Solenoid, in particular for a nuclear fusion plant, with a simplified production, assembly, and disassembly

Abstract

The invention relates to a solenoid (1, 1a) comprising a plurality of annular, stacked plate layers (3; 3a-3h), wherein each plate layer is constructed from sub-plates (5; 5a-5c; 9, 9a, 9b) secured to one another in succession; grooves (16, 21) run in the sub-plates, superconducting conductors (22) being placed in the grooves; a plurality of sections (ES, wES, WS, WS1-WS3, ZS, AS) are present, each of which forms part of the circumference of the solenoid and which are connected by stack joints (SJ1-SJ3); each stack joint comprises a plate layer joint (6; 6a-6h) in each plate layer; the sections have at least one insert section (ES, wES); in the insert section, the length (L8a-L8h) of the sub-plate layers becomes smaller towards the respective next inner plate layer starting from either a) just one stack end face (OSE), with respect to all the sub-plate layers (8; 8a-8e) or b) a first stack end face (SE1) for a first proportion (45) of the sub-plate layers (8; 8a-8d) and a second opposite stack end face ( SE2) for a second remaining proportion (46) of the sub-plate layers (8; 8e-8h); and in each stack joint belonging to the insert section, i) the plate layer joints are offset relative to one another and ii) with respect to the associated stack end face (OSE; SE1, SE2) according to a) or b), the plate layer joints of plate layers located further inward do not overlap with the sub-plates of the plate layers of the next section located further outward. The solenoid is easier to handle during production, assembly, disassembly, and in the event of any repairs or maintenance processes.

Description

[0001] SP14052PCT P October 16, 2025 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] Magnetic coil, especially for a nuclear fusion plant, with simplified manufacturing, assembly and disassembly

[0014] The invention relates to a magnetic coil,

[0015] especially stellarator coil or tokamak coil for a nuclear fusion plant,

[0016] wherein a plurality of ring-shaped plate layers are present, in each of which several turns of a superconducting conductor are formed, wherein in each plate layer a plurality of sub-plates are arranged ring-shaped one after the other and in each plate layer successive sub-plates are attached to one another,

[0017] and wherein the plate layers form a ring-shaped plate layer stack and successive plate layers are in contact with each other,

[0018] wherein each subplate forms several grooves into which the conductor is inserted,

[0019] wherein the grooves of the sub-plate run along a local longitudinal direction, and

[0020] Gauss Fusion GmbH 16.10.2025 SP14052PCT the grooves of the sub-plate are arranged consecutively in a local transverse direction,

[0021] where a local stacking direction is perpendicular to the local longitudinal direction and perpendicular to the local transverse direction,

[0022] and wherein the grooves of successive sub-plates of a plate layer are aligned with each other, and in particular connect to each other.

[0023] Such a magnetic coil was described by F. Schauer et al., “Extrapolation of the W7-X Magnet System to Reactor Size”, Contrib. Plasma Phys. 50, No. 8, 750-755 (2010).

[0024] Nuclear fusion is a promising technology for generating electricity. It involves fusing two light reactants, or rather their atomic nuclei, typically deuterium and tritium, releasing energy. The reaction takes place in a plasma. Currently, major efforts are underway worldwide to practically implement a fusion power plant. The most widely pursued development approach involves confining the plasma using appropriately shaped magnetic fields.

[0025] Typically, fusion reactors with a substantially toroidal plasma volume geometry are used; the tokamak and stellarator designs are well-known examples. In both cases, a multitude of superconducting magnetic coils are arranged along the substantially toroidal plasma volume, each locally enclosing the toroidal plasma volume in a ring-like fashion.

[0026] In the tokamak design, which is used, for example, in the ITER fusion reactor, the individual magnetic coils (or tokamak coils) typically have a planar, or two-dimensional, geometry; however, tokamak coils with non-planar geometries have also been discovered. A tokamak requires an electric current flowing in the plasma. In the stellarator design, the individual magnetic coils (or stellarator coils) each have a non-planar geometry.

[0027] Gauss Fusion GmbH 16.10.2025 SP14052PCT: Planar, 3D-shaped geometry; the setup is therefore somewhat more complex. No current flowing in the plasma is required in the stellarator.

[0028] A significant challenge in fusion reactors lies in assembling the necessary magnetic coils. A single magnetic coil in a fusion reactor can weigh up to 300 tons or even more, and often contains several thousand meters of superconducting wire. Due to the size of a fusion reactor compared to existing or under-construction fusion experiments, it is expected that the magnetic coils will have to be manufactured on-site. This makes manufacturing the magnetic coil complex and difficult. Repairs and maintenance of the magnetic coil are also complex and difficult. In the event of defects, for example in the conductor, the entire magnetic coil usually has to be replaced.

[0029] Furthermore, the magnetic coils encircle the plasma vessel of the fusion reactor, with the coils being distributed around the entire circumference of the essentially toroidal plasma vessel. This makes access to the plasma vessel difficult, which in turn complicates assembly, repairs, and maintenance work on and inside the plasma vessel.

[0030] F. Schauer et al. in Contrib. Plasma Phys., ibid., discussed the potential design of stellarator coils, particularly for the HSR50a reactor, which belongs to the HELIAS type, based on the design of the ITER tokamak coils. The stellarator coil they discussed consists of stacked radial plates, each containing conductor windings. They noted that the coil housing, radial plates, and conductors would need to be bent. Furthermore, the radial plates could be manufactured in segments and then welded together at accessible edges.

[0031] In A. van Arkel et al., “Unlocking maintenance - architecting STEP for maintenance and realizing remountable magnet joints”, coils with a rectangular ring-shaped structure are proposed for a STEP (Spherical Tokamak for Energy Production) fusion reactor TF (toroidal field) fusion reactor, with a corner

[0032] Gauss Fusion GmbH 16.10.2025 SP14052PCT a permanent joint is established, and re-assemblable joints are established at three corners. At the re-assemblable joints, it is proposed to connect the two conductor ends edge to edge, with stacked strip conductors running parallel to each other in the two conductor ends.

[0033] Disassemblable solder joints for coupling superconducting current paths have been disclosed in US patent 2023 / 0207171. For the D-shaped TF coils of a fusion reactor, it is proposed to incorporate joint regions that can be disassembled at two points between a straight section and a curved section, thus making the TF coil disassemblable. The two sections of the TF coil are formed by a straight plate and a curved plate, each containing channels for receiving HTS conductors. The ends of the sections overlap in a so-called praying hands configuration to form the joint regions.

[0034] In both the STEP joints (see A. van Arkel, op. cit.) and the joints from US 2023 / 0207171 Al, the superconducting conductors are routed out of the force-bearing line of the magnet coil, which is essentially caused by tensile stresses along the circumference of the coil due to magnetic forces. Furthermore, flanges are required for the mechanical design of these joints. Consequently, these joints occupy a considerable amount of installation space.

[0035] The subsequently published German patent application 10 2024 208 874.9 describes a stellarator coil for a nuclear fusion device in which a superconducting conductor runs in the grooves of support plates. A layer of plates is formed by a plurality of ring-shaped, interconnected support plates, and multiple layers of plates are stacked together and clamped with several clamps. The support plates have a cross-sectional area of ​​support material of at least 67% compared to the total area of ​​support material and conductor. Each layer of plates is preferably composed exclusively of support plates of three types, with the grooves forming only

[0036] Gauss Fusion GmbH 16.10.2025 SP14052PCT curved in the plane of the plate, or with the grooves only curved in parallel transverse planes, or straight grooves.

[0037] From German patent application 10 2024 125 717.2, published after the initial filing, a superconducting cable arrangement for use in a magnet coil of a nuclear fusion device is known. Two compound conductors have beveled end sections that are detachably connected to one another. A clamping device exerts a clamping force transverse to the longitudinal extent of the compound conductors. The compound conductors can be received in guide channels of guide plates, and the guide plates can be detachably fastened to one another by means of an overlapping connection.

[0038] EP 3 622 544 Bl describes a superconducting magnet with D-shaped double pancake coils, specifically for a set of tokamak magnets. Joints between the inner and outer partial coils are configured in the so-called praying hands configuration.

[0039] EP 4 258 284 A1 describes an arrangement comprising several modular MOCVD-based coils that are mechanically and electrically interconnected, each modular coil having a groove that divides the modular coil into at least two different electrically conductive regions. Two modular coils can be interlocked like puzzle pieces.

[0040] WO 2023 / 194227 Al describes a similar magnetic enclosure arrangement comprising several interconnected modules, wherein each module includes a first wall with a connecting surface and a groove divides the first wall into two different electrically conductive regions.

[0041] DE 693 13 891 T2 describes a method for joining ribbon-shaped superconducting wires. In this process, oxide strands are exposed, and plastic deformation of the areas to be joined, essentially perpendicular to the main surface of the ribbon-shaped wires, as well as heat treatment, are applied.

[0042] Gauss Fusion GmbH October 16, 2025 SP14052PCT H. Nakajima et al. in “Development of Optimum manufacturing technologies of radial plates for the ITER, toroidal field coils,” Fusion Engineering and Design, Vol.

[0043] 82, 2007, pp. 1473-1480, describe the fabrication of radial plates for toroidal field coils for ITER. The radial plates have grooves on both sides for inserting the superconducting wire.

[0044] F. Schauer et al. in "Coil winding pack FE-analysis for a HELIAS reactor", Fusion Engineering and Design, Vol. 86, No. 6-8, 2011, pp. 636-639, describe a non-planar winding pack for a stellarator fusion reactor, in which superconducting fibers are arranged in a square shell.

[0045] H. Hashizume et al., “Development of remountable joints and heat removable techniques for high-temperature superconducting magnets,” Nuclear Fusion, Vol.

[0046] 58, No. 2, 2018, 026014 (8 pp.), describe REBCO tape conductors connected with a bridge-like overlap joint. An indium foil is soldered between the tape conductors. A steel sheath is welded to ensure mechanical strength.

[0047] N. Yanagi et al., "Design and development of high-temperature superconducting magnet System with joint-winding for the helical fusion reactor", Nuclear Fusion, Vol. 55, No. 5, 2015, 053021 (7 pp.) describe a similar bridge-like overlap joint, where a pressure of 100 MPa is applied during joint fabrication.

[0048] Object of the invention

[0049] The object of the invention is to present a magnetic coil, in particular for use in large magnetic field-based applications such as magnetic resonance imaging systems, high-energy physics systems and nuclear fusion systems, which is easier to handle during manufacturing, assembly and disassembly and during any repairs or maintenance.

[0050] Gauss Fusion GmbH 16.10.2025 SP14052PCT Description of the invention

[0051] This problem is solved according to the invention by a magnetic coil of the type mentioned above, which is characterized in that

[0052] that the plate stack comprises several sections, each forming part of the circumference of the annular plate stack,

[0053] wherein each section is formed by a stack of partial plate layers, wherein a partial plate layer is formed by the partial plates of the section in a plate layer,

[0054] wherein in the ring-shaped stack of plates, successive sections are connected to each other by stack joints,

[0055] that each stack joint comprises a plate layer joint in each plate layer,

[0056] wherein each plate-layer joint in its associated plate layer electrically contacts the conductors in the grooves of an end-facing sub-plate of a first section with opposing conductors in the grooves of an end-facing sub-plate of a second section by means of several conductor joints, and the end-facing sub-plate of the first section is attached to the end-facing sub-plate of the second section,

[0057] and that the sections include at least one insertion section,

[0058] where in the insertion section

[0059] a) either from only one stack end along a common sequence direction with respect to all partial plate layers,

[0060] b) or from a first stack end along a first sequence direction for a first part of the partial plate layers and from a second, opposite stack end along a second, opposite sequence direction for a second, remaining part of the partial plate layers,

[0061] a length of the partial plate layers, measured along the local longitudinal direction into the plate layer stack, decreases towards the next inner plate layer,

[0062] Gauss Fusion GmbH 16.10.2025 SP14052PCT wherein in the stack joints belonging to the insertion section each

[0063] i) the plate layer joints are arranged offset from each other with respect to the local longitudinal direction, and

[0064] ii) in the plate layer stack with respect to the associated stack end side according to a) or b), the plate layer joints of more inwardly located plate layers do not overlap with the sub-plates of more outwardly located plate layers of the section which is connected at the stack joint to the insertion section.

[0065] An annular magnetic coil according to the invention is constructed from a plurality of stacked, annular plate layers, and each plate layer comprises a plurality of sub-plates that are connected to one another in a ring-like fashion. A plate layer stack is divided into sections, each forming a portion of the circumference of the annular plate layer stack, and these sections are connected to one another via stack joints. Each plate layer contains one such stack joint. At least one section is configured as an insertion section; the remaining magnetic coil or plate layer stack accordingly forms at least one further section.The insertion section is characterized by the fact that its partial plate layers are inserted into the stack either from only one stack end (also called the "single access side", case a) above) along a common sequence direction for all partial plate layers, or alternatively from both stack end sides (which are then also called the "first access side" and "second access side", case b) above) along a first sequence direction for a first part of the partial plate layers and along an opposite, second sequence direction for a second part of the partial plate layers, with respect to the local longitudinal direction. This is arranged such that at each stack joint, the plate layer joints in the stack (with respect to the associated stack end side or...) shorten into the stack with respect to the local longitudinal direction.the corresponding sequence direction according to a) or b) above) further inner plate layers do not overlap with the sub-plates of the further outer plate layers of the next section connected with the insertion section.

[0066] Gauss Fusion GmbH 16.10.2025 SP14052PCT This makes it possible, during the assembly of the magnetic coil, after the rest of the magnetic coil or the further section has been assembled, to attach the partial plate layers of the insertion section to the rest of the magnetic coil one after the other, from the inside out. Such partial plate layers are comparatively light, so that they can also be handled by a conventional industrial robot (without a crane). In addition, when installing a partial plate layer located further inside, its plate layer joints are still easily accessible, in particular for setting up and tightening screws or clamps at the respective plate layer joint; only when the next partial plate layer is placed does the plate layer joint of the underlying partial plate layer become inaccessible.At each plate layer joint, the opposing end-side sub-plates are also connected to each other, preferably in a non-destructively detachable way (e.g. by hooking and clamping or screwing or jamming), or alternatively permanently connected (i.e. only detachable by destruction, e.g. by sawing).

[0067] Conversely, for disassembly starting with a complete magnetic coil, it is possible to remove the partial plate layers of the insertion section successively from the outside in, away from the rest of the magnetic coil. The partial plate layers are comparatively light, so they can be handled by a conventional industrial robot (without a crane). Furthermore, when disassembling the outermost partial plate layer, its plate layer joints are freely accessible (from the corresponding stack end according to a) or b), i.e., from the access side / first access side / second access side), particularly to loosen screws or clamps at a respective plate layer joint and to separate the connection of the end plates, preferably non-destructively, but also destructively.After removing the outermost partial plate layer, the plate layer joints of the underlying, next inner partial plate layer become accessible, and this underlying partial plate layer can be detached, and so on.

[0068] Gauss Fusion GmbH 16.10.2025 SP14052PCT Depending on the design of the magnetic coil, the remaining magnetic coil or at least one further section can be assembled by stacking partial plate layers. Likewise, depending on the design of the magnetic coil, the remaining magnetic coil or at least one further section can be disassembled by unstacking partial plate layers. In the case of multiple partial plate layers, the processing of the further sections may follow a specific sequence, depending on the design of the magnetic coil. The partial plate layers are easy to handle, especially with an industrial robot and without a crane.

[0069] The interruption of the conductor's windings at the plate-layer joints eliminates the need to provide and wind long conductors (continuous over many turns) within the magnet coil. Instead, each segment of the superconducting conductor extends only the length of a slot in a partial plate layer, thus covering only a portion of the magnet coil's circumference. Such lengths of superconducting conductor are readily available at low cost, particularly for HTS-based and Nb3Sn-based conductors. The conductor segments can be easily inserted into the slots without the need for complex tools. Consequently, the partial plate layers, from which the magnet coil is assembled, can be manufactured in a particularly simple and cost-effective manner.

[0070] The sections of the magnet coil, or even the individual sub-plate layers of the sections, can easily be manufactured remotely from the installation site and then assembled into the magnet coil on-site. The superconducting conductor segments are typically inserted into the grooves of the sub-plate layers remotely from the installation site; however, if desired, the superconducting conductor segments can also be inserted on-site.

[0071] Preferably, all magnetic coils of a fusion reactor are constructed according to the invention in order to take advantage of their benefits during assembly and disassembly.

[0072] Gauss Fusion GmbH 16.10.2025 SP14052PCT If at least one subgroup of the magnetic coils of a fusion reactor is constructed according to the invention, a larger access point to the plasma vessel can be created, at least relatively easily, by dismantling one or more magnetic coils, typically adjacent in the circumferential direction of the toroidal plasma volume. This makes repair and maintenance work in and on the plasma vessel easier, for example, when a maintenance window on the plasma vessel, which is covered by the subgroup of magnetic coils, needs to be accessed.

[0073] Furthermore, for maintenance and repairs, for example for replacing sections of the conductor, the magnetic coil constructed according to the invention can be easily disassembled, thus providing access to certain partial plates or partial plate layers of the magnetic coil.

[0074] In the event of a local defect (for example, a poorly conductive area in a superconducting conductor or a damaged area in the insulation around a conductor) in the magnet coil, the affected partial plate layer in the affected section can be removed and replaced with a new (undamaged) partial plate layer. If necessary, a repair can also be carried out in the affected plate layer while this partial plate layer is removed, for example, by replacing a section of the conductor in a groove of the partial plate layer. In particular, it is not necessary to replace the entire magnet coil. This can result in significant cost savings. This applies both in the case of a manufacturing defect in the partial plate layer and in the case of damage to the partial plate layer that occurs during operation.

[0075] Each layer of plates is ring-shaped, meaning it is completely closed around its entire circumference. The partial layers of plates from the different sections are joined together at the plate-layer joints. Note that the plate layers do not necessarily have to be ring-shaped; usually, when viewed from above (along a "central" stacking direction), the plate layers are approximately oval or D-shaped. The plate layers can be flat.

[0076] Gauss Fusion GmbH 16.10.2025 SP14052PCT may be trained (for a tokamak coil), but they may also be untrained (usually for a stellarator coil).

[0077] The plate-layer joints can each be formed within the respective plate layer, particularly within a uniform plate height (measured along the local stacking direction). The conductor joints and the mechanical connection between the end plates of a respective plate-layer joint can be formed within the load-bearing line of the magnet coil (for special embodiments of the plate-layer joints, see below). The plate-layer joints—and thus also the stack joints—do not need to extend beyond the load-bearing line, and no special flanges are required on the stack joints. Overall, a particularly compact magnet coil design can be achieved.This makes it easier to integrate a magnetic coil according to the invention into stellarators, tokamaks or other applications (e.g., NMR measuring instruments or detectors in high-energy physics) for the superconducting magnetic coil.

[0078] In case a), the corresponding stack end is the aforementioned single stack end ("single access side") for all partial plate layers of the insertion section. In case b), the corresponding stack end is the first stack end ("first access side") for the first part of the partial plate layers, and the second stack end ("second access side") for the second part of the partial plate layers. The first part of the partial plate layers forms a first substack, and the second part of the partial plate layers forms a second substack, with the two substacks abutting each other at their narrow, innermost ends.

[0079] A typical number of plate layers in the plate-layer stack ranges from 4 to 20. A typical number of slots in a subplate (corresponding to the number of turns within a plate layer) ranges from 4 to 20. The superconducting conductor is typically a compound conductor comprising a multitude of superconducting wires (e.g., 100 or more bundled wires) or a multitude of superconducting tapes (e.g., 100 or

[0080] Gauss Fusion GmbH 16.10.2025 SP14052PCT (more bundled and / or stacked tapes), designed for a total operating current of 10 kA or more. The conductor may, in particular, be configured as a CICC (cable in conduit conductor). The conductor may, in particular, have a circular cross-section; alternatively, the conductor may also have a rectangular or square cross-section. The conductor may contain LTS material. Alternatively, the conductor may contain HTS material (typically supplied with superconducting tapes).

[0081] Preferred embodiments of the invention

[0082] In a particularly preferred embodiment of the magnetic coil according to the invention, it is provided that

[0083] that in the stack joints belonging to the at least one insertion section, the end plates of the insertion section and the end plates of the section connected to the insertion section at the stack joint are detachably fastened to one another at each plate-layer joint, and the conductor joints are detachably electrically contacted, wherein the loosening of this fastening and the loosening of these electrical contacts of the conductor joints can be carried out from the associated stack end according to a) or b). The detachable fastenings and electrical contacts (i.e., which can be removed and re-established without damage) enable simple temporary disassembly of the magnet coil (separation of the magnet coil at the stack joints), particularly for repair or maintenance purposes.The releasable fastenings and contacts are typically based on screw connections and / or clamp connections, and the screws and clamping elements (e.g., wedges) are then accessible from the associated stack end according to a) or b) or can at least be loosened from the associated stack end according to a) or b) so that the fastenings and contacts can be released (without prejudice to any necessary prior removal of more outwardly located partial plate layers of the insertion section). In general, it is preferably provided for all stack joints that at a respective plate layer joint, the end partial plates of the first section and the end partial plates of the...

[0084] Gauss Fusion GmbH 16.10.2025 SP14052PCT second section are detachably attached to each other and the conductor joints are detachably electrically contacted.

[0085] Another possible embodiment involves sections comprising multiple insertion sections. In this case, the magnetic coil can be subdivided or disassembled into even smaller units, particularly sections and partial plate layers. This further simplifies handling, especially by industrial robots. Each insertion section can be assembled and, if necessary, disassembled independently. In the ring-shaped plate layer stack, at least one other section is typically located between each pair of insertion sections.

[0086] One advantageous embodiment provides that

[0087] that the sections continue to include at least one intermediate section and one connecting section, wherein the intermediate section follows the insertion section in the ring-shaped plate layer stack, and the connecting section follows the intermediate layer,

[0088] where at the stack joint that connects the intermediate section to the connecting section,

[0089] i') the plate layer joints are arranged offset from each other with respect to the local longitudinal direction, and

[0090] ii') in the plate-layer stack with respect to the associated stack end face according to a) or b) of the insertion section followed by the intermediate section, the plate-layer joints of more inner plate layers do not overlap with the partial plates of more outer plate layers of the connection section. In this case, after mounting the intermediate section (on the connection section), the insertion section can then be mounted. Conversely, after dismounting the insertion section, the intermediate section can also be dismounted (leaving the connection section in place). In this case, the magnetic coil can again be subdivided or disassembled into even smaller units, in particular sections and partial plate layers. This further simplifies handling, especially by industrial robots. Preferably, the stack joint connecting the intermediate section to the connection section

[0091] Gauss Fusion GmbH 16.10.2025 SP14052PCT provides that at each plate layer joint the end-side sub-plates of the intermediate section and the end-side sub-plates of the connection section are detachably fastened to one another and the conductor joints are detachably electrically contacted, wherein the loosening of this fastening and the loosening of the electrical contacts of the conductor joints can be carried out from the associated stack end side according to a) and b) (the insertion section to which the intermediate section follows).

[0092] In an advantageous embodiment, the insertion section features a decreasing length of the partial plate layers, measured along the local longitudinal direction into the plate stack from only one stack end, towards the next inner plate layer. This corresponds to case a) above. In this case, the plate layer joints of the insertion section have a stepped profile across the plate layers at each stack joint, extending from the single stack end, and the insertion section has a tapered, trapezoidal profile across all plate layers. Assembly and / or disassembly of the insertion section can be performed from only one stack end ("one-sided access"). This is often particularly easy to implement structurally.

[0093] In another advantageous embodiment, in the insertion section, the length of the partial plate layers, measured from a first stack end for a first portion of the partial plate layers and from a second, opposite stack end for a second, remaining portion of the partial plate layers, decreases along the local longitudinal direction into the plate layer stack towards the next inner plate layer. This corresponds to case b) above. In this case, the plate layer joints of the insertion section have a (lying) V-shaped profile across the plate layers, and the insertion section has a chalice-shaped (or double-trapezoidal) profile across all plate layers, with a constriction in the middle.The insertion section is assembled and / or disassembled from both ends of the stack ("two-sided access"), which allows the extension of the stack joints along the local longitudinal direction to be kept small, approximately half as large as in the case of one-sided access.

[0094] Gauss Fusion GmbH 16.10.2025 SP14052PCT A preferred embodiment provides that different types of superconducting conductor are installed within at least one plate layer of the plate layer stack, such that at at least one plate layer joint of the plate layer, different types of superconducting conductor are electrically contacted with each other at at least one conductor joint.

[0095] in particular where

[0096] - the superconducting conductor in a first section and the superconducting conductor in a second section are partially or completely of different types; and / or

[0097] - in at least one section or all sections within a respective sub-layer of the plate, the superconducting conductor in a radially inner part of the slots and the superconducting conductor in a radially outer part of the slots are of different types. A different type of conductor can be due, in particular, to different sizes (especially cross-sectional areas) of the conductors and / or different superconducting materials in the conductors. For example, one installed type of conductor may be an HTS, and another installed type may be an LTS. Different types of conductors generally have different magnetic field resistance and different procurement costs, with higher magnetic field resistance usually being associated with higher costs.In this embodiment, the type of superconductor can be particularly easily adapted to the magnetic field strength occurring (or required) at the respective location within the magnet coil ("conductor grading"), thereby saving costs or optimizing the force distribution. In the case of nuclear fusion devices with a toroidal plasma volume, the magnetic field strength is unevenly distributed around the circumference of a magnet coil that poloidally surrounds the plasma volume (and thus across the successive sections along the circumference); the magnetic field strength is significantly higher on the side facing the center of the torus than on the side facing away from the center. Accordingly, conductors with lower magnetic field resistance, and therefore lower costs, can be used on the side facing away from the center of the torus than on the side facing the center. Furthermore, the magnet coil is generally contained within a ring-shaped plate layer.

[0098] Gauss Fusion GmbH 16.10.2025 SP14052PCT The magnetic field strength is higher radially inside than radially outside. Accordingly, less expensive conductors with lower magnetic field resistance can be used in radially outside slots than in radially inside slots.

[0099] Another advantageous embodiment features several clamps distributed and spaced apart around the circumference of the magnetic coil, which clamp the plate layers against each other, particularly in a releasable manner. This allows the stack of plate layers to be held together simply and with minimal material waste. The clamps also allow for the independent clamping of individual plate layers within each section. The clamps are typically releasable via screws and / or nuts.

[0100] In an advantageous further development of this embodiment, it is provided that the sub-plates are designed as support sub-plates, wherein, for a respective support sub-plate in cross-section perpendicular to the local longitudinal direction, the following applies to an area SF occupied by support material of the support sub-plate and an area LF occupied by the conductor in the grooves:

[0101] SF / (SF+LF)>0.50, preferably SF / (SF+LF)>0.67,

[0102] and that the support plates and the clamps together form a support structure for the magnetic coil, suitable for mechanically stabilizing the magnetic coil under the influence of magnetic forces on the conductor during operation. The support plates have a particularly high proportion of support material (usually steel) in their cross-section compared to the conductor, and are therefore particularly dimensionally stable. The support plates, including their ring connections (circumferentially) within the plate layers and the stacking of the plate layers held together by the clamps (typically clamped in the local stacking direction), sufficiently counteract the magnetic forces during operation to reduce deformations to an acceptable level and to guide the conductors securely in the slots.A housing enclosing the stack of plates (which would also make mounting and dismounting the magnetic coil more difficult) for mechanical stabilization can be dispensed with; instead, the stack of plates can be...

[0103] Gauss Fusion GmbH 16.10.2025 SP14052PCT can be arranged directly in a cryostat of the nuclear fusion facility. The overall design of the magnetic coil is simplified, and assembly and, if necessary, disassembly can be carried out with minimal effort.

[0104] A particularly preferred embodiment is one in which each sub-plate has exactly one row of grooves arranged consecutively in the local transverse direction. Typically, the grooves of this single row are open to the same side (stacking end) of the sub-plate, regardless of any cover that may be closing a particular groove. This design simplifies the setup and, if necessary, the disconnection of electrical contacts at the conductor joints from a specific access side (stacking end).

[0105] In a preferred embodiment, it is provided that

[0106] that at each plate layer joint at each conductor joint, an end section of the conductor of the first section and an end section of the conductor of the second section overlap along the local longitudinal direction,

[0107] and that a joint clamping device is present, with which a clamping force is exerted transversely to the local longitudinal direction, at least on the overlapping end sections. This design enables contact reinforcement of the overlapping end sections through transverse pressure. In the overlap area of ​​the end sections, current flow between the conductors of the conductor joint is easily possible. The joint clamping devices allow the overlapping end sections to be pressed together (directly or indirectly, e.g., via interface elements inserted between the end sections). Note that the conductor joints are usually resistant (typically with an ohmic resistance of 2 nΩ or less at each conductor joint). Applying the clamping force transversely to the (local) longitudinal direction of the conductors at the conductor ends simplifies (reversible) setup and release of the electrical contact from a specific access side (stack end).

[0108] Gauss Fusion GmbH 16.10.2025 SP14052PCT An advantageous further development of this embodiment is provided that in a respective conductor joint, the end section of the conductor of the first section is chamfered with a first cut surface and the end section of the conductor of the second section is chamfered with a second cut surface, wherein the cut surfaces are oriented obliquely to a direction of a longitudinal extension of the respective conductor, and the cut surfaces have the same chamfer angles o relative to the direction of the longitudinal extension.

[0109] and that the two cut surfaces are arranged parallel to each other and facing each other. This design (also called a "scarf joint") allows for low-resistance current flow between the conductors at the conductor joints in a small installation space. Furthermore, this design also makes it easy to align cooling channels for the conductors at opposite conductor ends. The direction of the conductor's longitudinal extension corresponds to the local longitudinal direction.

[0110] Another preferred embodiment provides that in each conductor joint, the joint clamping device comprises at least one joint clamping element which is pressed against at least one of the overlapping conductors, in particular wherein the joint clamping element is screwed in place. This is structurally simple and robust, and also easy to handle during assembly and disassembly. Reversible assembly and disassembly are also easily possible.

[0111] In a preferred embodiment, several grooves are formed at each plate layer joint in the end-side sub-plate of the first section, in which conductors are each inserted, and several grooves are formed in the end-side sub-plate of the second section, in which conductors are each inserted.

[0112] and that the two end plates are detachably fastened to each other with an overlapping connection. This allows a large number of conductor joints (corresponding to the number of slots) to be set up and, if necessary, disconnected essentially at the same time. This makes assembly and, if necessary, disassembly particularly quick.

[0113] Gauss Fusion GmbH 16.10.2025 SP14052PCT A further development of this embodiment is preferred, which provides that the end-side partial plate of the first section and the end-side partial plate of the second section are screwed together, wherein screws run at least in some spaces between successive grooves along the local transverse direction,

[0114] In particular, end-face sub-plates of a sub-plate layer, which are involved in forming plate layer joints, have a greater plate width JPB at their end facing the plate layer joint, measured along the local transverse direction, than a normal plate width NPB present at their end facing away from the plate layer joint, and / or which is present in a majority of the sub-plates of the associated plate layer. The screw connection is easy to set up. By increasing the plate width JPB ("joint plate width") at the joint-side end and correspondingly increasing the distance (in the local transverse direction) between the grooves there, additional space can be created for screwing the end-face sub-plates (or also for screwing joint clamping elements), and a particularly robust structure is achieved.However, it is also possible to apply a uniform plate width to the sub-plates in a given plate layer or in the entire plate layer stack (so to speak with JPB=NPB).

[0115] A further preferred embodiment is one in which, in the area of ​​the overlap joint, the end plates each have an exposed end in which the grooves are open towards the other end plate, wherein at least one projection and one recess are formed at the exposed end, and wherein a projection of each end plate is hooked into a recess of the other end plate. The hook-in connection is simple and robust to install.

[0116] An advantage here is a wedge element in the recess of the end-side partial plate of the first section between the projection of the partial plate of the second section and an unexposed section of the end-side partial plate of the first section.

[0117] Gauss Fusion GmbH 16.10.2025 SP14052PCT The wedge element clamps the interlocked sub-plates so that the projections of the two end plates are pressed against each other, and / or vice versa. The wedge element clamps the interlocked sub-plates together, ensuring that the pressed projections remain in contact under both tensile and (not excessive) compressive loads at the plate layer joint. This provides particularly precise mechanical stabilization for the conductors in the grooves. The wedge element is preferably inserted from the access side (stacking end side according to a) or b) above); however, alternatively or additionally, a wedge element can also be inserted from the opposite side, as long as it can be pressed in and, if necessary, loosened from the access side to secure and, if necessary, release the interlocking connection.

[0118] Inventive magnetic coil arrangements

[0119] The present invention also includes a magnetic coil arrangement, in particular a stellarator or a tokamak, for a nuclear fusion device,

[0120] wherein the magnetic coil arrangement is suitable for the magnetic confinement of at least an essentially toroidal plasma volume,

[0121] wherein the magnetic coil arrangement comprises a plurality of magnetic coils, in particular stellarator coils or tokamak coils,

[0122] wherein the magnetic coils are arranged in a toroidal direction of the plasma volume,

[0123] wherein the magnetic coils locally enclose the toroidal plasma volume in a ring shape,

[0124] and wherein at least one of these magnetic coils is designed according to the invention as described above. Preferably, all said magnetic coils (generally stellarator coils or tokamak coils) are designed according to the invention, which considerably simplifies their assembly and, if necessary, disassembly as well as their maintenance. If only one or a few (typically adjacent) magnetic coils are designed according to the invention, these are typically removable (with detachable

[0125] Gauss Fusion GmbH 16.10.2025 SP14052PCT (bar plate layer joints, see above). Easy access to the plasma vessel for maintenance work can be obtained at this point.

[0126] Inventive methods for manufacturing, assembling and disassembling magnetic coils

[0127] The present invention also includes a method for manufacturing a magnetic coil according to the invention as described above,

[0128] which is characterized by

[0129] that the partial plate layers are each manufactured by the following steps: 51) the partial plates of the partial plate layer are arranged successively and fastened to one another, wherein the grooves of the partial plates are aligned, and wherein no conductors are yet arranged in the grooves of the partial plates, in particular wherein butt joints of the partial plates are welded together;

[0130] 52) A piece of a superconducting conductor, the length of which corresponds to the length of the groove of the partial plate layer along the local longitudinal direction, is inserted into each of the grooves of the partial plate layer;

[0131] and that the magnetic coil is assembled from the partial plate layers manufactured in this way. For the production of the partial plate layers, and thus for equipping the magnetic coil according to the invention with the superconducting conductor, only sections of the conductor are required that are significantly shorter than the circumference of the magnetic coil. In particular, a continuous, defect-free conductor is not required over many or all turns of the plate layer or even the entire magnetic coil. This significantly reduces the procurement costs of the conductor (per length). Furthermore, the conductor can simply be inserted into the grooves of the partial plate layers in short sections, and the conductor does not need to be wound over a large number of turns (circles around the circumference of the plate layer or the magnetic coil) using complex tools. Preferably, the partial plates of a partial plate layer are welded together at their joints (end faces).For this purpose, a rib can initially remain at the ends of the grooves at the joints, so that during welding the joints (end faces) of the partial plates are still intact / groove-free (usually corresponding to a complete rectangle). This allows for a particularly...

[0132] Gauss Fusion GmbH 16.10.2025 SP14052PCT Stable welding of the joints is achieved. Subsequently, the webs can be removed (e.g., milled away), resulting in continuous grooves in the partial plate layer. The conductor sections can then be inserted into these continuous grooves.

[0133] The present invention also includes a method for assembling a magnetic coil according to the invention as described above, wherein the magnetic coil comprises at least one insertion section and at least one further section.

[0134] the procedure provides for,

[0135] that the next section is provided first, in particular wherein the partial plate layers of at least one further section are stacked next to each other,

[0136] and that subsequently the partial plate layers of the at least one insertion section are added, wherein, with respect to the associated stack end face according to a) or b), partial plate layers located further inside the plate layer stack are added before those located further outside, thereby obtaining the complete magnetic coil. The addition of the partial plate layers of the insertion section to the (at least one) provided further section takes place (with respect to the stacking) from the inside (bottom) to the outside (top), whereby the plate layer joints to be established in the process are accessible at the (resulting) stack joints belonging to the insertion section.

[0137] The present invention also includes a method for disassembling a magnetic coil according to the invention as described above, wherein the magnetic coil comprises at least one insertion section and at least one further section.

[0138] the procedure provides for,

[0139] that, starting from the complete magnetic coil, the partial plate layers of the at least one insertion section are first disassembled, wherein, with respect to the associated stack end side according to a) or b), partial plate layers located further out in the plate layer stack are removed before those located further inwards

[0140] Gauss Fusion GmbH 16.10.2025 SP14052PCT Partial plate layers are disassembled, leaving at least one further section of the magnetic coil,

[0141] In particular, the partial plate layers of at least one further coil section are then destacked. The removal of the partial plate layers of the insertion section from the (at least one) remaining further section is carried out (with respect to the stacking) from the outside (top) to the inside (bottom), whereby the plate layer joints to be separated in the process are accessible at the stack joints (being dismantled) belonging to the insertion section.

[0142] 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.

[0143] Detailed description of the invention and drawing

[0144] Fig. 1 shows an exemplary embodiment of a magnetic coil according to the invention with an insertion section and a further section, in the assembled state, in a schematic perspective view;

[0145] Fig. 2 shows the magnetic coil of Fig. 1, with separate sections, in a schematic perspective view;

[0146] Fig. 3 shows a stacked joint of the magnetic coil from Fig. 1, in a schematic perspective view;

[0147] Fig. 4 shows an example of a connection between the end-side sub-plates of two sub-plate layers at a plate layer joint, at which

[0148] Gauss Fusion GmbH 16.10.2025 SP14052PCT four conductor joints are set up, with still separate sub-plates, in a schematic perspective view, for the invention;

[0149] Fig. 5 shows the connection of Fig. 4 with connected partial plates;

[0150] Fig. 6 shows an example of a conductor joint with beveled cut surfaces, in a schematic longitudinal section, for the invention;

[0151] Fig. 7 shows an example of a conductor joint in cross-section (perpendicular to the local longitudinal direction) with a screwed joint clamping element, for the invention;

[0152] Fig. 8 illustrates in a schematic longitudinal section an insertion section and its associated stacking joints in case a) (length of the sub-plate layers decreases from only one stacking end side), for the invention;

[0153] Fig. 9 illustrates in a schematic longitudinal section an insertion section and its associated stacking joints in case b) (length of the sub-plate layers decreases from two stacking end sides), for the invention;

[0154] Fig. 10 illustrates in a schematic longitudinal section an insertion section, an intermediate section and part of a connecting section and their associated stacking joints in case a), for the invention;

[0155] Fig. 11 illustrates in a schematic longitudinal section a first insertion section, a second insertion section and another section in between, for the invention;

[0156] Fig. 12 illustrates in a schematic perspective view a sequence of three sub-plates in a plate layer, wherein three types of sub-plates are installed, for the invention;

[0157] Gauss Fusion GmbH 16.10.2025 SP14052PCT Fig. 13 illustrates an exemplary embodiment of a magnetic coil arrangement according to the invention, in a schematic top view;

[0158] Fig. 14 illustrates the magnetic coil arrangement of Fig. 13 in a schematic cross-section;

[0159] Fig. 15 illustrates an exemplary partial plate layer for the invention in a schematic oblique view, in which different types of conductors are installed;

[0160] Fig. 16 illustrates an exemplary embodiment of a magnetic coil according to the invention in a schematic oblique view, in which different types of conductors are installed in the two sections;

[0161] Fig. 17 shows by way of example the production of a partial plate layer in a variant according to the invention in a schematic top view, with still separate partial plates;

[0162] Fig. 18 shows the partial plate layer of Fig. 17, with adjacent and welded joints;

[0163] Fig. 19 shows the partial plate layer of Fig. 18, after removal of the webs;

[0164] Fig. 20 shows the partial plate layer of Fig. 19, with inserted conductors.

[0165] Fig. 1 shows a schematic perspective view of an exemplary magnetic coil 1 according to the invention. In the embodiment shown, the magnetic coil 1 comprises an insertion section ES and a further section WS.

[0166] The magnetic coil 1 is designed here as a 3D-shaped stellarator coil. The magnetic coil 1 is closed in a ring shape. The magnetic coil 1 rotates around

[0167] Gauss Fusion GmbH 16.10.2025 SP14052PCT a coil axis 2. The magnetic coil 1 is neither planar nor circular-ring shaped (but approximately D-shaped). The magnetic coil 1 can contribute to a magnetic field with which an approximately toroidal plasma volume can be confined in a stellarator (see Fig. 13 and Fig. 14).

[0168] The magnetic coil 1 comprises several plate layers 3, which are stacked approximately along the coil axis 2 and thereby form a plate layer stack 4 (in Fig. 1, for the sake of simplicity, the plate layers 3 are only marked at some points).

[0169] Each plate layer 3 comprises a plurality of sub-plates 5 (some sub-plates 5 for the uppermost plate layer are marked in Fig. 1), which are connected to one another in a ring-like fashion, e.g., welded together (notwithstanding the plate layer joints, where typically detachable connections are provided, see e.g., Fig. 4 and Fig. 5). Note that the sub-plates 5 also form sub-plate stacks 62 of sub-plates 5 (one such sub-plate stack 62 is shown in Fig. 1 with all boundaries between the sub-plates 5), and the plate layer stack 4, in the circumferential direction of the magnet coil 1, is essentially composed of a sequence of such sub-plate stacks 62. In other words, the ends of superimposed sub-plates 5 (insofar as they are not involved in plate layer joints 6) are aligned here. The transitions 63 between such partial plate stacks 62 are shown in Fig. 1 and marked in some places.Within a stack of sub-plates 62, the sub-plates 5 are of the same type (type 1, 2 or 3, see Fig. 12).

[0170] Each subplate 5 has a plurality of grooves 16 extending along a local longitudinal direction LLR and arranged in a row along a local transverse direction LQR (two grooves 16 are marked as examples in Fig. 1). A superconducting conductor runs in each of the grooves 16 (not shown in detail in Fig. 1, but see, for example, Fig. 4 and Fig. 12). The local stacking direction LSR of the plate layers 3 runs perpendicular to the local longitudinal direction LLR and the local transverse direction LQR.

[0171] Gauss Fusion GmbH 16.10.2025 SP14052PCT The plate-layer stack 4 comprises two sections: an insertion section ES and another section WS. Each section ES, WS forms part of the perimeter of the plate-layer stack 4. The sections ES, WS are connected to each other at a first stack joint SJ1 and a second stack joint SJ2.

[0172] Each stack joint SJ1, SJ2 comprises in each plate layer 3 a plate layer joint 6, at which the conductors from the respective plate layer 3 from two opposing, end-face sub-plates 9 are electrically connected (contacted) to each other and these end-face sub-plates 9 are attached to each other (more on this also in Fig. 4 to Fig. 7).

[0173] Fig. 2 shows the magnetic coil 1 from Fig. 1 with sections ES and WS separated from each other. It should be noted here that in the separated state of sections ES and WS, the insertion section ES is typically unstacked; however, Fig. 2 shows the insertion section ES stacked for illustrative purposes.

[0174] The insertion section ES forms a stack 7 of partial plate layers 8, and the further section WS forms a stack 7 of partial plate layers 8. Each partial plate layer 8 consists of the (sequentially connected) partial plates of the associated plate layer 3, which belong to the respective section ES, WS. In the assembled state (see Fig. 1), the stack 7 of partial plate layers 8 of the insertion section ES is connected at the two stack joints (SJ1, SJ2 in Fig. 1) to the stack 7 of partial plate layers 8 of the further section WS; each stack joint (SJ1, SJ2 in Fig. 1) is formed by the entirety of one plate layer joint 6 in each plate layer 3.

[0175] Each partial plate layer 8 comprises at each of its ends a terminal partial plate 9, on which a portion of a plate layer joint 6 is formed. The plate layer joint 6 provides electrical contact for the conductors in the terminal partial plate 9 of the partial plate layer 8 of a first section, here e.g.

[0176] Gauss Fusion GmbH 16.10.2025 SP14052PCT of the insertion section ES, to which the conductor in an opposite, terminal subplate 9 of a partial plate layer 8 of an adjoining second section, here e.g. the further section WS, is connected. The terminal subplate 9 of the second section WS forms a remaining part of the plate layer joint 6. In addition, the plate view joint 6 establishes a mechanical connection between the opposite terminal subplates 9 of the two partial plate layers 8.

[0177] In the embodiment shown in Fig. 2, the plate layer joints 6 (insofar as they are formed in the insertion section ES) are progressively recessed from the outside inwards, starting from a first stack end SEI and a second stack end SE2, so that the outermost plate layer joints 6 project beyond the innermost plate layer joints 6. Accordingly, in the insertion section ES, the lengths (along the local longitudinal direction LLR) of the innermost partial plate layers 8 are also shorter than the lengths of the outermost partial plate layers (see Figs. 8 and 9 for more details). This results in a stepped, approximately V-shaped, concave profile at the ends of the insertion section ES.

[0178] Conversely, the further section WS has a stepped, approximately V-shaped, plug-like (convex) profile.

[0179] As shown in Fig. 3 at the stack joint SJ1, in the illustrated embodiment, the width of the end-end partial plates 9 (measured in the local transverse direction LQR) varies along the local longitudinal direction LLR. This is explained by way of example with reference to the left-hand end-end partial plate 9a of the uppermost plate layer 3 in Fig. 3.

[0180] At the end facing away from the plate layer joint 6, the end-facing subplate 9a has a normal plate width NPB, which corresponds to the width of the subplates furthest from the plate layer joints 6. At the end facing the plate layer joint 6

[0181] Gauss Fusion GmbH 16.10.2025 SP14052PCT At the end, the end-facing sub-plate 9a has a larger plate width JPB, also called joint plate width. Therefore, JPB > NPB. The two end-facing sub-plates 9a, 9b overlap in the area of ​​the plate layer joint 6 (more on this in Fig. 4 and Fig. 5).

[0182] Due to the larger plate width JPB, it is possible to install screw connections 10 in the area of ​​the plate layer joint 6 with respect to the local transverse direction LQR between the grooves and without affecting the conductors in the grooves, with which the upper end-side partial plate 9a (left in Fig. 3) and the lower end-side partial plate 9b (right in Fig. 3) can be fastened to each other.

[0183] Figure 3 shows the holes for the screws of the fasteners 10 (see also Fig. 5). Due to the greater plate width JPB, the fasteners 10 can be made particularly robust (large diameter). The fasteners 10 thus allow the two end plates 9a, 9b to be securely but reversibly fastened to each other. Note that in the illustrated embodiment, the fasteners 10 are partially guided directly through the end plates 9a, 9b and screwed into the other end plate 9b, 9a, and partially guided by or screwed into wedge elements (more details in Fig. 5).

[0184] Figures 4 and 5 illustrate an exemplary plate-layer joint 6, in which four conductor joints 11a-11d are set up. The setup of Figures 4 and 5 can also be used analogously for the plate-layer joints of Figures 1 to 3. Figure 4 shows the plate-layer joint 6 in a separated state, with the left end-side sub-plate 9a turned over for better visibility. Figure 5 shows the plate-layer joint 6 in the connected (hooked) state of the end-side sub-plates 9a and 9b and with the joint clamping elements mounted. The end-side sub-plate 9a belongs to a first section, here the insertion section ES, and the end-side sub-plate 9b belongs to a second section, here the further section WS.

[0185] Gauss Fusion GmbH 16.10.2025 SP14052PCT In the illustrated design, five fingers 12 are formed on the end-facing sub-plate 9a, extending along the local longitudinal direction LLR relative to the other sub-plate 9a. Each finger 12 has a recess 13 and a projection 14. A rear portion of the recesses 13 is occupied by a wedge element 24, which abuts an exposed section 17a of the sub-plate 9a. Between the fingers 12, the conductors 22 run with a chamfered end section 15 in a groove 16; the chamfered end sections 15 overlap approximately the length of a respective recess 13 in front of the wedge element 24. The area of ​​the fingers 12 forms an exposed end 17 of the sub-plate 9a, in which the grooves 16 are open towards the other sub-plate 9b.

[0186] The partial plate 9b forms a cantilever 18 that projects from a non-exposed section 28a of the partial plate 9b. Five projections 19 protrude from the cantilever 18 (pointing upwards in Fig. 4). Behind the projections 19, i.e., between the projections 19 and the non-exposed section 28a, recesses 20 are formed. A rear portion of the recesses 20 is occupied by a wedge element 27, which abuts the non-exposed section 28a (shown only in Fig. 5). Grooves 21 run along the local transverse direction LQR between the projections 19, in which conductors 22 are inserted. The angled end sections 23 of the ladder 22 overlap approximately the length of the respective projection 18. The area of ​​the projection 18 forms an exposed end 28 of the partial plate 9b, in which the grooves 16 are open towards the other partial plate 9a.

[0187] The end sections 15 and 23 are each chamfered, so that first cut surfaces 25 and second cut surfaces 26 are present. In the joined state, these cut surfaces face each other and are parallel to each other, and lie against each other (see Fig. 6).

[0188] The length of the projections 18 corresponds approximately to the length of the recesses 13 in front of the wedge element 24 along the local longitudinal direction LLR. The length of the

[0189] Gauss Fusion GmbH 16.10.2025 SP14052PCT Recesses 20 in front of the wedge element 27 correspond approximately to the length of the projections 14.

[0190] To connect the partial plates 9a and 9b, partial plate 9a with its projections 14 (with an orientation rotated relative to Fig. 4, i.e., an orientation as shown in Fig. 5) is hooked into the recesses 20 of partial plate 9b in front of the wedge element 27. Simultaneously, partial plate 9b with its projections 19 is hooked into the recesses 13 in front of the wedge element 24. At this stage, the wedge elements 24 and 27 are not yet positioned in their corresponding recesses 22 and 13, or at least not yet fully inserted. By pressing the wedge elements 24, 27, cf. the pressing directions 29a, 29b, between the projections 19, 14 and the unexposed sections 17a, 28a, the rear faces 30a, 30b of the projections 14, 19 of the sub-plates 9a, 9b are pressed against each other. Accordingly, the sub-plates 9a, 9b are pushed away from each other, but are clamped together due to the interlocking of the projections 14, 19.

[0191] The wedge elements 24, 27 are pressed in (clamped) and secured in their pressed-in position by means of some of the screws 10 (see the holes shown in Fig. 5). Wedge element 27 is clamped and secured with screws (not shown) that extend through wedge element 27 and are screwed into the sub-plate 9b in the area of ​​the recesses 20. Wedge element 24 is clamped and secured with screws (not shown) that extend through sub-plate 9a in the area of ​​the recesses 13 and are screwed into wedge element 24. This already achieves a certain degree of cohesion between sub-plates 9a, 9b.

[0192] Furthermore, several screw connections 10 are provided in the area of ​​the fingers 12, particularly in the middle fingers 12 and thus between the grooves 16, 21. The corresponding screws (not shown) protrude through the sub-plate 9a in the area of ​​the fingers 12 and are screwed into the sub-plate 9b in the area of ​​the projections 19. This also fastens the sub-plates 9a and 9b directly to each other.

[0193] Gauss Fusion GmbH 16.10.2025 SP14052PCT In the hooked position, the cut surfaces 25, 26 face each other and are in contact with one another. Cooling channels 31, 32 formed in the conductor 22 for a cooling fluid (e.g., helium) are aligned in this position (the cooling channels 31, 32 are clearly visible in Fig. 4; see also Fig. 6). To establish a close, low-resistance electrical contact between the cut surfaces 25, 26, joint clamping elements 33 are placed on the partial plate 9a between the fingers 12 in the illustrated design. Shoulders 35 are formed on the fingers 12 for the correct alignment of the joint clamping elements 33. The joint clamping elements 33 are tightened and secured by means of screws 34. Associated screws (not shown) extend through the joint clamping elements 33 and are screwed into the fingers 12 in the area of ​​their shoulders 35.This exerts a clamping force 36 perpendicular to the local longitudinal direction LLR and also perpendicular to the local transverse direction LQR on the overlapping end sections 15, 23 of the conductor 22, and the clamping force 36 presses the cut surfaces 25, 26 together (more on this in Fig. 6 and Fig. 7).

[0194] In the connected (hooked) state, the exposed ends 17, 28 of the two end-facing partial plates 9a, 9b overlap and thus cover each other. The partial plates 9a, 9b are connected by an overlap connection 61 that can be released via the screws 10. If the connection of the partial plates 9a, 9b is to be released, the joint clamping elements 33 are first released by means of the screws 34.

[0195] In the embodiment shown in Fig. 5, the plate-layer joint 6 can be connected and disconnected from the top side (corresponding to an access side), both with respect to the mutual fastening of the sub-plates 9a, 9b, and with respect to the electrical contacts in the conductor joints 11a-11d. Furthermore, in the embodiment shown, the plate-layer joint 6 (and correspondingly the associated stack joint) is integrated into a straight section of the magnet coil, which is preferred. Alternatively, plate-layer joints 6 or stack joints can also be integrated into curved sections of the magnet coil (not shown in detail).

[0196] Gauss Fusion GmbH 16.10.2025 SP14052PCT Fig. 6 shows in a schematic longitudinal section a conductor joint 11, as it can be used, for example, in the plate layer joint of Fig. 4 and Fig. 5.

[0197] The conductor 22 on the left in Fig. 6 (which here belongs to the insertion section ES or first section) has the chamfered end section 15 with a cross-sectional surface 25. The conductor 22 on the right in Fig. 6 (which here belongs to the further section WS or second section) has the chamfered end section 23 with the cross-sectional surface 26. The conductor 22 on the left and the conductor 22 on the right are aligned. Both cross-sectional surfaces 25, 26 have the same chamfer angle α (here approximately α = 12°) with respect to the local longitudinal direction LLR, which also corresponds to the longitudinal extent of the respective conductor 22. In the illustrated configuration, the cross-sectional surfaces 25, 26 lie directly adjacent to each other; alternatively, an interface element, for example an indium disk, can be arranged between the cross-sectional surfaces 25, 26 (the latter not shown in detail). The (central) cooling channels 31, 32 of the conductor 22 are aligned, with a hydraulically tight flange connection of the cooling channels 31, 32 being established.

[0198] A clamping force 36 can be exerted by a joint clamping device 37, which here presses the end sections 15, 23 together in a clamping direction perpendicular to the local longitudinal direction LLR and perpendicular to the local transverse direction (the local transverse direction is perpendicular to the plane of the drawing). This causes the cut surfaces 25, 26 to be pressed towards each other (with a force component). This results in a low-resistance transfer of the electric current between the end sections 15, 23 of the two conductors 22.

[0199] If desired, the conductor 22 of the insertion section ES (left) can be of a first type 22a, and the conductor 22 of the further section WS (right) can be of a second, different type 22b. The conductor 22a of type 1 can, for example, contain Nb3Sn, and the conductor 22b of type 2 can, for example, contain NbTi. Alternatively, combinations of LTS (such as Nb3Sn) and HTS (such as ReBCO) are also possible. The conductor of the first type 22a and the conductor of the second type 22b can, if desired, also have different cross-sectional areas (in particular, different diameters); in the case of a scarf

[0200] Gauss Fusion GmbH 16.10.2025 SP14052PCT joints: preferably, at least one of the conductors 22 is plastically deformed in its end section 15, 23 such that the cross-section there corresponds to the cross-section of the other conductor 22 in its end section 15, 23 (e.g., a larger conductor 22 can be drawn to a smaller diameter in its end region 15, 23) (not shown in detail). By means of one or more conductor joints 11 that connect different types 22a, 22b of conductors 22, it is possible to install different types 22a, 22b of conductors 22 within a single layer of plates, or to change the conductor type between layers of plates (in which case a corresponding conductor joint 11 is usually located on a radially innermost or outermost turn of the layer of plates).However, it is also possible (and more common) that the conductors 22 of the insertion section ES (or generally first section) and the subsequent section WS (or generally second section) at a conductor joint 11 are of the same type. For plate layers and sections with different types 22a, 22b of conductors, see also Fig. 15 and Fig. 16.

[0201] Note that within the scope of the invention, conductor joints can also be used that are not constructed as scarf joints, for example overlap joints with conductor ends arranged parallel to each other in an overlap area, offset to each other with respect to the local transverse direction, but towards adjacent conductor ends.

[0202] Fig. 7 shows a section through the conductor joint 11, as shown in Fig. 6 at section plane AA; in addition, the associated end-side partial plates 9a, 9b are also shown here.

[0203] The partial plate 9b forms the groove 21 in which the end section 15 is inserted; the shape of the groove 21 corresponds to the shape of the conductor 22 (here round). The partial plate 9a forms the groove 16 into which the end section 23 projects. The groove 16 is largely occupied by a joint clamping element 33, which forms a contour 33a corresponding to the shape of the conductor 22 (here round). The end section 23 rests against this contour 33a. In the clamped state, the joint clamping element 33 of the joint clamping device 37 in Fig. 7 presses down on the end section 23 from above.

[0204] Gauss Fusion GmbH 16.10.2025 SP14052PCT The joint clamping element 33 is screwed and clamped by means of screws 39 of the screw connections 34. The screws 39 protrude through the joint clamping element 33 and are screwed into the partial plate 9a in the area of ​​the shoulders 35.

[0205] In the jammed position, the coolant channels 31, 32 in the ladders were aligned.

[0206] Note that the plate layer joints 6 and conductor joints 11 can be designed within the scope of the invention as described in the published German patent application 10 2024 125 717.2.

[0207] Figure 8 schematically illustrates, in a longitudinal section, a section of the stack of plates 4 of an exemplary embodiment of a magnetic coil 1 according to the invention. For ease of understanding, the magnetic coil 1 is shown in a planar projection in the section shown (as if unrolled and straightened). The longitudinal section lies along the local longitudinal direction LLR and along the local stacking direction LSR. The local transverse direction LQR, along which the grooves in the individual plates are arranged, lies perpendicular to the plane of the drawing (this also applies to Figures 9, 10, and 11).

[0208] In the embodiment of Fig. 8, a section is shown with an insertion section ES and partial sections of two adjacent (i.e., adjoining) further sections WS1, WS2.

[0209] Note that in the simplest case, the illustrated sections of the first (left) further section WS1 and the second (right) further section WS2 can belong to the same, single further section of the magnet coil (as shown in Fig. 1 and Fig. 2) (this also applies accordingly to Figures 9, 10 and 11 for the right and left outermost sections).

[0210] Gauss Fusion GmbH 16.10.2025 SP14052PCT In sections ES, WS1, WS2, or their subsections, the partial plate layers 8a-8e, 43a-43e, 44a-44e are shown connected in Fig. 8. In other words, the partial plates from which the partial plate layers 8a-8e, 43a-43e, 44a-44e are formed are not shown separately (see Fig. 12 for details). The plate layer joints 6 are simplified here by only two overlapping partial plate ends 41, 42; a typical configuration of plate layer joints 6 can, for example, include an interlock (see Fig. 4 and Fig. 5 for details) (this also applies to Figures 9, 10, and 11).

[0211] The insertion section ES, in the embodiment shown in Fig. 8, is of type a). The stack 7 of partial plate layers 8a-8e of the insertion section ES can be assigned two stack end faces with respect to the local stacking direction LSR: an upper stack end face OSE (shown in Fig. 8) and a lower stack end face USE (shown in Fig. 8). The upper stack end face OSE is also referred to here (in the case of type a, which is presented here) as the access face ZU.

[0212] The outermost partial plate layer 8a, with respect to the upper stack end face OSE, has a length L8a along the local longitudinal direction LLR; it is the longest partial plate layer 8a in the insertion section ES. The second outermost partial plate layer 8b has a length L8b that is shorter than L8a. The third outermost partial plate layer 8c has a length L8c that is shorter than L8b, and so on. The lengths L8a-L8e of all partial plate layers 8a-8e of the insertion section ES decrease progressively into the stack 7 of partial plate layers (from the outside in, along the common sequence direction AR from the upper stack end face OSE / access side ZU into the stack 7). The innermost partial plate layer 8e, with respect to the upper stack end face OSE, has the shortest length L8e in the insertion section ES.

[0213] The insertion section ES is connected on the left via the first stack joint SJ1 to the first further section WS1, and on the right via the second stack joint SJ2 to the second further section WS2.

[0214] Gauss Fusion GmbH 16.10.2025 SP14052PCT The first stack joint SJ1 comprises five plate layer joints 6a-6e, one in each plate layer 3a-3e. The plate layer joints 6a-6e are arranged in a step-like arrangement relative to each other with respect to the local longitudinal direction LLR. The plate layer joint 6b of the second outermost plate layer 3b with respect to the upper stack end face OSE (or the common sequence direction AR) is positioned such that the partial plate layer 43a of the first further section WS1 of the next outermost plate layer 3a (or its partial plates) does not overlap with the plate layer joint 6b. In particular, the partial plate end 42 of the partial plate layer 43a also does not overlap with the plate layer joint 6b.Furthermore, the plate layer joint 6c of the third outermost plate layer 3c with respect to the upper stack end face OSE is positioned such that the partial plate layer 43b of the first further section WS1 of the next outermost plate layer 3b (or its partial plates) does not overlap with the plate layer joint 6c, and so on.

[0215] The second stack joint SJ2 is constructed analogously. The plate layer joints 6a-6e are arranged in a step-like arrangement relative to each other with respect to the local longitudinal direction LLR. The plate layer joint 6b of the second outermost plate layer 3b with respect to the upper stack end face OSE (or the common sequence direction AR) is positioned such that the partial plate layer 44a of the second further section WS2 of the next outermost plate layer 3a (or its partial plates) does not overlap with the plate layer joint 6b. In particular, the partial plate end 42 of the partial plate layer 44a also does not overlap with the plate layer joint 6b. Furthermore, the plate layer joint 6c of the third outermost plate layer 3c with respect to the upper stack end face OSE is positioned such that the partial plate layer 44b of the second further section WS2 of the next outermost plate layer 3b (or its partial plates) does not overlap with the plate layer joint 6c, and so on.

[0216] This design allows all partial plate layers 8a-8e to be mounted sequentially from the upper stack end OSE / access side ZU when assembling the insertion section ES into the already existing (previously stacked) sections WS1 and WS2. The innermost partial plate is then mounted first.

[0217] Gauss Fusion GmbH 16.10.2025 SP14052PCT The sub-layer 8e is mounted to the sub-layers 43e and 44e; the sub-layer 8e can be easily passed through the space still available for the remaining sub-layers 8a-8d. The sub-layer joints 6e are easily accessible for establishing a mechanical connection to the sub-layers 43e and 44e of the adjacent sections WS1 and WS2, as well as for electrical contacts. Next, the second innermost sub-layer 8d can be mounted, and so on (mounting against the common sequence direction AR). Finally, the outermost sub-layer 8a is mounted.

[0218] Conversely, to disassemble the magnetic coil 1 (more precisely, to remove the insertion section ES from the other sections WS1 and WS2), it is possible to disassemble all partial plate layers 8a-8e sequentially from the upper stack end OSE / access side ZU. First, the outermost partial plate layer 8a is removed; the plate layer joints 6a for disconnecting the mechanical connection and electrical contact to the partial plate layers 43a and 44a of the adjacent sections WS1 and WS2 are immediately accessible. After removing partial plate layer 8a, the second outermost partial plate layer 8b is accessible from the upper stack end OSE, including its associated plate layer joints 6b, so that disconnecting the mechanical connections and electrical contacts to partial plate layers 43b and 44b is easily accomplished.After removing the partial plate layer 8b, the third outermost partial plate layer 8c becomes accessible from the upper stack end OSE, including the associated plate layer joints 6c, and so on (disassembly along the common sequence direction AR). Finally, the innermost partial plate layer 6e is disassembled. If desired, the further coil sections SW1 and SW2 can then also be disassembled (i.e., separated into their partial plate layers 43a-43e and 44a-44e), typically (with respect to the upper stack end OSE of the already removed insertion section ES) from the outside in. Alternatively, the further coil sections can also be handled as a whole, if necessary (in this case, a housing can be provided on the further coil sections WS1 and WS2, if desired; however, preferably no housing is provided here either).

[0219] Gauss Fusion GmbH 16.10.2025 SP14052PCT In the embodiment of Fig. 8, the insertion section ES (in the projection shown) has an approximately V-shaped contour.

[0220] Fig. 9 schematically illustrates in a longitudinal section a section of the plate stack 4 of another exemplary embodiment of a magnetic coil 1 according to the invention. In the embodiment of Fig. 9, a section is again shown with an insertion section ES and partial sections of two adjacent (i.e., adjoining) further sections WS1, WS2.

[0221] The insertion section ES is of type b) in the embodiment of Fig. 9. Two stack end faces can be assigned to the stack 7 of partial plate layers 8a-8h of the insertion section ES with respect to the local stacking direction LSR: a first stack end face SEI (in Fig. 9 above), also called first access face ZU1, and a second stack end face SE2 (in Fig. 9 below), also called second access face ZU2.

[0222] The insertion section ES is connected on the left via the first stack joint SJ1 to the first further section WS1, and on the right via the second stack joint SJ2 to the second further section WS2. Each of the stack joints SJ1, SJ2 comprises eight plate layer joints 6a-6h, namely one in each plate layer 3a-3h (shown only for example at SJ1).

[0223] The partial plate layers 8a-8h of the insertion section ES can be divided here into a first part 45, comprising the partial plate layers 8a-8d, and a second part 46, comprising the partial plate layers 8e-8h.

[0224] The outermost partial plate layer 8a with respect to the first stack end face SEI has a length L8a along the local longitudinal direction LLR; it is the longest partial plate layer 8a of the first part 45. The second outermost partial plate layer 8b has a length L8b that is less than L8a. The third outermost partial plate layer 8c has a length L8c that is less than L8b, and so on. The lengths L8a-L8d of the partial plate layers 8a-8d in the first part 45 take into the stack 7 of partial plate layers (from outside to inside, along the

[0225] Gauss Fusion GmbH 16.10.2025 SP14052PCT first sequence direction ARI from the first stack end side SEl / first access side ZU1 into stack 7) continuously. The innermost partial plate layer 8d with respect to the first stack end side SEI has the smallest length L8d in the first part 45.

[0226] The outermost partial plate layer 8h with respect to the second stack end SE2 has a length of L8h along the local longitudinal direction LLR; it is the longest partial plate layer 8h of the second part 46. The second outermost partial plate layer 8g has a length L8g that is less than L8h. The third outermost partial plate layer 8f has a length L8f that is less than L8g, and so on. The lengths L8h-L8e of the partial plate layers 8h-8e in the second part 46 decrease continuously into the stack 7 of partial plate layers (from the outside in, along the second sequence direction AR2 from the second stack end SE2 / second access side ZU2 into the stack 7). Note that the first stack end SEI and the second stack end SE2 are opposite each other, and the first sequence direction AR1 and the second sequence direction AR2 are opposite each other.The innermost part-plate layer 8e with respect to the second stack end SE2 has the smallest length L8e in the second part 45.

[0227] The plate layer joints 6a-6d and 6e-6h of the first part 45 and of the second part 46 are arranged in each of the stack joints SJ1, SJ2 in a step-like offset to each other with respect to the local longitudinal direction LLR.

[0228] In the first part 45, the respective plate layer joint 6b of the second outermost plate layer 3b with respect to the first stack end face SEI (or the first sequence direction AR1) is positioned such that the partial plate layer 43a or 44a of the first further section WS1 or second further section WS2 of the next outermost plate layer 3a (or its partial plates) does not overlap with the plate layer joint 6b. Furthermore, the respective plate layer joint 6c of the third outermost plate layer 3c with respect to the first stack end face SEI is positioned such that the partial plate layer 43b or 44b of the first further section WS1 or second further section WS2 of the next outermost plate layer 3b (or its partial plates) does not overlap with the plate layer joint 6c, and so on.

[0229] Gauss Fusion GmbH 16.10.2025 SP14052PCT In the second part 46, the respective plate layer joint 6g of the second outermost plate layer 3g with respect to the second stack end SE2 (or the second sequence direction AR2) is positioned such that the partial plate layer 43h or 44h of the first further section WS1 or second further section WS2 of the next outermost plate layer 3h (or its partial plates) does not overlap with the plate layer joint 6g. Furthermore, the respective plate layer joint 6f of the third outermost plate layer 3f with respect to the second stack end SE2 is positioned such that the partial plate layer 43g or 44g of the first further section WS1 or second further section WS2 of the next outermost plate layer 3g (or its partial plates) does not overlap with the plate layer joint 6f, and so on.

[0230] This assembly offers the possibility, when assembling the insertion section ES into the already existing (previously stacked) further sections WS1, WS2, to mount the partial plate layers 8a-8d of the first part 45 one after the other from the first stack end side SEI (first access side ZU1), and to mount the partial plate layers 8e-8h of the second part 46 one after the other from the second stack end side SE2 (second access side ZU2), analogous to Fig.

[0231] 8 described. The assembly begins with the innermost partial plate layers 8d, 8e with respect to the respective stack end side SEI, SE2 on the partial plate layers 43d, 44d and 43e, 44e, and the further assembly of partial plate layers 8c-8a and 8f-8h takes place from the inside out (assembly contrary to the sequence directions ARI, AR.2).

[0232] Conversely, to disassemble the magnetic coil 1 (more precisely, to remove the insertion section ES from the further sections WS1, WS2), it is possible to disassemble the partial plate layers 8a-8d of the first part 45 successively from the first stack end SEI (first access side ZU1), and to disassemble the partial plate layers 8e-8h of the second part 46 successively from the second stack end SE2 (second access side ZU2), analogously as described in Fig. 8. The disassembly begins with the outermost partial plate layers 8a, 8h with respect to the respective stack end SEI, SE2.

[0233] Gauss Fusion GmbH 16.10.2025 SP14052PCT The partial disassembly of the plate layers 43a, 44a and 43h, 44h, and the further disassembly of partial plate layers 8b, 8c, 8d and 8g, 8f, 8e, is carried out from the outside in (disassembly along the sequence directions ARI, AR2). If desired, the further coil sections SW1, SW2 can then also be disassembled (i.e., broken down into their partial plate layers 43a-43h, 44a-44h), typically (with respect to the stack end faces SEI, SE2 of the already removed insertion section ES) from the outside in. Alternatively, the further coil sections can also be handled as a whole, if necessary (in this case, a housing can be provided on the further coil sections WS1, WS2, if desired; however, preferably no housing is provided here either).

[0234] In the embodiment of Fig. 9, the insertion section ES (in the projection shown) has an approximately X-shaped contour (also referred to as chalice-shaped or double V-shaped).

[0235] Fig. 10 schematically illustrates in a longitudinal section a section of the plate layer stack 4 of a further, exemplary embodiment of a magnetic coil 1 according to the invention. In the embodiment of Fig. 10, a section is shown with an insertion section ES, an intermediate section ZS, as well as partial sections of a connection section AS and a further section WS.

[0236] The insertion section ES is connected to the intermediate section ZS via the first stack joint SJ1 on the left in Fig. 10, and to the further section WS via the second stack joint SJ2 on the right. Furthermore, the intermediate section ZS is connected to the terminal section AS via the third stack joint SJ3 on the left in Fig. 10.

[0237] The insertion section ES in the illustrated embodiment is of type a), as explained in Fig. 8. The partial plate layer 8a, which is located furthest out with respect to the upper stack end OSE (access side ZU), has the greatest length along the local longitudinal direction LLR, and the lengths of the partial plate layers 8a-8e decrease inwards (along the common sequence direction AR) in the stack 7.

[0238] Gauss Fusion GmbH 16.10.2025 SP14052PCT The third stack joint SJ3 comprises five plate layer joints 6a-6e, one in each plate layer 3a-3e. The plate layer joints 6a-6e are arranged in a stepped arrangement relative to each other along the local longitudinal direction LLR. The plate layer joint 6b of the second outermost plate layer 3b with respect to the upper stack end OSE (the "single" access side ZU) and with respect to the common sequence direction AR of the insertion section ES is positioned such that the partial plate layer 47a of the connection section AS of the next outermost plate layer 3a (or its partial plates) does not overlap with the plate layer joint 6b.Furthermore, the plate layer joint 6c of the third outermost plate layer 3c with respect to the upper stack end side OSE (the “only” access side ZU) of the insertion section ES is positioned such that the partial plate layer 47b of the connection section AS of the next outermost plate layer 3b (or its partial plates) does not overlap with the plate layer joint 6c, and so on.

[0239] This makes it possible to assemble the magnetic coil 1 section by section, and within each section the associated partial plate layers one after the other:

[0240] With a connecting section AS and a further section WS already in place, the intermediate section ZS can be assembled first. Initially, with respect to the upper stack end OSE (the access side) of the future insertion section ES, the innermost sub-plate layer 43e is mounted to the sub-plate layer 47e of the connecting section AS; the plate layer joint 6e of the third stack joint SJ3 is easily accessible from the upper stack end OSE. Subsequently, the next inner sub-plate layer 43d of the intermediate section ZS is mounted, and so on, until the intermediate section ZS is completely mounted to the connecting section AS (assembly contrary to the common sequence direction AR).

[0241] The insertion section ES is then assembled as described in Fig. 8, starting with the innermost section 8e with respect to the upper stack end side OSE, and then with the further partial plate layers 8d-8a from the inside out (assembly against the common sequence direction AR).

[0242] Gauss Fusion GmbH 16.10.2025 SP14052PCT It is also possible to disassemble the magnetic coil 1 section by section, and within each section to remove the associated partial plate layers one after the other:

[0243] First, the insertion section ES is disassembled as described in Fig. 8, starting with the outermost section 8a with respect to the upper stack end side OSE, and then with the further partial plate layers 8b-8e from the outside in (disassembly along the common sequence direction AR).

[0244] The intermediate section ZS can then be disassembled. First, with respect to the upper stack end OSE (the access side) of the already removed insertion section ES, the outermost sub-plate layer 43a is removed from the sub-plate layer 47a of the connecting section AS; the joint 6a of the third stack joint SJ3 is readily accessible from the upper stack end OSE. Removing the sub-plate layer 43a exposes the plate layer joint 6b of the third stack joint SJ3. Subsequently, the next outermost sub-plate layer 43b of the intermediate section ZS is disassembled, and so on, until the intermediate section ZS is completely disassembled from the connecting section AS (disassembly along the common sequence direction AR).

[0245] Fig. 11 schematically illustrates in a longitudinal section a section of the plate stack 4 of a further, exemplary embodiment of a magnetic coil 1 according to the invention. In the embodiment of Fig. 11, a section is shown with an insertion section ES, a further insertion section wES and three further sections WS1, WS2, WS3.

[0246] The insertion section ES and the further insertion section wES are designed here according to type a). The access sides ZU of the two insertion sections ES, wES are located on the same side of the plate layer stack 4, here in Fig. 11 each at the top, corresponding to an upper stack end side OSE.

[0247] Gauss Fusion GmbH 16.10.2025 SP14052PCT With this design, the assembly or disassembly of the magnetic coil 1 can be carried out or started independently at both insertion sections ES, wES.

[0248] Fig. 12 illustrates by way of example a section of a plate layer 3, as it can be installed in a magnetic coil according to the invention, here comprising three sub-plates 5a, 5b, 5c. The sub-plates 5a, 5b, 5c are attached to one another along the local longitudinal direction, for example by welding (welding not shown in detail).

[0249] Each subplate 5a-5c comprises ten slots 21, in each of which a conductor 22 is inserted (in one slot 21 at the top right, the conductor 22 is shown removed for illustrative purposes). In each complete plate layer 3, the entirety of the conductors 22 forms windings around the coil axis, typically in the form of a spiral ("pancake") (not shown in detail, but see, for example, Fig. 15).

[0250] Note that for the spiral configuration in each plate layer 3, a local change in the winding direction (also called slot offset) of the respective conductor is generally provided in one of the sub-plates; likewise, a conductor connection (conductor transition) is generally provided between adjacent plate layers at two superimposed sub-plates, often in the same sub-plates in which the change in the winding direction of the conductors is also provided. Sub-plates that provide a change in the winding direction of the conductors and / or a conductor connection between plate layers are typically arranged in a different section than the insertion section (sub-plates with a change in winding direction or layer change are not shown in detail, but see Fig. 15, Fig. 16 and the subsequently published German patent application 10 2024 208 874.9 for further information).

[0251] The grooves 21 are open only on one side of the sub-plates 5a-5c, here towards the top 49, and are closed with covers 48. The grooves 21, and correspondingly also the conductors 22, each run along a local

[0252] Gauss Fusion GmbH 16.10.2025 SP14052PCT Longitudinal direction LLR. The grooves 21 are further arranged along a local transverse direction LQR, here in only one row 50. The local stacking direction LSR runs perpendicular to the local longitudinal direction LLR and the local transverse direction LQR. The plate layers 3 are stacked in the plate layer stack along the local stacking direction LSR (see Fig. 1).

[0253] Preferably, a plate layer 3 comprises only partial plates 5a, 5b, 5c of the following three types (which are shown by way of example in Fig. 12), without prejudice to plate layer joints and layer changes:

[0254] In type 1 sub-plates, the grooves 21 are curved only within a common plate plane. This common plate plane contains the local longitudinal direction LLR and the local transverse direction LQR of the grooves 21. Note that the local longitudinal direction LLR and the local transverse direction LQR change along a groove 21, but not the local stacking direction LSR. The grooves 21 are curved in a circular arc with respect to a common center point. Sub-plate 5b is of this type 1.

[0255] In type 2 sub-plates, the grooves 21 are curved in a circular arc only in mutually parallel transverse planes. These mutually parallel transverse planes each contain the local longitudinal direction LLR of the groove 21 and are perpendicular to the local transverse direction LQR. Note that the local longitudinal direction LLR and the local stacking direction LSR change along a groove 21, but not the local transverse direction LQR. The grooves 21 have a common radius of curvature. Sub-plate 5c is of type 2.

[0256] In type 3 sub-plates, the grooves 21 all run straight. The local longitudinal direction LLR, the local transverse direction LQR, and the local stacking direction LSR are constant along a groove 21. Sub-plate 5a is of type 3.

[0257] The grooves align at the transitions between the sub-plates 5a, 5b, 5c.

[0258] Gauss Fusion GmbH 16.10.2025 SP14052PCT The sub-plates 5a, 5b, 5c are also designed here as support sub-plates 58. In the cross-section of the support sub-plates 58, perpendicular to the local longitudinal direction LLR (visible in Fig. 12 on the right end face of sub-plate 5c), the area SF of the support material 59 of the support sub-plate 58 (including the area of ​​all covers 48) is selected with Q=SF / (SF+LF) and Q>0.67 compared to the area LF occupied by (all) ladders 22. In the design shown, Q is approximately 0.70. The support material 59 is typically steel. The support sub-plates 58 are particularly robust mechanically and can therefore serve as part of a support structure 60 (see Fig. 14).

[0259] Stellarator coils (which are non-planar, 3D-shaped) typically incorporate all three types 1, 2, and 3. Tokamak coils typically incorporate either only types 1 and 3 (planar type) or all types 1, 2, and 3 (non-planar, 3D-shaped type). Note that each layer of plates typically contains several sub-plates 5a, 5b, and 5c of varying sizes, representing each type.

[0260] The assembly of the plate layers 3, including the sub-plates 5a, 5b, 5c used, and the assembly of the plate layer stack, including clamps (see also Fig. 14) within the scope of the invention can be set up as described in the subsequently published German patent application 10 2024 208 874.9.

[0261] Fig. 13 shows an exemplary embodiment of a magnetic coil arrangement 51 according to the invention in a schematic top view, and Fig. 14 shows the magnetic coil arrangement 51 in a schematic cross-section (centrally and perpendicular to the toroidal direction). In the embodiment shown, the magnetic coil arrangement 51 is configured as a stellarator. The magnetic coil arrangement 51 belongs to a nuclear fusion device, for example, a fusion power plant.

[0262] Gauss Fusion GmbH 16.10.2025 SP14052PCT The magnetic coil arrangement 51 is essentially toroidal. The magnetic coil arrangement 51, together with a plasma vessel 52, encloses an essentially toroidal plasma volume 53. A plurality of magnetic coils 1, which here are designed as 3D-shaped, non-planar stellarator coils, are distributed around the plasma volume 53 in a toroidal direction 54. Each magnetic coil 1 encloses the plasma volume 53 in a poloidal ring shape at its toroidal position.

[0263] The magnetic coils 1 are in turn arranged in a cryostat 55 to provide thermal insulation and thus keep the magnetic coils 1 (or more precisely: their superconducting conductors) at cryogenic temperature.

[0264] The sub-plates in the plate stack 4 are designed here as support plates (see Fig. 12). The plate stack 4 of each magnetic coil 1 is held together by a plurality of clamps 56, which compress the plate stack 4 along the local stacking direction. The clamps 56 are spaced apart from one another along the local longitudinal direction (i.e., essentially along the circumference of the respective magnetic coil 1). The support plates and the clamps 56 together form a support structure 60 for the respective magnetic coil 1, which can absorb the forces acting on the magnetic coil 1 during operation, and the magnetic coil 1 is thus mechanically stabilized. The plate stack 4 and the clamps 56 can be built directly in the cryostat 55; in particular, no housing is required for the mechanical stabilization of the plate stack 4.For the sake of simplicity, the external support of the individual magnetic coils 1 on the ground and also against each other is not shown in detail here.

[0265] In the illustrated embodiment, the magnetic coils 1 are each formed with at least one insertion section ES and at least one further section WS, which are connected to each other at stacking joints SJ1, SJ2. This allows all magnetic coils 1 to be mounted and, if necessary, dismounted particularly easily.

[0266] Gauss Fusion GmbH 16.10.2025 SP14052PCT Alternatively, it may also be provided that only one magnetic coil 1a or a part of the magnetic coils are designed with insertion section ES and further section WS as described, in particular to make a specific maintenance window 57 of the plasma vessel 52 easily accessible for maintenance work or repairs.

[0267] Fig. 15 shows, by way of example, a schematic oblique view of a plate layer 3 for a magnetic coil according to the invention.

[0268] The plate layer 3 comprises two sub-plate layers: a plate layer 8 of an insertion section ES and a plate layer 8 of a further section WS. The two plate layers 8 are connected to each other via two plate layer joints 6. In the example shown, the plate layer 3 is flat and approximately D-shaped, for example, for a tokamak coil. In the circumferential direction, the individual sub-plates 5 of the plate layer 3 connect to each other in a ring-like fashion and are attached to one another. The insertion section ES comprises four sub-plates 5, and the further section WS comprises five sub-plates 5. The sub-plates 5 that adjoin the plate layer joints 6 or that form the plate layer joints 6 are also referred to as end sub-plates (not specifically marked in Fig. 15, but see, for example, Figs. 4 and 5).

[0269] The superconducting conductors 22 installed in the partial plate layers 8 are shown schematically (associated grooves not shown). A conductor 22a of a first type (shown as a dotted line) and a conductor 22b of a second type (shown as a dashed line) were installed. The conductor 22 as a whole is formed in the form of a spiral with four turns in the plate layer 3; in the illustrated design, a local, step-like change of turns 40 of the respective conductors 22 is provided in the middle partial plate 5 of the further section WS.

[0270] The conductor 22a of the first type has a high magnetic field resistance (i.e., it remains superconducting even at high magnetic field strengths) and is, for example, chosen as an HTS (e.g., YBCO). It was installed in the radially innermost turn and a

[0271] Gauss Fusion GmbH 16.10.2025 SP14052PCT Part of the second innermost winding is installed, as the magnetic field strength is greater radially further inwards than radially further outwards.

[0272] The conductor 22b of the second type has a lower magnetic field resistance and is chosen, for example, as a cost-effective LTS (e.g., Nb3Sn) or as an HTS containing less superconducting material than the conductor 22a of the first type. The conductor 22b of the second type was installed in part of the second innermost turn and in the two outermost turns, since the magnetic field strength is lower here than radially further inwards.

[0273] At the conductor joint marked with reference numeral 11 on the upper plate-layer joint 6 in Fig. 15, conductor 22a of the first type and conductor 22b of the second type are connected to each other. At the remaining conductor joints (not marked separately), identical types of conductors 22a and 22b are connected to each other. At the spiral ends 63 and 64 of conductor 22, a connection to the next plate layer or to outside the magnet coil is provided.

[0274] Figure 16 shows an exemplary schematic oblique view of an embodiment of a magnetic coil 1 according to the invention. This coil comprises an insertion section ES and a further section WS, which are connected to each other at the stack joints SJ and SJ2. The magnetic coil 1 is approximately D-shaped and, in this case, planar, and is suitable as a tokamak coil. The magnetic coil 1 comprises four plate layers 3 in the plate layer stack 4; for simplification, the individual sub-plates in the plate layers 3 have not been marked separately. The insertion section ES is formed by the sub-plate layers 8a-8d, and the further section WS is formed by the sub-plate layers 43a-43d. In Figure 16, the (only) access side ZU of the insertion section ES is facing the viewer (see also Figure 8 for an analogous illustration).

[0275] Using the outermost plate layer 3 (comprising the partial plate layers 8a and 43a connected at the two plate layer joints 6) as an example, the conductor 22 installed in the magnet coil 1 is explained. The conductor 22 runs in the ge-

[0276] Gauss Fusion GmbH, October 16, 2025, SP14052PCT, showed a construction in the plate layers 3, each according to a spiral in the narrower sense with continuously distributed turns, here with four turns (alternatively, for example, a spiral arrangement of the turns with local, step-like turns of the respective conductors 22 would also be possible, cf. Fig. 15). In the uppermost plate layer 3, a connection to the next lower plate layer 3 is provided at the spiral end 63, and at the spiral end 65, the conductor 22 is led outside the magnet coil 1 (for example, to a power source and / or a superconducting short-circuit switch, not shown in detail). Two types of conductors 22a, 22b are installed in the magnet coil 1.

[0277] The conductor 22a of the first type (shown with dotted lines) has high magnetic field resistance and is, for example, selected as an HTS (e.g., YBCO). It was installed throughout the entire insertion section ES, which essentially forms the back of the D-shaped magnetic coil 1. This back faces the center of the plasma volume torus (see Fig. 13 or 14), where a particularly high magnetic field strength prevails.

[0278] The conductor 22b of the second type (shown with a dashed line) has a lower magnetic field resistance and is, for example, a cost-effective LTS (e.g., Nb3Sn) or an HTS containing less superconducting material than the conductor 22a of the first type. The conductor 22b of the second type was installed throughout the entire remaining section WS, which essentially forms the belly of the D-shaped magnet coil 1. This belly faces away from the center of the plasma volume torus (see Fig. 13 or 14). The magnetic field strength is significantly lower in the belly region than in the back region.

[0279] In this embodiment, different types of conductors 22a, 22b are connected to each other at all conductor joints 11 in the plate layer joints 6.

[0280] Gauss Fusion GmbH 16.10.2025 SP14052PCT Figures 17 to 20 illustrate, by way of example, the production of a partial plate layer 8 for a magnetic coil according to the invention in chronological sequence. In the example shown, three partial plates 5a, 5b, 5c are joined together and equipped with conductors 22. For the sake of simplicity, the partial plates 5a, 5b, 5c are shown here as a projection. A top view of the side towards which the grooves 21 are open is shown in each case.

[0281] Fig. 17 illustrates an initial situation in which the three sub-plates 5a, 5b, 5c are still separate. Sub-plates 5a and 5c are end-face sub-plates on which plate-layer joints 6 are prepared (see dotted areas, e.g., due to projections and recesses, not shown in detail, but see, e.g., Fig. 4 and Fig. 5). Sub-plate 5b is a middle sub-plate. The sub-plates 5a, 5b, 5c are to be joined to each other at the joints (end faces) 66, 67 and 68, 69. Grooves 21 have already been pre-machined in the sub-plates 5a, 5b, 5c. However, webs 70 remain towards the joints 66-69. In other words, the grooves 21 are not yet completely finished and are still closed towards the joints 66-69. Accordingly, the joints (end faces) 66-69 are still intact, and here rectangular in shape (only visible as a border line in the top view of Fig. 17).

[0282] Next, the partial plates 5a, 5b, 5c are placed against each other, see Fig. 18, with the joints 66, 67 and 68, 69 touching. The grooves 21 of the partial plates 5a, 5b, 5c are aligned. In the example shown, the still intact joints (end faces) 66, 67 and 68, 69 are now welded together over their entire surface, resulting in the weld seams 71, 72. This creates a continuous partial plate layer 8. The webs 70 are still present after welding.

[0283] In the next step, the webs (Fig. 70 in Fig. 18) are removed, for example by milling, resulting in continuous grooves 21 in the sub-plate layer 8 across all sub-plates 5a, 5b, 5c, as shown in Fig. 19. In other words, the grooves 21 are extended or completed in the areas of the webs up to the joints.

[0284] Gauss Fusion GmbH 16.10.2025 SP14052PCT Subsequently, pieces 73 of the conductor 22 (shown with a wave pattern) are inserted into the grooves 21 of the partial plate layer 8, see the resulting state in Fig. 20. Only pieces 73 of the conductor 22 with a length LS are required, which essentially corresponds to the length LN of the respective groove 21 of the partial plate layer 8 (measured along the local longitudinal direction LLR). Note that with curved partial plates 5a, 5b, 5c, the lengths LN of the grooves 21 within the partial plate layer 8 can vary (not shown in detail). The grooves 21 filled with conductor 22 are usually then closed with covers (not shown in detail).

[0285] The sections of a magnetic coil according to the invention can be assembled from partial plate layers 8 manufactured as shown in Figure 17-20.

[0286] In summary, the invention relates to a magnetic coil (1, 1a) comprising several annular, stacked plate layers (3; 3a-3h), each plate layer being composed of successively attached sub-plates (5; 5a-5c; 9, 9a, 9b), wherein grooves (16, 21) extend into the sub-plates in which superconducting conductors (22) are inserted, wherein several sections (ES, wES, WS, WS1-WS3, ZS, AS) are present, each forming a part of the circumference of the magnetic coil and being connected by stack joints (SJ1-SJ3), each stack joint comprising a plate layer joint (6; 6a-6h) in each plate layer, the sections comprising at least one insertion section (ES, wES), wherein in the insertion section

[0287] a) either from only one stack end (OSE) with respect to all partial plate layers (8; 8a-8e),

[0288] b) or from a first stack end (SEI) for a first part (45) of the partial plate layers (8; 8a-8d) and from a second, opposite stack end (SE2) for a second, remaining part (46) of the partial plate layers (8; 8e-8h),

[0289] a length (L8a-L8h) of the sub-plate layers decreases towards the next inner plate layer,

[0290] Gauss Fusion GmbH 16.10.2025 SP14052PCT and wherein in the stack joints belonging to the insertion section each

[0291] i) the plate layer joints are offset from each other, and

[0292] ii) with respect to the associated stack end face (OSE; SEI, SE2) according to a) or b), the plate layer joints of more inwardly located plate layers do not overlap with the sub-plates of more outwardly located plate layers of the next section. The magnetic coil is easier to handle during manufacturing, assembly, disassembly, and any repairs or maintenance.

[0293] Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT

[0294]

[0295] 1 magnetic coil

[0296] la magnetic coil

[0297] 2 Coil shaft

[0298] 3-layer plate

[0299] 4-layer plate stack

[0300] 5 partial plate

[0301] 5a Partial plate (with straight grooves)

[0302] 5b Partial plate (with grooves curved in the plane of the plate)

[0303] 5c Sub-plate (with grooves curved out of the plate plane) 6 Plate layer joint

[0304] 6a-6h Plate layer joints

[0305] 7 stacks of partial plate layers

[0306] 8 partial plate layer

[0307] 8a-8h Partial plate layers (insertion section)

[0308] 9 terminal subplate

[0309] 9a End-side partial plate (of the first section, left)

[0310] 9b end-side partial plate (of the second section, right)

[0311] 10 screw connections (for printed circuit boards)

[0312] 11 Leader Joint

[0313] lla-lld Leiter-Joints

[0314] 12 fingers

[0315] 13 Return (on the finger)

[0316] 14 ledge (on the finger)

[0317] 15 End section of a conductor (first section)

[0318] 16 Nut

[0319] 17 exposed end (of sub-plate 9a)

[0320] 17a Unexposed section (of sub-slab 9a)

[0321] 18 Cantilever

[0322] 19% overhang (at the cantilever)

[0323] 20 Retraction (at cantilever)

[0324] 21 Nut

[0325] Gauss Fusion GmbH 16.10.2025 SP14052PCT 22 Manager

[0326] 22a Conductor of a first type

[0327] 22b Conductor of a second type

[0328] 23 End section of a conductor (second section)

[0329] 24 wedge element

[0330] 25 first cut surface

[0331] 26 second cut surface

[0332] 27 Wedge element

[0333] 28 exposed end (of sub-plate 9b)

[0334] 28a Unexposed section (of sub-slab 9b)

[0335] 29a, 29b Press directions of the wedge elements

[0336] 30a, 30b reverse sides (of projections 14, 19)

[0337] 31, 32 cooling channels

[0338] 33 Joint clamping elements

[0339] 33a conductor-facing contour of the joint clamping element

[0340] 34 screw connections (of the joint clamping elements)

[0341] 35 Shoulder

[0342] 36 clamping force

[0343] 37 Joint clamping device

[0344] 39 screw

[0345] 40 step-like changes in winding

[0346] 41 Subplate end

[0347] 42 Subplate end

[0348] 43a-43h Partial plate layers (first further section or intermediate section) 44a-44h Partial plate layers (second further section)

[0349] 45 first part (of the partial plate layers of the insertion section)

[0350] 46 second part (of the partial plate layers of the insertion section)

[0351] 47a-47e Partial plate layers (connection section)

[0352] 48 Cover

[0353] 49 Top side of the sub-plates

[0354] 50 rows of grooves

[0355] 51 Magnetic coil arrangement

[0356] 52 Plasma vessel

[0357] Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT 53 plasma volume

[0358] 54 toroidal direction

[0359] 55 Cryostat

[0360] 56 terminals

[0361] 57 maintenance windows

[0362] 58 Carrier plate

[0363] 59 Support material

[0364] 60 Support structure

[0365] 61 Overlap connection

[0366] 62 partial plate stacks

[0367] 63-65 spiral ends

[0368] 66-69 butt joints (end faces of the sub-plates)

[0369] 70 bridges

[0370] 71, 72 welds

[0371] 73 pieces of a ladder

[0372] AR common sequence direction (from the stack end / single access side, from the outside in, into the stack) AR1 first sequence direction (from the first stack end / first access side, from the outside in, into the stack)

[0373] AR2 second sequence direction (from the second stack end / second access side, from the outside in, into the stack) AS connection section

[0374] ES insertion section (also example of a first section)

[0375] LF area of ​​the ladder

[0376] LLR local longitudinal direction

[0377] LN Length of the groove

[0378] LQR local transverse direction

[0379] LS Length of a section of a conductor

[0380] LSR local stacking direction

[0381] L8a-L8h Length of the partial plate layer

[0382] OSE upper stack end (in type a) insertion section, single access side) SEI first stack end (in type b) insertion section, first access side) SE2 second stack end (in type b, insertion section, second access side)

[0383] Gauss Fusion GmbH 16.10.2025 SP14052PCT SF Area of ​​support material

[0384] SJ1 first stack joint

[0385] SJ2 second stack joint

[0386] SJ3 third stack joint

[0387] USE bottom stack end

[0388] wES further insertion section

[0389] WS further section (also example of a second section) WS1 first further section

[0390] WS2 second further section

[0391] WS3 third further section

[0392] ZS Intermediate Section

[0393] Go to access page

[0394] ZU1 first access page

[0395] ZU2 second access page

[0396] a bevel angle

[0397] Gauss Fusion GmbH 16.10.2025 SP14052PCT

Claims

Patent claims 1. Magnetic coil (1, la), especially stellarator coil or tokamak coil for a nuclear fusion plant, wherein a plurality of ring-shaped plate layers (3; 3a-3h) are present, in each of which several turns of a superconducting conductor (22) are formed, wherein in each layer of plates (3; 3a-3h) a plurality of sub-plates (5; 5a-5c; 9, 9a, 9b) are arranged in a ring-like sequence and in each layer of plates (3; 3a-3h) successive sub-plates (5; 5a-5c; 9, 9a, 9b) are attached to one another, and wherein the plate layers (3; 3a-3h) form a ring-shaped plate layer stack (4) and successive plate layers (3; 3a- 3h) are adjacent to each other, wherein each subplate (5; 5a-5c; 9, 9a, 9b) forms several grooves (16, 21) into which the conductor (22) is inserted, wherein the grooves (16, 21) of the sub-plate (5; 5a-5c; 9, 9a, 9b) run along a local longitudinal direction (LLR), and the grooves (16, 21) of the sub-plate (5; 5a-5c; 9, 9a, 9b) are arranged consecutively in a local transverse direction (LQR), wherein a local stacking direction (LSR.) is perpendicular to the local longitudinal direction (LLR) and perpendicular to the local transverse direction (LQR), and wherein the grooves (16, 21) of successive sub-plates (5; 5a, 5b, 5c; 9, 9a, 9b) of a plate layer (3; 3a-3h) are aligned with each other, and in particular connect to each other, Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT characterized by that the plate stack (4) comprises several sections (ES, wES; WS; WS1, WS2, WS3; ZS, AS) which each form a part of the circumference of the annular plate stack (4), wherein each section (ES, wES; WS; WS1, WS2, WS3; ZS, AS) is formed by a stack (7) of partial plate layers (8; 8a-8h, 43a-43h, 44a-44h, 47a-47h), wherein a partial plate layer (8; 8a-8h, 43a-43h, 44a-44h, 47a-47h) is formed by the partial plates (5; 5a-5c; 9, 9a, 9b) of the section (ES, wES; WS; WS1, WS2, WS3; ZS, AS) in a plate layer (3; 3a-3h), wherein in the ring-shaped plate layer stack (4) successive sections (ES, wES; WS; WS1, WS2, WS3; ZS, AS) are connected to each other by stack joints (SJ1, SJ2, SJ3), that each stack joint (SJ1, SJ2, SJ3) comprises a plate layer joint (6; 6a-6h) in each plate layer (3; 3a-3h), wherein each plate layer joint (6; 6a-6h) in its associated plate layer (3; 3a-3h) electrically contacts the conductors (22) in the slots (16) of an end-side sub-plate (9, 9a) of a first section (ES) with opposing conductors (22) in the slots (21) of an end-side sub-plate (9, 9b) of a second section (WS) by means of several conductor joints (11; lla-lld), and the end-side sub-plate (9, 9a) of the first section (ES) is attached to the end-side sub-plate (9, 9b) of the second section (WS), and that the sections (ES, wES; WS; WS1, WS2, WS3; ZS, AS) include at least one insertion section (ES, wES), where in the insertion section (ES, wES) a) either from only one stack end (OSE) along a common sequence direction (AR.) with respect to all sub-plate layers (8; 8a-8e), Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT b) or from a first stack end (SEI) along a first sequence direction (AR1) for a first part (45) of the partial plate layers (8; 8a-8d) and from a second, opposite stack end (SE2) along a second, opposite sequence direction (AR2) for a second, remaining part (46) of the partial plate layers (8; 8e-8h), a length (L8a-L8h) of the partial plate layers (8; 8a-8h) measured along the local longitudinal direction (LLR) into the plate layer stack (4) decreases towards the next inner plate layer (3; 3a-3h), whereby in the stack joints (SJ1, SJ2, SJ3) belonging to the insertion section (ES, wES) each i) the plate layer joints (6; 6a-6h) are arranged offset from each other with respect to the local longitudinal direction (LLR.), and ii) in the plate layer stack (4) with respect to the associated stack end (OSE; SEI, SE2) according to a) or b) the plate layer joints (6; 6a-6h) of more inwardly located plate layers (3; 3a-3h) do not overlap with the sub-plates (5; 5a-5c; 9, 9a, 9b) of more outwardly located plate layers (3; 3a-3h) of the section (WS; WS1, WS2, WS3; ZS) which is connected at the stack joint (SJ1, SJ2, SJ3) to the insertion section (ES, wES).

2. Magnetic coil (1, ala) according to claim 1, characterized in that that in the stack joints (SJ1, SJ2, SJ3) belonging to the at least one insertion section (ES, wES), the end-face sub-plates (9, 9a) of the insertion section (ES, wES) and the end-face sub-plates (9, 9b) of the section (WS; WS1, WS2, WS3, ZS) connected to the insertion section (ES, wES) at the stack joint (SJ1, SJ2, SJ3) are detachably fastened to one another at a respective plate layer joint (6; 6a-6h), and the conductor joints (11; 11a-11d) are detachably electrically contacted, wherein the loosening of this fastening and the loosening of these electrical contacts of the conductor joints (11; 11a-11d) are carried out from the associated stack end (OSE, SEI, SE2) according to a) or b). can. Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT 3. Magnetic coil (1, ala) according to one of the preceding claims, characterized in that the sections (ES, wES; WS; WS1, WS2, WS3; ZS, AS) comprise several insertion sections (ES, wES).

4. Magnetic coil (1, ala) according to one of the preceding claims, characterized in that that the sections (ES, wES; WS; WS1, WS2, WS3; ZS, AS) further comprise at least one intermediate section (ZS) and one connecting section (AS), wherein the intermediate section (ZS) follows the insertion section (ES, wES) in the annular plate layer stack (4), and the connecting section (AS) follows the intermediate layer (ZS), where at the stack joint (SJ3), which connects the intermediate section (ZS) to the connecting section (AS), i') the plate layer joints (6; 6a-6h) are arranged offset from each other with respect to the local longitudinal direction (LLR), and ii') in the plate layer stack (4) with respect to the associated stack end side (OSE; SEI, SE2) according to a) or b) of the insertion section (ES, wES) followed by the intermediate section (ZS), the plate layer joints (6; 6a-6h) of more inwardly located plate layers (3; 3a-3h) do not overlap with the sub-plates (5; 5a-5c; 9, 9a, 9b) of more outwardly located plate layers (3; 3a-3h) of the connecting section (AS).

5. Magnetic coil (1, 1a) according to one of claims 1 to 4, characterized in that in the insertion section (ES, wES) from only one stack end side (OSE) with respect to all plate layers (3; 3a-3e) a length (L8a-L8h) of the partial plate layers (8; 8a-8h) measured along the local longitudinal direction (LLR.) into the plate layer stack (4) decreases towards the next inner plate layer (3; 3a-3h). Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT 6. Magnetic coil (1, 1a) according to one of claims 1 to 4, characterized in that in the insertion section (ES, wES) from a first stack end side (SEI) for a first part (45) of the partial plate layers (8; 8a- 8d) and from a second, opposite stack end side (SE2) for a second, remaining part (46) of the partial plate layers (8; 8e-8h) a length (L8a-L8h) of the partial plate layers (8; 8a-8h) is reduced along the local longitudinal direction (LLR.) into the plate layer stack (4) towards the next inner plate layer (3; 3a-3h).

7. Magnetic coil (1, ala) according to one of the preceding claims, characterized in that that within at least one plate layer (3; 3a-3h) of the plate layer stack (4) different types (22a, 22b) of superconducting conductor (22) are installed, such that at at least one plate layer joint (6; 6a-6h) of the plate layer (3; 3a-3h) at at least one conductor joint (11; 11a-11d) different types (22a, 22b) of superconducting conductor (22) are electrically contacted with each other, in particular where - the superconducting conductor (22) in a first section (ES) and the superconducting conductor (22) in a second section (WS) are partially or completely of different types (22a, 22b), and / or - in at least one section (ES, wES; WS; WS1, WS2, WS3; ZS, AS) or all sections (ES, wES; WS; WS1, WS2, WS3; ZS, AS) within a respective partial plate layer (8; 8a-8h, 43a-43h, 44a-44h, 47a-47h) the superconducting conductor (22) in a radially inner part of the slots (16; 21) and the superconducting conductor (22) in a radially outer part of the slots (16; 21) are of different types (22a, 22b).

8. Magnetic coil (1, ala) according to one of the preceding claims, characterized in that several terminals (56) are distributed around the circumference of the magnetic coil (1, ala) and spaced apart from one another, with Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT in which the plate layers (3; 3a-3h) are jammed against each other, in particular are detachably jammed.

9. Magnetic coil (1, ala) according to claim 8, characterized in that that the sub-plates (5; 5a-5c; 9, 9a, 9b) are designed as support sub-plates (58), wherein for a respective support sub-plate (58) in cross-section perpendicular to the local longitudinal direction (LLR) for an area SF occupied by support material (59) of the support sub-plate (58) and an area LF occupied by the conductor (22) in the grooves (16, 21) the following applies: SF / (SF+LF)>0.50, preferably SF / (SF+LF)>0.67, and that the support plates (58) and the clamps (56) together form a support structure (60) of the magnet coil (1, ala), suitable for mechanical stabilization of the magnet coil (1, ala) under the influence of magnetic forces on the conductor (22) during operation of the magnet coil (1, ala).

10. Magnetic coil (1, 1a) according to one of the preceding claims, characterized in that in each subplate (5; 5a-5c; 9, 9a, 9b) exactly one row (50) of grooves (16, 21) is formed, which are arranged successively in the local transverse direction (LQR).

11. Magnetic coil (1, ala) according to one of the preceding claims, characterized in that that at a respective plate layer joint (6; 6a-6h) at a respective conductor joint (11; lla-lld) an end section (15) of the conductor (22) of the first section (ES) and an end section (23) of the conductor (22) of the second section (WS) overlap along the local longitudinal direction (LLR), and that a joint clamping device (37) is provided with which a clamping force (36) transverse to the local longitudinal direction (LLR) is exerted at least on the overlapping end sections (15, 23). Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT 12. Magnetic coil (1, 1a) according to claim 11, characterized in that in a respective conductor joint (11; 11a-11d) the end section (15) of the conductor (22) of the first section (ES) is chamfered with a first cut surface (25) and the end section (23) of the conductor (22) of the second section (WS) is chamfered with a second cut surface (26), wherein the cut surfaces (25, 26) are oriented obliquely to a direction of a longitudinal extension of the respective conductor (22), and the cut surfaces (25, 26) have equal chamfer angles o relative to the direction of the longitudinal extension, and that the two cut surfaces (25, 26) are arranged parallel to each other and facing each other.

13. Magnetic coil (1, 1a) according to claim 11 or 12, characterized in that in a respective conductor joint (11; 11a-11d) the joint clamping device (37) comprises at least one joint clamping element (33) which is pressed against at least one of the overlapping conductors (22), in particular wherein the joint clamping element (33) is screwed in place.

14. Magnetic coil (1, ala) according to one of the preceding claims, characterized in that that at each plate layer joint (6; 6a-6h) in the end-side sub-plate (9, 9a) of the first section (ES) several grooves (16) are formed in which conductors (22) are each inserted, and in the end-side sub-plate (9, 9b) of the second section (WS) several grooves (21) are formed in which conductors (22) are each inserted, and that the two end-side partial plates (9, 9a, 9b) are detachably attached to each other by an overlapping connection (61).

15. Magnetic coil (1, 1a) according to claim 14, characterized in that the end-side partial plate (9, 9a) of the first section (ES) and the end- Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT The two side plates (9, 9b) of the second section (WS) are screwed together, with screws (39) running at least in some spaces between successive grooves (16, 21) along the local transverse direction (LQR), in particular wherein end-face subplates (9, 9a, 9b) of a sub-plate layer (8; 8a-8h; 43a-43h; 44a-44h; 47a-47h), which are involved in the formation of plate layer joints (6; 6a-6h), have at their end facing the plate layer joint (6; 6a-6h) a greater plate width JPB measured along the local transverse direction (LQR.) than a normal plate width NPB present at their end facing away from the plate layer joint (6; 6a-6h) and / or which have a majority of the subplates (5; 5a-5c; 9, 9a, 9b) of the associated plate layer (3; 3a-3h).

16. Magnetic coil (1, 1a) according to claim 14 or 15, characterized in that in the area of ​​the overlapping connection (61) the end-side partial plates (9, 9a, 9b) each have an exposed end (17, 28) in which the grooves (16, 21) are opened towards the respective other end-side partial plate (9, 9a, 9b), wherein at least one projection (14, 19) and a recess (13, 20) are formed at the exposed end (17, 28), and wherein a projection (14, 19) of a respective end-side partial plate (9, 9a, 9b) is hooked into a recess (13, 20) of the respective other end-side partial plate (9, 9a, 9b).

17. Magnetic coil (1, 1a) according to claim 16, characterized in that a wedge element (24) is clamped in the recess (13) of the end-side partial plate (9, 9a) of the first section (ES) between the projection (19) of the partial plate (9, 9b) of the second section (WS) and an unexposed section (17a) of the end-side partial plate (9, 9a) of the first section (ES), so that the projections (14, 19) of the two end-side partial plates (9, 9a, 9b) are pressed against each other, and / or vice versa. Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT 18. Magnetic coil arrangement (51), in particular a stellarator or a tokamak, for a nuclear fusion device, wherein the magnetic coil arrangement (51) is suitable for the magnetic confinement of at least substantially toroidal plasma volume (53), wherein the magnetic coil arrangement (51) comprises a plurality of magnetic coils (1, ala), in particular stellarator coils or tokamak coils, wherein the magnetic coils (1, ala) are arranged distributed in the toroidal direction (54) of the plasma volume (53), wherein the magnetic coils (1, ala) locally enclose the toroidal plasma volume (53) in a ring shape, and wherein at least one of these magnetic coils (1, ala) is configured according to any one of claims 1 to 17.

19. Method for manufacturing a magnetic coil (1, 1a) constructed according to any one of claims 1 to 17, characterized by that the partial plate layers (8; 8a-8h, 43a-43h, 44a-44h, 47a-47h) are each manufactured using the following steps: 51) the partial plates (5; 5a-5c; 9, 9a, 9b) of the partial plate layer (8; 8a-8h, 43a-43h, 44a-44h, 47a-47h) are arranged successively and fastened together, wherein the grooves (16; 21) of the partial plates (5; 5a-5c; 9, 9a, 9b) are aligned, and wherein no conductors (22) are yet arranged in the grooves (16; 21) of the partial plates (5; 5a-5c; 9, 9a, 9b), in particular wherein butt joints (70) of the partial plates (5; 5a-5c; 9, 9a, 9b) are welded together; 52) a piece (73) of a superconducting conductor (22) is inserted into each of the grooves (16; 21) of the partial plate layer (8; 8a-8h, 43a-43h, 44a-44h, 47a-47h), the length (LS) of which corresponds to the length (LN) of the groove (5; 5a-5c; 9, 9a, 9b) of the partial plate layer (8; 8a-8h, 43a-43h, 44a-44h, 47a-47h) along the local longitudinal direction (LLR); Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT and that the magnet coil (1, ala) is assembled from the partial plate layers (8; 8a- 8h, 43a-43h, 44a-44h, 47a-47h) produced in this manner.

20. Method for assembling a magnetic coil (1, 1a) constructed according to any one of claims 1 to 17, wherein the magnetic coil (1, 1a) comprises at least one insertion section (ES, wES) and at least one further section (WS; WS1, WS2, WS3, ZS, AS), characterized by that first the further section (WS; WS1, WS2, WS3, ZS, AS) is provided, in particular wherein the partial plate layers (43a-43h, 44a-44h, 47a-47h) of the at least one further section (WS; WS1, WS2, WS3, ZS, AS) are stacked next to each other, and that afterwards the partial plate layers (8; 8a-8h) of the at least one insertion section (ES, wES) are added, wherein with respect to the associated stack end side (OSE; SEI, SE2) according to a) or b) in the plate layer stack (4) partial plate layers (8; 8a-8h) located further inwards are added temporally before partial plate layers (8; 8a-8h) located further outwards, thereby obtaining the complete magnet coil (1, ala).

21. Method for disassembling a magnetic coil (1, 1a) constructed according to any one of claims 1 to 17, wherein the magnetic coil (1, 1a) comprises at least one insertion section (ES, wES) and at least one further section (WS; WS1, WS2, WS3, ZS, AS), characterized by that, starting from the complete magnet coil (1, a1a), the partial plate layers (8; 8a-8h) of the at least one insertion section (ES, wES) are first dismantled, wherein, with respect to the associated stack end side (OSE; SEI, SE2), according to a) or b) in the plate layer stack (4), the outermost partial plate layers (8; 8a-8h) are dismantled before the innermost partial plate layers (8; 8a-8h), whereby the at least one further section (WS; WS1, ) of the magnet coil (1, a1a) is removed. Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT WS2, WS3, ZS, AS) remains, in particular wherein the partial plate layers (43a-43h, 44a-44h, 47a-47h) of at least one further coil section (WS; WS1, WS2, WS3, ZS, AS) are then destacked. Gauss Fusion GmbH 10 / 16 / 2025 SP14052PCT

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