Abstract: A permanent magnet solenoid structure utilizes a hollow, tubular, toroidally-shaped flux source, an interior working space, a magnetizing member having an end magnet and two pole pieces. The magnetizing member intersects the flux source and the interior working space with the desired magnetic field being confined to the interior working space of the toroid by having a cladding magnet in contact with the outer surface of the toroidal supply magnet. In another embodiment, the interior working space is an annular ring rather than being toroidally-shaped. In yet another embodiment, the interior working space is an annular ring and an aperture or tunnel is provided through the magnetizing member so that electron particles can be electrostatically or thermally created, accelerated around the interior working space and then collected at a certain point within the interior working space.

Abstract: An open access MRI magnet includes a ferromagnetic frame open on at least two sides and having upper and lower end plates and at least two support columns. A superconducting coil assembly is mounted to each end plate for generating a magnetic flux field in a patient receiving area located between the end plates. Each superconducting coil assembly includes a toroidal vacuum tight vessel, insulation, and one or more temperature shields mounted within the vacuum tight vessel. One or more coils of superconducting wire is wound within the vacuum vessel, and is coupled to a power source and to a persistent switch for maintaining a constant flow of current with no power consumption. A return path for the flux is provided by the end plates and support posts of the frame.

Abstract: In combination with an electric apparatus emitting electromagnetic radiation, an arrangement for reducing the radiation hazards on an operator in front of the apparatus is provided, the arrangement comprising at least three magnetic devices approximately located at the apices of a triangle in front of the apparatus, each magnetic device including a closed housing made of a nonmagnetic material, a permanetn magnet located within the housing for producing a magnetic flux, and a bar of non-magnetic material located within the housing in a defined spaced-apart relationship such that the bar of non-magnetic material is placed in the effective flux area of the permanent magnet, the magnetic devices being positioned in front of the apparatus such that each permanent magnet has its north pole opposed to the south pole of the other magnets and such that each bar of non-magnetic material is situated behind the permanent magnet associated thereto.

Abstract: A magnetic levitation device and method of levitating a magnet without mechanical restraining elements are disclosed. The levitation device comprises a first magnet with a polygonal, preferably square, periphery and a substantially planar upper surface magnetized normal thereto and a second magnet with an apparatus to rotate or spin the same. The second magnet is rotated or spun on a lifter plate disposed on the upper surface of the first magnet with like polar orientations of the magnets in confronting relation. When the lifter plate is raised above the first magnet the spinning second magnet levitates above the first magnet and the lifter plate and the lifter plate is removed from between the first and second magnets. The weight of the second magnet may be varied to change the height above the first magnet at which the second magnet levitates.

Abstract: Display tube including a deflection unit which comprises a coil support (8), a field deflection coil (12), a line deflection coil (11) and a yoke ring (14). Plate-shaped metal field correction elements (15, 15', 15") are arranged between the field deflection coil (12) and the coil support (8), which elements are rigidly secured to the inner surface of the yoke ring by means of a form-filling adhesive which extends between the parts of the field deflection coil. Vibrations of the field correction elements and sound generated by transfer of these vibrations to the coil support are thereby substantially prevented.

Abstract: A magnet is specially designed for the creation of an extremely uniform magnetic field in a small volume for use in MRI mammography. A disk of ferromagnetic material has a surface having a well adapted to receive the object to be examined and lined with a solenoidal coil which provides the basic magnetic field. Uniformity is increased by three additional coils surrounding the solenoidal coil and placed in annular slots surrounding the well. Of these three additional coils, the middle one generates a magnetic field in the well which opposes the basic magnetic field, and the others supplement the basic magnetic field. The ampereturns of the three additional coils are selected to maximize uniformity of the magnetic field in the well.

Abstract: The invention is directed to an actuator which is mounted on a base to rotate a rotary member about a rotational axis thereof. The actuator includes a first magnetic rotary member which is rotatably mounted on the base about the axis, and provided with a first engaging portion which traces a peripheral locus about the axis. It also includes a second magnetic rotary member which is rotatably mounted about the axis, and provided with a second engaging portion engageable with the first engaging portion on the peripheral locus about the axis. The first engaging portion is moved to be engageable with the second engaging portion when the first rotary member is rotated in one direction relative to the second rotary member, and the first engaging portion is moved to be away from the second engaging portion when the first rotary member is rotated in the opposite direction.

Abstract: Various levitation devices are disclosed in which an array of permanent magnets is levitated by magnetic interaction with a diamagnetic material. Levitation is achieved without using a fixed permanent magnet or other device to supplement the magnetic field of the array. The cost and design constraints resulting from undesirable spring constants produced by such permanent magnets are thereby avoided.

Abstract: A magnetic resonance imaging (MRI) magnet having an annularly cylindrical-shaped vacuum enclosure with a longitudinal axis, first and second longitudinal ends, a first larger diameter bore extending from the first towards the second longitudinal end, and a second smaller diameter bore extending from the second longitudinal end to the first bore. First and second superconductive coils are placed in the vacuum enclosure with the first coil generally circumferentially surrounding the first bore and the second coil circumferentially surrounding the second bore, wherein the radial distance of the radially innermost portion of the second coil from the axis is smaller than the radius of the first bore. The second longitudinal end of the vacuum enclosure fits on a patient's shoulders with the patient's head passing through the second bore and extending into the first bore for MRI brain imaging.

Abstract: A superconducting magnet lead assembly for a cryocooler-cooled superconducting magnet having a design current of between generally 50 and 250 amperes. A DBCO (Dysprosium Barium Copper Oxide), YBCO (Yttrium Barium Copper Oxide), or BSCCO (Bismuth Strontium Calcium Copper Oxide) superconducting lead has its ends flexibly, dielectrically, and thermally connected, one end to the generally 30 to 50 Kelvin first stage and the other end to the generally 8 to 30 Kelvin second stage of the cryocooler coldhead. The superconducting lead has a generally constant cross-sectional area along its length. The design current, the lead's length, and the lead's cross-sectional area are chosen such that the design current times the lead's length divided by the lead's cross-sectional area is between generally 720 and 880 amperes per centimeter for a DBCO or YBCO lead and is between generally 180 and 220 amperes per centimeter for a BSCCO lead. The superconducting lead will not itself precipitate a magnet quench (i.e.

Abstract: A motion producing device in the form of a linear actuator, circular pump, or a robotic or prosthetic limb which functions to produce many kinds of work is provided. The device includes a linear series of alternately spaced fixed and polarity reversible magnets. The fixed and polarity reversible magnets may have more than one magnet assembled as a force unit of magnets of fixed polarity or reversible polarity which is surrounded by a rigid electrically insulating material and that carries rigid electrical conductors in the form of tubes. Between each magnetic force unit is an elastic electrically insulating material allowing expanding or shrinking of the distance between the magnetic force units in accordance with the polarity reversal of the reversible magnetic force units. The elastic expansion or contraction material carries flexible elastic tubes that connect with the rigid tubes to hold a current carrying electrolyte to carry electrical current from a D.C.

Abstract: Coils for electric appliances such as motor or generator are made with a superconducting material, and the width of the coil and the gap between the coils are so adjusted that the passage of magnetic flux generated by a magnetic flux generating member in the electric appliance is not influenced by the magnetic repulsion of the superconducting material.

Abstract: A magnetic grab has a pair of vertically elongated magnetic pole pieces each having an upper end and a lower end. The pole pieces diverge downward symmetrically with respect to a vertical symmetry plane with the upper ends substantially more closely spaced than the lower ends. A plurality of nonmagnetic elements fixed to the pole pieces secure same together and a generally cylindrical rotor engaged between the pole pieces and centered on and rotatable about a rotor axis extending horizontally parallel to and between the pole pieces is formed by a pair of soft-iron bodies one of which is substantially thicker in a direction transverse to the axis than the other. One or more permanent magnets are sandwiched between the bodies and polarized generally diametrically of the rotor axis.

Abstract: A permanent magnet comprising a shell of magnetic material having a hollow avity and an access port that passes through the shell and communicates with the cavity. The shell is permanently magnetized to produce a magnetic field in the cavity. A magnetic insert is located in the cavity. The insert has a tunnel aligned with the access port and is magnetized in a direction opposite to the direction of the magnetic field. Specifically, a spherical magnetic shell has a concentric cavity in which a spherical magnetic insert is housed. An access port in the form of an axial hole passes through the spherical center of the shell and the insert. The shell ("magic sphere") is magnetized such that it is capable of producing a uniform magnetic field in the cavity. The insert is uniformly magnetized in a direction opposite to that of the cavity field produced by the shell. As such a working field that has a strength greater than that of the cavity field produced by the shell is located in the tunnel.

Abstract: In the case of high-temperature superconductors (6) which are used as inductive current limiters, unless any special precautionary measure is taken, there is a risk that short-circuit currents can lead to local stress centers and hot spots, and to local destruction of the high-temperature superconductor. In order to avoid this, a hollow cylinder (SL) of the high-temperature superconductor (6) is coated with a 1 .mu.m thick conductive-silver layer (E1). A second 10 .mu.m thick metal layer of foil made of silver or aluminum can be deposited thereon. In order to reduce or to avoid tensile stresses in the ceramic of the hollow cylinder (SL) made of a high-temperature superconductor, and in order to reduce the electrical contact resistance of the metal layers, this hollow cylinder (SL) has a mechanical reinforcing element (7), made of an elastic steel wire, wound around it, at room temperature, under tensile stress.

Abstract: Described are magnetizing devices for permanent magnet rings that are bipolar on the end faces or multipolar on the lateral faces and have concentric North/South areas either on one of the two end faces or on their lateral faces. Magnetizing is performed by way of current pulses that are induced in annular current conductors arranged on the end faces or on the lateral faces of the permanent magnet rings.

Abstract: An oxide superconductive wire is provided by, for example, forming an oxide superconductive layer on a tape-type flexible base. A preliminary compressive strain is applied to the oxide superconductive layer in the longitudinal direction. The remaining strain can be provided by using a base having thermal expansion coefficient larger than that of the oxide superconductive layer and by cooling the same after heat treatment, due to contraction of the base. Since the preliminary compressive strain is applied to the oxide superconductive layer, degradation of superconductivity of the oxide superconductive layer can be suppressed even if the oxide superconductive wire is bent in any direction, compared with the wire without such strain. Therefore, the oxide superconductive wire can be coiled, for example, without much degrading the superconductivity.

Abstract: A superconducting apparatus including a superconducting solenoid coil made of a superconducting wire wound around a bobbin. The superconducting wire has a superconductor having a rectangular cross-section of a narrow width, and the superconductor of the superconducting wire has a larger sectional area at the end region of the superconducting solenoid coil than at the central region. The superconductor at the end region of the superconducting solenoid coil may comprise a plurality of superconducting wires with superconductors having a large sectional area, or may comprise a plurality of superconductors connected in parallel to each other, thereby increasing the effective sectional area of the superconductor in the end region.