US3924210A - Field shaping magnet structure - Google Patents

Field shaping magnet structure Download PDF

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Publication number
US3924210A
US3924210A US520074A US52007474A US3924210A US 3924210 A US3924210 A US 3924210A US 520074 A US520074 A US 520074A US 52007474 A US52007474 A US 52007474A US 3924210 A US3924210 A US 3924210A
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United States
Prior art keywords
array
soft magnetic
magnet structure
pole pieces
spaced
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Expired - Lifetime
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US520074A
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English (en)
Inventor
Norman J Dionne
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Raytheon Co
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Raytheon Co
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Publication date
Application filed by Raytheon Co filed Critical Raytheon Co
Priority to US520074A priority Critical patent/US3924210A/en
Priority to CA236,662A priority patent/CA1027626A/en
Priority to IL48228A priority patent/IL48228A/xx
Priority to IT51785/75A priority patent/IT1047775B/it
Priority to FR7532358A priority patent/FR2290008A1/fr
Priority to BE161204A priority patent/BE834817A/xx
Priority to DE2548439A priority patent/DE2548439C2/de
Priority to GB45422/75A priority patent/GB1480716A/en
Priority to CH1411775A priority patent/CH604345A5/xx
Priority to NLAANVRAGE7512795,A priority patent/NL172496C/xx
Priority to JP50131350A priority patent/JPS6044780B2/ja
Application granted granted Critical
Publication of US3924210A publication Critical patent/US3924210A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/02—Permanent magnets [PM]
    • H01F7/0273—Magnetic circuits with PM for magnetic field generation
    • H01F7/0278—Magnetic circuits with PM for magnetic field generation for generating uniform fields, focusing, deflecting electrically charged particles
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/20—Electromagnets; Actuators including electromagnets without armatures

Definitions

  • ABSTRACT A magnet structure having a pair of spaced pole pieces interconnected by a reluctor circuit comprising an operatively aligned array of soft magnetic members suitably spaced apart by interposed nonmagnetic material to provide between the pole pieces a preferred magnetic scalar potential and an associated magnetic flux distributed as desired over a relatively large volume adjacent the array.
  • This invention relates generally to magnet structures and is concerned more particularly with a magnet structure having field shaping means disposed between magnetically coupled pole pieces.
  • a magnetically coupled pair of spaced north and south poles have established therebetween a magnetic field potential and are linked to one another by associated lines of magnetic flux.
  • the lines of magnetic flux are crowded quite close together adjacent the respective magnetic poles and indicate correspondingly high field gradients in the regions adjacent the poles.
  • the lines of magnetic flux are spaced relatively wide apart in a central region between the respective poles, thus indicating a substantially lower magnetic field potential in this central region.
  • the pole pieces may be properly shaped to obtain a more uniform flux distribution in the gap. As a result, a correspondingly more uniform field potential is developed across the gap.
  • the geometry of the pole pieces can influence the flux distribution only over a limited distance from the respective pole pieces. Consequently, when the transverse dimension of the gap exceeds this limit of pole influence, other means must be found for distributing the magnetic flux between the respective pole pieces as desired.
  • this invention provides a magnet structure comprising a pair of spaced pole pieces interconnected by a reluctor circuit having means for shunting magnetic flux along preferred paths between the pole pieces.
  • the circuit includes an operatively aligned array of soft magnetic members disposed between the pole pieces and suitably spaced apart by interposed nonmagnetic material to provide a desired magnetic scalar potential along the array.
  • the magnetic potential decreases monotonically in a nonlinear manner along respective end portions of the array adjacent the pole pieces, and decreases linearly along a central portion of the array. As a result, there is established adjacent the array and at substantial radial distances therefrom a preferred magnetic flux distribution.
  • a specific embodiment of the invention includes a generally U-shaped magnet structure having respective terminal pole. pieces spaced apart by a relatively long gap therebetween.
  • the pole pieces are joined to one another by a low reluctance member which serves as a flux return path of a reluctor circuit interconnecting the pole pieces.
  • Disposed in the gap between the pole pieces is an array of soft magnetic members comprising a flux distributing portion of the reluctor circuit.
  • the soft magnetic members are suitably spaced from the pole pieces and from one another by respective interposed layers of nonmagnetic material to shunt magnetic flux in the direction of the flux return path in a predetermined manner.
  • the array may include respective intermediate portions disposed between the end portions and a central portion of the array.
  • Each of the intermediate portions may comprise a single magnetic member having a relatively longer axial dimension than the other members of the array or may comprise a plurality of closely spaced, soft magnetic members.
  • the intermediate portions provide respective constant values of magnetic scalar potential which serve as transitional regions of the desired gradient.
  • the lines of flux extending outwardly of the pole pieces are directed along preferred paths which are symmetrically disposed with respect to the array. From either end of the central portion of the array to the midpoint thereof, the spacing between successive soft magnetic members progressively increases to provide a magnetic scalar potential which decreases linearly along the central portion of the array. As a result, the magnetic lines of flux exterior of the magnet structure are maintained rectilinear and parallel with the array in a uniform symmetrical pattern.
  • An alternative preferred embodiment comprises a magnetic solenoid structure which may be evolved by rotating the above-described, U-shaped magnet structure about an imaginary axis spaced a predetemiined radial distance from the array.
  • the low reluctance member and the array of soft magnetic members are converted into respective outer and inner coaxial cylinders.
  • the gaps between the concentric cylinders are bridged by respective annular magnets which are radially polarized in opposite directions relative to one another.
  • the inner coaxial cylinder comprises an array of laminated rings disposed between the annular magnets, alternate rings being made of soft magnetic material and the interposed rings being made of nonmagnetic material.
  • the nonmagnetic rings are provided with respective thickness dimensions suitable for spacing the soft magnetic rings from the annular magnets and from one another as described in connection with the U-shaped magnet structure. Accordingly, the magnetic lines of flux extend radially inward and axially along the cylindrical volume in a uniform symmetrical manner over substantially the entire volume.
  • an electron device such as a proximity focused, image intensifier tube, for example, may be disposed in the central portion of the cylindrical volume such that the magnetic scalar potential decreases linearly from the input end of the tube to the output end thereof. In this manner, the resulting uniformity of the magnetic field will aid in proximity focusing an electron image within the tube onto the output viewing screen thereof.
  • FIG. 1 is an axial sectional view of a magnet structure embodying the invention
  • FIG. 2 is a schematic view of a prior art magnet struc ture
  • FIG. 3 is a graphical view of the component of flux density along a rectilinear line interconnecting the pole pieces and immediately exterior of the magnet structure shown in FIG. 2;
  • FIG. 4 is a graphical view of the approximate magnetic scalar potential along a rectilinear line interconnecting the pole pieces of the magnet structure shown in FIG. 2;
  • FIG. 5 is a schematic view of another magnet structure embodying the invention.
  • FIG. 6 is a graphical view of the component of flux density parallel to the reluctor array and immediately exterior of the magnet structure shown in FIG. 5;
  • FIG. 7 is a graphical view of the approximate magnetic scalar potential along the reluctor array between the pole pieces of the magnet structure shown in FIG.
  • FIG. 2 there is shown in FIG. 2 a U-shaped magnet structure 10 including spaced magnets 11 and 13, respectively, which are made of suitable ferromagnetic material, such as Samarium-cobalt, for example, and are oppositely polarized with respect to one another. Disposed adjacent the magnets 11 and 13 are respective terminal pole pieces 12 and 14 which are spaced apart by a relatively long gap 18 therebetween. The magnets 11 and 13 are joined to one another by a low reluctance member 16 which serves as a return path for lines of magnetic flux extending into gap 18 between the pole pieces 12 and 14.
  • suitable ferromagnetic material such as Samarium-cobalt, for example
  • the lines of magnetic flux generally curve arcuately adjacent the pole pieces 12 and 14, but do not necessarily extend across the gap 18 in a rectilinear manner.
  • Some flux lines such as 21-25 and 26-30, for examples, extend less than half way across the gap 18 and return through the low reluctance member 16.
  • Other flux lines such as 31-34, for examples, extend across the gap 18 but have arcuate central portions which curve in the direction of the low reluctance member 16.
  • few flux lines, such as 35 extend across the gap 18 and have central portions which are substantially rectilinear.
  • the resulting curve 36 generally has two crests, 38 and 40, respectively, separated by an intervening trough 42.
  • the crests 38 and 40 indicate that the magnetic flux is concentrated in corresponding regions of gap 18 adjacent the pole pieces, 12 and 14, respectively. Consequently, when the associated approximate magnetic scalar potential Vm is plotted as a function of the distance Z across gap 18, as shown in FIG. 4, the resulting curve generally is similar to the curve 44.
  • Curve 44 indicates that, adjacent the pole piece 12, the magnetic potential decreases rapidly from a maximum positive value and, after passing through an extended region of substantially zero value, rapidly approaches a maximum negative value adjacent the south pole piece 14.
  • the magnetic field established by the conventional magnet structure 10 shown in FIG. 2 is not very effective at substantial radial distances, as represented by the axial line 46, for example, from the pole pieces 12 and 14.
  • FIG. 5 there is shown a magnet structure 50 embodying this invention and comprising spaced magnets 51 and 53, respectively, which aremade of ferromagnetic material, such as Samarium-cobalt, for example, and are suitably coupled to adjacent pole pieces, 52 and 54, respectively.
  • the pole pieces 52 and 54 are spaced apart by an interposed gap 58 which may be equivalent to gap 18, for example.
  • the magnets 51 and 53 are magnetically coupled to one another through suitable flux return means, such as a member 56 similar in design to the member 16 shown in FIG. 2, for example.
  • the flux return member 56 is made of a readily available, low reluctance material, such as cold rolled steel, for example, and is provided with a configuration which is symmetrical with respect to the pole pieces 52 and 54.
  • the member 56 may be made of any magnetically permeable material and may have any configuration suitable for magnetically coupling the pole pieces 52 and 54 to one another.
  • the member 56 comprises a flux return portion of a reluctor circuit means for interconnecting the pole pieces 52 and 54, respectively, in a predetermined manner.
  • the circuit also includes a flux distributing array 60 disposed in operative alignment between the pole pieces 52 and 54.
  • Array 60 comprises alternative layers 62 of nonmagnetic material, such as air, for example, and interposed members 64 of soft magnetic material, such as iron, for example.
  • the layers 62 may be made of rigid nonmagnetic material, such as aluminum, for example, and may be secured, as by bonding, for example, to adjacent soft magnetic members 64 of the array 60.
  • the resulting rigid structural array 60 may have extreme end surfaces of respective nonmagnetic layers 62 disposed in interfacing relationship with pole pieces 52 and 54, respectively, and may be suitably secured thereto, as by bonding, for example.
  • the nonmagnetic layers 62 and the interposed soft magnetic members 64 may be provided with respective cross-sectional configurations similar to the pole pieces 52 and 54, respectively, or may be provided with any other suitable cross-sectional configuration.
  • the array 60 Adjacent the pole pieces 52 and 54, the array 60 is provided with respective end portions 60a, each including a plurality of soft magnetic members 64 having respective axial thicknesses which are substantially equal to one another.
  • each of the end portions 60a may be provided with soft magnetic members 64 having respective axial thicknesses which differ with respect to one another.
  • the soft magnetic members 64 in the respective end portions 60a are suitably spaced from the adjacent pole piece and from one another by interposed nonmagnetic layers 62 having steadily decreasing axial thickness dimensions with increasing distance from the adjacent pole piece.
  • the successive soft magnetic members 64 are spaced progressively closer together as a function of their respective distances from the adjacent pole piece.
  • the array 60 also may include respective intermedi ate portions 60b which are disposed in operative alignment between respective end portions 60a and a central portion 60c of the array.
  • the intermediate portions 60b may comprise respective unitary soft magnetic members 64 having substantially greater axial thicknesses than the soft magnetic members 64 in the respective end portions 60a.
  • each of the intermediate portions 60b may comprise a plurality of relatively thin soft magnetic members separated by interposed, relatively thin, nonmagnetic layers 62 such that the sum of the parts is comparative in axial length to the thickness of the unitary soft magnetic member 64.
  • the intermediate portions 60b are separated from the adjacent end portions 60a by respective interposed nonmagnetic layers 62 having axial thicknesses which conform to the pattern of progressively decreasing axial thicknesses of the nonmagnetic layers 62 in the respective end portions 60a.
  • the central portion 60c of array 60 includes a plurality of soft magnetic members 64 having respective axial thicknesses which, preferably are substantially equal to the axial thicknesses of soft magnetic members 64 in the respective end portions 60a for ease of fabrication.
  • the soft magnetic members 64 in the central axial portion 60c may be provided with respective axial thicknesses of any desired dimension.
  • the soft magnetic members 64 in the central portion 60c are spaced from the adjacent intermediate portions 60b by interposed nonmagnetic layers 62 having steadily increasing axial thickness dimensions with increasing distance from the adjacent intermediate portion 60b toward the midpoint of the central portion 60c.
  • successive soft magnetic members 64 in going from either end towardthe midpoint of the central portion are spaced progressively farther apart as a function of the distance from the adjacent intermediate portion 60b.
  • the soft magnetic members 64 of the array 60 conduct the magnetic flux relatively greater distances into the gap 58 from the associated pole pieces 52 and 54, respectively.
  • the soft magnetic members 64 are suitably spaced apart by the interposed nonmagnetic layers 62 to shunt the magnetic flux over to the return member 56 in a manner which will produce a desired magnetic scalar potential profile along the array 60.
  • magnetic lines of flux 21a-24a and 26a-29a which are equivalent to flux lines 21-24 and 26-29, respectively, (FIG. 1), extend farther into the gap 56 than would be expected without the array 60.
  • magnetic flux line 30a which is equivalent to joined flux lines 25 and 30, respectively, extends with flux lines 31a, which is equivalent to flux line 31, rectilinearly through the array 60 and between the pole pieces 52 and 54.
  • magnetic flux lines 32a-34a which are equivalent to flux lines 32-34, respectively, extend between the pole pieces in a substantially rectilinear manner.
  • the flux lines 32a34a in conjunction with the flux line 35a, which is equivalent to flux line 35 extend axially in a uniformly spaced, rectilinear manner at substantially greater radial distances, as represented by the axial line 46 from the pole pieces than would be the case without the flux distributing array 60 of the reluctor circuit means.
  • the resulting curve 66 generally has an extended central plateau with respective gradually sloping portions at either end thereof.
  • the curve 66 indicates that the major portion of the magnetic flux is distributed substantially uniformly over a corresponding extended central portion of gap 58 and decreases gradually toward the respective pole pieces 52 and 54.
  • the resulting curve 68 generally indicates that the magnetic potential varies monotonically in a nonlinear manner adjacent the respective pole pieces 52 and 54.
  • the magnetic scalar potential Vm may vary parabolically, that is it decreases as the square of the distance Z along the array.
  • the soft magnetic members 64 in the respective end portions 60a the array may be suitably spaced by interposed nonmagnetic layers 62 to provide a magnetic scalar potential profile which varies monotonically in any other nonlinear manner, such as exponentially, for example, adjacent the pole pieces 52 and 54, respectively.
  • the magnetic potential After passing through respective transitional regions of substantially constant value corresponding to the respective intermediate portions 60b of the array, the magnetic potential varies linearly along a central region corresponding to the central portion 600 of the array. Accordingly, as shown in FIG. 5, uniformly spaced equipotential lines 67 extend through the resulting field of flux and, in the central portion thereof, are substantially perpendicular to the array 60.
  • a permanent magnet solenoid structure 70 which, in a broad sense, may be considered as the magnet structure 50 rotated about the axial line 46.
  • the resulting hollow cylindrical structure 70 comprises spaced inner and outer coaxial cylinders, 72 and 74, respectively, which are bridged at respective ends of the structure 70 by annular magnets, 76 and 78, respectively.
  • the magnets 76 and 78 are made of suitable ferromagnetic material, such as samariumcobalt, for example, and are oppositely polarized in the radial direction. Consequently, lines of magnetic flux extend axially between the respective inner peripheries of the magnets 76 and 78, and return through the outer cylinder 74.
  • the outer cylinder 74 is made of suitable low reluctance material, such as cold rolled steel, for example, and comprises the flux return portion of a reluctor circuit means for interconnecting the magnets 76 and 78 in accordance with this invention.
  • the inner cylinder 72 constitutes the flux distributing portion of the reluctor circuit means and comprises a laminated array 80 of alternate rings 82 made of nonmagnetic material, such as aluminum, for example, and interposed rings 84 made of soft magnetic material, such as iron, for example.
  • the array 80 is provided with respective end portions 80a, each including a plurality of soft magnetic rings 84 suitably spaced from the adjacent annular magnet and from one another by interposed nonmagnetic rings 82, which steadily decrease in axial thickness with increasing distance from the adjacent annular magnet.
  • successive soft magnetic rings 84 in respective end portions 80a of the array are spaced progressively closer together as a function of their respective distances from the adjacent annular magnet.
  • the array 80 also may be provided with respective intermediate portions 8012 which are disposed in alignment between respective end portions 80a and a central portion 800 of the array.
  • the intermediate portions 80b comprise respective unitary soft magnetic rings 84 of substantially greater axial thicknesses than the soft magnetic rings 84 in the respective end portions 80a of the array.
  • Each of the intermediate portions 80b is separated from the adjacent end portion 80a by an interposed nonmagnetic ring 80b having an axial thickness conforming to the steadily decreasing thicknesses of the nonmagnetic rings 80b in the adjacent end portion 80a of the array.
  • the central portion 800 of the array 80 comprises a plurality of soft magnetic rings 84 suitably spaced from the adjacent intermediate portion 80b and from one another by interposed nonmagnetic rings 82.
  • the nonmagnetic rings 82 are provided with respective increasing axial thicknesses with increasing distance from the adjacent intermediate portion 80b toward the midpoint of the central portion 800.
  • successive soft magnetic rings 84 are spaced progressively farther apart as a function of their respective distances from the adjacent intermediate portion 80b.
  • the magnetic field established within the solenoid structure 70 is similar to the magnetic field of magnet structure 50 (FIG. rotated about the axial line 46.
  • the magnetic lines of flux extending from the respective annular magnets 76 and 78 are directed axially along the array 80 and are shunted over to the flux return cylinder 74 in the manner described in connection with the magnet structure 50. Consequently, a major portion of the magnetic flux is distributed substantially uniformly in a central region of the structure 70 interior of the cylindrical array 80.
  • the resulting approximate magnetic scalar potential established along the cylindrical array 80 decreases monotonically in a nonlinear manner, such as parabolically, for example, adjacent the annular magnets, 76 and 78, respectively.
  • the magnetic scalar potential remains substantially constant.
  • the extended central portion 80c of the array the magnetic scalar potential decreases linearly from one end to the other end of the central portion.
  • transverse equipotential surfaces (not shown) which are similar to equipotential lines 70 shown in FIG. 5, for example, are substantially equally spaced apart along the axis of the structure 70 and, in an extended central portion thereof, are substantially perpendicular to the cylindrical array 80.
  • an electron device such as image intensifier tube 90, for example, may be disposed axially within the central portion of the magnetic field generated within the solenoid structure 70.
  • the image intensifier tube 90 may be of the conventional proximity fo- 'cusing type, for example, having an input screen assembly 92 adjacent one end, an output screen assembly 94 adjacent the other end, and a conventional microchannel plate assembly 96 operatively disposed therebetween.
  • the input screen assembly 92 receives a dim visual image and emits a corresponding electron image which is electrostatically accelerated toward the microchannel plate assembly 96. While passing through aligned apertures in the microchannel plate assembly 96, the electron density of the image is increased correspondingly by secondary emission.
  • the resulting electron image is electrostatically accelerated cuit having a flux return portion and a flux distributing portion.
  • the flux distributing portion is operatively disposed between the pole pieces and comprises an aligned array of alternate nonmagnetic layers and interposed soft magnetic members.
  • the soft magnetic members are suitably spaced from the pole pieces and from one another by the interposed nonmagnetic layers in a manner which provides a desired magnetic scalar potential profile along the array and between the pole pieces.
  • the desired potential profile decreases monotonically in a nonlinear manner adjacent the pole pieces and decreases linearly in an extended central portion of the space between the pole pieces.
  • reluctor circuit of this invention has been illustrated with the use of permanent magnets, it may equally well be employed for interconnecting the pole pieces of electromagnets. Furthermore, the reluctor circuit may be employed for interconnecting the pole pieces of other magnet structures than cylindrical solenoid structure shown herein.
  • a magnet structure comprising:
  • reluctor circuit means interconnecting the pole pieces for providing a desired magnetic scalar potential profile
  • the reluctant circuit means including a linear array of alternate nonmagnetic layers and interposed magnetic members disposed between the pole pieces, the magnetic members being spaced progressively varying distances from one another.
  • a magnet structure as set forth in claim 2 wherein the array. also includes a central portion having a plurality of soft magnetic members spaced progressively farther apart as a function of their respective distances from the adjacent end of the central portion toward the midpoint thereof.
  • a solenoid magnet structure comprising:
  • a flux return cylinder made of magnetically permeable material and having respective end portions suitably coupled to outer peripheral portions of the annular magnets;
  • a flux distributing cylinder operatively disposed between respective inner peripheral portions of the annular magnets and comprising an aligned array of laminated rings, alternate rings being made of nonmagnetic material and the interposed rings being made of soft magnetic material.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
US520074A 1974-11-01 1974-11-01 Field shaping magnet structure Expired - Lifetime US3924210A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
US520074A US3924210A (en) 1974-11-01 1974-11-01 Field shaping magnet structure
CA236,662A CA1027626A (en) 1974-11-01 1975-09-29 Field shaping magnet structure
IL48228A IL48228A (en) 1974-11-01 1975-10-02 Field shaping magnet structure
IT51785/75A IT1047775B (it) 1974-11-01 1975-10-15 Struttura di magnete a conformazione di campo
FR7532358A FR2290008A1 (fr) 1974-11-01 1975-10-22 Structure d'aimant pour la mise en forme d'un champ magnetique
BE161204A BE834817A (fr) 1974-11-01 1975-10-23 Structure d'aimant pour la mise en forme d'un champ magnetique
DE2548439A DE2548439C2 (de) 1974-11-01 1975-10-29 Dauermagnetanordnung zur Erzeugung eines langgestreckten gleichförmigen Magnetfeldes
GB45422/75A GB1480716A (en) 1974-11-01 1975-10-31 Field shaping magnet structure
CH1411775A CH604345A5 (de) 1974-11-01 1975-10-31
NLAANVRAGE7512795,A NL172496C (nl) 1974-11-01 1975-10-31 Magneetconstructie voor het vormen van een constant homogeen veld.
JP50131350A JPS6044780B2 (ja) 1974-11-01 1975-10-31 磁石構造

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US520074A US3924210A (en) 1974-11-01 1974-11-01 Field shaping magnet structure

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US3924210A true US3924210A (en) 1975-12-02

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US520074A Expired - Lifetime US3924210A (en) 1974-11-01 1974-11-01 Field shaping magnet structure

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US (1) US3924210A (de)
JP (1) JPS6044780B2 (de)
BE (1) BE834817A (de)
CA (1) CA1027626A (de)
CH (1) CH604345A5 (de)
DE (1) DE2548439C2 (de)
FR (1) FR2290008A1 (de)
GB (1) GB1480716A (de)
IL (1) IL48228A (de)
IT (1) IT1047775B (de)
NL (1) NL172496C (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4646045A (en) * 1985-03-25 1987-02-24 General Electric Company Aperture sized disc shaped end caps of a ferromagnetic shield for magnetic resonance magnets
EP0416414A2 (de) * 1989-09-05 1991-03-13 Balzers Aktiengesellschaft Verfahren und Vorrichtung zur Umlenkung eines Strahls
US5949316A (en) * 1995-08-24 1999-09-07 The United States Of America As Represented By The Secretary Of The Army Magnetic reluctor structures and methods

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3193719A (en) * 1959-04-13 1965-07-06 Philips Corp Demountable magnetic focussing system for a traveling-wave tube
US3227931A (en) * 1963-07-18 1966-01-04 Zenith Radio Corp Permanent-magnet uniform-field-producing apparatus
US3304523A (en) * 1963-10-04 1967-02-14 Csf Magnetic field straightener
US3373389A (en) * 1965-02-19 1968-03-12 Int Standard Electric Corp Magnetic field straightener
US3404306A (en) * 1966-04-06 1968-10-01 Alltronics Inc Traveling-wave tube focusing field straightener

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1147461A (fr) * 1955-01-11 1957-11-26 Philips Nv Système magnétique à aimants annulaires
US2942141A (en) * 1957-06-06 1960-06-21 Bell Telephone Labor Inc Magnetic structures for traveling wave tubes

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3193719A (en) * 1959-04-13 1965-07-06 Philips Corp Demountable magnetic focussing system for a traveling-wave tube
US3227931A (en) * 1963-07-18 1966-01-04 Zenith Radio Corp Permanent-magnet uniform-field-producing apparatus
US3304523A (en) * 1963-10-04 1967-02-14 Csf Magnetic field straightener
US3373389A (en) * 1965-02-19 1968-03-12 Int Standard Electric Corp Magnetic field straightener
US3404306A (en) * 1966-04-06 1968-10-01 Alltronics Inc Traveling-wave tube focusing field straightener

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4646045A (en) * 1985-03-25 1987-02-24 General Electric Company Aperture sized disc shaped end caps of a ferromagnetic shield for magnetic resonance magnets
EP0416414A2 (de) * 1989-09-05 1991-03-13 Balzers Aktiengesellschaft Verfahren und Vorrichtung zur Umlenkung eines Strahls
EP0416414A3 (en) * 1989-09-05 1991-09-18 Balzers Aktiengesellschaft Procedure and device for deviating a beam
US5949316A (en) * 1995-08-24 1999-09-07 The United States Of America As Represented By The Secretary Of The Army Magnetic reluctor structures and methods

Also Published As

Publication number Publication date
JPS6044780B2 (ja) 1985-10-05
CH604345A5 (de) 1978-09-15
NL7512795A (nl) 1976-05-04
FR2290008B1 (de) 1980-12-05
IL48228A (en) 1978-01-31
DE2548439A1 (de) 1976-05-06
IL48228A0 (en) 1975-12-31
DE2548439C2 (de) 1985-10-31
FR2290008A1 (fr) 1976-05-28
CA1027626A (en) 1978-03-07
GB1480716A (en) 1977-07-20
JPS5167961A (de) 1976-06-12
IT1047775B (it) 1980-10-20
BE834817A (fr) 1976-02-16
NL172496C (nl) 1983-09-01

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