Abstract: A system for polarizing a material to be used in techniques employing magnetic resonance (MR) is provided. The polarizer system includes a cooling chamber having a cryogenic refrigerant therein for use in polarizing a substance. A sorption pump is connected to the cooling chamber to reduce a pressure therein to allow for hyperpolarizing of the sample. The sorption pump is cooled by a refrigeration system to promote molecular adsorption in the sorption pump. The cooling chamber, sorption pump, and refrigeration system are arranged in a closed system.

Abstract: Systems and methods are provided for a variable cooling capacity cryocooler for a superconducting magnetic resonance imaging device having a liquid cryogen pressure vessel to provide cryogenic temperatures to a magnet assembly, a vacuum vessel surrounding the pressure vessel and a radiation shield spaced from the cryogen pressure vessel, and a pressure sensor positioned inside the cryogen pressure vessel pressure boundary for sensing pressure variations. A controller for varying the heat removal rate of the cryocooler based on the pressure variations in the cryogen pressure vessel and where the cooling capacity of the cryocooler is adjusted by modifying the speed of the electric power drive (DC or AC motors) or by changing the mechanical transmission ratio between the constant speed electric power drive and the cryocooler displacer/piston to adjust the cooler oscillating frequency of the gas flow.

Abstract: A system and method for de-icing a recondensor includes at least one heating element configured to melt iced particles from a recondensing system. A power delivery circuit is included configured to deliver power to the at least one resistive heating element such that the at least one resistive heating element delivers a supply of heat sufficient to melt the iced particles from the recondensing system.

Abstract: Systems and methods are provided for a variable cooling capacity cryocooler for a superconducting magnetic resonance imaging device having a liquid cryogen pressure vessel to provide cryogenic temperatures to a magnet assembly, a vacuum vessel surrounding the pressure vessel and a radiation shield spaced from the cryogen pressure vessel, and a pressure sensor positioned inside the cryogen pressure vessel pressure boundary for sensing pressure variations. A controller for varying the heat removal rate of the cryocooler based on the pressure variations in the cryogen pressure vessel and where the cooling capacity of the cryocooler is adjusted by modifying the speed of the electric power drive (DC or AC motors) or by changing the mechanical transmission ratio between the constant speed electric power drive and the cryocooler displacer/piston to adjust the cooler oscillating frequency of the gas flow.

Abstract: A system and method for de-icing a recondensor includes at least one heating element configured to melt iced particles from a recondensing system. A power delivery circuit is included configured to deliver power to the at least one resistive heating element such that the at least one resistive heating element delivers a supply of heat sufficient to melt the iced particles from the recondensing system.

Abstract: The zero-backflow vent assembly (100) of the present invention prevents backflow into the magnet cryogen vessel (12) and therefore eliminates magnet icing. In general, the present invention employs a spring loaded valve in the magnet vent turret (38) to prevent the influx of air after a magnet quench event. The magnet vent turret (38) is the interface between the liquid helium vessel (12) in the magnet and the atmosphere (40). A vent stack is employed to channel any cryogenic exhaust gas out of the room, normally to the outside atmosphere (40).

Abstract: A magnetic resonance assembly comprising, a liquid cryogen vessel, a liquid cryogen cooled conducting magnet disposed within the liquid cryogen vessel, a closed vaccum vessel surrounding the liquid cryogen vessel and spaced from the liquid cryogen vessel, a cooling device fixably attached to the vacuum vessel operable for providing cryogenic temperatures to the superconducting magnet, a heat exchanger device in thermal contact with the liquid cryogen vessel operable for heat exchange, and a bus bar in thermal contact with the cooling device and the heat exchanger device. The cooling device may be a pulse tube cryocooler capable of providing temperatures of about 4 K. A thermal bus bar of high purity aluminum or copper is used to connect and provide a spatial separation of a pulse tube cryocooler and a remote recondenser unit, thus reducing the overall height of the magnet assembly.

Abstract: A magnetic resonance assembly comprising, a liquid cryogen vessel, a liquid cryogen cooled superconducting magnet disposed within the liquid cryogen vessel, a closed vacuum vessel surrounding the liquid cryogen vessel and spaced from the liquid cryogen vessel, a cooling device fixably attached to the vacuum vessel operable for providing cryogenic temperatures to the superconducting magnet, a heat exchanger device in thermal contact with the liquid cryogen vessel operable for heat exchange, and a bus bar in thermal contact with the cooling device and the heat exchanger device. The cooling device may be a pulse tube cryocooler capable of providing temperatures of about 4 deg K. A thermal bus bar of high purity aluminum or copper is used to connect and provide a spatial separation of a pulse tube cryocooler and a remote recondensor unit, thus reducing the overall height of the magnet assembly.

Abstract: A low cost diaphragm actuated absolute pressure regulator. The regulator comprises a housing having first and second sections that are secured together. The first section has a cavity and a diaphragm that seals the cavity and first section of the housing. An O-ring seal is disposed in a groove of the first section that seals against the diaphragm. The second section of the housing houses a movable and sealable vent plug that moves in response to movement of the diaphragm, and one or more vent openings for venting the interior of the second section to external pressure in response to motion of the diaphragm. The pressure regulator may be preferentially used in an upper atmospheric system that needs to maintain a specified pressure, but requires venting capabilities. Such systems include missiles that fly into the upper atmosphere.

Abstract: A pressure activated flow controller for use with a Joule-Thomson valve having a diaphragm actuator that is located outside a dewar, and which is not cooled. The diaphragm actuator limits flow based on gas pressure supplied to the dewar from a gas supply, not temperature, and does not impede cooldown of a device coupled to the dewar. The diaphragm actuator comprises a diaphragm and load plate that exert a force to open the Joule-Thomson valve. A wave spring provides a force to close the Joule-Thomson valve, thus balancing the back pressure of the gas supply. The diaphragm actuator is compact, and limits flow based on gas supply pressure, not temperature. The present invention thus uses pressure regulation instead temperature regulation to achieve flow control.

Abstract: A diaphragm pressure regulator comprising a housing having first and second sections. The first section 1a has a cavity or vacuum space, and a wave spring is disposed in the vacuum space, a load distributor is disposed adjacent to the wave spring, and a diaphragm seals the cavity and secures the wave spring and load distributor in the cavity. The second section of the housing comprises a movable and sealable vent stem that moves in response to movement of the diaphragm, and a vent opening for venting the interior of the second section of the housing to external pressure in response to motion of the diaphragm. The diaphragm pressure regulator may be preferentially used in an upper atmospheric system that needs to maintain a specified pressure, but requires venting capabilities. Such systems include missile systems that fly into the upper atmosphere.

Abstract: An in-line valve flow controller for a Joule-Thomson cryostat. The controller has an in-line valve stem that is part of, and is collinear with, an actuation stem of the cryostat. Both the in-line valve stem and actuation stem sit in an orifice of the Joule-Thomson cryostat. This arrangement automatically positions the valve stem over its valve seat. The in-line valve flow controller integrates with a temperature dependent snap disk that is used to close the valve stem against the valve seat. Initial flow rate is determined only by the diameter of the orifice of the Joule-Thomson cryostat, and not by valve position. Bypass flow is aso set by the diameter of the orifice, which is not subject wear, and the valve stem prevents contaminates from clogging the orifice.