Patent application number | Description | Published |
20090072939 | MAGNET SYSTEM AND MRI APPARATUS - A magnet system having a pair of parallel plate-like permanent magnets in which magnetic poles of reversed polarities are opposed to each other with a space therebetween. The pair of permanent magnets includes main portions magnetized in the same direction as their thickness direction, and peripheral portions magnetized in a direction different from their thickness direction. | 03-19-2009 |
20120098538 | SUPERCONDUCTING MAGNET HAVING COLD IRON SHIMMING CAPABILITY - A method of shimming a superconducting magnet assembly that includes a cryostat and a superconducting magnet configured to be installed in the cryostat. The method includes determining a plurality of field inhomogeneity characteristics of the superconducting magnet while the superconducting magnet is at room temperature and prior to the superconducting magnet being sealed in the cryostat, and installing an initial set of passive shims inside the cryostat while the superconducting magnet is at room temperature, the initial set of passive shims reducing the determined field inhomogeneity characteristics when the superconducting magnet is operating at a normal operational temperature. | 04-26-2012 |
20120182012 | APPARATUS AND METHOD FOR PROTECTING A MAGNETIC RESONANCE IMAGING MAGNET DURING QUENCH - A superconducting magnet assembly comprising a plurality of superconducting magnet coil portions forming a coil series circuit to provide a magnetic field, a power supply to supply power to the plurality of superconducting magnet coil portions during a magnet ramp mode of operation, and a ramp switch coupled to the superconducting magnet coil portions, wherein the ramp switch is configured to be open during a magnet ramp mode and closed during a persistent mode. A dump resistor is disposed externally to the vessel and is connectable by the ramp switch to the superconducting magnet coil portions. Further, a controller is coupled to at least one superconducting magnet coil portion and the ramp switch and is configured to detect a quench onset condition in the at least one superconducting magnet coil portion and to open the ramp switch upon detection of the quench onset condition in order to dump magnet energy. | 07-19-2012 |
20120306492 | PENETRATION TUBE ASSEMBLIES FOR REDUCING CRYOSTAT HEAT LOAD - A penetration assembly for a cryostat is presented. The penetration assembly includes an outer wall member having a first end and a second end and configured to alter an effective thermal length of the wall member, wherein a first end of the tube is communicatively coupled to a high temperature region and the second end of the tube is communicatively coupled to a cryogen disposed within a cryogen vessel of the cryostat. In addition, the penetration tube assembly includes a telescoping inner wall member comprising a plurality of tubes nested within one another, and wherein each tube in the plurality of tubes is operatively coupled to at least one other tube in series. | 12-06-2012 |
20120309630 | PENETRATION TUBE ASSEMBLIES FOR REDUCING CRYOSTAT HEAT LOAD - A penetration assembly for a cryostat is presented. The penetration assembly includes a wall member having a first end and a second end and configured to alter an effective thermal length of the wall member, where a first end of the wall member is communicatively coupled to a high temperature region and the second end of the wall member is communicatively coupled to a cryogen disposed within a cryogen vessel of the cryostat. | 12-06-2012 |
20130029849 | SUPERCONDUCTING MAGNET SYSTEM - 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. | 01-31-2013 |
20130154648 | SYSTEM AND APPARATUS FOR COMPENSATING FOR MAGNETIC FIELD DISTORTION IN AN MRI SYSTEM - A magnet apparatus for a magnetic resonance imaging system, the magnet apparatus includes a vacuum vessel, a helium vessel disposed within the vacuum vessel and a thermal shield disposed between the vacuum vessel and the helium vessel. A set of passive compensation coils are disposed within the vacuum vessel or the helium vessel and used to compensate for magnetic field distortion caused by mechanical vibrations within the magnet apparatus. | 06-20-2013 |
20130157865 | SYSTEM FOR MAGNETIC FIELD DISTORTION COMPENSATION AND METHOD OF MAKING SAME - A system and method for magnetic field distortion compensation includes a cryostat for a magnetic resonance imaging (MRI) system. The cryostat includes a vacuum casing having a vacuum therein. A cryogen vessel is disposed within the casing, the vessel having a coolant therein. A thermal shield is disposed between the vacuum casing and the cryogen vessel. An eddy current compensation assembly is disposed within the casing. The eddy current compensation assembly includes a plurality of electrically conductive loops formed on one of the vacuum casing, the cryogen vessel, and the thermal shield and constructed to mitigate vibration-induced eddy currents in the MRI system. | 06-20-2013 |
20140155268 | SYSTEM AND APPARATUS FOR COMPENSATING FOR MAGNETIC FIELD DISTORTION IN AN MRI SYSTEM - A magnet apparatus for a magnetic resonance imaging system, the magnet apparatus includes a cylindrical vacuum vessel, a closed loop cooling system disposed within the vacuum vessel and a cylindrical thermal shield disposed between the vacuum vessel and the closed loop cooling system. A set of passive compensation coils are disposed within the vacuum vessel and used to compensate for magnetic field distortion caused by mechanical vibrations within the magnet apparatus. | 06-05-2014 |
20150072864 | SUPERCONDUCTING MAGNET SYSTEM - 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. | 03-12-2015 |