Multi-layer shielding cabin and method for manufacturing a multi-layer shielding cabin

Abstract

Multi-layered shielded cabin that an outer shell (2) with a first soft magnetic alloy having an initial permeability µ i1 and a maximum permeability µ max1 exhibits an inner shell (3) with a second soft magnetic alloy having an initial permeability µ i2 and a maximum permeability µ max2 exhibits, exhibits where µ i denotes the initial permeability at a control output of H=0.1 A / m, and wherein the outer shell (2) encloses the inner shell (3) and µ max1 > µ max2 and µ i2 > µ i1 .

Description

[0001] The invention relates to a multi-layer shielding cabin and a method for manufacturing a multi-layer shielding cabin.

[0002] Magnetic shielding enclosures (MSR) serve to shield against external magnetic interference fields by surrounding the volume to be shielded with a highly permeable material. The magnetic flux is then preferably guided through this soft magnetic material.

[0003] Magnetic shielding chambers are used, for example, in the medical and research fields to shield magnetically sensitive devices such as magnetic encephalography (MEG) systems from external magnetic fields. The effectiveness of a shielding chamber is specified using the shielding factor S and the so-called residual field.

[0004] Documents DE 10 2007 017 316 A1, DE 41 26 690 A1 and DE 40 29 498 A1 each disclose a shielding cabin. Documents US 2015 / 0253391 A1 and US 2014 / 0320369 A1 each disclose a multi-layer arrangement for magnetic shielding.

[0005] The ratio of external field H a to inner field H i The shielding factor S within the shielded volume is also referred to as the shielding factor, i.e. S=Ha / Hi, where with good shielding effect H i << H a applies.

[0006] The shielding factor S depends on geometric factors, such as the thickness of the shielding wall or the size of the volume to be shielded. The permeability µ is a relevant material property. r decisive. For a simple spherical shell with diameter D and thickness d, for example, the following applies: S=43μrdD+1.

[0007] For a given geometry, S is approximately proportional to the permeability: S≈const⋅μr.

[0008] Therefore, highly permeable materials from the class of 80% NiFe alloys are typically used as materials for shielding cabins, for example MUMETALLO with the nominal composition 77% Ni 4.5% Cu 3.3% Mo, balance Fe (values ​​in wt.%).

[0009] Since the shielding effect of a single layer is limited, shielding cabins are typically manufactured from multiple shells of MUMETALL®, for example, up to seven shells. With a sufficiently large distance between the individual shells, the shielding effect is approximately multiplicative. In the analytically solvable spherical shell model, the shielding factor is calculated for two shells 1 (outer) and 2 (inner) with shielding factors S1 and S2, and two diameters D1 and D2 with D2. <D1 eine Gesamtschirmwirkung S ges as follows: Stotal=S1⋅S2⋅[1−(D2D1)3]+S1+S2+1≈S1⋅S2

[0010] Furthermore, one or more additional shells made of a highly electrically conductive material can be present to achieve additional shielding at higher frequencies (effectively even at f ≥ 1 Hz). An example of this is the use of an additional shell made of aluminum.

[0011] The goal is to achieve a better shielding effect in a multi-layered shielding cabin.

[0012] According to the invention, a multi-layered shielding cabin is provided, comprising an outer shell with a first soft magnetic alloy having an initial permeability µ. i1 and a maximum permeability µ max1 has an inner shell with a second soft magnetic alloy, which has an initial permeability µ i2 and a maximum permeability µ max2 exhibits, wherein µ iThe initial permeability at a modulation of H = 0.1 A / m is denoted. The outer shell encloses the inner shell and µ max1 > µ max2 and µ i2 > µ i1 .

[0013] The first and second alloys therefore have different maximum permeabilities and different initial permeabilities, and may also have different compositions.

[0014] In the shielding cabin according to the invention, the permeability of the individual shells is adjusted with respect to the position of the shell in the shielding cabin, such that the outer shell has a higher maximum permeability than the inner shell, i.e. µ max2 < µ max1 and the inner shell has a higher initial permeability than the outer shell, i.e., µ i1 < µ i2 The multi-layered shielding cabin according to the invention reduces the residual field in the cabin in addition to shielding against alternating magnetic fields.

[0015] Here, the initial permeability is denoted by µ. r at a control output of H=0.1 A / m.

[0016] The multi-layered shielding cabin according to the invention can have more than two layers, for example up to six or more layers, and can have n layers, where n is a natural number, where n ≥ 1. The n layers of the shielding cabin are arranged at intervals and essentially concentrically around a center point of the shielding cabin. Each layer is arranged separately from the adjacent layer(s).

[0017] With respect to the center point of the cabin, the inner shell, made of the second soft magnetic alloy, can be the innermost shell and directly define the interior of the shielded cabin, which is protected from external magnetic fields. The outer shell, made of the first alloy, can be arranged directly around the inner shell, or one or more additional shells can be placed between the inner and outer shells. These additional shells can be made of the same alloy as the outer shell, namely the first alloy. It is also possible that, with respect to the center point of the cabin, the inner shell is located within the outer shell, but is not the innermost shell.

[0018] The multi-layered shielding cabin can also have more than one layer with the second soft magnetic alloy.

[0019] In some embodiments, the multi-layered shielding cabinet further comprises one or more layers made of a non-magnetic, electrically conductive material to achieve additional shielding at higher frequencies f, for example, at f ≥ 1 Hz. For example, the multi-layered shielding cabinet may have one or more layers made of aluminum.

[0020] The residual field is calculated from the locally measured (static) earth field and the static shielding factor S. DC : HRest=Hearthfield / SDC

[0021] Typically H Erdfeld =32 A / m are approximately H in the center of a normal double-walled cabin made of MUMETALL® Rest Measured at 0.064 A / m. This corresponds to S DC=500. Investigations on multi-layered enclosures have shown that the residual field cannot be reduced arbitrarily by using additional layers. A limiting factor is the remanent magnetic stray field of the shielding plates themselves. In principle, this can be reduced by demagnetizing the walls of the shielding enclosure. However, due to the complex construction and geometry of the enclosure, optimal demagnetization has not yet been achieved. According to the invention, a material with low remanence is used for the innermost layer of a shielding enclosure, so that the negative influence of the shielding enclosure itself is reduced regardless of whether the enclosure is demagnetized.

[0022] By selecting different soft magnetic materials for the various shells, a better shielding effect is ensured according to the invention. This allows, on the one hand, more technically demanding specifications regarding the shielding factor and the residual field to be met. Furthermore, it is possible to achieve the same shielding effect with reduced material usage, instead of better shielding with the same amount of material.

[0023] The selection of alloys for the individual shells is based on the fact that the different shells of a shielded cabin are exposed to varying field strengths. Since permeability is field strength-dependent, the optimal permeability can be achieved for each shell by selecting the appropriate material. Increasing at least one individual shielding factor thus also significantly increases the shielding factor of the entire cabin.

[0024] Of all the shells in a shielded cabin, the outer shell is exposed to the highest magnetic field strength H1, i.e., the external field strength caused by magnetic interference fields. In contrast, the next shell is itself located within the area shielded by the outer shell. Therefore, the effective field strength is reduced to a value H2 << H1. This principle continues for the subsequent shells, so that: H1>>H2…>>Hn

[0025] The shielding factors of the outer shell (S1) and the inner shells (S2 to S) n ) are, for a given geometry, proportional to the permeability, which in turn depends on the field strength: S1=c1⋅μ(H1)S2=c2⋅μ(H2)…,Sn=cn⋅μ(Hn)

[0026] To optimize the overall shielding factor Stotal ≈ S1 ⋅ S2 ⋅ … ⋅ Sn For inner layers, a material is now used that exhibits higher permeability at low field strength. Thus, the multi-layered shielding cabin according to the invention has an outer layer with a first soft magnetic alloy that has an initial permeability µ. i1 and a maximum permeability µ max1 has an inner shell with a second soft magnetic alloy, which has an initial permeability µ i2 and a maximum permeability µ max2 exhibits. The ratios µ are thereby determined. max2 < µ max1 and µi1 < µ i2 complied.

[0027] In one embodiment, the first soft magnetic alloy for the outer shell has a ratio of B r / B s of greater than 0.5, and the second soft magnetic alloy for the inner shell a ratio of B r / B s from less than 0.5.

[0028] In one embodiment, the first and second soft magnetic alloys are NiFe-based alloys with different compositions, for example, 80% NiFe alloys. For instance, the composition of both the first and second soft magnetic alloys ranges from 70 to 82 wt.% nickel, up to 11 wt.% copper, up to 6.5 wt.% molybdenum, the remainder being iron and other additives, with a minimum iron content of 9 wt.%. The additives, such as manganese, silicon, and carbon, are present up to a total content of 1%. The first and second alloys have different compositions, such that the ratios µ max2 < µ max1 and µ i1 > µ i2 must be observed.

[0029] The first soft magnetic alloy for the outer shell can contain, for example, 76 to 78 wt.% nickel, 4.0 to 5.0 wt.% copper, 2.8 to 4.5 wt.% molybdenum and at least 13 wt.% iron, or 79 to 81 wt.% nickel, 4.6 to 5.6 wt.% molybdenum, and at least 13 wt.% iron.

[0030] An example of a commercially available alloy suitable for the outer shell is MUMETALL®.

[0031] The second soft magnetic alloy for the inner shell can contain, for example, 80 to 82 wt% nickel, 5.5 to 6.5 wt% molybdenum, and at least 10 wt% iron, or 77 to 79 wt% nickel, 4 to 5 wt% copper, 4 to 5 wt% molybdenum, and at least 10 wt% iron. An example of a commercially available alloy suitable for the inner shell is ULTRAVAC® 816. Another suitable alloy is ULTRAPERM® 91R.

[0032] Further structural features of the inner and outer shells can be determined to further improve the magnetic shielding. In one embodiment, the inner and outer shells each have a base plate and at least one sheet layer made of the first alloy and the second alloy, respectively. The base plate can be made of a vibration-damping material such as medium-density fiberboard (MDF).

[0033] In one embodiment, the sheet metal layer is formed from several sheets arranged side by side on the base plate. The sheet metal layers can have at least two stacked layers, each consisting of several sheets arranged side by side, with the sheets of adjacent layers running crosswise to each other. The sheets of adjacent layers can be bonded together using an adhesive.

[0034] In one embodiment, the adhesive is selected to provide vibration damping, thereby further improving magnetic shielding. The adhesive can be flexible, elastic, or viscoelastic. In one embodiment, the adhesive comprises a silane-modified polymer or polyurethane.

[0035] In one embodiment, the inner shell and the outer shell are each formed from several panels, with at least one of the panels having a linear dimension greater than 0.8 m.

[0036] A method for manufacturing a multi-layered shielding cabin is also provided. Several first panels are assembled to form an outer shell, the first panels having a first soft magnetic alloy with an initial permeability µ. i1 and a maximum permeability µ max1Several second panels are assembled to form an inner shell, the second panels having a second soft magnetic alloy that has an initial permeability µ. i2 and a maximum permeability µ max2 exhibits, wherein µ max2 < µ max1 and µ i1 < µ i2 . In the assembled shielding cabin, the outer shell encloses the inner shell.

[0037] The outermost shell can be assembled first, and then the second set of panels can be assembled inside the outer shell to form an inner shell, so that in the finished shielding cabin, the outer shell encloses the inner shell. This means that the multiple shells of the shielding cabin can be built from the outside in. However, it is also possible to reverse the process, assembling the second set of panels into an inner shell first, and then assembling the first set of panels into an outer shell outside the inner shell, thus enclosing the inner shell with the outer shell.

[0038] To manufacture a first panel, a first shielding layer consisting of at least one sheet of the first soft magnetic alloy can be attached to a non-magnetic base plate using an adhesive. Similarly, to manufacture a second panel, a second shielding layer consisting of at least one sheet of the second soft magnetic alloy can be attached to a non-magnetic base plate using an adhesive.

[0039] The adhesive can be a flexible adhesive, for example an elastic adhesive, or a viscoelastic adhesive such as a silane-modified polymer (SMP) adhesive or a polyurethane adhesive.

[0040] In one embodiment, to produce a first panel for the outer shell, several sheets of the first alloy are attached side by side to the base plate using the adhesive to form a first sheet layer of the first shielding layer. Several sheets of the first alloy can be attached side by side to the first sheet layer using the adhesive to form a second sheet layer of the first shielding layer, with the sheets of the second sheet layer being laid crosswise to the sheets of the first sheet layer.

[0041] This process can also be used to produce a second panel for the inner shell. Several sheets of the second alloy are bonded side by side to the base plate using adhesive to form the first layer of the second shielding layer. Several sheets of the second alloy can be bonded side by side to the first layer using adhesive to form the second layer of the second shielding layer, with the sheets of the second layer laid crosswise to the sheets of the first layer.

[0042] The base plate can be made of a vibration-damping material such as medium-density fiberboard (MDF). In one embodiment, at least one of the first panels or the second panel has a linear dimension greater than 0.8 m. The multi-layered cabin can have a floor on which the multiple layers are constructed.

[0043] According to the invention, the properties and compositions of the first and second alloys of the outer shell and inner shell, respectively, are selected such that µ max2 < µ max1 and µ i1 < µ i2 In one embodiment, µ max1 > 250,000, 100,000 ≤ µ max2 ≤ 350,000, 20,000 ≤ µ i1 ≤ 80,000 and µ i2 > 80,000. The alloy for the inner shell can have a ratio of B r / B s of less than 0.5 and the alloy for the outer shell a ratio of B r / B s exhibit values ​​greater than 0.5.

[0044] The first soft magnetic alloy for the outer shell and the second soft magnetic alloy for the inner shell can be NiFe-based alloys, for example 80% NiFe alloys of different compositions.

[0045] In one embodiment, the first soft magnetic alloy for the outer shell contains 76 to 78 wt.% nickel, 4.0 to 5.0 wt.% copper, 2.8 to 4.5 wt.% molybdenum, and at least 13 wt.% iron, or 79 to 81 wt.% nickel, 4.6 to 5.6 wt.% molybdenum, and at least 13 wt.% iron. In another embodiment, the second soft magnetic alloy for the inner shell contains 80 to 82 wt.% nickel, 5.5 to 6.5 wt.% molybdenum, and at least 10 wt.% iron, or 77 to 79 wt.% nickel, 4 to 5 wt.% copper, 4 to 5 wt.% molybdenum, and at least 10 wt.% iron.

[0046] In summary, a multi-layer shielded cabin is provided, in which the properties of the shell are selected depending on the position in the multi-layered construction in order to improve the shielding in the interior and, in particular, to reduce the residual magnetic field in the interior.

[0047] Examples of implementation will now be explained in more detail with reference to the drawings. Fig. Figure 1 shows a schematic representation of a shielding cabin with two shells. Fig. Figure 2 shows hysteresis curves of selected 80% NiFe alloys. Fig. Figure 3 shows µ(H) curves of selected 80% NiFe alloys.

[0048] Fig. Figure 1 shows a schematic representation of a multi-layered shielding cabin 1 with two layers 2, 3 to illustrate the invention. However, the shielding cabin 1 is not limited to two layers 2, 3 and can have more than two layers, for example six or seven layers.

[0049] Each shell 2, 3 of the shielding cabin 1 is constructed from a floor 4, walls 5, and a ceiling 6 to completely enclose a space. The outer shell 2 completely encloses the inner shell 3 and thus has larger linear dimensions than the inner shell 3. The shells 2, 3 are typically separated from each other. Furthermore, the shielding cabin 1 has a door 7 to allow access to the shielded interior 8 of the shielding cabin.

[0050] The shells 2, 3 each have a base plate 9 on which one or more sheet layers 10 made of a highly permeable soft magnetic material are applied to form a shielding enclosure 1. The sheet layers 10 can each have several adjacent sheets 11. The sheets 11, 11' of adjacent layers 10, 10' can be arranged crosswise to each other. The base plate 9 can be made of a vibration-damping material such as medium-density fiberboard (MDF). The sheets 11, 11' can be attached to the base plate 9 or the underlying sheet layer 10 by means of an adhesive. In one embodiment, the adhesive is a viscoelastic adhesive, such as a silane-modified polymer or polyurethane. Typically, the shells 2, 3 each have several panels, each of which has a base plate 9 with sheet layers 10 that are assembled with connecting pieces to form the shell 2, 3.

[0051] According to the invention, the highly permeable material of the sheet layers 10, 10' or the sheets 11, 11' of the shells 2, 3 is selected depending on the position of the shell in the shielding chamber 1 with respect to the center point 12 of the shielding chamber 1 and thus depending on the magnetic field to which the shell is exposed. Therefore, at least one of the shells, for example the inner shell 3, has a different composition than the other shells, for example the outer shell 2.

[0052] In one embodiment, the outer shell 2 has a sheet layer 10' made of a first soft magnetic alloy with an initial permeability µ i1 on, which is lower than that with an initial permeability µ i2 a second soft magnetic alloy of sheet layer 10 of the inner shell 3.

[0053] The maximum permeability µ can be determined in this case. max1 of the first alloy higher than the maximum permeability µ max2of the second alloy. This combination of properties makes it possible to provide a multi-layered shielding cabin 1 that has an improved shielding factor and / or a lower residual field in the interior 8.

[0054] The factors to be considered when selecting the alloys for the sheet layers 10, 10' and 11, 11' respectively are now presented based on the Fig. 2 and Fig. 3 explained in more detail.

[0055] Fig. Figure 2 shows hysteresis curves of selected 80% NiFe alloys. Compared to MUMETALL® (solid line), ULTRAVAC® 816 (dotted line) has a rounded hysteresis loop. ULTRAVAC® 80 (dashed line) has a slightly rounded loop.

[0056] Currently, MUMETALL® is used for all shells to shield against small interferences, as required in shielded enclosures. A possible alternative material for an inner shell could be ULTRAVAC® 816, for example, because it has a relatively round loop, as shown in [reference to relevant documentation]. Fig. 2 shown, i.e. the ratio of remanence to saturation is low.

[0057] Fig. Figure 3 shows µ(H) curves of selected 80% NiFe alloys. The control values ​​of walls H1, H2, H3 of a theoretical three-walled cabin are also shown. The µ(H) curve of the Fig. Figure 3 shows that the permeability of a material depends on the exposure level. The exposure level to which the material is subjected in a multi-layered shielding enclosure, in turn, depends on its position within the enclosure, since the outer layers already shield the inner layers. The precise exposure level of each layer is therefore highly location-dependent, and also depends on the size of the layer and its wall thickness. Consequently, by using different materials with varying permeabilities in different positions, shielding enclosures made of multiple layers of different materials can offer advantages in their overall shielding effectiveness.

[0058] As an example, during the measurement of a finished shielding cabin, a magnetic field is generated from the outside, which is located in the center of the cabin space H ExtIf the current were 1.1 A / m, there would be no shielding booth there. It can be estimated that the outer shell is controlled with H1 ≈ 0.08–0.3 A / m (hatched area H1 in the diagram). Fig. 3) As in Fig. Figure 3 shows that, at higher output levels, MUMETALLO of average quality has a higher permeability than the two ULTRAVAC® materials shown, for the curves shown from approximately H≥0.15 A / m. MUMETALL® is therefore suitable for the outer shell 2.

[0059] As in the Fig. As shown in Figure 3, the second shell H2 is now controlled much less strongly from the outside due to the shielding effect of the outer shell H1, for example H2 ≈ 0.02–0.04 A / m. ULTRAVAC® 816 has a similar level of power in this range, as shown in the illustration. Fig. Shell 3 already has the highest permeability and thus offers better shielding. The inner shell H3 is even less affected (H3 ≈ 0.002–0.004 A / m). Therefore, for multi-shell cabins, the effects of the inner shells are very low. For these shells, a high initial permeability of the material is therefore crucial.

[0060] As from Fig. As can be seen in Figure 3, the permeability of ULTRAVAC® 816 (dotted line) decreases only slightly at lower field strengths. In comparison, the curve for MUMETALL® (solid line) shows that at the lowest measured field strength of H = 0.03 A / m, the initial permeability is lower than that of ULTRAVAC® 816. Consequently, ULTRAVAC® 816 is more suitable for the innermost shell, as it has the highest permeability and thus offers better shielding. For the outermost shell, however, a material with higher permeability at higher field strengths can still be used, i.e., ULTRAVAC® 80 or MUMETALL®.

[0061] Other materials with similar characteristics to ULTRAVAC® 816 are also suitable for the inner shell(s). One example is the alloy ULTRAPERM® 91 R, which, unlike ULTRAVAC® 816, is a copper-containing 80% NiFe alloy, but exhibits similar permeability and remanence profiles.

[0062] Table 1 shows the composition and magnetic properties of some examples of usable 80% NiFe materials. Table 1 Werkstoff NominelleZusammensetzung µ i µ max B s / T B r / T MUMETALL® Fe Ni77 Cu4.5 Mo3.3 60.000 500.000 0,78 0,45 - 0,55 U LTRAVACO 80 Fe Ni80 Mo5.0 70.000 350.000 0,73 0,30 - 0,40 ULTRAPERM®91 R Fe Ni78 Cu4.5 Mo4.5 100.000 250.000 0,66 0,20 - 0,40 U LTRAVACO 816 Fe Ni81 Mo6 100.000 200.000 0,65 0,20 - 0,40

[0063] The multi-layered shielding cabin 1 according to the invention can have n layers, where n is a natural number and n ≥ 2. At least two of the n layers have a soft magnetic alloy, wherein a layer 3 arranged inner with respect to the center point 12 has a soft magnetic alloy with a higher initial permeability than a soft magnetic alloy of a layer 2 outer with respect to the center point 12. This outer layer 2 can have a soft magnetic alloy with a higher maximum permeability than the soft magnetic alloy of the inner layer 3. One or more further layers can be arranged between this outer and inner layers 2, 3, each having soft magnetic alloys. One or more layers can also be arranged outside this outer layer 2 and / or inside the inner layer 3.The multi-layer shielding cabin 1 can also have one or more layers made of a non-magnetic, electrically conductive material, for example a metal such as aluminium or an alloy.

Claims

[1] Multi-layer shielding cabin that an outer shell (2) with a first soft magnetic alloy having an initial permeability µ i1 and a maximum permeability µ max1 exhibits an inner shell (3) with a second soft magnetic alloy having an initial permeability µ i2 and a maximum permeability µ max2 exhibits, exhibits where µ i denotes the initial permeability at a control output of H=0.1 A / m, and wherein the outer shell (2) encloses the inner shell (3) and µ max1 > µ max2 and µ i2 > µ i1 . [2] Shielding cabin according to claim 1, wherein µ max1 > 250,000, 100,000 ≤ µ max2 ≤ 350,000, 20,000 ≤ µ i1 ≤ 80,000 and µ i2 > 80,000. [3] Shielding cabin according to claim 1 or claim 2, wherein the first soft magnetic alloy for the outer shell (2) has a ratio of Br / B s of greater than 0.5 and the second soft magnetic alloy for the inner shell (3) a ratio of B r / B s exhibits a value of less than 0.

5. [4] Shielding cabin according to one of the preceding claims, wherein the first soft magnetic alloy and the second soft magnetic alloy comprise NiFe-based alloys of different compositions, preferably different 80% NiFe alloys. [5] Shielding cabin according to one of the preceding claims, wherein the first soft magnetic alloy for the outer shell (2) 76 to 78 wt.% nickel, 4.0 to 5.0 wt.% copper, 2.8 to 4.5 wt.% molybdenum and at least 13 wt.% iron, or Contains 79 to 81 wt% nickel, 4.6 to 5.6 wt% molybdenum, and at least 13 wt% iron. [6] Shielding cabin according to one of the preceding claims, wherein the second soft magnetic alloy for the inner shell (3) 80 to 82 wt.% nickel, 5.5 to 6.5 wt.% molybdenum and at least 10 wt.% iron, or Contains 77 to 79 wt.% nickel, 4 to 5 wt.% copper, 4 to 5 wt.% molybdenum and at least 10 wt.% iron. [7] Shielding cabin according to one of the preceding claims, wherein the inner shell (3) and the outer shell (2) each have a base plate (9) made of a vibration-damping material and at least one sheet layer (10) made of the first alloy or the second alloy. [8] Shielding cabin according to claim 7, wherein the base plate (9) is made of medium-density fiberboard (MDF). [9] Shielding cabin according to claim 7 or 8, wherein the sheet layer (10) is formed from several sheets (11) arranged side by side on the base plate (9). [10] Shielding cabin according to claim 9, comprising at least two layers of sheet metal (10, 10') arranged one above the other, wherein these layers (10, 10') each consist of several sheets of metal (11, 11') arranged next to each other, and the sheets of metal (11, 11') of adjacent layers (10, 10') run crosswise to each other and are fastened together by means of an adhesive. [11] Shielding cabin according to claim 10, wherein the adhesive comprises a silane-modified polymer or polyurethane. [12] Shielding cabin according to one of the preceding claims, wherein the inner shell (3) and the outer shell (2) are each formed from several panels and at least one of the panels has a linear dimension greater than 0.8 m. [13] Method for manufacturing a multi-layer shielding cabin comprising the following: Assembling several first panels to produce an outer shell (2), wherein the first panels have a first soft magnetic alloy having an initial permeability µ i1 and a maximum permeability µ max1 exhibits, and Assembling several second panels to produce an inner shell (3), wherein the second panels have a second soft magnetic alloy having an initial permeability µ i2 and a maximum permeability µ max2 exhibits wherein the outer shell (2) encloses the inner shell (3) and µ max1 > µ max2 and µ i2 > µ i1 . [14] Method according to claim 13, wherein to produce a first panel a first shielding layer (10) consisting of at least one sheet (11) of the first soft magnetic alloy is attached to a non-magnetic base plate (9) by means of an adhesive and to produce a second panel a second shielding layer (10) consisting of at least one sheet (11) of the second soft magnetic alloy is attached to a non-magnetic base plate (9) by means of an adhesive. [15] Method according to claim 14, wherein the adhesive is a silane-modified polymer (SMP) adhesive or a polyurethane adhesive. [16] Method according to claim 14 or claim 15, wherein several sheets (11) are attached side by side to the base plate (9) by means of the adhesive to form a first sheet layer (10) of the first shielding layer. [17] Method according to claim 16, wherein several sheets (11') are attached side by side to the first sheet layer (10) by means of the adhesive to form a second sheet layer (10') of the first shielding layer, wherein the sheets (11') of the second sheet layer (10') are laid crosswise to the sheets (11) of the first sheet layer (10). [18] Method according to any one of claims 14 to 17, wherein several sheets (11) are attached side by side to the base plate (9) by means of the adhesive to form a first sheet layer (10) of the second shielding layer. [19] Method according to claim 18, wherein several sheets (11') are attached side by side to the first sheet layer (10) by means of the adhesive to form a second sheet layer (10') of the second shielding layer, wherein the sheets (11') of the second sheet layer (10') are laid crosswise to the sheets (11) of the first sheet layer (10). [20] Method according to any one of claims 14 to 19, wherein the base plate (9) comprises a vibration-damping material. [21] Method according to any one of claims 14 to 20, wherein the base plate (9) comprises medium-density wood fiber (MDF). [22] Method according to any one of claims 13 to 21, wherein µ max1 >250,000, 100,000 ≤ µ max2 ≤ 350,000, 20,000 ≤ µ i1 ≤ 80,000 and µ i2 > 80,000. [23] Method according to any one of claims 13 to 22, wherein the alloy for the inner shell (3) has a ratio of B r / B s of less than 0.5 and the alloy for the outer shell (2) a ratio of B r / B s exhibits a value greater than 0.

5. [24] Method according to any one of claims 13 to 23, wherein the first soft magnetic alloy for the outer shell (2) and the second soft magnetic alloy for the inner shell (3) comprise NiFe-based alloys of different compositions, preferably different 80% NiFe alloys. [25] Method according to any one of claims 13 to 24, wherein the first soft magnetic alloy for the outer shell (2) 76 to 78 wt.% nickel, 4.0 to 5.0 wt.% copper, 2.8 to 4.5 wt.% molybdenum and at least 13 wt.% iron, or Contains 79 to 81 wt% nickel, 4.6 to 5.6 wt% molybdenum, and at least 13 wt% iron. [26] Method according to any one of claims 13 to 25, wherein the second soft magnetic alloy for the inner shell (3) 80 to 82 wt.% nickel, 5.5 to 6.5 wt.% molybdenum and at least 10 wt.% iron, or Contains 77 to 79 wt.% nickel, 4 to 5 wt.% copper, 4 to 5 wt.% molybdenum and at least 10 wt.% iron. [27] Method according to any one of claims 13 to 26, wherein at least one of the first panels or the second panel has a linear dimension greater than 0.8 m.

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