摘要:
A composite sealed vessel is provided. The vessel includes a non-metallic, generally cylindrical inner containment piece, a non-metallic, generally cylindrical outer containment piece disposed around the inner containment piece. A pair of non-metallic flanges are disposed at ends of the inner and outer containment pieces to form a closed structure defining a cavity therein. The vessel also includes a metallic external lining disposed over the closed structure to form a leak-tight pressure boundary.
摘要:
A superconducting coil assembly includes a plurality of circuit branches. Each circuit branch of the plurality of circuit branches is electrically connected in parallel to each other. Each circuit branch is disposed at a structural core. Each circuit branch of the plurality of circuit branches includes a coil wound from a superconducting wire and a resistive means electrically connected in series to the coil. The coil from each circuit branch forms a plurality of coils with respect to the plurality of circuit branches.
摘要:
A magnetic resonance imaging (MRI) device for imaging a volume is provided with at least one main magnet for generating a magnetic field, and at least one gradient coil for manipulating the magnetic field generated by the at least one main magnet to image the volume. The magnetic fields generated by the at least one gradient coil are substantially unshielded.
摘要:
A system and method for protecting a superconductor from a quench condition. A quench protection system is provided to protect the superconductor from damage due to a quench condition. The quench protection system comprises a voltage detector operable to detect voltage across the superconductor. The system also comprises a frequency filter coupled to the voltage detector. The frequency filter is operable to couple voltage signals to a control circuit that are representative of a rise in superconductor voltage caused by a quench condition and to block voltage signals that are not. The system is operable to detect whether a quench condition exists in the superconductor based on the voltage signal received via the frequency filter and to initiate a protective action in response.
摘要:
A magnetic resonance imaging (MRI) device for imaging a volume is provided with at least one main magnet for generating a magnetic field, and at least one gradient coil for manipulating the magnetic field generated by the at least one main magnet to image the volume. The magnetic fields generated by the at least one gradient coil are substantially unshielded.
摘要:
A rotor is disclosed for a super-conducting synchronous machine having: a rotor core; a super-conducting coil extending around at least a portion of the rotor core, the coil having coil side sections on opposite sides of the rotor core; a vacuum housing covering at least one of the coil side sections, and a conductive shield over the vacuum housing and coil side sections.
摘要:
A method for shimming a magnetic resonance imaging magnet requiring higher magnetic field homogneity on a small imaging volume and by magnetic field measurements on a larger volume providing small measurement error and practical field strength measurements and utilizing the spherical harmonic coefficients of the measurements.
摘要:
A correction coil current adjustment circuit for a superconducting magnet to selectively switch various coils in circuit with a power source to provide the desired superconducting current flow and magnetic field homogeneity for magnetic resonance imaging eliminating the need for some of the mechanical leads which extend from the exterior of the magnet to the interior of the cryogen vessel minimizing thermal leak paths and including simplified switching of the various main and correction magnet coils to provide the desired current flow. Inductive coupling from outside the magnet to induce correction coil current flow eliminates additional mechanical leads.
摘要:
A suspension system for a superconducting magnet for supporting and spacing the thermal radiation shield and vacuum vessel about the cryogen vessel utilizing a carbon fiber reinforced composite assembly with a first frustro-conical member positioned between the cryogen vessel and radiation shield and a second frustro-conical member extending from the vacuum vessel to overlap the radiation shield with a radially extending connecting member between the interior ends of the members to provide a tortuous generally Z-shaped lengthened thermal path and thermal resistance plus mechanical support in both the axial and radial directions.
摘要:
A new design for an aluminum stabilized superconductor which embeds the superconducting cable within a high purity aluminum stabilizer. This stabilizer is, in turn, partially surrounded by an aluminum alloy sheath. The aluminum alloy sheath is constructed and arranged so that at least one exterior surface of the stabilizer is open for exposure to a coolant. Preferably, this open exterior surface of the stabilizer will be knurled for greater cooling efficiency.