Abstract: A magnet having an imaging volume, a pole piece with a laminated portion including a first surface hole, a non-magnetizable first insert with an internally-threaded hole, and a first shim with a shape of an externally-threaded bolt. The first insert is positioned in the first surface hole and is attached to the pole piece. The first shim is threaded into the hole of the first insert. Additional shims for additional inserts for additional surface holes are used to shim the magnet to reduce magnetic field inhomogeneities in the imaging volume.

Abstract: Disclosed is an apparatus and process for magnetizing permanently magnetizable strip and sheet material to form a pattern of band-like poles on the material. Two parallel stacks of permanent magnets are used, each magnet in each stack having a direction of magnetization which is perpendicular to a slot-like air gap between the stacks. The magnets in each stack are parallel to one another, with unlike poles of adjoining magnets proximate so that they mutually attract one another. Unlike poles of the respective magnets in opposite stacks are positioned diametrically opposite each other across the air gap. The apparatus does not use electromagnetic coils and can form very narrow, contiguous band-like poles on magnetizable sheet or strip material which is passed through the air gap.

Abstract: An extremely efficient magnet system having a comparatively large angle of aperture can be obtained for magnetic resonance imaging by a reduction of fields of all orders in a common approach affecting active and passive as well as positive and negative oriented coil elements. Passive soft-magnetic ring segments are arranged in two pairs and located within a plurality of larger diameter active magnetic coils. The active coils include a central coil and outer coils wherein the outer coils are smaller than the central coil. The coils are in a helium Dewar vessel and arranged such that the system has an aperture of about 90.degree.. The central active coil may have a larger radius than the smaller outer coils.

Abstract: The invention concerns a bistable magnetic drive with an assembled armature 3, 4 consisting of a high-grade, disk-shaped permanent magnet 3 with two appropriately shaped pole pieces 4,4' and displaceable sideways off the coil 1 transversely to its axis inside an electromagnetic annular pole-piece Rp between two electromagnetic stop pole-pieces 5, 5'. The invention describes illustrative embodiments and applications of this drive as an excursion and oscillating magnet, further a circuit for DC operation. A capacitor circuit furthermore allows mono-stable operation. The advantages are a lightweight armature, high efficiency, bilateral operation, versatility and simplicity.

Abstract: A magnet device for MRI system is provided with a main coil assembly including a plurality of ring-like main coils wound around a reel element and a sub-coil assembly including at least one pair of ring-like sub-coils wound around the reel element. All the coils are arranged symmetric with respect to an axial direction of the reel element. The sub-coils are disposed at axially inner predetermined positions apart from the axial outermost main coils. A coil driving element, provided in the device, makes the main coils generate a main magnetic field in the space and makes the sub-coils generate a magnetic field inverse to the main magnetic field to form a high-uniform static magnetic field as a diagnostic space. Magnetomotive forces of the main coils and sub-coils are adjusted so that the diagnostic space having a longer radial axis than its longitudinal axis is formed in the cylindrical space.

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 device for converting magnetic force to mechanical force including a member having an axis about which it is rotatable, the member having a peripheral edge portion formed of a material that is effected by the presence of a magnetic force adjacent thereto, at least one magnetic member positioned adjacent the peripheral portion of the rotatable member to produce a magnetic coupling force therebetween, the peripheral portion of the rotatable member having a shape such that the magnetic coupling between the magnetic member and the peripheral portion of the rotatable member varies continuously as the rotatable member rotates.

Abstract: A positive displacement pump is provided which is especially suited to be used as a left ventricle assist device (LVAD). The pump is electromagnetically actuated. An electromagnet produces a pulse which repels a magnet mounted in a diaphragm which forms one wall of a pumping chamber. The pumping chamber thereby constricts and fluid is expelled. The electromagnet has a reverse taper core and core cup magnet which produce a bipolar field effect upon a diaphragm magnet to cause the return of the diaphragm to its starting position, without the application of external power.

Abstract: A coil device includes two magnetic cores each having a U-shape in section forming a closed magnetic path therein with their legs being opposed to each other and having a gap in such path, and a coil wound so as to cover the gap. In this structure, the mutually opposed portions of the magnetic cores in the region to form the gap are so shaped that the cross-sectional area of the fore end becomes smaller than that of the base end, thereby preventing concentration of any leakage magnetic flux on the gap portions while averting abnormal generation of heat in the coil to consequently eliminate harmful influence of noise on peripheral apparatus or components.

Abstract: A method and apparatus for producing complex magnetization patterns in a sheet of magnetic material. A fixture having top and bottom plates with a matching conductor pattern embedded in one surface of each plate. The conductor pattern covers substantially the entire surface of each plate. To magnetize the sheet of magnetic material, it is placed between the plates and a magnetizing current is applied to the conductors with a capacitor discharge magnetizer. The resulting sheet of magnetized material is useful as a magnetic deactivator for electromagnetic security articles.