Abstract: A magnetic resonance apparatus which may include: a body portion having a cavity with a first and second ends and at least one opening situated at one of the first and second ends. The cavity may define a longitudinal axis (LA) extending between the first and second ends. At least one main magnet may generate a main magnetic field having a substantially homogenous magnetic field within the cavity. A center shim (CS) which may be formed from a ring having opposed edges and which may extend along a length of the longitudinal axis of the cavity. One or more discrete shims (DSs) may be situated between the CS and at least one of the first and second ends.

Abstract: The following relates generally to use of magnetic resonance (MR) imaging as guidance in radiation therapy, and more specifically to use of MR imaging as guidance in proton therapy. In some embodiments, a cryogenic dewar is provided with multiple channels allowing a proton beam from a proton beam source to pass through. The proton beam may first be aligned with a first channel, and the dewar may then be rotated along with the proton source. The dewar may then be rotated to align a second channel with the proton beam.

Abstract: A valve is configured to control a flow of a gas disposed within a convective cooling loop. The valve can be actuated between an open position and a closed position via a magnetic field generated by at least one electrically conductive coil disposed within a cryostat.

Abstract: A magnetic resonance apparatus which may include: a body portion having a cavity with a first and second ends and at least one opening situated at one of the first and second ends. The cavity may define a longitudinal axis (LA) extending between the first and second ends. At least one main magnet may generate a main magnetic field having a substantially homogenous magnetic field within the cavity. A center shim (CS) which may be formed from a ring having opposed edges and which may extend along a length of the longitudinal axis of the cavity. One or more discrete shims (DSs) may be situated between the CS and at least one of the first and second ends.

Abstract: A chamber (422) for a cryostat (420) includes: first and second annular sections (4221, 4222) separated and spaced apart from each other along a first direction, and a third annular section (4223) extending in the first direction between the first and second annular sections and connecting the first and second annular sections to each other. The first and second annular sections define corresponding first and second internal volumes, the third annular section defines a third internal volume, and the third internal volume is substantially less than the first internal volume and substantially less than the second internal volume.

Abstract: An apparatus includes: a getter material disposed within a vacuum chamber to absorb stray molecules within the vacuum chamber; a thermal mass disposed adjacent the getter material and in thermal communication with the getter material; a cold station disposed within the vacuum chamber above the thermal mass; and a convective cooling loop connected between the thermal mass and the cold station and configured to convectively cool the thermal mass when the cold station is at a lower temperature than the thermal mass, and to thermally isolate the thermal mass from the cold station when the cold station is at a higher temperature than the thermal mass. The thermal mass may be water ice and may be thermally isolated from the walls of vacuum chamber by low loss support links and/or thermal reflective shielding.

Abstract: An apparatus includes: a getter material disposed within a vacuum chamber to absorb stray molecules within the vacuum chamber; a thermal mass disposed adjacent the getter material and in thermal communication with the getter material; a cold station disposed within the vacuum chamber above the thermal mass; and a convective cooling loop connected between the thermal mass and the cold station and configured to convectively cool the thermal mass when the cold station is at a lower temperature than the thermal mass, and to thermally isolate the thermal mass from the cold station when the cold station is at a higher temperature than the thermal mass. The thermal mass may be water ice and may be thermally isolated from the walls of vacuum chamber by low loss support links and/or thermal reflective shielding.

Abstract: A magnetic resonance (MR) imaging system (100) including a housing (102) having first and second openings (110, 116), and first and second solenoid coils (160, 150), the first and second solenoid coils (160, 150) generate a magnetic field suitable for imaging within a region of interest (ROI). The first and second solenoid coils (160, 150) have a common longitudinal axis (LA). The first and second openings (110, 116) are situated on opposite sides of the housing (102) along the longitudinal axis (LA). The first solenoid coil (160) has a different inside diameter than the second solenoid coil (150) and is positioned adjacent the first opening (110). The second solenoid coil (150) is positioned adjacent the second opening (116). Accordingly, the system provides improved access to the patent during imaging, e.g. for MR guided interventional procedures.

Abstract: An apparatus includes an electrically conductive coil which produces a magnetic field when an electrical current passes therethrough; a selectively activated persistent current switch connected across the electrically conductive coil; a cryostat having the electrically conductive coil and the persistent current switch disposed therein; an energy dump; at least one sensor which detects an operating parameter of the apparatus and outputs at least one sensor signal in response thereto; and a magnet controller. The magnet controller receives the sensor signal(s) and in response thereto detects whether an operating fault (e.g. a power loss to the compressor of a cryocooler) exists in the apparatus, and when an operating fault is detected, connects the energy dump unit across the electrically conductive coil to transfer energy from the electrically conductive coil to the energy dump unit. The energy dump unit disperses the energy outside of the cryostat.

Abstract: An apparatus includes: a getter material (310) disposed within a vacuum chamber (210) to absorb stray molecules within the vacuum chamber; a thermal mass (340) disposed adjacent the getter material and in thermal communication with the getter material; a cold station (312) disposed within the vacuum chamber above the thermal mass; and a convective cooling loop (310) connected between the thermal mass and the cold station and configured to convectively cool the thermal mass when the cold station is at a lower temperature than the thermal mass, and to thermally isolate the thermal mass from the cold station when the cold station is at a higher temperature than the thermal mass. The thermal mass may be water ice and may be thermally isolated from the walls of vacuum chamber by low loss support links (360, 362, 364) and/or thermal reflective shielding.

Abstract: A superconducting magnet system, including a cryostat, and a ride-through system for the superconducting magnet system include: one or more gravity-fed cooling tubes configured to have therein a cryogenic fluid; a first heat exchanger configured to transfer heat from the one or more gravity-fed cooling tubes to a cryocooler; a storage device having an input connected to the first heat exchanger and configured to receive and store a boiled-off gas from the first heat exchanger; and a thermal regenerator having an input connected to the output of the storage device.

Abstract: An apparatus includes at least a first electrically conductive coil having at least first and second coil sections which are separated and spaced apart from each other, and a support structure disposed to support the first and second coil sections. The support structure, and an associated method of supporting the electrically conductive coil, maintain relative axial positions of the first and second coil sections to be fixed when the first electrically conductive coil is energized and de-energized, and allow each of the first and second coil sections to expand radially when energized.

Abstract: A superconducting magnet device (14; 46), including at least one coil winding (161-164) of superconducting wire, configured for generating a static magnetic field B0, wherein the at least one coil winding (161-164) is adapted to establish a thermally conductive contact with a cold head (38) of a cryocooler that is configured for bringing to and keeping the at least one coil winding (161-164) at a temperature below the critical temperature, and at least one gas-tight container (40;48) that permanently contains an amount of helium, wherein the at least one gas-tight container (40; 48) is in thermally conductive contact to the at least one coil winding (161-164) for taking up thermal energy from the at least one coil winding (161-164) in at least one operational state; and a magnetic resonance imaging system (10) that is configured for acquiring magnetic resonance images from at least a portion of a subject of interest (22), comprising such a superconducting magnet device (14; 46) for generating a static magneti

Abstract: The following relates generally to use of magnetic resonance (MR) imaging as guidance in radiation therapy, and more specifically to use of MR imaging as guidance in proton therapy. In some embodiments, a cryogenic dewar is provided with multiple channels allowing a proton beam from a proton beam source to pass through. The proton beam may first be aligned with a first channel, and the dewar may then be rotated along with the proton source. The dewar may then be rotated to align a second channel with the proton beam.

Abstract: An apparatus including a persistent current switch of a superconducting material which is electrically superconducting at a superconducting temperature and electrically resistive at a resistive mode temperature which is greater than the superconducting temperature. The apparatus further includes a first heat exchange element; a convective heat dissipation loop thermally coupling the persistent current switch to the first heat exchange element; a second heat exchange element spaced apart from the first heat exchange element; and a thermally conductive link thermally coupling the persistent current switch to the second heat exchange element. The first heat exchange element is disposed above the persistent current switch. The thermally conductive link may have a greater thermal conductivity at the superconducting temperature than at a second temperature which is greater than the superconducting temperature.

Abstract: An apparatus including an electrically conductive coil which produces a magnetic field when an electrical current passes therethrough; a selectively activated persistent current switch connected across the electrically conductive coil; a cryostat having the electrically conductive coil and the persistent current switch disposed therein; an energy dump; at least one sensor which detects an operating parameter of the apparatus and outputs at least one sensor signal in response thereto; and a magnet controller. The magnet controller receives the sensor signal(s) and in response thereto detects whether an operating fault exists in the apparatus, and when an operating fault is detected, connects the energy dump unit across the electrically conductive coil to transfer energy from the electrically conductive coil to the energy dump unit. The energy dump unit disperses the energy outside of the cryostat.

Abstract: An apparatus includes an electrically conductive coil which produces a magnetic field when an electrical current passes therethrough; a selectively activated persistent current switch connected across the electrically conductive coil; a cryostat having the electrically conductive coil and the persistent current switch disposed therein; an energy dump; at least one sensor which detects an operating parameter of the apparatus and outputs at least one sensor signal in response thereto; and a magnet controller. The magnet controller receives the sensor signal(s) and in response thereto detects whether an operating fault (e.g. a power loss to the compressor of a cryocooler) exists in the apparatus, and when an operating fault is detected, connects the energy dump unit across the electrically conductive coil to transfer energy from the electrically conductive coil to the energy dump unit. The energy dump unit disperses the energy outside of the cryostat.

Abstract: An apparatus includes: a getter material (310) disposed within a vacuum chamber (210) to absorb stray molecules within the vacuum chamber; a thermal mass (340) disposed adjacent the getter material and in thermal communication with the getter material; a cold station (312) disposed within the vacuum chamber above the thermal mass; and a convective cooling loop (310) connected between the thermal mass and the cold station and configured to convectively cool the thermal mass when the cold station is at a lower temperature than the thermal mass, and to thermally isolate the thermal mass from the cold station when the cold station is at a higher temperature than the thermal mass. The thermal mass may be water ice and may be thermally isolated from the walls of vacuum chamber by low loss support links (360, 362, 364) and/or thermal reflective shielding.

Abstract: A superconducting magnet device (14; 46), including at least one coil winding (161-164) of superconducting wire, configured for generating a static magnetic field B0, wherein the at least one coil winding (161-164) is adapted to establish a thermally conductive contact with a cold head (38) of a cryocooler that is configured for bringing to and keeping the at least one coil winding (161-164) at a temperature below the critical temperature, and at least one gas-tight container (40; 48) that permanently contains an amount of helium, wherein the at least one gas-tight container (40; 48) is in thermally conductive contact to the at least one coil winding (161-164) for taking up thermal energy from the at least one coil winding (161-164) in at least one operational state; and a magnetic resonance imaging system (10) that is configured for acquiring magnetic resonance images from at least a portion of a subject of interest (22), comprising such a superconducting magnet device (14; 46) for generating a static magnet

Abstract: An apparatus includes at least a first electrically conductive coil having at least first and second coil sections which are separated and spaced apart from each other, and a support structure disposed to support the first and second coil sections. The support structure, and an associated method of supporting the electrically conductive coil, maintain relative axial positions of the first and second coil sections to be fixed when the first electrically conductive coil is energized and de-energized, and allow each of the first and second coil sections to expand radially when energized.