Abstract: An electromagnetically actuator is disclosed having an electromagnet, a core element, the core element having a normally biased initial spaced apart first position distal from the electromagnet when the electromagnet is off and a second stop position proximal from the electromagnet when the electromagnet is on, a first resilient member adapted to bias said core element in the normally biased first position, and a second resilient member adapted to bias the electromagnet away from the core. The first resilient member is more resilient than the second resilient member. Therefore, the core approaches the electromagnet when the electromagnet is on until the core reaches the fixed stop position, and the electromagnet subsequently approaches the core to the fixed stop position. The actuator may further include an adjustment member that engages the electromagnet so as to control the pressure of the electromagnet against the second resilient member, whereby the axial position of the electromagnet is controlled.

Abstract: A composite magnet comprising a core of R-Ba-Cu-O type bulk superconductor (R denotes rare-earth elements) made by melt process, enclosed around it with normal conductive or superconductive coil, or a composite magnet including a center of normal conductive or superconductive coil, enclosed around it with ring-shaped R-Ba-Cu-O type bulk superconductor (R denotes rare-earth elements) made by melt process is disclosed, which allows easy control of generating magnetic field and gives a relatively strong magnetic field even at a temperature as high as that of liquid nitrogen.

Abstract: The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube.

Abstract: A trapped flux, iron structure, which prevents bunching of interior flux es during an application of a field force, is provided. This iron structure includes a plurality of elongate identical subassemblies, each subassembly having a rod composed of a soft ferromagnetic material and each rod having a superconductive sheath.

Abstract: The magnet roll of the present invention includes a shaft and a permanent magnet member fixed to the shaft, the permanent magnet member being composed of a hollow, cylindrical magnet body, and a magnetic pole piece fixed to a recess of the hollow, cylindrical magnet body, the hollow, cylindrical magnet body having a plurality of axially extending magnetic poles arranged circumferentially on the surface, the magnetic pole piece being provided with two magnetic poles having the same polarity for constituting a developing magnetic pole, and a thermally demagnetized portion being formed substantially at a center of the developing magnetic pole such that the permanent magnet member generates a magnetic flux density distribution having two peaks of the same polarity at a position of the developing magnetic pole.

Abstract: A magnet including spaced-apart first and second pole pieces with generally opposing first and second pole faces. The first pole face has an axis extending generally towards the second pole face and has a surface region which includes at least two frustoconical surfaces. The frustoconical surfaces are generally coaxially aligned about the axis, and radially-adjacent frustoconical surfaces abut each other. In a second embodiment, points on the surface region located an identical radial distance from the axis are also located a common axial distance along the axis, and a graph of axial distance along the axis versus radial distance from the axis for such points is a curve having a continuous slope with at least two sign reversals. Such contoured pole faces allow for a smoother magnetic field to better reduce axisymmetric magnetic field inhomogeneity.

Abstract: A deactivator for use in an electronic article surveillance system has a housing having a first receptacle containing a deactivator for deactivating a theft-deterrent marker carried on an object such as a compact disk case, an audio cassette case or a video cassette case. The first receptacle is made up of a base, a first wall and a second wall, the walls being spaced apart such that an object carrying the theft-deterrent marker can be placed between the walls. The first wall is slidable relative to the second wall. The housing also has a second receptacle with a deactivator for deactivating a theft-deterrent marker carried on a generally rectangular object such as an audio cassette box having a top and a bottom, first and second sides and first and second ends, the marker being carried by one of the sides or one of the ends. The device comprises a housing having a receptacle comprising first, second and third walls arranged so as to form three sides of a box.

Abstract: A superconducting device, such as a superconducting rotor for a generator or motor or a superconducting magnet for a magnetic resonance imaging machine, etc. A vacuum enclosure surrounds and is spaced apart from a superconductive coil. Apparatus supports the coil in the enclosure during operation of the device, such apparatus including a first thermally insulative honeycomb assemblage positioned between the coil and the enclosure. In a first preferred construction, the first honeycomb assemblage is positioned between and connected to the coil and a thermal shield, and a second honeycomb assemblage is positioned between and connected to the shield and the enclosure. In a second preferred construction, the second honeycomb assemblage is replaced with a first suspension strap.

Abstract: A force rebalance accelerometer includes a proof mass suspended by one or more flexures between stationary mounted upper and lower excitation rings. Pick-off capacitance plates formed on opposing sides of the proof mass form capacitance elements whose capacitance varies in response to displacement of the proof mass to provide a displacement signal. The displacement signal is applied to one or more electromagnets, used to force the proof mass back to a null or at-rest position. The drive current applied to the electromagnets thus represents the force or acceleration applied to the accelerometer. The electromagnets include a magnet and a pole piece which forms a magnetic return path. In order to relieve stresses due to thermal expansion, the magnet is spaced apart from the pole piece to enable the bonding area to be constrained to a minimum which, in turn, reduces the overall stress on the accelerometer.

Abstract: A superconductive magnet having a superconductive coil located within a thermal shield located within a vacuum enclosure. A magnet re-entrant support assembly includes an outer support cylinder located between the vacuum enclosure and the thermal shield and includes an inner support cylinder located between the thermal shield and the superconductive coil. The outer support cylinder's first end is rigidly connected to the vacuum enclosure, and its second end is rigidly connected to the thermal shield. The inner support cylinder's first terminus is rigidly connected to the thermal shield near the outer support cylinder's second end, and its second terminus is located longitudinally between the outer support cylinder's first and second ends and is rigidly connected to the superconductive coil. Buckling resistance is improved by adding stiffening rings to the support cylinders.

Abstract: An electromagnetic system for a magnetic levitation vehicle comprises a "W" shaped magnet core having a center pole wound by a superconducting coil and side poles on opposite sides of the center pole, each wound by an ambient temperature coil. Quasi-dc power is supplied to the central superconducting coil for levitation of the vehicle with respect to a rail along which the vehicle is meant to move. The ambient temperature coils are connected in series to each and other and powered with ac power for trimming and controlling the gap between the magnet and the rail.

Abstract: A magnetic base including a rotary magnetic element, two symmetrical magnetic plate assemblies covered around the rotary magnetic element, and two non-magnetic blocks connected between the magnetic plate assemblies at different elevations; in which, each magnetic plate assembly consists of a stack of iron plates, each iron plate having two notches at one side near two opposite ends, and a flange at each notch; each non non-magnetic block has two opposite projecting portions respectively fitted into the respective notches of the iron plates and engaged with the respective flanges.

Abstract: An inductive superconducting current storage (2), characterized in that it comprises an inner coil (4) wound from superconducting material and an outer coil (6) wound from superconducting material and disposed around the inner coil (4) in spaced manner therefrom, said inner coil (4) and said outer coil (6) in operation having current flowing therethrough in opposite directions so that the same magnetic flux as in the inner space (14) of the inner coil (4), but of opposite direction, is present in the annular space (12) between inner coil (4) and outer coil (6).

Abstract: A permanent magnet structure providing an internal magnetic field having an djustable magnitude and direction. The structure utilizes a shell composed of a predetermined number of concentric permanent magnet cylinders, each of which generates a discrete tunable magnetic field for tuning the magnitude and direction of the internal working field. Depending on the magnitude and direction of each discrete magnetic field, the magnitude and direction of the working field can be controlled and adjusted as desired.

Abstract: A simplified method of making permanent magnet structures, such as magic rings and magic spheres, from a uniformly magnetized permanent magnet shell. Thus, through the inventive method, building such structures requires only one remanence. For example, to make a magic ring providing a uniform internal magnetic field that can be accessed through non-distorting ports, a uniformly magnetized cylindrical shall is cut into ultra-thin washer shaped pieces. One half of the washer shaped pieces are radially cut into pie shaped pieces. The pie shaped pieces of each sliced-up washer-shaped piece are then rotated or transposed to form ultra-thin magic ring slices. The magic ring slices are then alternately stacked with the remaining washer shaped pieces to form a magic ring having predetermined regions wherein the shell magnetization is zeroized. Thus, the shell material in these regions can be removed to provide distortion-free access to the internal field.

Abstract: A superconducting current limiter comprising a bar or tube of high temperature superconducting material of the composite type made up of glass and a high temperature superconducting oxide, the volume fraction of the glass lying in the range 10% to 40%, the bar or tube being selected to comply with the following inequalities:.rho.>10.sup.-4 .OMEGA..multidot.mj.sub.c >10.sup.+5 A/m.sup.2.rho.x.sup.2 <10.sup.11 W/m.sup.3in which inequalities:.rho. designates the resistivity of the material in the normal, i.e. the non-superconducting, state;j.sub.c designates the critical current density;.rho.x.sup.2 designates the power density dissipated in the bar or tube during the transition stage;it being specified that the critical current density is defined as the density which produces an electric field of 10.sup.-4 V/m along the tube or bar and that it is accepted that limitation takes place for a current density equal to five times the critical current density.

Abstract: An open magnetic resonance imaging (MRI) magnet having first and second spaced-apart superconductive coil assemblies each including a toroidal-shaped coil housing containing a superconductive main coil. A generally annular-shaped resistive coil is associated with each coil assembly, being generally coaxially aligned with the associated coil assembly and being spaced radially inward and radially apart from the associated coil assembly's superconductive main coil. The resistive coils overcome the gross magnetic field distortions in the imaging volume of the superconductive main coils (created by the open space between the magnet's superconductive coil assemblies) to produce a magnetic field of high uniformity within the imaging volume.

Abstract: A method of manufacturing a spherical pigging device for passing through a pipeline by forming a water soluble spherical core, affixing numerous magnets to the surface of the core, suspending the core within a spherical mold, pouring a liquid between the mold and the core that will cure to form a spherical body, removing the spherical body and dissolving the core to leave a hollow spherical body with the magnets encased within it.

Abstract: The invention relates to a dipole ring magnet for use in magnetron sputtering apparatus or magnetron etching apparatus to produce a uniform magnetic field. Essentially the dipole ring magnet is an assembly of a plurality of pillar-like, anisotropic magnet segments in a circumferential arrangement. Each of the pillar-like magnet segments is magnetized in a direction normal to its longitudinal axis, and in assembling the ring magnet the magnet segments are differently oriented such that a magnetic field in the direction of a diameter of the ring is produced inside the ring magnet. To improve the uniformity of the magnetic field, particularly in respect of a component normal to the longitudinal axis of the ring magnet, each pillar-like segment is devoid of a lengthwise middle part to provide a vacant space in place of the middle part, and the length of the vacant space is regulated according to the position of the segment in the ring magnet.

Abstract: The horizontal deflection apparatus has a separator whose cross-section takes a saddle-shape form, and horizontal deflecting coils are comprised of three coil groups connected in a series to each other. The first coil group is wound on the outermost circumference on the inside of the main structure of the separator, the second coil group is wound at a predetermined distance from the first coil group, and the third coil group is wound at a predetermined distance from the second coil group. Deflecting efficiency at the deflection center is improved because the deflection magnetic field generated from the second and third coil groups is generated at the deflection center.