摘要:
An apparatus and method for shimming a magnetic field of a magnet in a volume of interest includes a nonmagnetic holder configured with an array of fluid containing pockets; and a solidified ferromagnetic fluid in each pocket of the array of fluid containing pockets, wherein the solidified ferromagnetic fluid is fabricated from a ferromagnetic fluid, a diluting liquid, a hardener, and an accelerator agent. The ferromagnetic fluid includes a carrier liquid, ferromagnetic particles, and a surfactant.
摘要:
An apparatus and method for shimming a magnetic field of a magnet in a volume of interest includes a nonmagnetic holder configured with an array of fluid containing pockets; and a solidified ferromagnetic fluid in each pocket of the array of fluid containing pockets, wherein the solidified ferromagnetic fluid is fabricated from a ferromagnetic fluid, a diluting liquid, a hardener, and an accelerator agent. The ferromagnetic fluid includes a carrier liquid, ferromagnetic particles, and a surfactant.
摘要:
In the installation of a superconducting magnet for magnetic resonance imaging at a preselected position in a mobile van, preselected curvilinear magnetic segments are applied to preselected locations on the exterior of the magnet to counteract magnet inhomogeneities in the imaging bore which would otherwise occur because of magnetic material in the van structure.
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 superconducting magnet electrical circuit is provided for quench protection. A superconducting coil assemblage is provided including a plurality of spatially separated main and secondary magnet coil portions. The main magnet coil portions are connected in series to form at least one main coil series circuit. The secondary magnet coil portions are also connected in a series to form at least one secondary coil series circuit. At least one temperature limiting circuit is also provided. The temperature limiting circuit may be a quench heater circuit or a quench resistor circuit. The temperature limiting circuit has a plurality of quench heaters or a plurality of quench resistors connected with the superconducting coil assemblage. A superconductive switch is coupled with the superconducting coil assemblage.
摘要:
A superconducting magnet system includes a coil support structure, superconducting coils, and electrically and thermally conductive windings. The superconducting coils and the conductive windings are supported by the coil support structure. Each conductive winding is electromagnetically coupled with a corresponding superconducting coil. Each conductive winding is electrically shorted.
摘要:
A superconducting magnet system includes a coil support structure, superconducting coils, and electrically and thermally conductive windings. The superconducting coils and the conductive windings are supported by the coil support structure. Each conductive winding is electromagnetically coupled with a corresponding superconducting coil. Each conductive winding is electrically shorted.
摘要:
The present invention provides a method and apparatus for measuring the level of a liquid cryogen. The invention provides for use of a current source (52), a length, or multiple lengths, of superconducting filament (40) situated within a cryostat (1) containing a cryogenic fluid (2) and a voltmeter (51) for measuring the voltage drop across the filament (40). The invention further provides a method for using said apparatus.
摘要:
A superconducting magnet system includes a coil support structure, superconducting coils, and electrically and thermally conductive windings. The superconducting coils and the conductive windings are supported by the coil support structure. Each conductive winding is electromagnetically coupled with a corresponding superconducting coil. Each conductive winding is electrically shorted.
摘要:
A method and apparatus for actively controlling quench protection of a superconducting magnet includes a magnetic resonance imaging (MRI) system and a computer readable storage medium having stored thereon a computer program comprising instructions which when executed by a computer cause the computer to detect a quench condition of the superconducting magnet. The instructions also cause the computer to actively control a quench protection system of the superconducting magnet in response to the detected quench condition.