WO1992006576A1 - Magnetically shielding structure - Google Patents
Magnetically shielding structure Download PDFInfo
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- WO1992006576A1 WO1992006576A1 PCT/JP1991/001279 JP9101279W WO9206576A1 WO 1992006576 A1 WO1992006576 A1 WO 1992006576A1 JP 9101279 W JP9101279 W JP 9101279W WO 9206576 A1 WO9206576 A1 WO 9206576A1
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- WIPO (PCT)
- Prior art keywords
- cylinder
- magnetic field
- cylindrical
- permeability material
- magnetic
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0073—Shielding materials
- H05K9/0075—Magnetic shielding materials
- H05K9/0077—Magnetic shielding materials comprising superconductors
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
- G01R33/42—Screening
- G01R33/421—Screening of main or gradient magnetic field
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S505/00—Superconductor technology: apparatus, material, process
- Y10S505/825—Apparatus per se, device per se, or process of making or operating same
- Y10S505/872—Magnetic field shield
Definitions
- the present invention relates to the structure of a magnetic shield using a superconductor.More specifically, the magnetic shield performance is improved by combining magnetic shield materials having different properties, and the magnetic shield structure is improved from the opening of the superconductor cylinder.
- a magnetic shield that can reduce the intrusion magnetic field to increase the usable high magnetic field shielding space, or realize a very small magnetic field in the space inside a predetermined cylinder even with a short superconducting cylinder, and thus can efficiently realize a magnetic field much lower than the external magnetic field Regarding the structure. Background art
- a magnetic shield structure using a superconductor is a magnetic shield structure using the Meissner effect.
- a material having the Meissner effect is formed into a cylindrical shape to form a shield body, which is formed at a critical temperature Tc or lower.
- the magnetic shielding efficiency of a cylindrical shield body is good for a magnetic field (longitudinal magnetic field) parallel to the central axis of the cylinder, but is good for the central axis. Since the shielding efficiency against a magnetic field perpendicular to the horizontal direction (transverse magnetic field) is not good, there is a problem that the length must be longer than the inner diameter of the cylinder.
- a cylindrical shield body made of a high magnetic permeability material has poor shielding efficiency against a vertical magnetic field as compared with a horizontal magnetic field, and because of its finite magnetic permeability, the shielding efficiency is not high in a single layer.
- the object of the present invention was made in view of the above various points.By combining magnetic shielding materials having different properties, the magnetic shielding performance was improved, and the invasion magnetic field from the opening of the superconductor cylinder was reduced.
- a magnetic shield structure that can increase the high magnetic field shielding space that can be used as a magnetic field, or can realize a very small magnetic field in a predetermined cylindrical space even with a short superconductor cylinder, and thus can efficiently realize a magnetic field much lower than the external magnetic field The purpose is to provide.
- the magnetic induction is applied to the high magnetic permeability member with respect to the invasion magnetic field that shows an attenuation distribution toward the center on the longitudinal axis of the cylindrical shield body made of the material exhibiting the Meissner effect.
- a magnetic shield is formed by a superconducting material exhibiting the Meissner effect so that an intrusion magnetic field is absorbed by the high magnetic permeability member and magnetically short-circuited, and the longitudinal length of the cylindrical magnetic shield
- Various high-permeability cylindrical members having openings along the direction are provided in combination.
- Fig. 20 shows a schematic diagram of the invading magnetic vector inside the superconductor cylinder when a transverse magnetic field is applied to the superconductor cylinder.
- the internally penetrating magnetic field distributed in this way is magnetically short-circuited to reduce the amount of penetration into the superconductor cylinder.
- the high permeability member since the high permeability member has a residual magnetic field, it must be placed in a position where the residual magnetic field does not affect the target low magnetic field space.
- FIG. 1 is an explanatory diagram showing a configuration of a general embodiment of the present invention.
- the figure shows the end of a cylindrical magnetic shield (1) composed of an oxide superconductor.
- the length of the magnetic shield (1) is usually required to be about 2 to 20 times the cross-sectional length. Note that this range can vary depending on the size of the shield space and the strength of the magnetic field. Needless to say.
- a large-diameter ferromagnetic cylinder (2) and a small-diameter ferromagnetic cylinder (3) are arranged concentrically at the opening of the cylindrical magnetic shield (1) to prevent intrusion of a magnetic field.
- the cross section is shown.
- the figure also shows the space and distance between the magnetic shield (1) and the large-diameter ferromagnetic cylinder (2), the large-diameter ferromagnetic cylinder (2) and the small-diameter ferromagnetic cylinder (3).
- space G 2 and the distance d 2 small ferromagnetic cylinder made (3)
- (4) is a sensor placed in the target low magnetic field space.
- equation (I) is the strength Ht of the magnetic field (transverse magnetic field) when an external magnetic field is applied in a direction perpendicular to the cylinder axis
- equation (II) is the external magnetic field applied in a direction parallel to the cylinder axis.
- the magnetic field strength (longitudinal magnetic field) is Ha.
- R 1 is the radius of the superconductor cylinder
- Z is the distance from the opening. More magnetic penetration from equation is greater when applied from an external magnetic field the cylindrical axis perpendicular direction, for example when you'll reduce the magnetic field penetration depth up to 10 8 is required to enter the interior 10 times the radius. In other words, the length of the cylinder needs 10 times the radius.
- a high-permeability material cylindrical body is disposed from a center portion of a superconductor cylinder toward an end portion, a portion disposed near an end portion, There are a plurality of cylindrical members made of a high permeability material laminated in the longitudinal direction near the end portion, and a plurality of cylindrical members made of a high magnetic permeability material laminated in the radial direction.
- the high-permeability material cylindrical bodies are used independently. This is to further reduce the magnetic field that enters the inside of the cylindrical superconducting shield body as compared with the case.
- the shape of the high-permeability material cylindrical body can be inserted into the inside of a cylindrical shield body made of a superconducting material, magnetic induction occurs in the high-permeability material cylindrical body, and an intrusion magnetic field is generated by the high-permeability material.
- Any shape can be used, as long as it is absorbed into the material and magnetically short-circuited Noh. More specifically, it is an open-ended or open-ended cylindrical body having a cylindrical length larger than the thickness of the constituent members, and can have a cross-sectional shape of the cylindrical body, an ellipse, a polygon, or the like.
- a tapered shape in which the inner diameter is reduced along the longitudinal direction, a shape in which the inner and outer portions have irregularities and the inner and outer cross-sectional shapes are different, a type in which the inner opening is wider than the end opening, Includes bellows, L-shaped, T-shaped, H-shaped, + -shaped, U-shaped shapes, and combinations thereof.
- the ratio of the outer diameter of the high-permeability material cylindrical body to the inner diameter of the cylindrical shield body made of the superconducting material is, as shown in the embodiment described later, when used independently, the cylinder made of the superconducting material.
- a cylindrical body made of a high-permeability material having an outer diameter of 1 Z5 or more of the inner diameter of the cylindrical shield body is disposed inside the superconductor cylinder, a better shielding effect than that of the superconductor cylinder alone can be obtained.
- the present invention clarified a method for calculating the attenuation of a magnetic field penetrating into the gap between the superconductor and the ferromagnetic material in order to shorten the length of the cylindrical shield, and as a result, Based on this, the present invention has been accomplished.
- Fig. 2 is a diagram showing the calculation results of the attenuation of the magnetic field penetrating into the gaps between various superconductors and the ferromagnetic material.
- the vertical axis shows the K value of exp (-z / d) or the value of 10 — K ' z / d '
- the horizontal axis shows the relative value of the inner cylinder with the outer cylinder having a diameter of 1. The diameter D or the gap g between the inner and outer cylinders is shown.
- MSt is the magnetic field attenuation constant in the gap between the two cylindrical bodies due to the external magnetic field (t) perpendicular to the cylindrical axis of the inner cylindrical ferromagnetic material (M) and the outer cylindrical superconductor (S), and SMa is the inner cylindrical superconductor.
- S shows the magnetic field decay constant of the outer cylindrical ferromagnetic material (M) in the gap between the two cylindrical bodies due to the external magnetic field (a) in the cylindrical axial direction.
- G 1 is a gap composed of a ferromagnetic material and a superconductor. From Fig. 2, the attenuation of the magnetic field in the gap is approximately when d1 ⁇ 0.5 R1.
- the attenuation of the magnetic field in the gap of G 2 is approximately when d 2 is 0.5 R 2
- n If n is increased, the magnetic field attenuation can be increased, but the gap becomes smaller, so there is no limit You. In particular, the gap between the superconductor and the magnetic material is limited because the superconductor requires cooling.
- a uniform transverse magnetic field H is generally applied to an infinitely long cylinder with high permeability.
- the internal magnetic field H i when
- H i H o (III) ⁇ : magnetic permeability, t: wall thickness, r: radius
- the magnetic field attenuation remains at a finite value.
- the magnetic permeability of a ferromagnetic material is significantly reduced, and the amount of magnetic field attenuation is limited. 10- 5 degree of attenuation is Ru practical limit der.
- the value of ⁇ is determined in consideration of these points.
- a high permeability material can be used for an invading magnetic field which shows an attenuation distribution toward the center on the longitudinal axis of a cylindrical shield body made of a material exhibiting the Meissner effect.
- Magnetic induction is generated in the cylindrical body, and as a result, the penetrating magnetic field is absorbed by the high-permeability material and magnetically short-circuits, thereby further reducing the magnetic field penetrating into the cylindrical superconducting shield.
- a cylinder made of a high-permeability material is disposed inside a superconductor cylinder, one disposed near an end, and a plurality of cylinders made of a high-permeability material are disposed near an end. And those in which a plurality of cylindrical members made of a high magnetic permeability material are laminated in the radial direction.
- the high-permeability material cylindrical bodies are used independently. The magnetic field penetrating into the inside of the cylindrical superconducting shield is further reduced.
- the shielding effect that cannot be obtained by various cylinders alone can be obtained, the usable low magnetic field space can be increased, or the intended magnetic field shielding space or low magnetic field space can be obtained.
- the cost can be reduced because the length of the cylindrical superconducting shield required to obtain it can be reduced.
- FIG. 1 is an explanatory diagram showing a configuration of a general embodiment of the present invention
- Figure 2 is a diagram showing the calculation results of the attenuation of the magnetic field that penetrates into the gaps between various superconductors and the ferromagnetic material.
- Fig. 3 is a cross-sectional view in which a cylinder made of a high-permeability material that changes the size of the outer diameter D is arranged.
- Fig. 5 is a diagram showing the relationship between the outer diameter D of the cylinder made of a high permeability material and the shielding effect E.
- Fig. 6 is a cross-sectional view of a cylinder made of a high permeability material with an open-ended superconductor cylinder.
- Fig. 7 is a cross-sectional view of a superconducting cylinder with open ends, and a tapered cylinder made of high permeability material.
- Fig. 8 is a cross-sectional view in which a cylinder made of a high permeability material having a length of 2 P is arranged,
- Figure 9 is a diagram showing the distribution of the internal magnetic field on the superconductor cylindrical shaft when the length of the cylinder made of high permeability material was changed by 2 P.
- FIG. 10 is a diagram showing the relationship between the length 2 P of the high-permeability material cylinder and the internal magnetic field
- FIG. 11 is a cross-sectional view in which a high-permeability material cylinder whose length L is changed is arranged.
- Fig. 12 is a diagram showing the relationship between the length L of the cylinder made of high permeability material and the shielding effect
- Fig. 13 shows two cylinders made of high permeability material stacked in the longitudinal direction of the cylinder made of superconductor. Cross section,
- Fig. 14 is a diagram showing the internal magnetic field distribution on the superconductor cylinder axis when two high permeability cylinders are stacked in the longitudinal direction.
- Fig. 15 is a cross-sectional view in which two cylinders made of high permeability material are superposed in the radial direction of the cylinder made of superconductor.
- Fig. 16 is a diagram showing the internal magnetic field distribution on the superconducting cylinder axis when two high-permeability cylinders are superposed in the radial direction.
- Figures 17A, B, and C are cross-sectional views of multiple high-permeability material cylinders arranged in multiple layers and multiple layers in the radial and longitudinal directions.
- Figure 17A shows two long high-permeability material cylinders.
- Fig. 17B Fig. 17B Fig. 17B Fig. 17B Fig. 17B is a cross-sectional view in which three sets of two high-permeability cylinders are arranged in the radial direction and stacked in the longitudinal direction.
- C is a small diameter high permeability material Sectional view in which cylinders and cylinders of high permeability material with large diameter are alternately stacked.
- Fig. 18 Fig. 17 Superconductivity when cylinders of high permeability material of A, B and C are arranged A diagram showing the internal magnetic field distribution on the cylindrical shaft of the body,
- FIG. 19 is an explanatory view showing a configuration of another embodiment of the present invention, that is, a configuration in which a cylindrical body made of a high magnetic permeability material is installed near the end of the superconducting cylinder (that is, inside and outside).
- FIG. 20 is an explanatory diagram showing a magnetic field distribution when a transverse magnetic field is applied to the superconducting cylinder.
- FIG 3 is a cross-sectional view in which a cylinder made of a high-permeability material whose outer diameter D is changed is arranged.
- superconductor cylinder One high-permeability cylinder (FM) was placed 80 mm from the center of (SC).
- the former size is about 100 inside diameter, 240mm in length, and 5 min in thickness.
- the latter has a length of 10 o'clock, a thickness of 0.2 cages, a permeability of 10,000, and a different outer diameter D.
- FIG. 4 shows the internal magnetic field distribution (Hi (Z)) on the superconducting cylinder (SC) axis when the outer diameter D of the high permeability material cylinder (FM) was changed (hereafter, Z in all examples).
- Hi the internal magnetic field distribution
- the vertical axis indicates the internal magnetic field (Hi)
- the horizontal axis indicates the distance Z from the open end of the superconductor cylinder (SC), where SC is the superconductor without using the high permeability material cylinder (FM).
- the penetration magnetic field at the center position of the superconductor cylinder (SC) is smaller when the high-permeability cylinder (FM) is inserted than when the superconductor cylinder (SC) is used alone.
- the high permeability material cylinder (FM) absorbed the longitudinal component of the penetrating magnetic field into itself by magnetic induction, and caused a magnetic short circuit.
- FIG. 9 is a diagram showing a shielding effect E, which is normalized by a magnetic field Hsc (120), and a function as a function of an outer diameter D of a high-permeability cylinder (FM).
- the shielding effect becomes better. This is because the longitudinal component of the penetrating magnetic field, which increases in the radial direction inside the superconductor cylinder (SC), is increased by increasing the outer diameter of the high-permeability cylinder (FM). It was absorbed and magnetically short-circuited. Conversely, when the outer diameter is 20 marauders, the shielding effect is 1, indicating that the high-permeability material cylinder (FM) has no effect. In the radial direction of this range, a magnetic short-circuit effect is hardly obtained because the longitudinal component of the penetrating magnetic field is small.
- FIG. 6 is a cross-sectional view in which a cylinder made of high permeability material (FM) is arranged on a cylinder (SC) made of a superconductor with an open end.
- One high-permeability cylinder (FM) was placed 80 mni from the bottom of the open-ended superconductor cylinder (SC).
- the former has an inner diameter of l O Omnu, a length of 120 and a wall thickness of 5 mm.
- the latter has a length of 10 mm, a wall thickness of 0.2 mm, a magnetic permeability of 10,000 and a different outer diameter D mm.
- a uniform transverse magnetic field of 1 [G] was applied to the superconducting cylinder (SC), and the magnetic field at a position 30 mm from the bottom surface on the cylinder axis was measured.
- FIG. 7 is a cross-sectional view in which a taper-shaped cylinder made of a high-permeability material (FM) is disposed on a superconductor cylinder (SC) having both ends open. That is, one cylinder of high permeability material (FM) was placed at 80 positions from the center of the superconductor cylinder (SC) with open ends.
- the size of the former is 100 inner diameters, 240 mra in length, and 5 mm in wall thickness.
- the latter has a maximum outer diameter of 80 strokes, a minimum outer diameter of 60 strokes, Height lOranu Wall thickness 0.2mm, permeability 10,000.
- FIG. 8 is a cross-sectional view in which a cylinder (FM) made of a high-permeability material having a length of 2 P is arranged.
- a 2P long cylinder made of a high permeability material (FM) was placed near the center of the open-ended bismuth-based oxide superconductor cylinder (Bi-Sr-Ca-Cu-0).
- the size of the former is 100 mm in inner diameter, 150 mm in length, and 5 thickness.
- the latter has an inner diameter of 75 mm, a wall thickness of 2 mm, a magnetic permeability of 10,000 and a length of 2 Pmni.
- FIG. 9 is a diagram showing the internal magnetic field distribution on the axis of the superconductor cylinder (SC) when the length 2 P of the cylinder made of high magnetic permeability material (FM) is changed.
- the vertical axis represents the internal magnetic field (Hi)
- the horizontal axis represents the distance Z from the center of the cylinder.
- SC + FM25 represents a cylinder made of superconductor (SC) and a cylinder made of high permeability material (FM).
- FIG. 10 is a diagram showing the internal magnetic field (Hi) when the length of the high permeability material cylinder (FM) is variously changed.
- the vertical axis indicates the internal magnetic field (Hi)
- the horizontal axis indicates the length P of the high-permeability member cylinder (FM).
- the internal magnetic field (Hi) is the magnetic field at the center of the cylinder. The results for the case where the cylinder made of the body (SC) and the cylinder made of the high-permeability material (FM) are combined are shown.
- FIG. 11 is a cross-sectional view in which a cylinder made of a high magnetic permeability material (FM) whose length L is changed is arranged.
- FM magnetic permeability material
- SC superconductor cylinder
- One high-permeability cylinder (FM) was installed for each.
- the former has an inner diameter of lOOtrniu, a length of 240 mm and a thickness of 5 strokes.
- the latter has an outer diameter of 70 marauders, a wall thickness of 0.2 mm, and a permeability of 10,000, and has a different length.
- FIG. 12 is a diagram showing the relationship between the length L of the cylinder (FM) made of a high magnetic permeability material and the shielding effect. That is, the vertical axis represents the above equation (IV).
- the shielding effect E shown in) is the length L of the cylinder (FM) made of a material with high magnetic permeability on the horizontal axis. From this figure, it can be seen that the longer the length L of the cylinder made of high permeability material (FM), the better the shielding effect.
- FIG. 13 is a cross-sectional view in which two cylinders made of high magnetic permeability material (FM) are stacked and arranged in the longitudinal direction of the cylinder made of superconductor (SC).
- high permeability is provided at 80 mni and 60 mm from the center of a bismuth-based oxide superconductor cylinder (Bi-Sr-Ca-Cu-O) (hereinafter referred to as superconductor cylinder (SC)) with open ends.
- SC bismuth-based oxide superconductor cylinder
- the size of the superconductor cylinder (SG) is 100 inner diameter, 240mm in length, and 5 wall thickness.
- the high permeability cylinder (FM) has a length of 70, a wall thickness of 0.2 min, and a permeability of 10,000.
- FIG. 14 is a diagram showing the internal magnetic field distribution H i (Z) on the axis of the superconductor cylinder (SG) when two cylinders made of high permeability material (FM) are stacked in the longitudinal direction.
- the vertical axis represents the internal magnetic field (Hi)
- the horizontal axis represents the distance Z from the center of the superconductor cylinder (SC).
- the internal magnetic field distribution is also shown for a cylinder (FM) located 80 stiff from the center.
- the SC shows the internal magnetic field distribution Hsc (Z) for a superconducting cylinder (SC) without using a cylinder made of a high permeability material (FM).
- the result is divided into more intervals than increasing the length of the high permeability village cylinder (FM). This shows that the arrangement improves the shielding effect.
- the shielding effect was not improved by a certain length even if the length was increased, but the short-length high permeability cylinders (FM) were spaced apart in the cross-sectional direction.
- the high permeability material cylinders (F) were not magnetically connected because they were not magnetically connected, and it was found that the more layers were stacked, the better the shielding effect was.
- the desired magnetic field can be obtained efficiently and inexpensively.
- Fig. 15 is a cross-sectional view in which two high-permeability cylinders (FM) are superposed in the radial direction of the superconductor cylinder (SC).
- the outer ends of the open-ended bismuth-based oxide superconductor cylinder (Bi-Sr-Ca-Cu-0) (hereinafter referred to as superconductor cylinder (SC)) are located at 80 ram from the center.
- Two high-permeability cylinders (FM) with different diameters were layered.
- the size of the superconductor cylinder (SC) is 100 mm in inner diameter, 240 mm in length, and 5 walls in thickness.
- the cylinder made of high permeability material (FM) has a length of 10mm, a wall thickness of 0.2mra, a permeability of 10,000, and an outer diameter of 80mm and 60mm respectively.
- FIG. 16 is a diagram showing the internal magnetic field distribution H i (Z) on the axis of the superconductor cylinder (SC) when two high-permeability cylinders (FM) are superposed in the radial direction.
- the vertical axis represents the internal magnetic field (Hi), and the horizontal axis represents the distance Z from the center of the superconductor cylinder (SC).
- the target magnetic field can be obtained efficiently and inexpensively, even if the high permeability material cylinders (FM) are layered at intervals in the radial direction as in Example 4.
- Figures 17A, B, and C are cross-sectional views of multiple high-permeability cylinders (FM) arranged in multiple layers and multiple layers in the radial and longitudinal directions.
- Figure 17A shows two long high-permeability cylinders.
- Figure 17B shows three sets of two high-permeability cylinders (FM) arranged in the radial direction. Three sets of two cylinders (FM) arranged in the radial direction are arranged in the longitudinal direction.
- FIG. 17C is a cross-sectional view in which small-diameter high-permeability material cylinders (FM) and large-diameter high-permeability material cylinders (FM) are alternately stacked. That is, FIGS.
- FIG. 17A to 17C show the inside of an open-ended bismuth-based oxide superconductor cylinder (Bi-Sr-Ca-Cu-O) (hereinafter referred to as superconductor cylinder (SG)).
- Cylinders (FM) made of a high magnetic permeability material with the shape shown in Fig. 1 were laminated.
- the superconductor cylinder (SG) has an inner diameter of 100 mm, a length of 240 dragons, and a wall thickness of 5 m.
- the permeability of all cylinders made of high permeability material (FM) is 10,000.
- a uniform transverse magnetic field of 1 [G] was applied to the superconductor cylinder (SC), and the magnetic field distribution on the cylinder axis was measured.
- Fig. 17A shows a high permeability material cylinder (FM1) with an outer diameter of 80 and a length and a high permeability material cylinder (FM2) with an outer diameter of 60IM and a length of 50 mm laminated in the radial direction. It was done.
- Fig. 17B shows a high permeability material cylinder (801) with an outer diameter of 80 imn and a length of 10 ( ⁇ 1) and a high permeability material cylinder (FM2) with an outer diameter of 60 and a length of 10 (length) in the radial direction.
- Fig. 17C shows a high permeability material cylinder (FM1) with an outer diameter of 80mra and a length of 10mm and a high permeability material cylinder (FM2) with an outer diameter of 60 and a length of 10mm alternately in the longitudinal direction.
- FM1 high permeability material cylinder
- FM2 high permeability material cylinder
- Fig. 18 is a line showing the internal magnetic field distribution H i (Z) on the axis of the superconductor cylinder (SC) when the high-permeability cylinders (FM) of A, B, and C are installed.
- the vertical axis represents the internal magnetic field (Hi) and the horizontal axis represents the distance Z from the center of the superconductor cylinder (SC).
- SC is a superconducting cylinder (SC) without using a high permeability material cylinder (FM).
- the internal magnetic field distribution Hsc (Z) the mouth is as shown in Fig. 17 ⁇ , ⁇ is as shown in Fig. 17B, and x is as shown in Fig. 17C.
- Fig. 17A shows that the high permeability material has a finite permeability and magnetically saturates when there is a magnetic field gradient inside the superconducting cylinder (SC), similar to the result of Example 3 described above. As a result, it is expected that longer lengths will not improve the shielding effect anymore.
- FIG. 17C shows an example in which cylinders having different outer diameters are alternately stacked in the longitudinal direction.
- the shielding effect is better than that of Fig. 17A by stacking them at intervals.
- an outer diameter of 80 ram x 2 and a cylinder of high permeability material (FM) with 60 strokes x 3 are used. From the results of Example 1, the outer diameter is 8 Omm x 3, 60 mm x 2 It is easily presumed that the use of a high-permeability material cylinder (FM) improves the shielding effect.
- FM high-permeability material
- Fig. 17 For each of the models A, B, and C, the open-ended superconductor cylinder with half the length of the open-ended superconductor cylinder (SC) is used. The same effect can be obtained by using (SC) and arranging a high permeability cylinder (FM) at the same position from the open end.
- SC open-ended superconductor cylinder with half the length of the open-ended superconductor cylinder
- FIG. 19 is an explanatory view showing the structure of another embodiment of the present invention.
- the opening covering (42) of a superconductor cylinder (41) with an inner diameter of 1 m and a length of 2 m of the circular cross section is 150 cm long, and (43) and (44) are long. It has a diameter of 80 cra and a concentrically fitted cylinder made of ferromagnetic material (permalloy) with a thickness of 5 mm and diameters of 110 cm, 81 cm, and 52 cm, respectively.
- ferromagnetic material permalloy
- the internal magnetic field strength 1 9 A was measured, was respectively 1 (gamma 4, 4x10 fold against the magnetic field Ho external magnetic field B points. On the other hand was measured by removing the structure 1 9 a, respectively to the magnetic field Ho external magnetic field B points 10 1, was 6 ⁇ ⁇ 10- 4 times. the magnetic field that invades can be significantly reduced in the superconductor made cylinder by the present invention from this that (SC) I understand.
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Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
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DE69124221T DE69124221D1 (de) | 1990-09-28 | 1991-09-26 | Magnetische abschirmungsstruktur |
EP91916939A EP0503085B1 (en) | 1990-09-28 | 1991-09-26 | Magnetically shielding structure |
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
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JP25718990 | 1990-09-28 | ||
JP2/257189 | 1990-09-28 | ||
JP2/263843 | 1990-10-03 | ||
JP2263843A JP2795531B2 (ja) | 1990-10-03 | 1990-10-03 | 磁気シールド構造 |
JP3080464A JP2825363B2 (ja) | 1990-09-28 | 1991-03-20 | 磁気シールド構造 |
JP3/80464 | 1991-03-20 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US08/308,474 Continuation US6486393B1 (en) | 1990-09-28 | 1994-09-19 | Magnetically shielding structure |
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WO1992006576A1 true WO1992006576A1 (en) | 1992-04-16 |
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PCT/JP1991/001279 WO1992006576A1 (en) | 1990-09-28 | 1991-09-26 | Magnetically shielding structure |
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US (1) | US6486393B1 (ja) |
EP (1) | EP0503085B1 (ja) |
CA (1) | CA2069637A1 (ja) |
DE (1) | DE69124221D1 (ja) |
WO (1) | WO1992006576A1 (ja) |
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US7026905B2 (en) * | 2000-05-24 | 2006-04-11 | Magtech As | Magnetically controlled inductive device |
JP4243691B2 (ja) * | 2003-01-29 | 2009-03-25 | 独立行政法人情報通信研究機構 | 脳磁界計測装置とその使用方法 |
US7305836B2 (en) * | 2004-05-19 | 2007-12-11 | Eden Innovations Ltd. | Cryogenic container and superconductivity magnetic energy storage (SMES) system |
JP4595102B2 (ja) * | 2004-12-20 | 2010-12-08 | 独立行政法人情報通信研究機構 | 超伝導磁気シールド脳磁界計測装置の計測構造体 |
GB201116948D0 (en) | 2011-10-03 | 2011-11-16 | Rolls Royce Plc | A magnetic shield |
US10755190B2 (en) | 2015-12-21 | 2020-08-25 | D-Wave Systems Inc. | Method of fabricating an electrical filter for use with superconducting-based computing systems |
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Publication number | Priority date | Publication date | Assignee | Title |
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JPS58148499A (ja) * | 1982-02-27 | 1983-09-03 | 富士通株式会社 | 超低温用磁気遮蔽容器 |
JPS5990997A (ja) * | 1982-11-17 | 1984-05-25 | 富士通株式会社 | 磁気遮へい容器 |
JPH03197897A (ja) * | 1989-12-26 | 1991-08-29 | Furukawa Electric Co Ltd:The | 超電導磁気シールド構造体 |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2721995A (en) * | 1953-06-15 | 1955-10-25 | Magnetic Metals Company | Cathode ray tube shield structures |
US3361940A (en) * | 1959-09-29 | 1968-01-02 | Rand Corp | Process of forming a super-conductive magnetic shield |
JP2527554B2 (ja) * | 1987-03-23 | 1996-08-28 | 大阪府 | 超電導磁気遮蔽体 |
JPS63313900A (ja) * | 1987-06-17 | 1988-12-21 | Kawasaki Steel Corp | 複合超電導磁気遮蔽材料 |
JPH01253690A (ja) * | 1988-04-01 | 1989-10-09 | Shimadzu Corp | 磁気シールド装置 |
US5466885A (en) * | 1990-09-27 | 1995-11-14 | Furukawa Denki Kogyo Kabushiki Kaisha | Magnetically shielding structure |
JP2768815B2 (ja) * | 1990-09-27 | 1998-06-25 | 古河電気工業株式会社 | 磁気シールド構造 |
JP3197897B2 (ja) | 1990-11-16 | 2001-08-13 | 株式会社壽 | シャープペンシル |
-
1991
- 1991-09-26 EP EP91916939A patent/EP0503085B1/en not_active Expired - Lifetime
- 1991-09-26 DE DE69124221T patent/DE69124221D1/de not_active Expired - Lifetime
- 1991-09-26 CA CA002069637A patent/CA2069637A1/en not_active Abandoned
- 1991-09-26 WO PCT/JP1991/001279 patent/WO1992006576A1/ja active IP Right Grant
-
1994
- 1994-09-19 US US08/308,474 patent/US6486393B1/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS58148499A (ja) * | 1982-02-27 | 1983-09-03 | 富士通株式会社 | 超低温用磁気遮蔽容器 |
JPS5990997A (ja) * | 1982-11-17 | 1984-05-25 | 富士通株式会社 | 磁気遮へい容器 |
JPH03197897A (ja) * | 1989-12-26 | 1991-08-29 | Furukawa Electric Co Ltd:The | 超電導磁気シールド構造体 |
Non-Patent Citations (1)
Title |
---|
See also references of EP0503085A4 * |
Also Published As
Publication number | Publication date |
---|---|
EP0503085A1 (en) | 1992-09-16 |
EP0503085A4 (en) | 1993-03-17 |
US6486393B1 (en) | 2002-11-26 |
EP0503085B1 (en) | 1997-01-15 |
DE69124221D1 (de) | 1997-02-27 |
CA2069637A1 (en) | 1992-03-29 |
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