摘要:
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.
摘要:
A magnetic resonance apparatus which includes: a body portion (102) having a cavity (106) 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 (131) 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.
摘要:
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.
摘要:
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.
摘要:
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 magnetic field B0 in an examination space (20) of the magnetic resonance imaging system (10).
摘要:
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.