Abstract: A cryostat (12) with an actuator (40) which reacts to sensed temperature changes via externally controlled thermal heating generated therein. The actuator (40) is constructed with material having a high coefficient of thermal expansion. A flexible heating element (44) is embedded in the actuator material. A temperature sensor (62) provides a signal to cryostat control electronics. Responding to the temperature signal, the control circuitry (60) regulates current to the heating element (44) in the actuator (40). As the actuator temperature increases due to the heat generated by the heating element (44), it expands and moves open an attached needle (50) relative to an orifice (30), thereby increasing cryogen flow and regulating cooling. When the desired cold temperature is attained, current and heating are stopped. Flowing cryogen cools the actuator which shortens the actuator and pulls the attached needle into the orifice to regulate flow.

Abstract: A method, and apparatus for implementing the method, utilize cryogenic fluids to cool a fluid. The method includes receiving and allowing expansion of a first compressed cryogenic fluid within a chamber; flowing a second fluid past said chamber; and allowing the transfer of heat between the chamber and the second fluid. The method may further include maintaining the second fluid at a predetermined temperature by controlling the transfer of heat between the chamber and the second fluid. The apparatus includes a chamber for receiving therein and allowing expansion of a compressed cryogenic fluid. The chamber includes at least one wall formed of a material having a high thermal conductivity and high resistivity to low temperature. The chamber may include an insert for receiving cryogenic fluid therein and dispersing the cryogenic fluid through a plurality of holes into the chamber. The apparatus may also include a fluid path component for circulating therethrough the second fluid.

Abstract: A refrigeration cycle that controls the deposit of foreign matter at inlet or outlet of a capillary tube, which forms an expansion device in the refrigeration, regardless of changeover from a cooling operation to a heating operation. In particular, in a refrigeration cycle using an alternative refrigerant, a junction is provided for joining an end of a capillary tube forming an expansion device to the piping through which the refrigerant flows. The junction has a slope defined by the inside diameter thereof, which gradually decreases from the side of the junction that joins the piping to the side of the junction that joined the capillary tube. An end portion of the capillary tube projects into the junction at the piping side. The projecting end of the capillary tube is opened obliquely to the axial line of the capillary tube. A hole is formed in the peripheral wall of the projecting end of the capillary tube.

Abstract: A superconducting magnet is accessible for ramping within a cryostat by inserting flexible current leads through openings in the cryostat and pushing and twisting these leads inward until connections are made with electrical contacts provided on the superconducting magnet. For each current lead, a permanently installed channel guides the lead as it is pushed through the external opening and extends to make contact with the magnet terminal. The guide channel extends outside of the cryostat and includes an internal or external bend, whereby the overhead space required for the cryostat/magnet assembly may be reduced. After ramping, the leads are withdrawn.

Abstract: An open flow helium cryostat system for cooling a sample crystal to be examined using X-ray diffraction, neutron diffraction, or a similar method. The cryostat system including a primary helium supply to provide a first stream of liquid helium onto the sample crystal and a secondary helium supply to provide a second stream of gaseous helium around at least a portion of the primary helium supply at a temperature warmer than the first stream of liquid helium to prevent the formation of ice on the sample crystal.

Abstract: A system for providing a fluid refrigerant to a cooling element is provided herein. The system includes a vessel which holds the fluid refrigerant, a heat source evaporating a portion of the fluid in the vessel, and a heat exchanger condensing a portion of the gaseous phase of the fluid in the vessel. A conduit establishes fluid communication between: (i) the vessel and the cooling element; and (ii) the cooling element and the heat exchanger. Importantly, the system controls the flow rate of the fluid refrigerant to the cooling element by controlling the pressure of the fluid in the vessel. The system is particularly useful with cryogenic fluid refrigerants to cool a superconductor for an MRI System.

Abstract: A high temperature superconductor lead assembly for reducing the heat leak into a cryocooled system features a shroud configured for at least partial submersion in a cryogenic fluid contained within a bath chamber, and a high temperature superconductor lead element at least partially contained within the shroud. In use, a portion of the high temperature superconductor lead element contained within the shroud extends below a fluid level of the cryogenic fluid in the bath chamber. The portion of the high temperature superconductor lead element is thermally shielded by the shroud such that it is maintained at a temperature higher than the temperature of the cryogenic fluid. The shroud is a double-walled vacuum structure with a sealed end and an open end. In use, the open end is submerged in the cryogenic fluid.

Abstract: In a cooling apparatus for a high-frequency receiver having an input circuit which carries signals that are not yet sufficiently amplified, the input circuit is thermally connected to a miniature cooler and is thermally insulated, including a cold output of the miniature cooler, from the environment. It is particularly favorable if the miniature cooler has no moving parts on the cooling end. The miniature receiver is preferably configured as a pulse tube cooler.

Abstract: A refrigerator for cooling a sample (16,17) comprising a reservoir (1) for storing gaseous .sup.4 He when in use; a cooler (13) for cooling gaseous .sup.4 He from the reservoir; and a helium vessel (18,19) for containing .sup.4 He, the .sup.4 He in the helium vessel being in fluid communication with the reservoir (1) via the cooler (13). The sample (16,17) is mounted, in use, in thermal contact with the .sup.4 He in the helium vessel whereby the .sup.4 He in the helium vessel provides a path for heat to transfer from the sample to the cooler.

Abstract: An electrically cooled detecting system comprises: two or more heat regenerative refrigerators each having a cylinder with a cooling head at its one end; a holder for supporting the two or more heat regenerative refrigerators to dispose the one ends of the cylinders along a certain plane and the other ends of the cylinders on one side of the certain plane; a connector for thermally and rigidly connecting the cooling heads; and a detector being thermally connected to the connector. This system is not necessary to use liquid nitrogen. This system is compact and has a high energy resolution.

Abstract: A universal focal plane DEWAR assembly for cryogenic cooling of an infrared detector DEWAR, which includes an infrared transmissive window attached to a hollow support cylinder under vacuum conditions, with a glass bore in the cylinder, which contains focal plane infrared structure inside of a cold shield, which is attached to a cold plate, with a cold button in contact therewith, and with a cold finger from a cryogenically cooled expander, which is spring mounted in the glass bore for removal and replacement without disturbing the focal plane structure.

Abstract: An automotive air conditioning system orifice tube type refrigerant expansion valve is axially symmetrical, so as to be error proof at installation, and/or so as to operate in a bi directional refrigerant flow. A pair of coaxial screens surrounding each end of the orifice tube, an inner noise attenuation screen of finer mesh, and an outer particulate screen of coarser mesh, provide upstream particulate exclusion and downstream noise attenuation without the potential for reverse installation. In addition, by pass ports allow for a by pass flow should the downstream inner screen become plugged.

Abstract: A superconducting magnet system, such as an NMR apparatus, is outfitted with a compact-size refrigerator that prevents mechanical vibrations produced by the refrigerator from being transmitted to the superconducting magnet system. The refrigerator is in the form of a pulse tube refrigerator having a cold head and a pressure oscillation generating source. The cold head of the pulse tube refrigerator is connected directly to a vacuum insulation vessel of the superconducting magnet system. Cold generated from the cold head cools a cooling device, for example, a liquid helium tank for cooling the superconducting coil, or a heat penetration reducing device, for example, a liquid nitrogen tank, for reducing heat penetration from outside.

Abstract: In the adiabatic apparatus of the present invention, a vessel includes an adiabatic layer in which an object is taken. A plurality of thermal shield plates are located in the adiabatic layer. Each thermal shield plate concentrically surrounds the object. A temperature control section cools or heats the object and the plurality of thermal shield plates. A switch section thermally connects the temperature control section to the plurality of thermal shield plates and the object if temperature of the plurality of thermal shield plates and the object is controlled, and thermally separates the temperature control section from the plurality of thermal shield plates and the object if control of the temperature of the plurality of thermal shield plates and the object is completed.

Abstract: A cryostat having inner and outer vessels, with a containment vessel disposed in the interior of the cryostat spaced from the inner vessel wall. The containment vessel houses a superconducting coil immersed in a liquid helium bath which is prevented from contacting the inner vessel wall. Primary and secondary shielding arrangements help to intercept heat transferred by gas conduction and radiation. For relatively high power operation wherein the coil is charged and discharged frequently, the inner and outer vessels are fabricated of a non-magnetic composite material.

Abstract: A cryostat includes an upper shell and a lower shell connected along a seam. The shells are made of a relatively thin material which would be subject to collapse once the cryostat is evacuated. In order to resist collapsing forces, a brace is placed inside the cryostat between opposing walls of the shells. The brace has a connecter which includes a pin and post that has an opening for receiving the pin. The connectors allow easy assembly and disassembly of the cryostat while still resisting compressive forces.

Abstract: A microminiature Stirling cycle engine or cooler is formed utilizing semiconductor, planar processing techniques. Such a Stirling cycle thermomechanical transducer has silicon end plates and an intermediate regenerator. The end plates are formed with diaphragms and backspaces, one end plate forming the expansion end and the opposite end plate forming the compression end, with the regenerator bonded in between. A control circuit apparatus is linked to the diaphragms for controlling the amplitude, phase and frequency of their deflections. The control circuit apparatus is adapted to operate the transducer above 500 Hz and the passages and the workspace, including those within the regenerator, expansion space and compression space, are sufficiently narrow to provide a characteristic Wolmersley number, which is characteristic of the irreversibilities generated by the oscillating flow of the working fluid in the workspace, below substantially 5 at the operating frequency above 500 Hz.

Abstract: A cooling system for indirect cooling of a device, in particular a superconducting device, located in a vacuum chamber includes at least one refrigerating machine component. This refrigerating machine component includes an ambient temperature section and a low-temperature section, projects into the vacuum housing, is secured thereto via spring elements and, at its low-temperature end, is heat conductively connected to the device to be cooled. To reduce the vibrations transmitted to the device, the ambient temperature section of the refrigerating machine component may be arranged in the evacuatable compartment of a housing unit rigidly connected to the vacuum chamber.

Abstract: A storage unit includes a housing with a storage chamber, a carrier disposed inside the chamber for supporting a plurality of specimens in a predetermined array, and an access port on the housing for enabling access to the chamber for insertion and retrieval of specimens from the carrier. The access port includes an opening in the housing and a plug member removably located in the opening. The carrier is provided with a seat for receiving the plug member during an access operation, so that the plug member is located in the chamber during the access operation. A drive is operatively connected to the carrier for moving the carrier in the chamber to juxtapose different specimens to the access port. An insertion and removal mechanism is coupled to the housing for alternately inserting and removing specimens from the chamber via the access port during the access operation.

Abstract: A recondensing zero boiloff superconducting magnet assembly utilizing a cryocooler with a compressible indium gasket positioned between the cryocooler and the recondenser and with the gasket containing a plurality of spaced parallel grid wires with interconnecting web segments of a lesser thickness interconnecting the mid sections of ends of adjacent wires to facilitate compression of the gasket to control improved thermal conductivity while minimizing the pressure and forces on the assembly.

Abstract: Within a cryostat housing (17), an antenna device (7) having an antenna (16) to be cooled by a cryogenic medium (M). The cryostat housing includes a cold head (15) of a pulse tube cooler, whose cold part (20), which is at a low temperature (TT), is thermally coupled to the antenna (16). The coupling can take place via a dielectric thermal contact member (27).

Abstract: A varying cross-sectional area capillary tube for a refrigeration system. The capillary tube comprises at least a first portion and a second portion. The first portion has a cross-sectional area that is effectively smaller than the cross-sectional area of the second portion. By doing so, any contaminants contained in the refrigerant will deposit themselves within the second portion of the capillary tubes, but because of the increased cross-sectional area, will not clog the capillary tube.

Abstract: A system for storing a plurality of cryopreservable samples is provided, comprising a liquid nitrogen Dewar flask having a substantially circular opening of diameter X defined therein, the Dewar flask containing therein a plurality of Dewar flask-compatible storage racks, each storage rack comprising at least one substantially rectangular container, having a first set of opposite sides in substantially perpendicular relationship with a second set of opposite sides, the first set of opposite sides and the second set of opposite sides defining an inner space therebetween, and a plurality of strips, located in the inner space and each in contact with at least one side, formed in substantially parallel relationship with the first set of opposite sides, the plurality of strips forming a plurality of storage slots in the inner space, wherein at least one of the plurality of storage slots contains a cassette containing therein a cryopreservable sample.

Abstract: A sleeve structure and method are provided for use with a cryogenic specimen container which is maintained at a cryogenic temperature below -80.degree. C. to allow for labeling of the specimen container. The sleeve structure includes sidewalls defining a cylindrically shaped interior chamber sized for telescopically receiving a lower portion of a cryogenic specimen container in nested engagement. The sleeve structure has a locking mechanism for holding the sleeve structure in removably secured engagement with specimen container when the specimen container is in nested engagement with the sleeve structure. Identification markings are secured to an exterior side of the sleeve structure.

Abstract: A crystal freezing apparatus in accordance with the invention includes a first chamber for receiving a macromolecular structure and a second chamber which includes a cryogenic liquid holder. Gas inlets are provided for introducing a defined gas, such as Xenon at an elevated pressure, into both chambers. Introduction of the defined gas into the first chamber, enables atoms of the defined gas to enter void spaces in or onto the surface of the macromolecular structure while it is held in the first chamber. A valve structure is provided to connect the first and second chambers. A push rod assembly enables movement of the macromolecular structure from the first chamber to the second chamber, via the valve structure, all while under the influence of the defined gas. Once the macromolecular structure enters the second chamber, it is immersed into a cryogenic liquid so as to freeze the macromolecular structure with its included atoms of the defined gas.

Abstract: A shut-off valve for pressurized fluids in particular for air cooling/heating apparatus includes at least one condenser and at least one fluid evaporator communicating with each other by a pipe at least one duct which has inside a nozzle coaxially formed with a capillary duct designed to cause rapid expansion of the fluid when it emerges from the nozzle, and a retainer securing the pipe to the valve.

Abstract: An evaporator (10), e.g. in a domestic refrigerator, for refrigerating air in a space for goods, which space is confined against ambient atmosphere (14) by a wall (16), is constituted by a tubular element (18), through which a refrigerant flows from a capillary pipe (20), which is connected to the element at a joint (28) at one end of the element. The element (18) comprises an inner tube (24), through which the refrigerant flows, outside which inner tube an outer tube (26) is arranged, the outer tube (26) extending through the wall (16) and the joint (28) being arranged between the capillary pipe (20) and the inner tube (24) inside the wall (16) in a chamber (38) formed in the outer tube (26). A sealing means (36) arranged between the capillary tube (26) prevents humidity of the ambient atmosphere (14) from forcing its way into the chamber (38).

Abstract: A dual stage active magnetic regenerator refrigerator as well as method using the Joule-Brayton thermodynamic cycle includes a high temperature stage refrigerant comprising DyAl.sub.2 or (Dy.sub.1-x Er.sub.x)Al.sub.2 where x is selected to be greater than 0 and less than about 0.3 in combination with a low temperature stage comprising (Dy.sub.1-x Er.sub.x)Al.sub.2 where x is selected to be greater than about 0.5 and less than 1 to provide significantly improved refrigeration efficiency in the liquefaction of gaseous hydrogen.

Abstract: A super-conducting electro-magnet for use in an MRI system comprising a helium vessel within which magnet windings are positioned, a vacuum chamber within which the helium vessel is contained, at least one thermal shield positioned between the helium vessel and the vacuum chamber in spaced apart relationship, a service turret including a refrigerator thermally coupled to the said at least one shield for cooling purposes, a tube which extends through the turret from the windings to facilitate filling, and conductors which extend through the turret from the windings to facilitate current injection to the windings and to provide a vent for the helium gas.

Abstract: A throttle device provides a large number of small flow channels generally in parallel rather than a single flow path. The throttling device, a porous cartridge within a tube, may be porous metal, packed ferrous spheres or other particles, packed fibrous material, a plurality of smaller capillaries joined together in parallel, etc. The number and size of the channels provide proper pressure drop performance of the throttle, and flow is laminar with a Reynolds number less than 2,000. Vibrations are low. With certain refrigerant components, and small openings in the porous throttle device, refrigerant flow resistance increases until all flow ceases below selected and repeatable temperature levels. Thus, a temperature-dependent, variable on to off throttle device is provided without moving parts. This self adjusting throttle device can operate in parallel with a fixed throttle device.

Abstract: A refrigerant expansion device for a refrigeration cycle comprises a housing, a passage formed penetrating the housing, an expansion means for expanding the refrigerant passing through the passage and a flow rate control means for bypassing some of the refrigerant passing through the expansion means according to the pressure of the refrigerant, for supplying to the low pressure portion of the passage, and for controlling the flow rate of the refrigerant through the expansion means.

Abstract: Vibration and noise isolation for a magnetic resonance imager (MRI) superconducting magnet cryocooler includes a bellows between the cryocooler and its vacuum sleeve in the magnet, a mass suspended along the axis of, but at a distance from, the cryocooler, elastomeric blocks parallel to the axis, and braided copper wires connecting the vacuum sleeve and the heat shields of the MRI. Motion limiters and bellows flexures are provided for dynamic loads which might be encountered during transport of the magnet.

Abstract: An apparatus for mounting a superconducting element includes a first chamber which accommodates a first coolant and maintains the superconducting element at a very low temperature, a second chamber which accommodates a second coolant and is thermally connected to the first chamber via a barrier member, the second coolant being liquidized at a temperature lower than that of the first coolant, and a cooling device which is connected to the second chamber and liquidizes the first coolant.

Abstract: A temperature controlled cryogenic package system for efficiently and precisely monitoring and controlling the operating temperature of a high temperature superconductor circuit placed on a substrate. The cryogenic package system comprises a heating element formed on the same substrate as the high temperature superconductor circuit, a control circuit capable of activating and deactivating the heating element, and a temperature sensor placed in thermal proximity to the high temperature superconductor circuit. The temperature sensor monitors the operating temperature of the high temperature superconductor circuit, and conveys temperature information to the control circuit. The control circuit activates or deactivates the heating element according to the warming or cooling effect that is necessary in order to maintain the high temperature superconductor circuit within a predetermined temperature range, where the range of temperature fluctuation is within plus or minus 0.1 K of a predetermined temperature.

Abstract: There is disclosed a sample-cooling device for efficiently cooling a sample observed with a scanning probe microscope down to a cryogenic temperature. Cryogenic temperature provided by liquid nitrogen is transferred to a stage base plate from a liquid nitrogen vessel via a heat shield on the side of the cryogenic source, a first flexible conductor, and a heat shield on the sample side. The whole stage base plate is cooled to the liquid nitrogen temperature. Cryogenic temperature provided by liquid helium is transferred from a liquid helium vessel to a heat conductor on the sample side via a heat conductor on the side of the cryogenic source, a heat shield on the side of the cryogenic source, a second flexible heat conductor, and a heat shield on the sample side. The heat conductor on the sample side is cooled to the liquid helium temperature. The cryogenic temperature is then transferred to the sample via a probe electrode in contact with the heat conductor on the sample side.

Abstract: A cooling system is configured to control the flow of a refrigerant by controlling the rate at which the refrigerant is heated, thereby providing an efficient and reliable approach to cooling a load (e.g., magnets, rotors). The cooling system includes a conduit circuit connected to the load and within which a refrigerant circulates; a heat exchanger, connected within the conduit circuit and disposed remotely from the load; a first and a second reservoir, each connected within the conduit, each holding at least a portion of the refrigerant; a heater configured to independently heat the first and second reservoirs. In a first mode, the heater heats the first reservoir, thereby causing the refrigerant to flow from the first reservoir through the load and heat exchanger, via the conduit circuit and into the second reservoir.

Abstract: A magnetic telescope utilized to detect flaws in underground articles such as underground piping, implements multiple stages in the form of geometric and electronic configurations to enhance noise suppression. The geometric configuration includes a differential configuration of two pair of source coils which generate the magnetic flux, and gradiometers which pick-up the magnetic flux. A superconducting quantum interference device (SQUID) is utilized to detect the magnetic flux. The electronic configuration includes circuitry to adjust the current in the source coil pairs to minimize the signal seen by the SQUID when no underground article is present. The electronic configuration also includes feedback circuitry to feed back magnetic flux to the SQUID based on the signal detected by the SQUID. Combining the geometric and electronic configurations provides enhanced noise suppression so that the SQUID is capable of detecting smaller flaws in the underground piping for the same amount of source magnetic flux.

Abstract: A cryogenic cooling apparatus including a vacuum container for containing an object to be cooled, at least one refrigerator for cooling the object, and a thermal switch unit. The refrigerator has a high-temperature cooling stage and a low-temperature cooling stage connected to the high-temperature cooling stage via a low-temperature cylinder. The thermal switch unit has at least one high-temperature heat transfer member attached to the high-temperature cooling stage, at least one low-temperature heat transfer member attached to the low-temperature cooling stage and separated from the high-temperature heat transfer member, and a sealed container provided between the high-temperature cooling stage and the low-temperature cooling stage.

Abstract: An apparatus for cryogenically freezing tissue specimens includes a linear motion platform and a pair of rotary motion platforms. The rotary motion platforms can be used alternatively with respect to the linear motion platform and a mechanism is provided to automatically trigger the linear motion platform for movement and to reset the linear motion platform when the rotary motion platforms are placed in covering relationship with or removed from covering relationship with respect to the linear motion platform. Cryogenic fluids are supplied to tissue receiving cryogenic discs on the various platforms through flexible plastic tubing. The tubing that supplies cryogenic fluid to the rotary motion platforms is constructed so as to form a series of loose loops in conjunction with tails that are mounted over a central rod to allow movement at cryogenic temperatures.

Abstract: A temperature controlled cryogenic package system for efficiently and precisely monitoring and controlling the operating temperature of a high temperature superconductor circuit placed on a substrate. The cryogenic package system comprises a heating element formed on the same substrate as the high temperature superconductor circuit, a control circuit capable of activating and deactivating the heating element, and a temperature sensor placed in thermal proximity to the high temperature superconductor circuit. The temperature sensor monitors the operating temperature of the high temperature superconductor circuit, and conveys temperature information to the control circuit. The control circuit activates or deactivates the heating element according to the warming or cooling effect that is necessary in order to maintain the high temperature superconductor circuit within a predetermined temperature range, where the range of temperature fluctuation is within plus or minus 0.1 K of a predetermined temperature.

Abstract: An improved X-ray spectrometer detector system includes a mechanical cooling system with a compressor connected by supply and return lines to a cryocooler connected to an X-ray dispersive spectrometer detector for an electron microscope. Within a housing containing a cryocooler heat exchanger, a heat sink thermal mass is thermally connected to a cold finger heat conducting structure which has the X-ray detector mounted at its distal end. The housing insulates the cryocooler heat exchanger and the heat sink from the external ambient. The compressor unit is operated to cool the detector to a desired low operating temperature at which precision measurements may be made. When such measurements are to be made, the compressor is turned off to minimize vibrations that could interfere with X-ray detector measurements or the operation of the electron microscope.

Abstract: A device for controlling or metering fluid flow in either direction through a conduit. The device comprises an elongated body having two end walls forming an internal chamber therebetween. One end wall of the device has a first metering orifice. The other end wall has one or more bypass openings. Disposed within the chamber is a free piston having a rod portion extending therefrom and disposed within the first metering orifice. The free piston and rod portion has a second metering orifice axially extending therethrough and in axial alignment with the first metering orifice. Fluid flow through the device urges piston against the end wall in the direction of fluid flow. In one position, fluid flowing into the device passes through the bypassing the opening(s) of the opposite end wall. Fluid flowing out of the device passes through the second metering orifice in the piston. Upon a flow reversal, the piston is urged against the opposite end wall.

Abstract: A cooling apparatus includes a dewar and a quantity of liquid nitrogen within the container. Gaseous helium is contacted to the liquid nitrogen, either by contacting its top surface or by being bubbled through the liquid nitrogen. The temperature of the cryogenic liquid is lowered by the contact of the gas.

Abstract: A method is provided for cooling a high temperature superconductor such as an oxide superconductor to a lower temperature at a lower cost with a more simple system. A superconducting coil is attached to a cooling stage of a refrigerator. By immersing the superconducting coil on the cooling stage in liquid nitrogen, the superconducting coil is cooled rapidly. Then, the superconducting coil is further cooled by the refrigerator. By the cooling operation of the refrigerator, the liquid nitrogen is solidified. Thus, the superconducting coil is surrounded with solidifed nitrogen. The superconducting coil covered with the solidified nitrogen is further cooled by the refrigerator. In the superconducting coil cooled to a lower temperature and covered with solid nitrogen, quenching is suppressed to allow a higher current to be conducted.

Abstract: Methods and apparatus for gasification of liquid nitrogen and other cryogenic liquids are provided. The apparatus includes a gasification unit capable of refrigerating at least one cryoelectronics energy converter and utilizing the heat generated thereby to gasify a cryogenic fluid. Refrigeration is provided by the cryogenic fluid in the gasification unit. The gasification unit is preferably capable of gasifying at least 1 liter/hour of cryogenic fluid. The gasification unit can be coupled to a chemical processing unit such that gasified cryogenic fluid produced in the gasification unit can be introduced into the chemical processing unit for use therein. A secondary heat recovery unit can be provided upstream of the chemical processing unit to separate entrained liquid particles from the gasified cryogenic fluid produced by the gasification unit. Cryogenic fluid can be supplied to the gasification unit from an air liquefaction plant, a storage tank, a truck or the like.

Abstract: A helium cooled superconducting magnet assembly with helium gas recondensing apparatus to return liquid helium to the helium supply in the helium vessel in which the recondensing apparatus positioned within the space between the vacuum vessel and surrounding vacuum vessel in thermal contact with a cryocooler within a fixed cryocooler sleeve in the vacuum vessel with the cryocooler positioned to minimize magnetic disturbances to the magnet assembly magnetic field and the recondenser connected through thin corrugated steel tubing to the helium vessel with the tubing sized to provide thermal and vibration isolation of the helium vessel.

Abstract: The present invention is an improved modular cooling device for cooling gas chromatography analyte sample injectors. The invention is embodied in a series of tubes connected in fluid communication from a coolant supply valve to the injector heating block. A flexible supply tube capable of carrying coolant while maintaining structural integrity at temperatures up to about 150.degree. C., and having a low thermal conductivity is connected in fluid connection with a coolant supply at one end, and a transition tube at the other. A transition tube, in fluid communication with the supply tube at one end and with the cooling tube at the other, is selected to maintain structural integrity at temperatures up to 450.degree. C. and to have a low thermal conductivity. The cooling tube is in fluid communication with the transition tube at a receiving end and with an exhaust at an exhaust end, and has an outer surface that is physically engageable with a surface of the heating block.

Abstract: A multipass evaporator for an air conditioner includes a pair of spaced-apart and parallel headers, a plurality of microchannels extending between and connected to the headers, at least one throttling microchannel extending between and connected to the headers, and at least two baffles provided within the headers. The baffles are located in the headers to divide the plurality of microchannels and the throttling microchannel into at least three passes. The three passes include a first pass, a last pass, and at least one intermediate pass between the first pass and the last pass. The first pass includes the throttling microchannel which provides a desired restriction to obtain constant enthalpy expansion so that no restriction device is required between a condenser and the evaporator.

Abstract: A method and apparatus for the cleaning of residue from the surface of a container where the method comprises adhering a bulk material to the residue, cooling the container and residue adhered to the container surface to a low temperature, substantially embrittling the residue and then impacting the container to fragment and separate the residue from the surface of the container. The cooling may be effected to multiple containers in a semi-continuous fashion placing the containers sequentially in one end of an enclosure, contacting cold cryogen to the residue and container, advancing the containers to the other end of the enclosure and withdrawing the containers sequentially.

Abstract: A refrigeration system includes a dewar and a refrigerator/liquefier which meets the variable demands of a superconducting magnet within the dewar. The system is sized to meet average loads over a defined duty cycle, and is variably operable to meed demands. In the preferred embodiment, a first supply of fluid circulates through a "condenser" element positioned in a dewar ullage to liquefy a separate supply of fluid in the dewar, and to refrigerate a pulsed cryogenic load therein, such as a superconducting magnet. A portion of the first supply of fluid may be diverted to refrigerate a second pulsed cryogenic load, such as magnet current leads permanently connected to the magnet. The dewar includes a cold gas vapor storage chamber separate from the dewar ullage, and the chamber is preferably located within the inner core of a solenoid superconducting magnet for compact and thermally efficient design. Responsive, independent adjustment of refrigeration to pulsed cryogenic loads is made possible.