Abstract: An open superconductive magnet useful in magnetic resonance imaging (MRI) applications. The magnet has two spaced-apart assemblies and preferably has a "C" shape. Each assembly has: a vacuum enclosure having a longitudinal axis and surrounding a bore; a magnetizable pole piece located within the bore and outside the vacuum enclosure; and a superconductive main coil, a superconductive shielding coil, and a magnetizable ring positioned within the vacuum enclosure. There is no magnetizable solid path between the two pole pieces. Preferably, the ring is positioned longitudinally between the main and shielding coils.

Abstract: An open superconductive magnet useful in magnetic resonance imaging (MRI) applications. The magnet has two spaced apart assemblies, wherein each assembly has a magnetizable pole piece and a magnetizable ring radially spaced outwardly apart from, and at least partially longitudinally overlapping, the pole piece. A superconductive main coil is positioned radially between the pole piece and the ring. A superconductive shielding coil is positioned radially outward from the superconductive main coil and longitudinally outward from the longitudinally outer end of the ring.

Abstract: An open superconductive magnet useful in magnetic resonance imaging (MRI) applications. The magnet has two spaced apart assemblies, wherein each assembly has a superconductive shielding coil spaced longitudinally outward and apart from a superconductive main coil. A magnetizable pole piece is spaced apart from the coils, has a radially-outer portion at least partially radially overlapping the main coil, and has a longitudinally-inner portion which projects longitudinally inward past the longitudinally outer end of the main coil.

Abstract: A magnetic resonance imaging (MRI) magnet includes different-diameter, longitudinally-proximate, first and second coil form segments. First and second superconductive coils are wound, respectively, around the first and second coil form segments. A first spacer ring is attached to the first coil form segment and longitudinally abuts a lateral side of the first superconductive coil, and a second spacer ring circumferentially surrounds and is attached to the second coil form segment and longitudinally abuts a lateral side of the second superconductive coil. Two or more circumferentially-spaced-apart plate members are attached to, and extend radially outward from, the first and second spacer rings.

Abstract: A superconducting device, such as a superconducting rotor for a generator or motor. A vacuum enclosure has an interior wall surrounding a cavity containing a vacuum. A superconductive coil is placed in the cavity. A generally-annularly-arranged, thermally-conductive sheet has an inward-facing surface contacting generally the entire outward-facing surface of the superconductive coil. A generally-annularly-arranged coolant tube contains a cryogenic fluid and contacts a generally-circumferential portion of the outward-facing surface of the sheet. A generally-annularly-arranged, thermally-insulative coil overwrap generally circumferentially surrounds the sheet. The coolant tube and the inward-facing surface of the coil overwrap together contact generally the entire outward-facing surface of the sheet.

Abstract: A superconductive device (e.g., magnet) having a superconductive lead assembly and cooled by a cryocooler coldhead having first and second stages. A first ceramic superconductive lead has a first end thermally connected to the first stage and a second end thermally connected to the second stage. A jacket of open cell material (e.g., polystyrene foam) is in surrounding compressive contact with the first ceramic superconductive lead, and a rigid, nonporous support tube surrounds the jacket. This protects the first ceramic superconductive lead against shock and vibration while in the device. The rigid support tube has a first end and a second end, with the second end thermally connected to the second stage.

Abstract: A closed magnetic resonance imaging (MRI) magnet has a single superconductive coil assembly including a coil housing containing a cryogenic fluid dewar containing a pair of longitudinally-outermost impregnated superconductive main coils and at-least-one cryostable additional superconductive coil such as a pair of additional main coils, a pair of bucking coils, and/or a pair of shielding coils. An open MRI magnet has two spaced-apart superconductive coil assemblies and an imaging volume having a center. Each coil assembly has a cryostable superconductive main coil and an impregnated bucking coil with the impregnated bucking coil being the closest superconductive coil to the center of the imaging volume.

Abstract: A superconductive lead assembly for a superconductive device (e.g., magnet) cooled by a cryocooler coldhead having first and second stages. A first ceramic superconductive lead has a first end flexibly, dielectrically, and thermally connected to the first stage and a second end flexibly, dielectrically, and thermally connected to the second stage. A first glass-reinforced-epoxy lead overwrap is in general surrounding contact with and attached to the first superconductive lead. The first lead overwrap has a coefficient of thermal expansion generally equal to that of the first superconductive lead. The lead overwrap protects the lead from moisture damage and from breakage during handling. For added protection against shock and vibration while in the device, the lead assembly is surrounded by a (e.g., polystyrene foam) jacket surrounded by a helically-wound metallic wire surrounded by a glass-reinforced-epoxy jacket overwrap surrounded by a rigid support tube.

Abstract: Apparatus for winding an electrical conductor, having a compressible electrical insulation, on a coil form to make a conductive coil. A rotating device rotates the coil form. A guiding device guides the conductor, near the coil form, longitudinally toward the second end of the coil form so that successive turns of the conductor are generally abutting and are laid down in a first layer. A locating and longitudinally-translating device moves a rotatable wheel so that its rim contacts, and is rotated by, the rotating coil form and so that a side of the wheel applies a first longitudinally-compressive force to a portion of a presently-wound turn of the first layer of the conductor in a direction toward the first end of the coil form.

Abstract: A planar magnetic resonance imaging (MRI) magnet having a superconductive coil assembly including a toroidal-shaped coil housing which surrounds a bore, has a longitudinal axis, and contains at least three concentric, annular-shaped superconductive coils coaxially aligned with the axis. The coils produce a magnetic resonance imaging volume having a center located outside the bore. Preferably, the bore is generally completely filled with magnetic material, and the magnetic resonance imaging volume is located completely outside the bore which provides for improved patient and physician access during MRI-guided biopsy as well as during MRI imaging.

Abstract: A superconducting field winding assemblage for an electrical machine, such as a rotary generator or a linear motor. The field winding assemblage includes at least two pole assemblies. Each pole assembly has a direction of motion, a solid core, a superconductive coil assembly generally surrounding the solid core, and a first cooling conduit. The superconductive coil assembly has a generally longitudinally extending axis positioned generally perpendicular to the direction of motion and has an epoxy-impregnated, generally racetrack-shaped superconductive coil having a minor axis positioned generally parallel to the direction of motion. The first cooling tube contains a gaseous cryogen (such as gaseous helium) and is positioned to be in thermal contact with the superconductive coil.

Abstract: A method for making an electrical coil such as a superconductive switch or an energy dump resistor. The midportion of a coil wire, whose ends are wound around two supply spools, is looped around a radially-extending pin on a shaft. The shaft is turned in one direction and the coil wire is guided such that segments are paid out from the first supply spool and sections are paid out from the second supply spool, such segments and sections being wound from the middle to a corresponding end, then being wound from the corresponding end to the middle where they are crossed over, and then being wound from the middle to the other associated end. A stratum of electrical insulation is positioned, at the appropriate time, on the second segment and second section, and, in the case of the switch, an electrical heater is positioned, at the appropriate time, on the first segment and first section.