Superconductor cable assembly with a detachable connection of compound conductors, magnet coil, and use of a superconductor cable assembly

Abstract

The invention relates to a superconductor cable assembly (1) for use in a magnet coil for a nuclear fusion plant, having a first superconducting compound conductor (2a) and a second superconducting compound conductor (2b). The superconductor cable assembly is characterized in that the compound conductors (2a, 2b) have a beveled end portion (3a, 3b) with a cut surface (5a, 5b), the cut surfaces being oriented obliquely with respect to the direction of the longitudinal extent of the respective compound conductor (2a, 2b), and the cut surfaces (5a, 5b) having the same bevel angle with respect to the direction of the longitudinal extent, and in that the end portions (3a, 3b) of the two compound conductors (2a, 2b) are detachably connected together in a connecting portion (4), in which the two cut surfaces (5a, 5b) are parallel to one another and face one another and in which cooling channels of the two compound conductors (2a, 2b) are aligned, the connecting portion (4) being equipped with a clamping device (7) which clamps the end portions (3a, 3b) of the compound conductors together with a clamping force transversely to the longitudinal extent of the compound conductors (2a, 2b), preferably perpendicularly to the longitudinal extent of the compound conductors (2a, 2b), so that the cut surfaces (5a, 5b) are pressed against one another.

Description

[0001] Applicant:

[0002] Gauss Fusion GmbH

[0003] Parkring 29

[0004] 85748 Garching near Munich

[0005] Germany

[0006] Representative:

[0007] KOHLER. SCHMID FURNITURE

[0008] patent attorneys

[0009] limited liability partnership

[0010] Gropiusplatz 10

[0011] 70563 Stuttgart

[0012] Germany

[0013] Superconductor cable arrangement with detachable connection of compound conductors, magnetic coil and use of a superconductor cable arrangement Background of the invention

[0014] The invention relates to a superconducting cable arrangement for use in a coil for a nuclear fusion device, comprising a first superconducting compound conductor and a second superconducting compound conductor, each of which has a plurality of superconducting wires or tapes, a cooling channel for conveying a cooling fluid, and a sheath made of a conductive material.

[0015] The material comprises the multitude of superconducting wires or tapes and the cooling channel.

[0016] Gauss Fusion GmbH 11.08.2025 SP14028PCT Coils for nuclear fusion devices comprise winding packages of superconducting compound conductors, with each coil having many conductor turns (typically between 100 and 1000). Since superconducting compound conductors are only supplied in limited lengths, several superconducting compound conductors must be joined together to achieve the length required for the coil windings.

[0017] A method for joining individual high-temperature superconductor (HTS) tape conductors is disclosed in [EP0556837] in which two beveled surfaces of the tape conductor are pressed against each other and heat-treated at a temperature of 800°C to 900°C, thereby creating a permanent bond. The superconducting filaments are to be aligned in such a way that a superconducting connection is formed by pressing and heating. This requires precise alignment of the beveled surfaces so that the filaments of the HTS conductor are aligned with each other and a superconducting connection is achieved. However, a compound conductor comprises a multitude of such HTS conductors, which in turn contain a multitude of filaments. Precise alignment of the enormous number of filaments in a compound conductor is not possible, even with considerable effort.Another disadvantage of the method known from [EP0556837] is that the HTS tape conductors are permanently connected and cannot be disassembled non-destructively.

[0018] To connect superconducting cables (compound conductors), it is known to join two superconducting cables using a lap joint. For this purpose, the two cables are arranged overlapping in a connection section and connected together. The current then flows laterally from the first cable into the second cable, for example, via "interface elements" or via a copper sheath of the cables. [US20210376498] discloses such a lap joint for HTS cables, in which the lap joint elements are directly connected to the cable surface. [Rolando] discloses a lap joint for low-temperature superconducting (LTS) cables, in which each cable is enclosed by a copper sheath and the copper surfaces are pressed together and soldered.

[0019] Gauss Fusion GmbH 11.08.2025 SP14028PCT A disadvantage of such overlap connections is that each cable must be cooled via external cooling lines, requiring complex welding work on the cooling lines. Furthermore, the connection has an increased diameter in the joint section, which complicates the handling of the cable arrangement.

[0020] Another way to join two superconducting compound conductors is by butt jointing. In this process, two flat-cut ends of the cables to be joined are compacted and then welded together at high temperature with an intermediate copper section. Since the ends of the superconducting wires in the cable are very close to each other, low resistance can be achieved. For example, a butt joint connection of Nb3Sn cables is disclosed in [Takahashi]. There, the cable sheaths and the central cooling channel are first removed, and the two cable ends are inserted into copper tubes. The copper tubes are compacted to reduce the void content in the cable and prevent damage to the strands at the cable ends. The cable assembly is then heat-treated to form Nb3Sn with the compacted sections.A disadvantage of this method is that the two ends must be pressed together under high pressure while being heated to 800 °C. The tools required for this necessitate considerable space around the joint, making it impossible to create multiple joints side-by-side in a confined space. Furthermore, such a joint cannot be disassembled; it must be cut.

[0021] A special type of butt joint is the CCJ (coax compacted joint) connection. Here, the cables to be joined are coaxially constructed. The ends of the cables are cut flat and brought into contact with each other. However, no current is transmitted at the contact point. To ensure current transmission from one cable to the other, two 180-degree shells made of NbTi strands and copper are used, which overlap the two conductor ends (laced unions). These are pressed onto the cables, with contact to the cable conductor being made either with solder or indium. In the connection-

[0022] Gauss Fusion GmbH 11.08.2025 SP14028PCT In the junction section, the current flows laterally out of the cable into the "laced unions", from there to the second cable and from the side back into the second cable [Nguyen]. Such connections are used as connections between coil windings or at coil terminals.

[0023] Both the coaxial connection and the previously described overlap and butt joint serve to permanently connect superconducting cables. Magnetic coils constructed from such cable arrangements cannot be disassembled without damage and are therefore cumbersome to handle, especially when the magnetic coil needs to be removed.

[0024] The object of the invention is to propose a superconductor cable arrangement comprising several superconductor compound cables from which easily demountable magnetic coils for nuclear fusion plants can be manufactured.

[0025] This problem is solved according to the invention by a superconductor cable arrangement according to claim 1, a magnet coil according to claim 18 and a use of a superconductor cable arrangement according to claim 19.

[0026] In the superconducting cable arrangement according to the invention, each of the superconducting compound conductors has a beveled end section with a cut surface, wherein the cut surfaces are oriented obliquely to a direction of a longitudinal extension of the respective superconducting compound conductor. The cut surfaces have the same bevel angles relative to the direction of the longitudinal extension. The end sections of the two superconducting compound conductors are detachably connected to one another in a connecting section, wherein in the connecting section the two cut surfaces are arranged parallel to and facing each other, and the two cooling channels are aligned. According to the invention, a clamping device is mounted in the connecting section, which clamps the end sections of the superconducting compound conductors with a clamping force transverse to the longitudinal extension of the superconducting compound conductors, preferably perpendicular to the direction of the longitudinal extension.

[0027] Gauss Fusion GmbH 11.08.2025 SP14028PCT for the longitudinal expansion of the superconducting compound conductors, clamped together so that the cut surfaces are pressed against each other.

[0028] A compound conductor is a composite conductor made up of a plurality of superconducting wires (e.g., 100 or more bundled wires, typically containing LTS material) or a plurality of superconducting tapes (e.g., 100 or more bundled and / or stacked tape conductors, typically containing HTS material), designed for a total operating current of 10 kA or more. A superconducting compound conductor comprises a sheath (also referred to as a tube) in which the plurality of twisted superconducting wires (CICC (cable-in-conduit-conductor) cables) or the plurality of stacked HTS tape conductors are located. The sheath is preferably made of copper in the connection section and preferably of steel, titanium, or Inconel® (a nickel-chromium-based superalloy) outside the connection section.The casing serves as protection against physical damage and can also provide an ohmic current path in the connection section.

[0029] The superconducting wires are typically multifilament wires with diameters of preferably 0.5–5 mm. Each wire comprises a plurality of superconducting filaments embedded in a matrix, preferably 200–10,000 filaments. The superconducting wires can be in the form of round wires and are bundled in the superconducting compound conductor (typically about 100–300 wires per superconducting compound conductor). The superconducting compound conductors can additionally contain copper wires to improve the heat protection of the superconducting compound conductor in the event of a quench.

[0030] The HTS tape conductors (preferably with a width of 3–12 mm and a thickness of 0.05–1 mm) are typically stacked within the superconducting compound conductor; multiple stacks can be arranged side by side. A superconducting compound conductor with HTS tape conductors has a copper core that serves as a support for the HTS tape conductor bundles. The cladding encloses the HTS tape conductors.

[0031] The cut surfaces of the end sections are preferably produced by means of a formwork cut. They encompass the entire cross-sections of the superconducting

[0032] Gauss Fusion GmbH 11.08.2025 SP14028PCT Wires of the respective compound conductor and are preferably manufactured by fine blanking. The surfaces of the cut surfaces may additionally be polished. The surface roughness of the cut surfaces is preferably < 0.1 mm.

[0033] The bevel angle with respect to the direction of the longitudinal extension of the superconducting compound conductor is preferably between 5° and 45°, and particularly between 10° and 20°. Maintaining a bevel angle of less than 45° allows for the effective application of transverse pressure to pressurize the cut surfaces.

[0034] In a given superconducting compound conductor, the cooling channel typically runs along the center. The cooling channel can, for example, be shaped like a helix.

[0035] Supercritical helium is preferably used as the cooling fluid. Neon, hydrogen, or a mixture of both are also possible. The cooling channels of the superconducting compound conductors are interconnected via hydraulic connecting elements.

[0036] According to the invention, the end sections of the two superconducting compound conductors are detachably connected to one another, i.e., the connection between the two compound conductors can be broken without damage. This is achieved in particular by the clamping device, which remains mounted during operation of the superconductor-cable assembly but can be detached, for example, for assembly and disassembly purposes. The connection of the end sections is preferably made exclusively via the clamping device. That is, the end sections are not joined to one another by heat treatment or bonding.

[0037] The clamping device preferably exerts a pressure of at least 20 MPa, particularly preferably in the range of 25 to 40 MPa, on the cut surfaces.

[0038] The proposed connection establishes a low-resistance electrical contact between the two cut surfaces of the superconducting compound conductors by pressing them together. The clamping device exerts a clamping force perpendicular to the longitudinal dimension of the compound conductors. This ensures both a low-resistance connection and easy disconnection.

[0039] The superconducting compound conductors are preferably arranged in alignment with each other.

[0040] Gauss Fusion GmbH 11.08.2025 SP14028PCT In a particularly preferred embodiment, an interface element made of a low-resistance material, preferably indium or a solder material, is arranged between the cut surfaces. The interface element acts as a current bridge and improves current distribution in the connection section. It enables a uniform distribution of the current across the diameter of the superconductor-cable assembly without requiring precise alignment of the filaments in the connection section. This facilitates easy joining of the ends of the superconducting compound conductors. A "low-resistance material" is defined as a material exhibiting a resistance of less than 5 nanoohms at the operating temperature of the coil of a fusion magnet (< 10 K for LTS coils, < 50 K for HTS coils).

[0041] Preferably, the interface element is a closed, ring-shaped component that surrounds the aligned cooling channels. This allows the interface element to seal the cooling channels. Preferably, the interface element is a perforated disc that (preferably completely) covers the area where the superconducting wires or tapes are exposed and provides a cutout for the cooling channel cross-section. The thickness of the interface element is preferably approximately 0.5–2 mm.

[0042] In a particular embodiment of the superconductor-cable arrangement according to the invention, the superconductor-cable arrangement exhibits resistance in the connection section and, in particular, a resistance of less than 2 nanoohms. The connection of the superconducting compound conductors is therefore not superconducting. However, the resistance should not exceed a value of 2 nanoohms, preferably 0.5 nanoohms.

[0043] To optimize current transmission in the connection section, it is advantageous if the spaces between the superconducting wires or tapes in the superconducting compound conductors are filled with a solder material, preferably lead and / or silver and / or bismuth and / or indium, at least in the end sections, within a respective connection area of ​​preferably 3 cm to 25 cm. Preferably, the connection area is longer than the connection section. This ensures that current is already being conducted (in the current direction) before and after the cut surfaces between the superconducting wires (or their

[0044] Gauss Fusion GmbH 11.08.2025 SP14028PCT filaments or tape conductors) and, on the other hand, also between superconducting wires and any copper wires or copper extrusion profiles that may be present between the superconducting wires. In general, this achieves a distribution of the current across the entire cross-section of the superconducting compound conductors. Even if the superconducting wires or tapes of the two superconducting compound conductors are not aligned at their opposite intersection points, current can still be effectively transferred between the superconducting compound conductors in this way. This connection between the superconducting wires or tapes of the superconducting compound conductors, created by the solder material (and, if applicable, the interface element), prevents unwanted current flow in two ways: firstly, between the sheathing material (e.g.,The solder material is used to create a bond between the copper and superconducting material, and between the sheathing materials of the two superconducting compound conductors (typically copper to copper), as occurs, for example, in known overlap or coaxial connections. This improves current distribution and stability in the connection section. Furthermore, the solder material prevents the wires from breaking when the cut surface is cut, as this requires mechanical support. This is particularly advantageous for superconducting wires made of a brittle material such as Nb3Sn. Solder materials containing a selection of Pb, Sn, Ag, Bi, and / or In are especially well-suited for this purpose, as they have a melting point below 200°C, good wetting properties, and low resistance at cryogenic temperatures.The length of the connection area filled with solder material preferably depends on the chamfer angle of the cut surfaces of the end sections and is in particular greater than the length of the connecting section.

[0045] In a preferred embodiment, the superconducting compound conductors are compressed to the same diameter in the connection section. This ensures that compound conductors with different diameters have the same diameter in the connection area where they are contacted. Furthermore, gaps between the wires or strips are minimized, and the current distribution can be uniform within the cross-section of the compound conductors. Due to the compressed

[0046] Gauss Fusion GmbH 11.08.2025 SP14028PCT In the end sections, the compound conductors have a smaller diameter than in the rest of the superconducting compound conductors. The compound conductors can also be compressed beyond the connection section.

[0047] In a particular embodiment, the two superconducting compound conductors have the same diameter, preferably over their entire length, but at least in the connecting section. This allows for simple complementary cross-sectional surfaces of both end sections, i.e., cross-sectional surfaces that have the same size and shape. The end sections then complement each other in the contacted state, so that the connecting section has a uniform diameter that essentially corresponds to the diameter of the superconducting compound conductors (neglecting the clamping device).

[0048] Alternatively, the superconducting compound conductors can also have different diameters. In this case, it is advantageous to compress the end sections of the two superconducting compound conductors to the same diameter, at least in the connection section. Alternatively, a copper sleeve with the same outer diameter but different inner diameters can be fitted over each end section of the superconducting compound conductors. This ensures a uniform outer diameter in the connection section, even if the diameters of the superconducting compound conductors do not match. While some superconducting strips or wires of the smaller-diameter compound conductor will then contact the copper sleeve of the larger-diameter compound conductor, rather than its superconducting strips or wires, the current can quickly flow back into the smaller-diameter compound conductor via the copper sleeve.

[0049] The clamping device of the superconductor cable arrangement according to the invention preferably comprises at least one clamping element which is pressed against at least one of the superconducting compound conductors, wherein the clamping element is preferably screwed on.

[0050] In a magnetic coil with windings from the superconductor-cable arrangement according to the invention, a longitudinal tension exists, caused by magnetic forces. The clamping element absorbs this tension and ensures

[0051] Gauss Fusion GmbH 11.08.2025 SP14028PCT (especially in combination with at least one wedge element - see below) ensures that the tensile force acting on the superconducting compound conductor along the longitudinal extension is separated from the contact pressure at the cut surfaces.

[0052] The superconducting cable arrangement according to the invention can have more than two compound conductors connected to one another, wherein two compound conductors that share a connection section form a compound conductor pair. Preferably, a separate clamping element is provided for each superconducting compound conductor pair, which presses the cut surfaces of the two superconducting compound conductors against each other in the connection section.

[0053] Preferably, the clamping device is designed and mounted such that the clamping force acts at least substantially parallel to a clamping plane that is perpendicular to the two cutting planes and contains the direction of the longitudinal extension of the superconducting compound conductors, and that this clamping force acts at least substantially perpendicular to the direction of the longitudinal extension of the superconducting compound conductors. This results in a particularly effective clamping of the two cut surfaces.

[0054] In one embodiment, the two superconducting compound conductors that are joined together are of the same type. That is, they have, in particular, the same number and type of superconducting wires or tapes. Alternatively, the two compound conductors can also be of different types (e.g., with a different number of wires or tapes).

[0055] In a special embodiment of the superconductor cable arrangement according to the invention, the first superconducting compound conductor contains HTS and the second superconducting compound conductor contains LTS.

[0056] Furthermore, it is also possible to use superconducting wires or tapes for the first and second superconducting compound conductors, which have different internal configurations (e.g., different numbers, types, and diameters of the wires or tapes). This allows for variation of the superconducting material within the superconductor cable arrangement. This is particularly advantageous for high-field applications, where more superconducting material is required for the inner windings of the coil than for the outer windings. With the

[0057] Gauss Fusion GmbH 11.08.2025 SP14028PCT According to the invention, such inner and outer windings can be realized with only one superconductor cable arrangement (graded coils).

[0058] The superconductor cable arrangement according to the invention preferably has a current-carrying capacity of at least 5 kA, more preferably at least 10 kA, and more preferably at least 50 kA. A single superconducting wire typically has a current-carrying capacity of approximately 200 A to 500 A, and HTS tape conductors up to 1250 A. The superconductor cable arrangement according to the invention comprises a plurality of approximately 100 to 2000 superconducting wires or tapes. A compound conductor made of Nb3Sn or NbTi wires can contain between 100 and 2000 wires, some of which may consist of pure copper (as thermal insulation in the event of a quench). An HTS compound conductor made of REBCO (rare-earth barium copper oxide) can have approximately the same number of tapes, depending on the tape width, arranged on a copper support that acts as thermal insulation.

[0059] With the superconductor cable arrangement according to the invention, a current carrying capacity of up to 150kA can be achieved.

[0060] A particularly preferred embodiment of the superconductor cable arrangement according to the invention provides that a first guide plate is present in which at least one first guide channel is formed, in which an end section of the first superconducting compound conductor is received. Furthermore, a second guide plate is present in which at least one second guide channel is formed, in which an end section of the second superconducting compound conductor is received. The first guide plate is detachably attached to the second guide plate by means of an overlapping connection. The guide plates serve to guide the compound conductors and to absorb forces acting on the compound conductors.

[0061] Preferably, each guide plate has a plurality of guide channels so that several superconducting compound conductors or their end sections are guided parallel to each other.

[0062] Gauss Fusion GmbH 11.08.2025 SP14028PCT The guide plates, in which the end sections of the two compound conductors are received, are mechanically connected to each other. For this purpose, it is advantageous if the guide plates each have an exposed end in the area of ​​the overlapping connection, in which at least one guide channel is open towards the other guide plate, wherein at least one projection and one recess are formed at the free end, and wherein a projection of each guide plate is hooked into a recess of the other guide plate. The projections thus interlock with each other. This ensures that tensile stresses acting on the compound conductors are absorbed by the guide plate. The connection of the two guide plates corresponds to a folded joint with a raised area at each end (tableted half-lap scarf joint).

[0063] In a particularly preferred embodiment, a wedge element is clamped in the recess of the first guide plate between the projection of the second guide plate and an exposed section of the first guide plate, so that the projections of the first and second guide plates are pressed against each other. Without the wedge element, the interlocked projections have some play (in the direction of the longitudinal expansion of the compound conductors), and this play is clamped against each other by the wedge element. The projections thus lie firmly against each other, regardless of any momentary clamping force acting on the connecting section. As a result, the tensile forces acting on the coil, which result from the magnetic forces during coil operation, are transmitted directly and do not affect the clamping effect of the clamping device.

[0064] The wedge element is preferably attached to the first guide plate, in particular screwed to it.

[0065] Additionally, a further wedge element can be clamped in the recess of the second guide plate between the projection of the first guide plate and a recessed section of the second guide plate. This further wedge element is preferably attached to the second guide plate, in particular by screws.

[0066] Gauss Fusion GmbH 11.08.2025 SP14028PCT The invention also relates to a magnetic coil for a nuclear fusion device, wherein the magnetic coil is preferably a stellarator coil or a tokamak coil comprising a plurality of superconducting compound conductor windings, wherein the magnetic coil forms at least one previously described superconductor cable arrangement.

[0067] The invention also relates to a use of the previously described superconducting cable arrangement or the previously described magnetic coil, wherein a current flows superconducting in the first superconducting compound conductor, the current in the connecting section from the first superconducting compound conductor to the second superconducting compound conductor, in particular in a normal-conducting manner, and the current flows superconducting in the second superconducting compound conductor, wherein the cooling channels of the two superconducting compound conductors are traversed by a cooling fluid, wherein the cooling fluid in the connecting section passes from the cooling channel of the first superconducting compound conductor to the cooling channel of the second superconducting compound conductor, in particular wherein the cooling fluid is a supercritical cooling fluid, in particular a supercritical gas or a supercritical liquid, and wherein the two cut surfaces are pressed against each other by means of the clamping device in the connecting section.The superconductor cable assembly is therefore used with the clamping device mounted, according to the invention. The clamping device is only removed for disassembly or maintenance.

[0068] Further advantages of the invention will become apparent from the description and the drawing. Likewise, the features mentioned above and those described in more detail below can each be used individually or in any combination according to the invention. The embodiments shown and described are not to be understood as an exhaustive list, but rather serve as examples for illustrating the invention.

[0069] Gauss Fusion GmbH 11.08.2025 SP14028PCT Fig. aa shows a schematic diagram of a simple embodiment of a superconductor cable arrangement according to the invention.

[0070] Fig. 1b shows a schematic diagram of a preferred embodiment of a superconductor cable arrangement with interface element according to the invention.

[0071] Fig. 2a shows a schematic representation of a superconductor cable arrangement according to the invention with a guide plate with compound conductor pairs in the unconnected state.

[0072] Fig. 2b shows the superconductor cable arrangement from Fig. 2a in the connected state.

[0073] Fig. 3 shows a detailed view of a cross-section of the superconductor cable arrangement shown in Fig. 2b through the mounted clamping element.

[0074] Fig. 4a shows a schematic cross-section of a compound conductor with a plurality of wires.

[0075] Fig. 4b shows a schematic cross-section of a compound conductor with a plurality of HTS bands.

[0076] Fig. 5 shows a magnetic coil for a nuclear fusion plant with a superconductor cable arrangement according to the invention.

[0077] Figures 1a and 1b show side views of two superconducting cable arrangements 1, 1' according to the invention, each comprising a first compound conductor 2a with an electrically conductive sheath 18a and a second compound conductor 2b with an electrically conductive sheath 18b. The compound conductors 2a, 2b have end sections 3a, 3b which are connected to each other. For this purpose, the end sections 3a, 3b are chamfered in a connecting section 4, such that each end section 3a, 3b has a cross-sectional surface 5a, 5b with a chamfer angle α. The end sections 3a, 3b are connected to each other via the cross-sectional surfaces 5a, 5b, such that the cross-sectional surfaces 5a, 5b are aligned parallel to each other. In this way, an electrically conductive connection between the end sections 3a, 3b of the compound conductors 2a, 2b is established in the connecting section 4.

[0078] Gauss Fusion GmbH 11.08.2025 SP14028PCT The compound conductors 2a, 2b comprise connection areas 19a, 19b which are preferably filled with a solder material in order to achieve a distribution of the current over the entire cross-section of the superconducting compound conductors 2a, 2b before the connection section 4.

[0079] In the superconducting cable arrangement 1 shown in Fig. 1a, the compound conductors 2a, 2b are directly contacted via their cross-sectional surfaces 5a, 5b, i.e., the cross-sectional surfaces 5a, 5b are in contact. In the superconducting cable arrangement 1' shown in Fig. 1b, the compound conductors 2a, 2b are contacted via an interface element 6 (for example, made of indium), i.e., the cross-sectional surfaces 5a, 5b are in contact with the interface element 6. The interface element 6 forms a resistive but low-impedance electrical connection between the two compound conductors 2a, 2b. Current that is superconducting within the individual compound conductors 2a, 2b is conducted through the interface element from the first compound conductor 2a to the second compound conductor 2b, even if the superconducting components of the individual compound conductors 2a, 2b are not aligned. The interface element 6 therefore serves as a current bridge between the two compound conductors 2a, 2b.

[0080] The end sections 3a, 3b of the two compound conductors 2a, 2b are connected by means of a clamping device 7, wherein the clamping device 7 presses the cut surfaces 5a, 5b against each other with a clamping force FK transverse to the longitudinal extent of the superconducting compound conductors 2a, 2b.

[0081] Figures 2a and 2b show a preferred embodiment of the superconductor cable arrangements 1" according to the invention, in which the compound conductors 2a, 2b are arranged in guide channels 8a, 8b of guide plates 9a, 9b. The compound conductors 2a, 2b can be completely enclosed in one or more guide plates. At a minimum, however, the end sections 3a, 3b are enclosed in the guide plate 9a, 9b. The compound conductors 2a, 2b each have a central cooling channel 17a, 17b through which a cooling fluid can be guided. The cooling channels 17a, 17b penetrate the cut surfaces 5a, 5b, whereby in Figure 1a the cut surface 5b is covered by the interface element 6 and is therefore not visible.

[0082] Gauss Fusion GmbH 11.08.2025 SP14028PCT In the embodiment shown in Fig. 2a and Fig. 2b, several compound conductor pairs (compound conductors 2a, 2b to be connected) are provided. The respective first compound conductors 2a are housed in first guide channels 8a of the first guide plate 9a, while the respective second compound conductors 2b are housed in second guide channels 8b of the second guide plate 9b.

[0083] The guide plates 9a, 9b have exposed ends 10a, 10b, in which the guide channels 8a, 8b are open towards the respective other guide plate 9a, 9b. At least one projection 11a, 11b and one recess 12a, 12b are formed at each of the exposed ends 10a, 10b.

[0084] Fig. 2b shows the superconducting cable assemblies 1" in the assembled state, in which the two guide plates 9a, 9b are interlocked, with the projection 11a of the first guide plate 9a engaging in the recess 12b of the second guide plate 9b and vice versa. The projections 11a, 11b and recesses 12a, 12b are dimensioned to allow for some play. This play is eliminated by wedging a first wedge element 13a. For this purpose, the first wedge element 13a is clamped between the projection 11b of the second guide plate 9b and an exposed section of the first guide plate 9a, so that the projection 11a of the first guide plate 9a and the projection 11b of the second guide plate 9b are pressed against each other. Additionally, a second wedge element 13b can be provided, which is clamped between the projection 11a of the first guide plate 9a and an exposed section. is clamped to the second guide plate 9b.

[0085] The cut surfaces 5a, 5b of the end sections 3a, 3b of the compound conductors 2a, 2b are pressed together in connection section 4 by means of clamping elements 14, so that the interface element 6 is clamped between the cut surfaces 5a, 5b and forms a current bridge between the cut surfaces 5a, 5b and seals the cooling channels 17a, 17b. The clamping element 14 is mechanically connected to the first guide plate 9a by means of fasteners 15 (e.g., screws) and presses the end sections 3a, 3b in connection section 4 against the guide channel 8b of the second guide plate 9b. The clamping elements 14, together with the fasteners 15 and the first guide plate 9a, thus form the clamping device 7.

[0086] Gauss Fusion GmbH 11.08.2025 SP14028PCT In the embodiment shown in Fig. 2b, a separate clamping element 14 is provided for each compound conductor pair. However, it is also conceivable that a common clamping element is provided for several compound conductor pairs (not shown).

[0087] A detailed cross-sectional view of the superconductor cable arrangement 1" shown in Fig. 2b is shown in Fig. 3. The clamping element 14 is mounted in a recess in the first guide plate 9a. On the side facing the end section 3a of the first compound conductor 2a, the clamping element 14 preferably has a groove 16, with which the clamping element 14 presses onto the end section 3a of the first compound conductor 2a. The shape of the groove follows the conductor shape and, in particular, includes a circular segment. The groove 16 forms the contact area with the end section 3a. Overall, the clamping element 14 preferably has a T-shape, with the clamping element 14 being attached to the first guide plate 9a in an area where the T-shaped clamping element 14 overlaps the contact area. The clamping element 14 preferably terminates flush with the guide plate 9a, as shown in Fig. 3.

[0088] The structure of compound conductors 2a, 2b, which are preferably used for the superconductor cable arrangement 1, 1', 1'' according to the invention, is shown schematically in Figs. 4a, 4b. Fig. 4a shows a cross-section of a compound conductor 2a, 2b with a plurality of superconducting wires 20, the cooling channel 17a, 17b for conveying the cooling fluid, and the sheath 18a, 18b, which surrounds the plurality of superconducting wires 20. A solder material 21 can be introduced between the wires 20. Fig. 4b shows a cross-section of a compound conductor 2a, 2b with HTS strip conductor stacks 22, the cooling channel 17a, 17b for conveying the cooling fluid, and the sheath 18a, 18b, which surrounds the HTS strip conductor stacks 22. The HTS strip conductor stacks 22 each contain a plurality of stacked strip conductors 23 and are mounted on a copper core 24, which surrounds the cooling channel 17a, 17b.

[0089] Fig. 5 shows a magnetic coil 25 for a nuclear fusion device (here, by way of example, a tokamak coil) which forms a superconducting cable arrangement 1, 1', 1" . The

[0090] Gauss Fusion GmbH 11.08.2025 SP14028PCT Magnetic coil 25 comprises a multitude of superconducting compound conductor windings 26.

[0091] List of reference signs

[0092] 1 Superconductor cable assembly without interface element

[0093] 1' Superconductor cable arrangement with interface element

[0094] 1" superconducting cable assembly with guide plate

[0095] 2a, 2b Compound conductor

[0096] 3a, 3b End sections of the compound conductor

[0097] 4 Connection section

[0098] 5a, 5b Intersection of the end sections

[0099] 6 Interface element

[0100] 7 Clamping device

[0101] 8a, 8b Guide channels of the guide plates

[0102] 9a, 9b Guide plates

[0103] 10a, 10b exposed ends of the guide plates

[0104] 11a, 11b Projections of the exposed ends

[0105] 12a, 12b Backwards of the exposed ends

[0106] 13a, 13b Wedge elements

[0107] 14 Clamping element of the clamping device

[0108] 15 Fasteners

[0109] 16 U-shaped groove of the clamping element

[0110] 17a, 17b Cooling channels of the compound conductor

[0111] 18a, 18b Sheaths of the compound conductor

[0112] 19a, 19b Connection areas (possibly filled with solder)

[0113] 20 superconducting wires

[0114] Gauss Fusion GmbH 08 / 11 / 2025 SP14028PCT 21 solder material

[0115] 22 HTRS tape ladder stacks

[0116] 23 HTS belt ladder

[0117] 24 copper core

[0118] 25 Magnetic coil

[0119] 26 Compound-Leiter-Wicklungen. a Abschrägwinkel

[0120] Referenzliste

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[0126] [Rolando] Rolando et al.

[0127] Performance assessment and optimization of the ITER toroidal field coil join

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[0129] [US20210376498] US 2021 / 0376498 Al

[0130] [Nguyen] Nguyen et al.

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[0133] [EP0556837] EP 0 556 837 Al

[0134] Gauss Fusion GmbH 11.08.2025 SP14028PCT

Claims

Patent claims 1. Superconducting cable arrangement (1; 1'; 1") for use in a magnet coil (25) for a nuclear fusion device, comprising a first superconducting compound conductor (2a) and a second superconducting compound conductor (2b), each of the compound conductors (2a, 2b) comprising a plurality of superconducting wires (20) or tapes (23), a cooling channel (17a, 17b) for conveying a cooling fluid, and a sheath (18a, 18b) of a conductive material surrounding the plurality of superconducting wires or tapes and the cooling channel (17a, 17b), characterized in that each of the superconducting compound conductors (2a, 2b) has a chamfered end section (3a, 3b) with a cut surface (5a, 5b), the cut surfaces being inclined to a direction of a longitudinal extension of the respective superconducting Compound conductors (2a, 2b) are aligned, and wherein the cut surfaces (5a, 5b) have equal bevel angles α relative to the direction of longitudinal extension,that the end sections (3a, 3b) of the two superconducting compound conductors (2a, 2b) are detachably connected to each other in a connecting section (4), wherein in the connecting section (4) the two cut surfaces (5a, 5b) are arranged parallel to each other and facing each other and the cooling channels (17a, 17b) of the two compound conductors (2a, 2b) are aligned, and wherein a clamping device (7) is mounted in the connecting section (4), which clamps the end sections (3a, 3b) of the superconducting compound conductors together, Gauss Fusion GmbH 08 / 11 / 2025 SP14028PCT a clamping force transverse to the longitudinal extent of the superconducting compound conductors (2a, 2b), preferably perpendicular to the longitudinal extent of the superconducting compound conductors (2a, 2b), clamps together, so that the cut surfaces (5a, 5b) are pressed against each other.

2. Superconductor cable arrangement (1', 1") according to claim 1, characterized in that an interface element (6) made of a low-resistance material, preferably indium or a solder material, is arranged between the cut surfaces (5a, 5b).

3. Superconductor cable arrangement (1', 1") according to claim 2, characterized in that the interface element (6) is formed in a closed ring shape and surrounds the aligned cooling channels (17a, 17b).

4. Superconductor cable arrangement (1; 1'; 1") according to one of the preceding claims, characterized in that the superconductor cable arrangement (1; 1'; 1") has resistance in the connection section, in particular a resistance of less than 2 nOhm.

5. Superconductor cable arrangement (1; 1'; 1") according to one of the preceding claims, characterized in that the spaces between the superconducting wires or tapes in the superconducting compound conductors are filled with a solder material, in particular with lead and / or silver and / or bismuth and / or indium, at least in the region of the end sections (3a, 3b), in a respective connection area (19a, 19b) of preferably 3 cm to 25 cm.

6. Superconductor cable arrangement (1; 1'; 1") according to one of the preceding claims, characterized in that the superconducting compound conductors (2a, 2b) are each compressed to the same diameter in the connecting section (4). Gauss Fusion GmbH 08 / 11 / 2025 SP14028PCT 7. Superconductor cable arrangement according to one of the preceding claims, characterized in that the two superconducting compound conductors (2a, 2b) have the same diameter.

8. Superconductor cable arrangement according to one of the preceding claims, characterized in that the clamping device (7) comprises at least one clamping element (14) which is pressed against at least one of the superconducting compound conductors (2a, 2b), in particular wherein the clamping element (14) is screwed on.

9. Superconductor cable arrangement (1; 1'; 1") according to one of the preceding claims, characterized in that the clamping device (7) is designed and mounted such that the clamping force FK acts at least substantially parallel to a clamping plane which is perpendicular to the two cut surfaces (5a, 5b) and contains the direction of the longitudinal extension of the superconducting compound conductors (2a, 2b), and that this clamping force FK acts at least substantially perpendicular to the direction of the longitudinal extension of the superconducting compound conductors.

10. Superconductor cable arrangement (1; 1'; 1") according to one of the preceding claims, characterized in that the first superconducting compound conductor (2a) contains HTS and the second superconducting compound conductor (2b) contains LTS.

11. Superconductor cable arrangement (1; 1'; 1") according to one of the preceding claims, characterized in that the clamping device (7) exerts a pressure of at least 20 MPa, preferably in the range of 25 to 40 MPa, on the cut surfaces. Gauss Fusion GmbH 08 / 11 / 2025 SP14028PCT 12. Superconductor cable arrangement (1; 1'; 1") according to one of the preceding claims, characterized in that the cut surfaces (5a, 5b) are manufactured by fine blanking.

13. Superconductor cable arrangement (1; 1'; 1") according to one of the preceding claims, characterized in that the bevel angle α with respect to the direction of the longitudinal extension of the superconducting compound conductor (2a, 2b) is between 5° and 45°, preferably between 10° and 20°.

14. Superconductor cable arrangement (1; 1'; 1") according to one of the preceding claims, characterized in that the superconductor cable arrangement (1; 1'; 1") has a current-carrying capacity of at least 5 kA, preferably at least 10 kA, particularly preferably at least 50 kA.

15. Superconductor cable arrangement (1") according to one of the preceding claims, characterized in that a first guide plate (9a) is provided in which at least one first guide channel (8a) is formed in which an end section (3a) of the first superconducting compound conductor (2a) is received, and a second guide plate (9b) is provided in which at least one second guide channel (8b) is formed in which an end section (3b) of the second superconducting compound conductor (2b) is received, and that the first guide plate (9a) is detachably attached to the second guide plate (9b) by means of an overlap connection.

16. Superconductor cable arrangement (1") according to claim 15, characterized in that in the area of ​​the overlap connection the guide plates (9a, 9b) each have an exposed end (10a, 10b) in which the at least one guide channel (8a, 8b) is opened towards the respective other guide plate (9a, 9b), wherein at the exposed end (10a, 10b) each Gauss Fusion GmbH 08 / 11 / 2025 SP14028PCT at least one projection (11a, lib) and one return (12a, 12b) is formed, and wherein a projection (11a, 11b) of one guide plate (9a, 9b) is hooked into a return (12a, 12b) of the other guide plate (9a, 9b).

17. Superconductor cable arrangement (1") according to claim 16, characterized in that a wedge element (13a) is clamped in the recess (12a) of the first guide plate (9a) between the projection (11b) of the second guide plate (9b) and an unexposed section of the first guide plate (9a), so that the projections (11a) of the first guide plate (9a) and the second guide plate (9b) are pressed against each other.

18. Magnetic coil (25) for a nuclear fusion device, in particular wherein the magnetic coil (25) is a stellarator coil or a tokamak coil, comprising a plurality of superconducting compound conductor windings (26), wherein the magnetic coil (25) forms at least one superconductor cable arrangement (1; 1'; 1") according to one of the preceding claims.

19. Use of a superconducting cable arrangement (1; 1'; 1") according to any one of claims 1 to 17 or a magnetic coil (25) according to claim 18, wherein a current flows superconductingly in the first superconducting compound conductor (2a), the current passes in the connecting section (4) from the first superconducting compound conductor (2a) to the second superconducting compound conductor (2b), in particular passing in a normal-conducting manner, and the current flows superconductingly in the second superconducting compound conductor (2b), wherein the cooling channels (17a, 17b) of the two superconducting compound conductors (2a, 2b) are traversed by a cooling fluid, wherein the cooling fluid passes in the connecting section from the cooling channel (17a) of the first superconducting compound conductor (2a) to the cooling channel (17b) of the second superconducting compound conductor (2b), in particular wherein the Cooling fluid is a supercritical cooling fluid, in particular a supercritical gas or a supercritical liquid, Gauss Fusion GmbH 08 / 11 / 2025 SP14028PCT and wherein the two cut surfaces are pressed against each other by means of the clamping device in the connecting section. Gauss Fusion GmbH 08 / 11 / 2025 SP14028PCT

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