Abstract: The invention relates to refrigerated superconducting MR magnets having integrated gradient coils. In particular, the amount of eddy currents produced by the magnet are substantially reduced while reducing the size and weight, and, therefore, the cost of the superconducting magnet required to produce an MR image.

Abstract: A cryogenic containment vessel for use with a pulsed superconducting magnet system includes a superconducting coil positioned within the cryogenic containment vessel for providing a magnetic field. The containment vessel includes a relatively thin metallic inner tube for holding liquid helium and the coil. The containment vessel also includes a relatively thick outer tube encompassing the inner tube with a relatively rigid insulative spacer positioned between the inner and outer tubes so that the tubes are not in contact with each other. The outer tube is predominantly metallic and has at least one joint formed of insulative material to prevent the outer tube from forming a low electrical resistance loop. The inner tube provides a vacuum seal and the outer tube provides structural support for the inner tube so that eddy current losses resulting from ramping of the current to the coil are reduced. A method of fabricating the containment vessel is also disclosed.

Abstract: A deflection yoke mounted on a television picture tube comprises a horizontal deflection coil, a vertical deflection coil and a separator for isolating the horizontal deflection coil from the vertical deflection coil, wherein the separator is a molded product of a mixture of plastics and granular ceramics having high thermal conductivity.

Abstract: In a magnetic resonance imaging apparatus, there are provided: an MR (magnetic resonance) imaging unit having an imaging hole at a substantially central portion thereof, into which an object under medical examination is inserted; a superconducting coil unit stored within an outer vessel which is positioned around the imaging hole, and including a superconducting coil assembly for uniformly producing a static magnetic field to be applied to the object, and at least one heat shield tube or thermally shielding the superconducting coil assembly stored therein; a gradient field coil assembly provided between the outer vessel and imaging hole; for producing a gradient magnetic field so as to be superimposed with the static magnetic field.

Abstract: A device for storing electromagnetic energy in toroidal superconducting windings of circular right cross-section, wherein the device is constituted by a plurality of flat cylindrical coils having a plane of symmetry perpendicular to their own axes and including the axis of the torus, and which are separated by wedge-shaped spacers. The invention is applicable to distribution networks or to electrical machines.

Abstract: A superconducting magnetic energy storage apparatus comprising a cylindrical superconducting coil; a cylindrical coil containment vessel enclosing the coil and adapted to hold a liquid, such as liquefied helium; and a cylindrical vacuum vessel enclosing the coil containment vessel and located in a restraining structure having inner and outer circumferential walls and a floor; the apparatus being provided with horizontal compression members between (1) the coil and the coil containment vessel and (2) between the coil containment vessel and the vacuum vessel, compression bearing members between the vacuum vessel and the restraining structure inner and outer walls, vertical support members (1) between the coil bottom and the coil containment vessel bottom and (2) between the coil containment vessel bottom and the vacuum vessel bottom, and external supports between the vacuum vessel bottom and the restraining structure floor, whereby the loads developed by thermal and magnetic energy changes in the apparatus can

Abstract: A superconductive magnet having at least one superconductive coil is provided. A thermal radiation shield is situated inside a vacuum vessel and the thermal radiation shield encloses the superconductive coil. A thermal diode is provided for thermally linking the superconductive coil and the thermal radiation shield when the thermal radiation shield is colder than the superconductive coil.

Abstract: In a superconducting magnet apparatus including one winding of coiled superconductor wire, another winding of coiled superconductor wire, a cooling device for supplying coolant to cooling vessels which contain the respective windings therein and a non-magnetic partition wall interposed between the cooling vessels containing the respective windings to airtightly separate them, with these windings being located at relative positions enabling mutual inductance therebetween, even if quenching occurs in the superconducting magnet apparatus. It is designed to not lose the magnetic repulsive force such that equipment traveling at high speed can be safely transferred at least to the nearest station. In addition, electromagnetic levitation traveling equipment on which the above-described apparatus is installed and a control method therefore is also described.

Abstract: A magnetic field generating system comprises a magnetic field generator (1); and a cooling system (4) having at least one thermal shield (6) surrounding the magnetic field generator. The system further comprises a temperature monitor (14, 15) for monitoring the thermal shield temperature; and a heater (13) for selectively heating the thermal shield so as substantially to maintain the monitored temperature substantially constant.

Abstract: A spacer bar, or system of spacer bars, interposed between coil layers of a coil structure. The spacer bar comprises a block of electrical insulating material adapted to be arranged between adjacent layers of a coil. The spacer bar may comprise several spacer bar sections segmented axially and provided with flexible joints (e.g., Belleville washers) between sections to permit each section to move with the adjacent coil layers (the coil layers between which the section is interposed). The sections of the spacer bar are held together by passing a rod through holes provided through each section. Between each pair of spacer sections, a Belleville washer is installed to assure that under continued cycling (e.g., expansion and contraction of the coil), the spacer sections return to their original location. To maintain an adequate creep path at the ends of the blocks or sections, notches can be cut into a face of each block or section.

Abstract: The device for protecting the poles of an electromagnetic inductor comprises a heat exchanger formed by one or more co-planar metal tubes (6) designed to allow the circulation of a cooling fluid therein and of such an arrangement that there is at most one electrical junction between any two tubes or tube elements. The exchanger is fastened to a rigid electrically insulating support plate (5) coated with refractory concrete (10) and covers the entire polar surface as far as the cowls (3). The exchanger can be shaped in the form of a series of alternating hairpins or in the form of a spiral with one or more branches. The device serves especially for protecting the poles of inductors used for the induction heating of metal products.

Abstract: In an installation including a superconducting solenoid coil in the form of an annulus having a vertical axis, a first vessel having an annular form and enclosing the coil for containing a primary cryogen at a temperature sufficient to maintain the coil superconductive, and at least one second vessel having an annular form and enclosing the first vessel for containing a secondary cryogen at a selected temperature, there are provided: cryogen storage containers spaced horizontally from the coil and the vessels for receiving the cryogens contained in the vessels; and conduit systems coupled between the vessels and the storage containers for permitting the flow of cryogens therebetween.

Abstract: An electromagnetic drag pad, particularly for providing all the drag force needed where slit ferrous strip is to be coiled at a coiling station, comprises a panel of drag friction material covering pole faces of an electromagnet which magnetically attracts the moving ferrous strip into frictional engagement with the panel of drag friction material thereby establishing a back tension to permit satisfactory formation of a stable coil of each strip at a coiling station; the electromagnet has a core comprising a multiplicity of elongated spaced apart substantially parallel pole elements defining therebetween gaps which accommodate an electric winding which is connected to a power supply (such as a low voltage DC high amperage supply) for energizing the electromagnet, the pole elements having respective pole faces which provide an alternating array of north and south poles.

Abstract: In a superconducting solenoid disposed in a cryogenic bath, the solenoid being in the form of a cylindrical annulus having a vertical axis and being composed of: two conductors (2,4) each containing superconductive material and each wound into a single layer helical coil; first and second support units (6) each supporting a respective conductor (2,4); and insulation members (8,12,14) composed of horizontal insulating layers (12) interposed between successive turns of each of the conductors (2,4), and vertical insulating layers (10) interposed between the first support unit (6) and the second support unit (6), the insulation members (8,12,14) being constructed such that variations in the current flowing through the conductors (2,4) produce varying magnetic fields which cause the insulation members (8,12,14) to experience heat-generating frictional movements, the support units (6) and the insulation members (8,12,14) are provided with a network of interconnected flow channels (22,24,26) communicating with the b

Abstract: A two stage cryocooler sleeve is provided having a second stage heat exchanger system capable of achieving lower temperatures than the first stage heat exchanger. A current lead comprising a ceramic superconductor having a critical temperature greater than the operating temperature of the first stage is tapered. The broader end is thermally coupled to the first stage heat exchanger and the narrow end coupled to the second stage heat exchanger. The tapered ceramic lead reduces the heat conduction from the first heat exchanger to said second heat exchanger.

Abstract: A magnetic system comprises a frame with at least one coil arranged coaxially thereon and providing for the setting-up of a magnetic field, and a cooling system. Wound in layers on a former of each coil are conducting and insulating tapes encompassed by a serving on an outer surface. Means for circulating coolant are disposed in close proximity to end surfaces of the coils, a gap being provided to allow flow of said coolant between the end surface of the coils and said means. The end surfaces of the coils are formed substantially by extremities of the conducting and insulating tapes.

Abstract: The torodial ring magnet is cooled by a gaseous cooling medium which is conducted through a first cooling circuit through the channels of the magnet coils of the magnet. The gaseous cooling medium exiting the magnet is cooled by a second liquid cooling medium in a second cooling circuit within an auxiliary cooler. Temperature sensors are provided to sense the temperature of the exiting gaseous cooling medium from the magnet sections to permit the opening or closing of a valve in the auxiliary cooler to cause the gaseous coolant to be cooled or not by the liquid cooling medium.

Abstract: Conventional superconducting magnet systems supply coolant centrally from a refrigerating system and have a current input provided separately in each case or through special magnets at the beginning and end of a section formed from superconducting electromagnets. The superconducting magnet system of the invention, which is to be used in particular for accelerator units, provides a control cryostat between the refrigerating system and the magnet cryostats encompassing the magnet coils of the electromagnets. The control cryostat at the same time has a current supply lead from which the magnet cryostats associated with the respective control cryostat are supplied with the current necessary for excitation through superconducting cables.

Abstract: A superconducting magnet arrangement for magnetic resonance systems including a cryomagnetic dewar containing magnetic coils in a helium vessel surrounded by a nitrogen vessel. A separate support structure is used to support the vessels in the dewar.

Abstract: A cryostat for a magnetic resonance magnet is provided comprising a cylindrical helium vessel concentrically situated in the cryostat. A first cylindrical shield is situated in the cryostat surrounding the first shield. A plurality of tubular struts are affixed to both the helium vessel circular end faces and the second shield. The tubular struts are circumferentially spaced and extend radially, parallel to the end shields of the helium vessel. The struts support the second shield spaced away from the helium vessel. Plate means are circumferentially spaced about the circular end faces of the first shield and affixed thereto. The plates extend radially, parallel to the end faces of the first shield and affixed to the inner circular end faces of the second shield, supporting the first shield spaced away from the second shield.

Abstract: A magnet system for a nuclear spin tomography installation contains annular superconducting coils for generating a magnetic background field and nonsuperconducting gradient coils. A hollow cylindrical thermal shield fits between the gradient coils and the superconducting coils. According to the invention, the thermal shield at the front faces is formed from tubular end pieces. The front faces have a greater specific electrical resistance than a tubular intermediate piece of the thermal shield that extends between the end pieces and cover at least the area of the gradient coils.

Abstract: Apparatus for simultaneously generating an intense toroidal magnetic field and an intense poloidal magnetic field in a compact aspect-ratio configuration and quasi-stationarily in time, characterized in that in the inner part of the electrical winding which generates the magnetic field (namely in that part of such winding which is nearest to the toroidal axis of symmetry) the turns of the conductor are tilted approximately 45 degrees relative to the meridian plane. Such said toroidal and respectively poloidal magnetic fields generate largely self-compensating mechanical loads on the winding, thus producing a highly optimized distribution of mechanical stresses in the apparatus, as a result also of favorable spring-like properties of the winding's turns, such properties originating in the turns being tilted. The said stress configuration in the apparatus is also compatible with the fitting of adequately sized cooling ducts between the winding's turns, whenever required.

Abstract: A coil designed for providing a highly uniform magnetic field suitable for use in nuclear magnetic resonance computer-aided tomography is provided with preheating apparatus which uses forced circulation of warmed liquid along the path normally circulated with the cooling liquid whereby there are simulated the normal operating coil heating conditions even when the coil is not operating so that the start-up stabilization time can be shortened.

Abstract: A superconducting coil apparatus comprises a first coil unit and second coil unit disposed concentrically outside the first coil unit. The second coil unit includes a cylindrical former having a spiral groove formed on an outer surface thereof, and a coil element constituted by a superconducting wire fitted in the spiral groove to form a spiral shape. The former is composed of a plurality of former segments which are assembled into a cylindrical foam. Each segment has a plurality of recess portions formed on the outer surfaces thereof and defining the spiral groove when the segments are assembled into the former. Each segment has a fluid passage formed on the outer surfaces thereof to permit the cooling medium to flow therethrough to come in contact with the superconducting wire. Thus, the coil apparatus is easy to assemble and relatively compact. Further, the spiral groove has V-shaped cross section, so that the superconducting wire will not be shifted in the axial direction of the coil element.

Abstract: There is provided a forced-cooled superconductor including a conduit and a plurality of superconducting strands disposed within the conduit in spaced relationship. A coolant passes through the spaces between the strands for cooling the conduit and strands. The conduit and strands are further cooled by means of an additional separate cooling channel which cooperates with the coolant for cooling the conduit and strands.

Abstract: A superconducting synchrotron orbital radiation (SOR) apparatus having a plurality of deflecting electromagnets each comprising first and second superconducting coils which are immersed in liquid helium contained in helium tanks. The helium tanks are surrounded by nitrogen shields which are cooled by liquid nitrogen in nitrogen contained tanks. One of the helium tanks is equipped with a liquid helium supply port and a helium gas exhaust port. All of the other helium tanks are connected with this helium tank such that liquid helium which is supplied to this one helium tank automatically flows to the other helium tanks and such that helium gas from the other helium tanks automatically flows to this helium tank and is exhausted.

Abstract: A resistive solenoid magnet with homogeneous field is provided more particularly for NMR image formation.According to the invention, the magnet comprises several coils preferably Bitter coils and some parameters such as the lengths of the coils, the distances which separate them and their outer diameter are chosen for optimizing the power-mass product of the magnet.

Abstract: A device for treating aqueous solutions with magnetic lines of force includes a pipe through which the solution passes. An electromagnetic coil surrounds the pipe and a core consisting of endwise connected alternating short sections of magnetic and non-magnetic material is disposed coaxially with and spaced from the pipe. Located between the pipe and the core is a helical baffle. A housing is spaced from and surrounds the coil. Air circulation vents are located at the upper and lower ends of the housing. Annular cooling fins extend outwardly through the coil with their outer peripheries terminating in the gap between the coil and the housing. A plurality of apertures are formed in the exposed outer portions of each cooling fin with the apertures of one fin being staggered relative to the apertures of the adjacent fins.

Abstract: A structure is provided for connecting the disks of a Bitter coil. The disks each include a cut out in the form of a slit, for example undulating so as to define from one disk to another zones with overlapping of turns divided into two groups and the electric connections are provided by junctions of said overlapping zones of one group or the other, alternatively from one disk to another.

Abstract: A solenoidal magnet is provided with high magnetic field homogeneity, including a connection structure between spaced coils. The current between two adjacent spaced coils is transmitted in one direction by a longitudinal conductor and in the other direction by two longitudinal conductors disposed on each side of said first conductor.

Abstract: A cryostat comprising an outer closed cylindrical vacuum vessel and a helium vessel is situated inside the vacuum vessel. The helium vessel has on its outside surface four radially extending trunnions situated on a horizontal plane passing through the center of the helium vessel. The trunnions are symmetrically spaced on either side of the helium vessel, about the helium vessel's axial midplane. Four straps have one end of each of the strap looping about a respective one of the four trunnions. The other end of each of the straps is rotatably secured to the circular end faces of the vacuum vessel, with the two straps from the trunnions closest to an end face secured to that end face.

Abstract: In a forced flow cooling-type superconducting coil apparatus including a superconducting coil having superconducting wires inserted into a hollow conduit, current leads for supplying a current to said superconducting coil, and cooling means for cooling said superconducting wires by forcibly flowing the coolant through said hollow conduit, a part of the coolant flowing through said cooling means is branched to cool said current leads.

Abstract: An unimpregnated winding for use in a cryostat of a superconducting magnet is provided comprising a form including a shell having the shape of two truncated cones attached to one another at their respective bases. Superconducting wire is wrapped around the form under tension so that during superconducting magnet operation, the form remains under compression.

Abstract: A magnetic field generating device for a nuclear magnetic resonance-computerized tomography comprising a pair of permanent magnets magnetized in the same direction with different-polarity poles opposing mutually to define an air gap, whose maximum energy product, (BH).sub.max, is not less than 30 MGOe (240 KJ/m.sup.3), on each of the opposing faces of the permanent magnets a magnetic pole segment being provided which has an annular projection and, as occasion demands, at least one central convex projection inside the annular projection, and the permanent magnets being coupled magnetically by a yoke to generate a magnetic field within the air gap.The present device is able to create a uniform and stable magnetic field, in spite of its small-sized body.

Abstract: A coolant arrangement is disclosed for magnetic coil turn assemblies in which cooling fluid is flowed through a supply header along the face of a coil turn and into coolant inlet openings positioned along the face of the coil turn beneath the supply header structure. Coolant is directed through coolant channels around the magnetic coil turn, and into outlet openings. The outlet openings are in fluid communication with a return header also positioned on a flat face of a magnetic coil turn. There is also disclosed a method and apparatus for passing coolant through adjacent coolant channels in a magnetic coil turn in opposite directions. The cooling means disclosed avoids creating hot spots in the vicinity of the coolant inlets and outlets and reduces stresses in the coil in the vicinity of the coolant inlets and outlets. It also provides for maintaining a uniform average temperature throughout the coil turn.

Abstract: A magnetizing device for generating magnetic poles of alternating polarity in a magnetic body includes a supporting plate of electrically insulating material having a surface formed to closely conform with the surface of the magnetic body and an electrically conductive array of low electrical resistivity which includes magnetized sections of wire, or rod, recessed in the insulating plate and positioned in such a manner as to generate the desired magnetic poles in a magnetic body when supported by the plate when the array is subjected to a high-intensity unidirectional current, the array also including cooling sections of wire, or rod, twisted in the form of a double helix, interspersed between the magnetizing sections and disposed away from the magnetic body. The electrical array may be formed by a series of short lengths of wire, or rods, the respective ends of the short lengths being twisted together to form the cooling sections.

Abstract: The invention is intended for incorporation into an enclosure confining fluid about an electromagnet of the type having a core, at least one coil disposed about the core and a current source coupled to the coil to establish a magnetic field. According to the invention, at least a portion of the peripheral wall of the enclosure surrounding the core axis resides in non-parallel relationship with the axis of the core. As a result, a part of the peripheral wall portion is in closer proximity to the wire coil than the remainder of the wall portion. As a result, the heat readily conducts through the wall portion and is dissipated efficiently. The surface exposed to the atmosphere with the above construction has a greater area than would a planar wall parallel to the core axis so that heat dissipation is enhanced.

Abstract: A device for cooling a magnet system, especially in an installation for nuclear spin tomography which magnet system comprises several annular magnet coil windings which are made of ribbons of normal conducting material and are connected at their end faces over a large area to cooling elements in a heat conducting manner, the cooling elements cooled by a cooling medium flowing in coolant lines under forced flow. To assure an effective and reliable cooling of the coil windings on each end face of a magnet coil winding, a predetermined number of identically designed cooling elements uniformly distributed in the circumferential direction is cemented on, each cooling element comprising at least a heat conduction plate of annular sector shape which is provided with a predetermined number of slots uniformly distributed in the circumferential direction and to which the coolant line is connected over several turns in a heat conducting manner.

Abstract: In an electromagnetic beam respectively a beam- or carrier-like worktable for pressure coating and other processing machines operating with magnetic contact pressure, at least one pole end of the magnet cores of the electromagnet is connected in a heatproof manner by means of a magnet-connecting bridge with a support profile symmetric to the plane of the magnet core axes.

Abstract: A bakeable electromagnet assembly is made of coils of metal foil either anodized to insulate between turns or separated by a film of Kapton. Cooling plates connected to a source of cooling fluid are used to remove heat. Heat is conducted from the coils to the cooling plates by a powder which is a heat conductor and electrical insulator such as boron nitride. An external shell made of high magnetic permeability material provides a return path for the magnetic field.

Abstract: A print head for impact type dot matrix printer having means for air-cooling the interior of the print head elevated in temperature due to the generation of heat of solenoid coils, the air cooling means is constituted in such a manner that the outer face of the print head along the direction of movement thereof is formed so as to cause the faster flow of air along said outer face when the print head is moved, and said outer face is provided with ventilating hole means which communicates the interior of the print head and the outside. When the print head is moved, it causes the faster flow along said outer face to thereby draw the air from the interior of the print head through the ventilating hole means due to the difference in pressure.

Abstract: In an electromagnetic relay, a first stationary contact member (25) has a first, elongated portion (25a) extending between first and second insulative supports and a second portion (25b) extending in a direction normal to the first portion. The second portion includes a first stationary contact (25c) element and a heat radiating surface (25b, 25f) for radiating a substantial amount of heat generated by an arc so that the amount of heat which is conducted to the first support (13) is insufficient to cause a fusion to occur therein. A second stationary contact member (26) has a third, elongated portion (26a) extending between the first and second supports and a fourth, elongated portion (26b) extending in a direction normal to the third portion in spaced relationship to the second portion (25b) and having a second stationary contact element (26c) in opposed relationship with the first stationary contact element.

Abstract: Disclosed is a method and apparatus for controlling coolant distribution in ohmic heating and other poloidal field magnetic coils. The apparatus consists of a coolant inlet and outlet arrangement with spiral coolant channels positioned therebetween. The spiral coolant channels are designed to control the coolant pressure drop within the coil turns and hence the coolant flow distribution within the entire coil. The coolant channels of the present invention provide coil turns with improved structural and cooling characteristics over the prior art. The method disclosed consists of controlling the flow distribution of cooling fluid through coolant channels in a magnetic coil by using spiral channels of a specially designed length, width and spiral configuration.

Abstract: A double-pancake coil having first and second pancakes may comprise a plurality of conductor means, each conductor means having a different grade and having one or more conductors, wherein each pancake of said double-pancake coil is comprised of inner and outer turns; wherein said inner turns are comprised of at least one of said conductor means wound about an axis and nested within one another; wherein said outer turns are comprised of said inner conductor means and at least one other conductor means co-wound about said inner turns and nested within one another; wherein each of said conductor means is wound along said axis from said first pancake to said second pancake at a different turn.

Abstract: A printing apparatus including a plurality of drive coils for driving printing hammers arranged longitudinally in side-by-side relation at one side of a core of the U-shape. A first cooling fluid passageway is defined inside the core of the U-shape to allow a cooling fluid for cooling the drive coils to flow therethrough, and a second cooling fluid passageway is defined outside the core by a duct to allow the cooling fluid for cooling the drive coils to flow therethrough without escaping to the outside by diffusion. A current of cooling fluid is forcibly fed into these cooling fluid passageways by a fluid machine.

Abstract: A heat exchange system for an electromagnetically operated print hammer of a print hammer bank provides internal and external heat transfer for the operating windings. A non-magnetic metal bobbin of the heat exchange system provides conductive transfer of heat from the interior of the operating winding to the magnetic core. Flat parallel plates of magnetic material are attached to the sides of the operating winding for external heat transfer and magnetic flux shielding. The plates may have multiple laminations having different saturation and permeability characteristics.

Abstract: A lifting magnet for warm steel slabs and the like incorporating means for cooling the metallic shell of the magnet to prevent damage to coil insulation due to overheating.

Abstract: The invention relates to a magnet coil arrangement for generating a magnetic field which is homogeneous at least in its center, preferably for magnetic resonance spectroscopy. The arrangement consists of four flat ring coils whose coil planes extend perpendicularly to an axis of examination which extends through the coil centers. The coils are symmetrically arranged with respect to a point situated on this axis. By means of a magnetic coil arrangement of this kind, a magnetic field can be generated which extends in the direction of the axis of examination and rotationally-symmetrically with respect thereto and which, in comparison with the magnetic fields generated by means of known coil arrangements, has an improved homogeneity in the direction perpendicular to the axis of examination over a larger range which extends in the direction perpendicular to the axis of examination in the center of the magnetic coil arrangement.

Abstract: A pressure support unit for limiting strain in a superconducting winding including a restraining member surrounding the superconducting winding; and a pressure compartment, having at least one segment for receiving pressurized fluid, disposed between the superconducting winding and the restraining member; and a pressure support system comprising a plurality of such pressure support units.

Abstract: An improved print hammer actuator for dot matrix printers employs a substantially closed loop magnetic path including a resilient magnetic hammer, a number of such hammers being aligned in a hammer bank assembly which is shuttled back and forth along a printing line at a high rate of speed, while the hammers are individually actuated by energizing coils which overcome a permanent magnetic field normally maintaining the hammers in retracted position. Heat conducting elements are mounted in heat transfer relationship with each of the different ones of the coils in the hammer bank, and high surface area fins on the elements extend into an air flow directed across one side of the hammer bank. For this purpose the hammer bank assembly is configured to define an interior air channel along its length and includes a fixed top cover and spaced apart circuit board forming part of a plenum and directing air frontwardly from a rear mounted fan.