center point coil and the symmetrical coil are both parallel to the y-axis direction. One of the symmetrical coils is set on the second compensation bracket, and the other is set on the fourth compensation bracket. The line connecting the center point coil and the two symmetrical coils is parallel to the x-axis, thereby realizing the response of the Gyx magnetic field gradient component. In the sixth second-order gradient coil group, the normal directions of the center point coil and the symmetrical coils are both parallel to the x-axis direction. One of the symmetrical coils is located on the second compensation bracket, and the other is located on the fourth compensation bracket. The line connecting the center point coil and the two symmetrical coils is parallel to the x-axis, thereby realizing the response of the Gxx magnetic field gradient component.

9. A method for manufacturing the superconducting second-order gradient coil structure according to any one of claims 1-8, characterized in that, The manufacturing method includes the following steps: Provide the second-order gradient coil support; Six sets of the aforementioned second-order gradient coils are wound separately; Connect the coils in each group of second-order gradient coils.

10. A superconducting quantum interference gradient meter, characterized in that, It includes a SQUID chip and a superconducting second-order gradient coil structure as described in any one of claims 1 to 8, wherein the superconducting second-order gradient coil structure is connected to the SQUID chip.

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