Superconducting strip structure for improving resistance of superconducting constant-current switch, and manufacturing method

Abstract

Provided in the present invention are a superconducting strip structure for improving the resistance of a superconducting constant-current switch, and a manufacturing method. The structure comprises conductive layers, a superconducting layer, a buffer layer and a substrate layer, wherein the substrate layer, the buffer layer and the superconducting layer are sequentially arranged in a stacked manner; and the face of the superconducting layer that faces away from the buffer layer comprises, along a strip, at least two conductive layers arranged spaced apart from each other, and a superconducting path for communicating the two conductive layers is arranged on the superconducting layer. The superconducting path is arranged on the superconducting layer between the two conductive layers, so that the current can only flow from one conductive layer to the other conductive layer by means of the superconducting path. Therefore, the characteristic of the superconducting layer, when in a non-superconducting state, presenting a relatively large resistance can be utilized, so that the whole superconducting constant-current switch presents a relatively large resistance. The switch has a small structure and is capable of performing fast switching. The resistance of the superconducting constant-current switch, when turned on, can further be increased by means of reducing the conduction cross-sectional area of the superconducting path and increasing the path length of the superconducting path.

Description

Superconducting tape structure and manufacturing method for improving resistance of superconducting constant current switch Technical Field

[0001] The present invention relates to the technical field of superconducting tape structure design, and in particular to a superconducting tape structure for improving the resistance of a superconducting constant current switch and a manufacturing method thereof. Background Art

[0002] Superconducting constant-current switches exploit the critical properties of superconducting tape to achieve the transition between "on" and "off" states. Superconducting materials have three critical parameters: temperature, current, and magnetic field. Therefore, depending on the transition conditions, superconducting constant-current switches can be divided into three types: thermally controlled, flow-controlled, and field-triggered.

[0003] As shown in Figure 1, the structure of the second-generation high-temperature superconducting tape includes a conductive layer, a superconducting layer, and a base layer. The conductive layer is a single layer or multiple layers, and the material of the conductive layer is copper and / or silver. The material of the superconducting layer is preferably REBCO. Below the superconducting layer is a buffer layer, which is a dielectric material that is basically insulating. Below the buffer layer is the base layer, which is mostly made of Hastelloy. The copper and / or silver are wrapped in the outermost layer, including the top, bottom, and sides. After the superconducting layer in the tape is converted to a non-superconducting state, the resistance of the superconducting layer after quenching is greater than that of the copper and / or silver layer at the same temperature. Therefore, a large amount of current originally flowing through the superconducting layer will be diverted to the copper and / or silver layer wrapped around it.

[0004] As shown in the equivalent circuit in Figure 2, since it is difficult to directly excite a superconducting closed-loop coil, a superconducting constant current switch is usually needed to temporarily "open" the coil loop to form a similar open circuit (not a complete open circuit, as the resistance of a complete open circuit is infinite. The similar open circuit here means that there is still a certain resistance value at both ends of the switch) so that the power supply can excite the superconducting coil.

[0005] Since the superconducting constant current switch itself is also part of the closed-loop coil, when excited, the superconducting tape in the superconducting constant current switch is not actually open-circuited, but instead changes to a non-superconducting state. At this time, the large resistance presented by the superconducting constant current switch is also compared to the extremely small resistance of the superconductor. Therefore, it is more accurate to regard the superconducting constant current switch as a variable resistor. During the charging process, the greater the resistance presented to the outside of the superconducting constant current switch, the better, so that the external DC power supply can have more current flowing into the coil during the process of exciting the superconducting magnet, reducing the shunt through the superconducting constant current switch strip, which is conducive to reducing Joule heating, which is particularly important for superconducting magnets that require a low-temperature environment.

[0006] At present, the method of increasing the resistance of a thermally controlled superconducting constant current switch is to increase the resistance by lengthening the superconducting tape used to make the superconducting constant current switch. This method uses a large amount of tape and is costly. The resulting superconducting constant current switch is large in size, resulting in a large heat capacity. As a result, the speed of the superconducting switch switching between the resistive state and the non-resistive state is relatively slow, which is not conducive to the thermal stability of the low-temperature cavity. There is room for improvement.

[0007] Summary of the Invention

[0008] In view of the defects in the prior art, the purpose of the present invention is to provide a superconducting tape structure and a manufacturing method for improving the resistance of a superconducting constant current switch.

[0009] According to the present invention, a superconducting tape structure for improving the resistance of a superconducting constant current switch includes a conductive layer, a superconducting layer, a buffer layer, and a base layer, wherein the base layer, the buffer layer, and the superconducting layer are stacked in sequence; the surface of the superconducting layer facing away from the buffer layer includes at least two conductive layers spaced apart along the direction of the tape, and a superconducting path is provided on the superconducting layer for connecting the two conductive layers.

[0010] Preferably, the superconducting path extends from one conductive layer to another conductive layer; the superconducting path includes continuous regular straight line segments, connected regular arc segments and / or irregular shape segments.

[0011] Preferably, the superconducting path is formed by subtractive material in the superconducting layer and / or is formed by physical isolation in the superconducting layer, the current is transmitted along the direction of the tape, and the current flows from one conductive layer to another conductive layer along the direction of the superconducting path.

[0012] Preferably, the superconducting layer is provided with groove lines, the depth of the groove lines is greater than or equal to the thickness of the superconducting layer; and the superconducting path is formed by being fully or partially surrounded by the groove lines.

[0013] Preferably, the superconducting layer is provided with reduced material areas on both sides along the length direction and / or both sides along the width direction of the tape; and the superconducting path is formed entirely or partially by reducing material in the superconducting layer.

[0014] Preferably, the conductive layer includes a silver covering layer and / or a copper stabilization layer; and the area of ​​the conductive layer is smaller than or equal to the area of ​​the superconducting layer.

[0015] Preferably, the conductive layer covers the surface of the base layer facing away from the buffer layer.

[0016] According to the present invention, a method for manufacturing a superconducting tape structure for improving the resistance of a superconducting constant current switch is provided, the manufacturing method comprising the following steps:

[0017] Step S1: prepare a superconducting tape for standby use;

[0018] Step S2: removing unnecessary conductive layers;

[0019] Step S3: destroy or remove unnecessary superconducting layers, and form a superconducting path between two adjacent conductive layers.

[0020] Preferably, the method for step S3, of removing the unnecessary conductive layer or superconducting layer, comprises chemical etching and / or mechanical processing.

[0021] Preferably, when the side of the tape is wrapped with a superconducting layer, after removing the silver covering layer and / or copper stabilization layer on the superconducting layer, the silver covering layer and / or copper stabilization layer on the side of the superconducting tape are removed at the same time, and then the superconducting layer that needs to be reduced is destroyed or removed.

[0022] Preferably, for step S3, groove lines may be processed on the superconducting layer to form a superconducting path between two adjacent conductive layers.

[0023] Preferably, for step S3, the unnecessary superconducting layer may be destroyed or removed, and grooves may be processed on the superconducting layer to form a superconducting path; methods for reducing the unnecessary conductive layer or superconducting layer include chemical etching and / or mechanical processing.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention provides a superconducting path on the superconducting layer between two conductive layers so that current can only flow from one conductive layer to the other conductive layer through the superconducting path. In this way, the characteristic that the superconducting layer exhibits a large resistance in the non-superconducting state can be utilized, so that the entire superconducting constant current switch exhibits a large resistance, has a small structure, and has fast switching.

[0026] 2. The present invention cuts off the electrical connection between the two sides of the tape to ensure that most of the current flows on the superconducting layer side of the superconducting tape. When the shunt current during excitation flows through the superconducting layer side of the superconducting tape, the current will flow through the gap between the two conductive layers located on the side of the superconducting layer away from the buffer layer. Since the buffer layer below the superconducting layer is basically insulating and the superconducting layer will exhibit a large resistance in the non-superconducting state, the entire superconducting constant current switch will exhibit a large resistance.

[0027] 3. The present invention can form a subtractive area by removing the material at the peripheral edge of the superconducting layer to further increase the resistance of the superconducting constant current switch when it is turned on, and further remove the exposed area of ​​the superconducting layer in the width direction of the superconducting tape, and reduce the conduction cross-sectional area on the current path to further increase the resistance of the superconducting constant current switch when it is turned on; it can also isolate the superconducting path from the non-superconducting path by setting groove lines in the superconducting layer, and further increase the resistance of the superconducting constant current switch when it is turned on by setting the track length and width of the superconducting path. It can also combine material reduction and setting groove lines, so that the current can only pass from one conductive layer through the superconducting path to another adjacent conductive layer, so that the entire superconducting constant current switch will present a larger resistance; and in terms of process, physical isolation (similar to groove lines) is easier to form a relatively complex superconducting path than material reduction.

[0028] 4. The present invention increases the length of the superconducting path and the length of the current path, thereby further increasing the resistance of the superconducting constant current switch when it is turned on.

[0029] 5. The present invention uses laser technology to make groove lines to form a superconducting path between two adjacent conductive layers, and isolates the two conductive layers from the part of the superconducting path, which helps to improve the accuracy of making the superconducting path, helps to improve the convenience of making high-resistance superconducting constant current switches, and can further increase the resistance value of its disconnection resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0031] FIG1 is a schematic diagram of the structure of a second-generation superconducting tape in the background technology of the present invention;

[0032] FIG2 is a diagram showing the working principle of a superconducting switch in the background art according to the present invention;

[0033] FIG3 is a schematic diagram of the axial structure of the embodiment 1 of the present invention, in which the unnecessary conductive layer away from the buffer layer of the superconducting layer is removed;

[0034] FIG4 is a schematic top view of the structure of the first embodiment of the present invention, in which an unnecessary conductive layer away from the buffer layer of the superconducting layer is removed;

[0035] FIG5 is a schematic diagram of the axial structure of the first embodiment of the present invention, in which the conductive layer on the side of the superconducting tape and the conductive layer on the portion of the superconducting layer facing away from the buffer surface are removed;

[0036] FIG6 is a schematic top view of the structure of the first embodiment of the present invention, in which the conductive layer on the side of the superconducting tape and the conductive layer on the portion of the superconducting layer facing away from the buffer surface are removed;

[0037] FIG7 is a schematic diagram of the axial structure of the first embodiment of the present invention in which the material surrounding the superconducting layer cover is removed;

[0038] FIG8 is a schematic top view of the structure of the first embodiment of the present invention in which the material surrounding the superconducting layer cover is removed;

[0039] FIG9 is a schematic diagram of the axial structure of the first embodiment of the present invention in which the superconducting layer subtractive area is removed;

[0040] FIG10 is a schematic top view of the structure of the subtractive area where the superconducting layer is removed in the first embodiment of the present invention;

[0041] FIG11 is a schematic diagram of the axial structure of the first embodiment of the present invention in which unnecessary portions of the superconducting layer in the width direction are removed;

[0042] FIG12 is a schematic top view of the structure of the first embodiment of the present invention in which unnecessary portions of the superconducting layer in the width direction are removed;

[0043] FIG13 is a schematic diagram of the axial structure of the undulations formed in the exposed area of ​​the superconducting layer in accordance with the main embodiment of the present invention;

[0044] FIG14 is a schematic top view of the structure of the undulations formed in the exposed area of ​​the superconducting layer in an embodiment of the present invention;

[0045] FIG15 is a schematic diagram of a first embodiment of the present invention, in which a groove line is used to physically isolate the conductive layer in the superconducting layer to form a straight superconducting path;

[0046] FIG16 is a schematic diagram of a curved superconducting path formed by using a groove line in the first embodiment of the present invention;

[0047] FIG17 is a schematic diagram of the depth of the groove line in the first embodiment of the present invention;

[0048] FIG18 is an axial schematic diagram of a structure of the present invention that mainly utilizes groove lines and subtractive materials to form a superconducting path;

[0049] FIG19 is a top view of a structure of the present invention that mainly utilizes groove lines and subtractive materials to form a superconducting path;

[0050] FIG20 is a graph showing the relationship between resistance and temperature of a high-resistance superconducting constant current switch according to an embodiment of the present invention;

[0051] FIG21 is a schematic diagram of an axial structure of the present invention that mainly utilizes a groove line to isolate the two sides of the superconducting layer width;

[0052] FIG22 is a top view showing the present invention mainly embodying the use of groove lines to isolate the two sides of the superconducting layer;

[0053] FIG23 is an axial schematic diagram of the present invention mainly showing the reduction of the superconducting layer on both sides of the width of the conductive layer;

[0054] FIG24 is a top view showing the main embodiment of the present invention in which the superconducting layer is reduced in material on both sides of the width of the conductive layer;

[0055] FIG25 is a schematic diagram of the axial structure of the present invention, which mainly embodies the use of groove lines to form a superconducting path between two conductive layers;

[0056] FIG26 is a top view of the present invention showing the use of a groove line to form a superconducting path between two conductive layers;

[0057] FIG27 is a schematic diagram of an axial structure of the present invention that mainly embodies the use of subtraction to form a superconducting path between two conductive layers;

[0058] FIG28 is a top view showing the main embodiment of the present invention using subtraction to form a superconducting path between two conductive layers.

[0059] As shown in the figure: 1. Base layer; 2. Buffer layer; 3. Superconducting layer; 4. Silver covering layer; 5. Copper stabilization layer; 6. Conductive layer; 7. Slot line; 8. Superconducting path. DETAILED DESCRIPTION

[0060] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0061] It should be noted that the length direction of the present application refers to the direction of the strip, and the width direction of the present application refers to the width direction of the strip. It should also be noted that the dotted lines in Figures 1 to 28 of the present application all represent the groove lines 7.

[0062] Example 1

[0063] As shown in Figures 3, 4, 5, and 6, a superconducting tape structure and manufacturing method for improving the resistance of a superconducting constant current switch provided by the present invention includes a conductive layer 6, a superconducting layer 3, a buffer layer 2, and a base layer 1. The base layer 1, buffer layer 2, and superconducting layer 3 are stacked in sequence. The surface of the superconducting layer 3 facing away from the buffer layer 2 includes at least two conductive layers 6 spaced apart along the direction of the tape. A superconducting path 8 is provided on the superconducting layer 3 to connect the two conductive layers 6.

[0064] Since the buffer layer 2 in the second-generation superconducting tape is basically insulating, the superconducting tape structure of the present application can ensure that most of the current flows on the superconducting layer 3 side of the superconducting tape compared with the prior art. When the shunt during excitation flows through the superconducting layer 3 side of the superconducting tape, the current will flow through the gap between the two conductive layers 6 located on the side of the superconducting layer 3 facing away from the buffer layer 2. Since the buffer layer 2 below the superconducting layer 3 is basically insulating, and the superconducting layer 3 will exhibit a larger resistance in the non-superconducting state, the entire superconducting constant current switch will exhibit a larger resistance.

[0065] The superconducting path 8 of the present application is conductive below a critical temperature and exhibits a high-resistance state above the critical temperature. Current is transmitted along the strip, flowing from one conductive layer 6 along the superconducting path 8 to the other conductive layer 6, ensuring the stability of the switch. The path length of the superconducting path 8 can be adjusted according to actual needs to achieve the desired resistance value when the superconducting constant-current switch is turned on.

[0066] Specifically, the conductive layer 6 of the present application includes a silver capping layer 4 and / or a copper stabilization layer 5. The superconducting tape structure of the present application can select the silver capping layer 4 as the conductive layer 6, or can select the copper stabilization layer 5 as the conductive layer 6, or can select the silver capping layer 4 and the copper stabilization layer 5 to form the conductive layer 6. The present application preferably includes the conductive layer 6 including the silver capping layer 4 and the copper stabilization layer 5.

[0067] Furthermore, the present application is explained by taking the conductive layer 6 as a silver covering layer 4 and a copper stabilization layer 5, and two conductive layers 6 arranged at intervals along the length direction of the superconducting tape on the surface of the superconducting layer 3 facing away from the buffer layer 2 as an example: the silver covering layer 4 covers the surface of the superconducting layer 3 facing away from the buffer layer 2, and the copper stabilization layer 5 covers the surface of the silver covering layer 4 facing away from the superconducting layer 3.

[0068] It should be noted that the superconducting layer 3 of the present application can be completely located on the side of the buffer layer 2 facing away from the base layer 1, and can also partially or completely wrap the side of the buffer layer 2 and / or the base layer 1. If the superconducting layer 3 wraps the buffer layer 2 and / or partially or completely wraps the side of the base layer 1, the superconducting layer 3 wrapping the side of the buffer layer 2 and / or the base layer 1 can be removed or destroyed by mechanical or chemical means. It is also possible to physically isolate the unnecessary superconducting layer 3 from both the superconducting path 8 and the conductive layer 6.

[0069] As shown in Figures 7, 8, 9, and 10, more specifically, the area of ​​the conductive layer 6 is less than or equal to the area of ​​the superconducting layer 3, the area of ​​the superconducting layer 3 is less than or equal to the area of ​​the buffer layer 2, and the area of ​​the buffer layer 2 is less than or equal to the area of ​​the base layer 1. Material reduction can be performed on both sides of the length direction and / or the width direction of the superconducting layer 3 to make the area of ​​the superconducting layer 3 less than or equal to the area of ​​the buffer layer 2, thereby further increasing the resistance of the superconducting constant current switch when it is turned on while ensuring the superconducting constant current switch function.

[0070] The superconducting path 8 extends from one conductive layer 6 to the other conductive layer 6 and can electrically connect two adjacent conductive layers 6. The resistance of the superconducting constant current switch when it is turned on can be further increased by reducing the conductive cross-sectional area of ​​the superconducting path 8 and increasing the path length of the superconducting path 8. The superconducting path 8 includes continuous regular straight line segments, connected regular arc segments and / or irregular shaped segments. In actual production, a superconducting path 8 of a specific shape that meets actual design requirements can be formed by combining regular straight line segments, connected regular arc segments and / or irregular shaped segments. Therefore, all improvements made to the path and shape of the superconducting path 8 fall within the scope of protection of this application.

[0071] It should be noted that the subtractive treatment of the superconducting layer 3 can be to remove the superconducting material at the corresponding position, or to destroy the superconducting properties of the superconducting material in the corresponding area. The material in the superconducting layer 3 that has lost its superconducting properties is no longer regarded as part of the superconducting layer 3, so as to further increase the resistance when the superconducting constant current switch is turned on.

[0072] It should be noted that the present application does not make any specific restrictions on the number of conductive layers 6 arranged along the direction of the tape on the superconducting layer 3 or the spacing between two adjacent conductive layers 6. Any number of conductive layers 6 can be inserted between two adjacent conductive layers 6 described in the application. Any improvement on the number of conductive layers 6 or the spacing between them falls within the scope of protection of the present application.

[0073] As shown in FIG7 , FIG8 , FIG9 , FIG10 , FIG11 and FIG12 , for ease of understanding, the present application provides a specific embodiment of forming a superconducting path 8 by subtracting material:

[0074] The superconducting layer 3 is provided with a material reduction zone on both sides along the length direction and / or the width direction of the strip, and the superconducting path 8 is formed entirely or partially by material reduction in the superconducting layer 3. The material on both sides of the superconducting layer 3 in the length direction can be removed or destroyed to form a preliminary material reduction on both sides of the superconducting layer 3 in the length direction. The material on both sides of the superconducting layer 3 in the width direction can also be removed or destroyed. Furthermore, the material on both sides of the superconducting layer 3 between two adjacent conductive layers 6 in the width direction is removed or destroyed so that the width of the superconducting layer 3 between the two conductive layers 6 is the same as the width of the conductive layer 6, and finally the width of the superconducting layer 3 as a whole is the same as the width of the conductive layer 6. The material on both sides of the superconducting layer 3 in the width direction between the two adjacent conductive layers 6 is further reduced or destroyed so that the width of the superconducting layer 3 between the two adjacent conductive layers 6 is smaller than the width of the conductive layer 6. By reducing the conductive cross-sectional area of ​​the superconducting path 8, the resistance of the superconducting constant current switch when it is turned on is further increased. As shown in Figures 13 and 14, preferably, the superconducting path 8 can extend from one of its conductive layers 6 first in a first direction and then in a second direction, and the first direction and the second direction are not parallel, thereby increasing the path length of the superconducting path 8 to further increase the resistance when the superconducting constant current switch is turned on.

[0075] As shown in FIG15 , FIG16 and FIG17 , for ease of understanding, the present application provides a specific implementation method of forming a superconducting path 8 by physical isolation:

[0076] The superconducting layer 3 is provided with groove lines 7, the depth of the groove lines 7 is greater than or equal to the thickness of the superconducting layer 3, and the superconducting path 8 is formed by fully or partially surrounding the groove lines 7. The groove lines 7 can isolate the two conductive layers 6 arranged at adjacent intervals except for the part of the superconducting path 8. Since the groove lines 7 can be made by laser ablation, the operation is convenient and the precision is high. At least two groove lines 7 are provided between two adjacent conductive layers 6 to form a superconducting path 8 connecting the two adjacent conductive layers 6. The groove lines 7 are also provided around the circumference of the two conductive layers 6 respectively. The groove lines 7 provided around the circumference of the conductive layer 6 intersect with the groove lines 7 forming the superconducting path 8 or extend into the superconducting path 8, ensuring that the two adjacent conductive layers 6 are electrically connected only through the superconducting path 8. Therefore, it should be emphasized that any setting of the direction and shape of the groove lines 7, as long as it satisfies the requirement of electrically connecting the two adjacent conductive layers 6 and falls within the scope of protection of this application.

[0077] As shown in Figures 18 and 19, for ease of understanding, the present application provides a specific embodiment of forming a superconducting path 8 using subtraction and physical isolation: material on both sides of the superconducting layer 3 in the length direction can be removed or destroyed, forming a preliminary subtraction on both sides of the superconducting layer 3 in the length direction. Material on both sides of the superconducting layer 3 in the width direction can also be removed or destroyed. Furthermore, a superconducting path 8 electrically connecting two adjacent conductive layers 6 can be formed by processing grooves 7 in the superconducting layer 3. Furthermore, grooves 7 can be further processed in the superconducting layer 3 to ensure that the two adjacent conductive layers 6 are electrically connected only through the superconducting path 8. In terms of technology, physical isolation makes it easier to form a relatively complex superconducting path 8 than subtraction.

[0078] It should be further explained that the superconducting tape structure of the present application can be directly processed, or it can be made on the basis of the second-generation superconducting tape in the prior art. The superconducting tape structure of the present application can make the conductive layer 6 cover the surface of the base layer 1 facing away from the buffer layer 2. It is only necessary to ensure that the conductive layer 6 located on the surface of the base layer 1 facing away from the buffer layer 2 is not connected to the conductive layer 6 located on the surface of the superconducting layer 3 facing away from the buffer layer 2. At this time, the silver covering layer 4 can be selected as the conductive layer 6, the copper stabilization layer 5 can be selected as the conductive layer 6, and the silver covering layer 4 and the copper stabilization layer 5 can also be selected to form the conductive layer 6. Specifically, the silver covering layer 4 covers the surface of the base layer 1 facing away from the buffer layer 2, and the copper stabilization layer 5 covers the surface of the silver covering layer 4 facing away from the base layer 1. The structure of the superconducting tape can also be selected to be a structure without the conductive layer 6 covering the surface of the base layer 1 facing away from the buffer layer 2.

[0079] As shown in Figure 20, the resistance and temperature relationship curve of the high-resistance superconducting constant current switch is shown. The experiment was repeated five times. The superconducting tape structure of the present application and the conventional second-generation superconducting tape in the prior art were used for testing.

[0080] The test data is shown in Figure 20. The resistance of the high-resistance superconducting constant current switch using the superconducting tape structure of the present application in the open state (temperature is 110K) is about 976mΩ, and the resistance of the superconducting constant current switch made of the conventional second-generation superconducting tape in the same prior art is only about 1mΩ in the open state. Compared with the conventional second-generation superconducting tape in the prior art, the resistance of the superconducting constant current switch made of the superconducting tape of the present application in the open state is increased by nearly 1000 times.

[0081] The present invention also provides a method for manufacturing a superconducting tape structure for improving the resistance of a superconducting constant current switch, the manufacturing method comprising the following steps:

[0082] Step S1: prepare a superconducting tape for standby use.

[0083] Step S2: removing unnecessary conductive layer 6.

[0084] Step S3: destroy or remove unnecessary superconducting layers 3 and form a superconducting path 8 between two adjacent conductive layers 6.

[0085] It should be noted that methods for removing unnecessary conductive layer 6 or superconducting layer 3 include chemical etching and / or mechanical processing. Mechanical processing methods include polishing. The chemical etching method includes etching the copper stabilization layer 5 with a ferric chloride ethanol solution prepared by mixing ferric chloride powder and anhydrous ethanol solution at a ratio of 1g:10ml. Etching the silver cover layer 4 with a mixed solution prepared by mixing ammonia water and hydrogen peroxide solution at a volume ratio of 1:2. The concentration of the ammonia water is 25%, and the concentration of the hydrogen peroxide solution is 30%.

[0086] The superconducting layer 3 is corroded using an acidic solution. Specifically, the acidic solution etching of the superconducting layer 3 includes three stages, depending on the time period: the first stage is to destroy the superconducting properties of the superconducting material, at which point the superconducting properties of the superconducting material are destroyed. The second stage is to remove the material of the superconducting layer 3, at which point the material of the superconducting layer 3 is removed. The third stage is to partially remove the material of the buffer layer 2. It should be emphasized that the three stages of treatment of the superconducting layer 3 described above can all solve the technical problems of this application and achieve the inventive objectives of this application. Therefore, the three stages described above are all within the scope of protection of this application.

[0087] More specifically, based on the second-generation superconducting tape, the silver capping layer 4 and / or copper stabilization layer 5 on the superconducting layer 3 can be partially removed. Some superconducting tapes may be coated with a superconducting layer 3 on the side during actual production. To prevent current from conducting between the superconducting and non-superconducting surfaces through the coated superconducting layer 3 below the superconducting critical temperature, after removing the silver capping layer 4 and copper stabilization layer 5 on the superconducting layer 3, the silver capping layer 4 and / or copper stabilization layer 5 on the side of the superconducting tape are preferably removed at the same time. The superconducting layer 3 in the reduced material area of ​​the superconducting tape is then destroyed or removed to increase the resistance of the superconducting constant current switch when it is turned on. Preferably, the superconducting layer 3 in the middle of the superconducting tape can be further destroyed or removed in the width direction to reduce the conductive cross-sectional area of ​​the current path, thereby further increasing the resistance of the superconducting constant current switch when it is turned on. It is also preferred that the superconducting layer 3 in the middle of the tape be further destroyed or removed to reduce the cross-sectional area while increasing the length of the current path, thereby further increasing the resistance of the superconducting constant current switch when it is turned on.

[0088] In another feasible embodiment, for step S3 , laser ablation may be used to form groove lines 7 on the superconducting layer 3 , and a superconducting path 8 may be formed between two adjacent conductive layers 6 .

[0089] In another feasible embodiment, for step S3 , unnecessary parts of the superconducting layer 3 may be destroyed or removed, and laser processing may be used to form groove lines 7 on the superconducting layer 3 to form superconducting paths 8 .

[0090] Preferred Example 1

[0091] Based on the first embodiment, the present invention further provides a method for manufacturing a superconducting tape structure for improving the resistance of a superconducting constant current switch. First, a superconducting tape is prepared:

[0092] (1) Ferric chloride powder and anhydrous ethanol solution were prepared at a ratio of 1 g:10 ml to form a ferric chloride ethanol solution to remove the unnecessary copper layer.

[0093] (2) Place the strip prepared in step (1) into a mixed solution of ammonia water and hydrogen peroxide solution at a volume fraction ratio of 1:2 to remove the unwanted silver layer. The concentration of the ammonia water is 25%, and the concentration of the hydrogen peroxide solution is 30%.

[0094] (3) The tape treated in step (2) is placed in an acetic acid solution to react and destroy / remove the superconducting layer 33 in the reduced area of ​​the superconducting tape and the superconducting layer 3 that may be wrapped around the side of the superconducting tape.

[0095] Preferred Example 2

[0096] Based on the first embodiment, the present invention further provides a method for manufacturing a superconducting tape structure for improving the resistance of a superconducting constant current switch. First, a superconducting tape is prepared:

[0097] (1) Ferric chloride powder and anhydrous ethanol solution were prepared at a ratio of 1 g:10 ml to form a ferric chloride ethanol solution to remove the unnecessary copper layer.

[0098] (2) Place the strip prepared in step (1) into a mixed solution of ammonia water and hydrogen peroxide solution at a volume fraction ratio of 1:2 to remove the unwanted silver layer. The concentration of the ammonia water is 25%, and the concentration of the hydrogen peroxide solution is 30%.

[0099] (3) The two side surfaces in the length direction of the strip processed in step (2) are polished with a grinder to remove the superconducting layer 3 that may be wrapped around the side surface of the superconducting strip, and to cut off the connection between the superconducting layer 3 and the Hastelloy layer on the side surface of the superconducting strip; for the two side surfaces in the width direction, an acidic solution is used to destroy / remove the superconducting layer 3 that may be wrapped around the side surface of the superconducting strip.

[0100] Preferred Example 3

[0101] Based on the first embodiment, the present invention further provides a method for manufacturing a superconducting tape structure for improving the resistance of a superconducting constant current switch. First, a superconducting tape is prepared:

[0102] (1) The two longitudinal side surfaces of the tape are polished with a polishing machine to remove the copper layer, silver layer and superconducting layer 3 on the side surfaces of the superconducting tape.

[0103] (2) Ferric chloride powder and anhydrous ethanol solution are prepared in a ratio of 1 g:10 ml to form a ferric chloride ethanol solution to remove the unnecessary copper layer.

[0104] (3) Place the strip prepared in step (1) into a mixed solution of ammonia water and hydrogen peroxide solution at a volume fraction ratio of 1:2 to remove the unwanted silver layer. The concentration of the ammonia water is 25%, and the concentration of the hydrogen peroxide solution is 30%.

[0105] Preferred Example 4

[0106] As shown in Figures 15 and 16, based on Example 1, the present invention provides a superconducting tape structure for a superconducting constant current switch, in which a groove line 7 is formed on the superconducting layer 3 to connect two adjacent conductive layers 6, and the groove line 7 partially isolates the two adjacent conductive layers 6 except for the superconducting path 8. This specific embodiment provides a feasible technical solution.

[0107] In the top view of the superconducting tape, a superconducting path 8 is formed between two conductive layers 6 in an isolated island state through a groove line 7 . The superconducting path 8 extends from one conductive layer 6 to the other conductive layer 6 .

[0108] This specific embodiment provides a feasible extension solution for the superconducting path 8 : one end of the superconducting path 8 directly extends from one of the conductive layers 6 to the other conductive layer 6 along the length direction of the superconducting tape.

[0109] This embodiment provides another feasible extension scheme for superconducting path 8: one end of superconducting path 8 extends from one conductive layer 6 along the length of the superconducting tape for a certain length, then turns and extends along the width of the superconducting tape for a certain length, then turns and extends along the length of the superconducting tape for a certain length until it reaches another conductive layer 6. It should be noted that the number of turns and angles in the extension of superconducting path 8 can be designed based on actual conditions.

[0110] The groove lines 7 are also arranged on the outer periphery of the two conductive layers 6 to isolate the two conductive layers 6 except for the portion of the superconducting path 8. Specifically, the groove lines 7 form a rectangular frame in the top view of the superconducting tape, and the rectangular frame surrounds the two conductive layers 6. The superconducting path 8 extends a groove line 7 perpendicular to the groove lines 7 on both sides of the extension direction.

[0111] Among the groove lines 7, one groove line 7 extending from the upper side of the superconducting path 8 is connected to the upper side of the rectangular frame, and one groove line 7 extending from the lower side of the superconducting path 8 is connected to the lower side of the rectangular frame, thereby isolating two adjacent conductive layers 6 except for the part of the superconducting path 8.

[0112] It should be noted that the two groove lines 7 extending from the superconducting path 8 can also extend into the superconducting path 8, as long as the superconducting path 8 is conductive when the temperature is below the critical temperature and is in a high-resistance state when the temperature is above the critical temperature.

[0113] Preferred Example 5

[0114] As shown in Figures 18, 19, 21, 22, 23, 24, 25, 26, 27 and 28, based on Example 1, a superconducting tape structure for a superconducting constant current switch provided by the present invention can first reduce the material on both sides of the length direction of the superconducting layer 3 by chemical or physical means, and then use laser processing to form groove lines 7 on both sides of the width of the superconducting layer 3.

[0115] It should be noted that the technical solution of the present application utilizes subtractive processing followed by laser processing to form the superconducting path 8 , and ensures that current can only be transmitted between the two conductive layers 6 through the superconducting path 8 .

[0116] As shown in Figures 18 and 19, part of the superconducting layer 3 material is retained on both sides of the width of the two conductive layers 6, and a groove line 7 parallel to the length direction of the strip is set on both sides of the width of the two conductive layers 6 for physical isolation. The current can only be transmitted between the two conductive layers 6 through the superconducting path 8.

[0117] As shown in FIG21 and FIG22, a groove line 7 parallel to the length direction of the strip is provided on both sides of the width of the two conductive layers 6 for physical isolation, ensuring that the current flows within the surface of the superconducting layer 3 where the conductive layer 6 is located.

[0118] As shown in Figures 23 and 24, the superconducting layers 3 on both sides of the two conductive layers 6 in the width direction are partially reduced to ensure that the superconducting layer 3 material retained on both sides of the conductive layer 6 in the width direction is integrated with the superconducting layer 3 material located between the two conductive layers 6. A groove line 7 parallel to the length direction of the strip is provided on both sides of the width of the two conductive layers 6 for physical isolation. The current can only be transmitted between the two conductive layers 6 through the superconducting path 8.

[0119] As shown in Figures 25 and 26 , based on Figures 23 and 24 , laser processing of groove lines 7 in superconducting layer 3 increases the length and reduces the width of superconducting pathway 8 connecting two conductive layers 6. Laser processing of groove lines 7 makes it easier to form relatively complex superconducting pathways 8 than by subtractive methods. Conductive layer 6 may include a silver capping layer 4 and / or a copper stabilization layer 5.

[0120] As shown in Figures 27 and 28, the superconducting layer 3 material on both sides of the width of the two conductive layers 6 can be completely reduced, and the superconducting layer 3 material located between the two conductive layers 6 can be partially reduced. Then, by setting a groove line 7 parallel to the length direction of the strip on both sides of the width of the superconducting layer 3 for physical isolation, the current can only be transmitted between the two conductive layers 6 through the superconducting path 8.

[0121] It should be noted that the present application does not impose any specific restrictions on the shape of the superconducting path 8 formed by material reduction and laser processing of the groove line 7. Any improvement on the shape of the superconducting path 8 falls within the scope of protection of the present application.

[0122] Variation Example 1

[0123] Based on the first embodiment, the present invention provides a superconducting tape structure for a superconducting constant current switch, wherein the surface of the base layer 1 facing away from the buffer layer 2 may or may not be provided with the conductive layer 6 .

[0124] The conductive layer 6 may be a copper stabilization layer 5 . The conductive layer 6 located on the surface of the substrate 1 facing away from the buffer layer 2 may be the copper stabilization layer 5 covering the surface of the substrate 1 facing away from the buffer layer 2 .

[0125] The conductive layer 6 may also be a silver covering layer 4 , and the conductive layer 6 located on the side of the base layer 1 facing away from the buffer layer 2 may be the silver covering layer 4 covering the side of the base layer 1 facing away from the buffer layer 2 .

[0126] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0127] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A superconducting tape structure for improving the resistance of a superconducting constant current switch, characterized in that: It comprises a conductive layer (6), a superconducting layer (3), a buffer layer (2) and a base layer (1), wherein the base layer (1), the buffer layer (2) and the superconducting layer (3) are stacked in sequence; The surface of the superconducting layer (3) facing away from the buffer layer (2) comprises at least two conductive layers (6) arranged at intervals along the direction of the strip, and a superconducting path (8) for connecting the two conductive layers (6) is arranged on the superconducting layer (3).

2. The superconducting tape structure for improving the resistance of a superconducting constant current switch according to claim 1, characterized in that: The superconducting path (8) extends from one conductive layer (6) to another conductive layer (6); The superconducting path (8) comprises continuous regular straight line segments, connected regular arc segments and / or irregular shape segments.

3. The superconducting tape structure for improving the resistance of a superconducting constant current switch according to claim 1, characterized in that: The superconducting path (8) is formed by material reduction in the superconducting layer (3), and / or is formed by physical isolation in the superconducting layer (3), and the current is transmitted along the direction of the strip, and the current flows from one of the conductive layers (6) along the direction of the superconducting path (8) into another conductive layer (6).

4. The superconducting tape structure for improving the resistance of a superconducting constant current switch according to claim 3, characterized in that: The superconducting layer (3) is provided with a groove line (7), and the depth of the groove line (7) is greater than or equal to the thickness of the superconducting layer (3); The superconducting path (8) is formed by being completely or partially surrounded by the groove line (7).

5. The superconducting tape structure for improving the resistance of a superconducting constant current switch according to claim 3, characterized in that: The superconducting layer (3) is provided with reduced material areas on both sides along the length direction of the strip and / or on both sides along the width direction; The superconducting path (8) is formed entirely or partially by reducing the material of the superconducting layer (3).

6. The superconducting tape structure for improving the resistance of a superconducting constant current switch according to claim 1, characterized in that: The conductive layer (6) comprises a silver covering layer (4) and / or a copper stabilizing layer (5); The area of ​​the conductive layer (6) is smaller than or equal to the area of ​​the superconducting layer (3).

7. The superconducting tape structure for improving the resistance of a superconducting constant current switch according to claim 1, characterized in that: The conductive layer (6) covers the surface of the substrate layer (1) facing away from the buffer layer (2).

8. A method for manufacturing a superconducting tape structure for improving the resistance of a superconducting constant current switch, characterized in that: A method for manufacturing a superconducting tape structure for improving the resistance of a superconducting constant current switch according to any one of claims 1 to 7 comprises the following steps: Step S1, prepare a superconducting tape for standby use; Step S2, removing unnecessary conductive layer (6); Step S3: destroy or remove unnecessary superconducting layers (3), and form a superconducting path (8) between two adjacent conductive layers (6).

9. A method for manufacturing a superconducting tape structure for improving the resistance of a superconducting constant current switch as claimed in claim 8, characterized in that: The method for removing the unnecessary conductive layer (6) or superconducting layer (3) in step S3 includes chemical etching and / or mechanical processing.

10. A method for manufacturing a superconducting tape structure for improving the resistance of a superconducting constant current switch as claimed in claim 9, characterized in that: When the side of the tape is coated with a superconducting layer (3), after removing the silver covering layer (4) and / or the copper stabilizing layer (5) on the superconducting layer (3), the silver covering layer (4) and / or the copper stabilizing layer (5) on the side of the superconducting tape are removed at the same time, and then the superconducting layer (3) to be reduced is destroyed or removed.

11. A method for manufacturing a superconducting tape structure for improving the resistance of a superconducting constant current switch as claimed in claim 8, characterized in that: With respect to step S3, a groove line (7) may be processed on the superconducting layer (3), and a superconducting path (8) may be formed between two adjacent conductive layers (6).

12. A method for manufacturing a superconducting tape structure for improving the resistance of a superconducting constant current switch as claimed in claim 8, characterized in that: With respect to step S3, it is also possible to destroy or remove unnecessary superconducting layers (3), and process groove lines (7) on the superconducting layers (3) to form superconducting paths (8).

Images