Abstract: Cryostat systems for magnetic resonance imaging system are provided. The cryostat system may include a tank containing a cavity to accommodate a cooling medium and a superconducting coil. The system may also include a cold head assembly configured to cool the cooling medium to maintain the superconducting coil in a superconducting state. The cold head assembly may be mounted on the tank. The cold assembly may include at least a first cold head and a second cold head. The second cold head may include a taper shape with a first end surface close to the first cold head and a second end surface away from the first cold head. A diameter of the first circular end is greater than a diameter of the second circular end.

Abstract: A cooling apparatus includes a container configured to contain a coolant within a space. The apparatus further includes a cooling block positioned substantially within the space and having a high heat capacity such that the space not occupied by the cooling block is filled with a coolant to a level at or below the top of the cooling block, and a placement structure having high thermal conductivity positioned on top of the cooling block and outside of the space. A method for cooling an object is also provided, which includes inserting a coolant into a container configured to contain the coolant within a space, and placing the object on a placement structure outside the space. For this method, the placement structure has a high thermal conductivity and is coupled to a cooling block, the cooling block having a high heat capacity and positioned substantially within the space.

Abstract: A cooling apparatus includes a container configured to contain a coolant within a space. The apparatus further includes a cooling block positioned substantially within the space and having a high heat capacity such that the space not occupied by the cooling block is filled with a coolant to a level at or below the top of the cooling block, and a placement structure having high thermal conductivity positioned on top of the cooling block and outside of the space. A method for cooling an object is also provided, which includes inserting a coolant into a container configured to contain the coolant within a space, and placing the object on a placement structure outside the space. For this method, the placement structure has a high thermal conductivity and is coupled to a cooling block, the cooling block having a high heat capacity and positioned substantially within the space. A two-stage cooling apparatus and method is also described.

Abstract: A cryocooler superconducting quantum interference (SQUID) system includes a cryocooler including a cold head, a cold head chamber in which the cold head is disposed, a sensor chamber including a SQUID sensor cooled to a low temperature by the cryocooler; and a connection block connecting the cold head and a thermal anchor disposed in the sensor chamber to each other to cool the SQUID sensor in the sensor chamber.

Abstract: An arrangement for mounting a two stage cryogenic refrigerator into a cryostat has a vacuum sock accommodates at least a part of the refrigerator, attachment means and attaches an upper part of the refrigerator to a surface of the cryostat around an opening of the vacuum sock, a thermally conductive portion of a wall of the vacuum sock that, in use, is thermally and mechanically in contact with a second cooling stage of the refrigerator, and arrangements are provided that thermally connect a first stage of the refrigerator to a thermal radiation shield of the cryostat.

Abstract: An arrangement for mounting a two stage cryogenic refrigerator (17) into a cryostat, the arrangement comprising a vacuum sock (15) for accommodating at least a part of the refrigerator, attachment means (32, 34) for attaching an upper part of the refrigerator to a surface (14) of the cryostat around an opening of the vacuum sock, a thermally conductive portion (26) of a wall of the vacuum sock which, in use, is thermally and mechanically in contact with a second cooling stage (24) of the refrigerator, and arrangements (40, 42) are provided for thermally connecting a first stage (22) of the refrigerator to a thermal radiation shield (16) of the cryostat.

Abstract: A cryostat has a cooling arm with a first thermal contact surface which can be brought into thermal contact with a second thermal contact surface on an object to be cooled. A hollow volume (2) between the inner side of the neck tube, the cooling arm, and the object is filled with gas and the cooling arm is pressurized by the inner pressure of the gas and also by atmospheric pressure. A contact device brings the first and the second contact surfaces into thermal contact below a threshold gas pressure and moves them away from each other when the threshold pressure has been exceeded such that a gap (13) filled with gas thermally separates the first and second contact surfaces. Operationally safe and fully automatic reduction of the thermal load acting on the object to be cooled is thereby obtained in case the cooling machine fails.

Abstract: A refrigerator that has a fresh food compartment, a freezer compartment, and a door that provides access to the fresh food compartment is disclosed. An icemaker is mounted remotely from the freezer compartment. The icemaker includes an ice mold. A thermoelectric device is provided and includes a warm side and an opposite cold side. A flow pathway is connected in communication between the cold side of the thermoelectric device and the icemaker. A fan is operatively positioned to move air from the fresh food compartment across the warm side of the thermoelectric device. A pump moves fluid from the cold side of the thermoelectric device to the icemaker. Cold air, such as from the refrigerator compartment, is used to dissipate heat from the warm side of the thermoelectric device for providing cold fluid to and for cooling the ice mold of the icemaker.

Abstract: A cryosorber panel having nanomaterials used for the cryosorption material, with nanomaterial either grown directly on the cryopanel or freestanding nanomaterials attached to the cryopanel mechanically without the use of adhesives. Such nanomaterial cryosorber materials can be used in place of conventional charcoals that are attached to cryosorber panels with special low outgassing, low temperature capable adhesives. Carbon nanotubes and other nanomaterials could serve the same purpose as conventional charcoal cryosorbers, providing a large surface area for cryosorption without the need for adhesive since the nanomaterials can be grown directly on a metallic substrate or mechanically attached. The nanomaterials would be capable of being fully baked by heating above 100° C.

Abstract: Methods and systems are disclosed for saving energy while a superconducting magnet system is not being used and for reducing the time required for the re-establishment of the operating conditions of the system. Traditionally, during an inactive time interval, the temperature of the magnet coils is not allowed to rise, and the system is kept ON, in operating conditions. This results in wasting a large amount of energy for keeping the magnet coils at cryogenic temperatures. Turning the system OFF has never been an option since re-establishment of the operating conditions is very time consuming and costly. The present disclosure offers methods and systems that allow idling of a system in temperatures higher than the magnet coils' intended operating temperature, which results in noticeable savings.

Abstract: A new multifunctional, thermoelastic cellular structure is described. The new structure provides tunable thermal transport behaviors particularly important for thermal switching. In its simplest example embodiment of a single or unit cell, opposing bimetallic elements bend in response to temperature changes and, below a tunable switching temperature, are separated in an open or insulating position and, at and above the switching temperature, bend to come into contact in a closed or conducting position. Multiple cells are combined in different lattice arrays to create structures that are both switchable and load bearing. The cells can be switched by both temperature and other external fields.

Abstract: The invention generally relates to ventilation systems and methods, and more particularly to selectively configurable climate control systems and methods for use in data centers and the like. A system includes a first structural element and a second structural element spaced apart from first structural element to define a space between the first and second structural elements. The system also includes a plurality of partitions moveable into the space between the first and second structural elements and a controller arranged to control movement of the plurality of partitions.

Abstract: A thermal generator (1) comprises at least one thermal flow generation unit (2) that is provided with at least one thermal module (3) each containing a magnetocaloric member (4) through which a coolant flows. A magnetic arrangement (9) is actuated for alternatively subjecting each magnetocaloric member (4) to a variation in magnetic field, the alternating movement of the coolant is synchronized with the magnetic field variation, the magnetocaloric member (4) is integrated into a closed flow circuit (6) that connects the two opposite ends (7) of the magnetocaloric member (4), and the closed circuit includes a single element (5) for moving the coolant through the magnetocaloric member (4).

Abstract: A device has a passive cooling device having a surface, at least one active cooling device on the surface of the passive cooling device, and a thermal switch coupled to the passive cooling device, the switch having a first position that connects the active cooling device to a path of high thermal conductivity and a second position that connects the passive cooling device to the path of high thermal conductivity.

Abstract: A locking device providing thermal management for an electrical assembly board is described and includes a fluid-permeable member saturated with a fluid and disposed between the electrical assembly board and a heat sink; a pair of locking device substrates substantially orthogonal to the electrical assembly board and the heat sink; and an actuator coupled to at least one of the locking device substrates. The fluid-permeable member is disposed between the locking device substrates. The actuator is configured to compress the fluid-permeable member by at least one of the locking device substrates forcing a portion of the fluid out of the fluid-permeable member and forming at least one fluid contact interface with the electrical assembly board and the heat sink in a reversible process. A method for making a locking device is also described.

Abstract: A heat exchanger apparatus includes a housing having a sidewall defining a chamber in the housing for containing a cryogen; and a first insulation member movably mounted for coaction with the sidewall, the first insulation member moveable to a position to expose or cover a select portion of the sidewall to provide a heat transfer effect.

Abstract: A method of rotating a sample for use in a cryocooler, having the steps of mounting a sample in a sample mounting apparatus, the apparatus comprising a housing having an outer wall surface, an inner wall surface, a mount attached to the inner wall surface for supporting the sample, and a motor for rotating the sample, and an exchange gas to provide thermal communication between the moving sample and the inner housing surfaces; sealing the housing by applying a sealant to adjoining parts of the housing such that the joints are air tight; evacuating the housing; adding an inert gas to the housing; sealing the inert gas in the housing; attaching the outer wall surface of the housing to a cryocooler; and rotating the sample by engaging the motor. Also disclosed is a cryogenic apparatus having a sample holder; a cryo-cooler; a thermal link connecting the sample holder and the cryo-cooler; and a motor attached to the sample holder for rotating a sample.

Abstract: Method and apparatus (1) for receiving, storing and distributing blood bags including a cabinet (2) for containing all the components of the apparatus (1); a refrigerated space (21) for containing the bags; a magazine (3) housed inside the refrigerated space (21) comprising a plurality of cells (31), each capable of containing a single bag, each of the cells being identified by a cell code. The apparatus (1) further includes a data processing system (7) housed inside the cabinet (2), capable of controlling a movement system (5) and a cooling system (6) each housed inside the cabinet (2), and capable of controlling the receiving, the preservation and the releasing of the bags, and capable of exchanging data from and to an external data-management system (17) with which the apparatus (1) can interact.

Abstract: This disclosure presents a stackable, multicompartment portable cooler with enhanced climate control and delivery features. The cooler may include adjustable vents for precisely controlling the temperature differential between adjacent compartments, a brochure receptor for including information about the delivery, and/or an automatic delivery flag for notification purposes. In addition, the cooler is modular and may be assembled/disassembled through the use of removable compartment dividers that subdivide the stacked main compartments into many subcompartments.

Abstract: The present invention is a thermally controlled switch with high thermal or electrical conductivity. Microsystems Technology manufacturing methods are fundamental for the switch that comprises a sealed cavity formed within a stack of bonded wafers, wherein the upper wafer comprises a membrane assembly adapted to be arranged with a gap to a receiving structure. A thermal actuator material, which preferably is a phase change material, e.g. paraffin, adapted to change volume with temperature, fills a portion of the cavity. A conductor material, providing a high conductivity transfer structure between the lower wafer and the rigid part of the membrane assembly, fills another portion of the cavity. Upon a temperature change, the membrane assembly is displaced and bridges the gap, providing a high conductivity contact from the lower wafer to the receiving structure.

Abstract: A thermal conduction switch includes a thermally-conductive first member having a first thermal contacting structure for securing the first member as a stationary member to a thermally regulated body or a body requiring thermal regulation. A movable thermally-conductive second member has a second thermal contacting surface. A thermally conductive coupler is interposed between the first member and the second member for thermally coupling the first member to the second member. At least one control spring is coupled between the first member and the second member. The control spring includes a NiTiFe comprising shape memory (SM) material that provides a phase change temperature <273 K, a transformation range <40 K, and a hysteresis of <10 K. A bias spring is between the first member and the second member. At the phase change the switch provides a distance change (displacement) between first and second member by at least 1 mm, such as 2 to 4 mm.

Abstract: In a cooling station having lifter pins positioned within respective sockets, the lifter pins being positioned for translational movement within platform openings, the improvement comprising forming the lifter pins of aluminum or polymer. A cooling station comprising a cooling station body, a series of sockets affixed to the cooling station body a respective series of lifter pins comprised of aluminum or polymer affixed to the series of sockets, and an platform positioned on the cooling station body. The platform having respective openings positioned above the series of sockets and lifter pins for translational movement of the lifter pins into the platform openings.

Abstract: The invention relates to a refrigerating arrangement (100) comprising a hot connection element and a cold connection element (101, 103) and a heat exchanger tube arranged between said connection elements (101, 103). The heat exchanger tube (105) is to be at least partially filled with a liquid (106) that can be circulated in the heat exchanger tube (105) by a thermosiphon effect. The parts (102) to be cooled of a device, especially used in superconductivity technology, are connected to the hot connection element (101), and a heat sink (104) is connected to the cold connection element (103). In order to thermally separate the connection elements (101, 103), the liquid (106) can be pumped out by means of a pipeline (107) connected to the inside of the heat exchanger tube (105).

Abstract: The present disclosure concerns embodiments of a thermal switch used to control the transfer of heat from a heat source to a heat sink. According to one aspect, the thermal switch can be activated, or turned “on”, so as to establish a path of low thermal resistance between the heat source and the heat sink to facilitate the transfer of heat therebetween. The thermal switch can also be de-activated, or turned “off”, so as to establish a path of high thermal resistance between the heat source and the heat sink to minimize or totally prevent the transfer of heat between the heat source and heat sink. In certain embodiments, the thermal switch includes at least drop of a thermally conductive liquid that thermally couples the heat source to the heat sink whenever the switch is activated.

Abstract: Described here are systems for regulating the temperature of a heating or cooling device without adjusting the input power. In general, the systems described here comprise a heating or cooling device and a controller. The heating or cooling device typically comprises a cold region and a hot region, there being a temperature difference between the two, and an input power. The controllers are configured to be placed in thermal contact with at least a portion of the cold region and at least a portion of the hot region, and are configured to create a path for heat exchange between the portions of the contacted hot and cold regions. The heat exchanged may be controlled and the temperature of the system may be user adjustable, or it may be automatically controlled.

Abstract: A thermal switch selectively couples a heat source to a pair of heat sinks. The thermal switch includes a shunt that is thermally coupled to the heat source. The shunt has a pair of posts. End portions of the posts are at least partially radially surrounded by respective cups. The cups in turn are thermally coupled to respective of the heat sinks. The cups are made of a material with a larger coefficient of thermal expansion than the material of the posts. Activation of one of the heat sinks causes the cup corresponding to that heat sink to contract, bringing it into contact with the corresponding post of the shunt. This opens a heat path through the switch from the heat source to the activated heat sink. Thermal isolation of the second cup is facilitated by an axial isolator of high thermal impedance, facilitating isolation of the inactive heat sink.

Abstract: A cage in which is mounted a reducer of cold room that can be manually raised and blocked during the loading or unloading of the goods, and that automatically slopes down above the frozen foods when the door is closed for reducing the space preserving the frozen foods either by using the ice bags or dry ice during the delivery of the frozen foods.

Abstract: An interruptible thermal bridge system including: a first thermally conductive surface positioned proximate an object which absorbs energy; a second thermally conductive surface thermally connected to the first conductive surface positioned proximate to an object which dissipates energy, a thermal switch positioned between the first and second conductive surfaces for regulating a thermal connection between the first and second surfaces by alternatively switching between a first position, blocking the conductive path and thermally insulating the first conductive surface from the second conductive surface, and a second position, opening the conductive surface with the second conductive surface.

Abstract: A thermal link assembly provides thermal connection between a first thermally conductive part to which it is secured, and a second thermally conductive part which is generally disk-shaped and has a peripheral cylindrical surface. The thermal link assembly includes an annular ring made of thermally conductive material, generally in a shape of a revolution with respect to an axis, including an annular base portion to be secured to the first part and a series of contact tongues arranged along the base portion. Each contact tongue has a stem and a head. The stem has i) a longitudinal axis extending generally parallel to the axis of the annular ring, ii) a first longitudinal end connected to the base portion, and iii) a second longitudinal end connected to the head. The head has a contact surface to be in contact with the peripheral cylindrical surface of the second part.

Abstract: A heat switch includes two symmetric jaws. Each jaw is comprised of a link connected at a translatable joint to a flexible arm. Each arm rotates about a fixed pivot, and has an articulated end including a thermal contact pad connected to a heat sink. The links are joined together at a translatable main joint. To close the heat switch, a closing solenoid is actuated and forces the main joint to an over-center position. This movement rotates the arms about their pivots, respectively, forces each of them into a stressed configuration, and forces the thermal contact pads towards each other and into compressive contact with a cold finger. The closing solenoid is then deactivated. The heat switch remains closed due to a restoring force generated by the stressed configuration of each arm, until actuation of an opening solenoid returns the main joint to its starting open-switch position.

Abstract: An interruptible thermal bridge system including: a first thermally conductive surface positioned proximate an object which absorbs energy; a second thermally conductive surface thermally connected to the first conductive surface positioned proximate to an object which dissipates energy, a thermal switch positioned between the first and second conductive surfaces for regulating a thermal connection between the first and second surfaces by alternatively switching between a first position, blocking the conductive path and thermally insulating the first conductive surface from the second conductive surface, and a second position, opening the conductive surface with the second conductive surface.

Abstract: In an exemplary configuration, an air container is placed in a vacant portion of a structure and substantially prevents convection between an air mass in that portion and an adjacent air mass of an occupied portion of the structure. By thus isolating the air masses, the air container restricts heat transfer between them and advantageously allows the occupied portion's air mass to heat up and cool down without requiring substantial heating and cooling (at least initially) of the vacant portion's air mass. Other methods and structures with different advantageous features are also described.

Abstract: An interruptible thermal bridge system including: a first thermally conductive surface positioned proximate an object which absorbs energy; a second thermally conductive surface thermally connected to the first conductive surface positioned proximate to an object which dissipates energy, a thermal switch positioned between the first and second conductive surfaces for regulating a thermal connection between the first and second surfaces by alternatively switching between a first position, blocking the conductive path and thermally insulating the first conductive surface from the second conductive surface, and a second position, opening the conductive surface with the second conductive surface.

Abstract: Coolant (3) whose boiling point is higher than the temperature of cooled SQUID elements (2) as cooled objects is poured into an inner container (37) for containing SQUID elements. The SQUID elements (2) are soaked in the coolant (3). Before the inner container (37) for containing SQUID elements is used, the coolant (3) is cooled and solidified by a refrigerator (7).

Abstract: Self-triggering cryogenic heat flow switches are used particularly with cooling systems that require a redundant operation. The self-triggering cryogenic heat flow switch has the simplest possible construction while providing a reliable, maintenance-free mode of operation, and ensures a self-switching connection between a heat sink and an end use device or application that is to be cooled. The heat flow switch includes an outer hollow cylinder 1 that is connected with a heat sink 9, and an inner body 2 that is arranged coaxially to the outer hollow cylinder 1 and connected to the end use device or application to be cooled. When the heat sink 9 is switched off, a concentric annular gap 4 fixed by spacers is provided between the hollow cylinder 1 and the inner body 2.

Abstract: A cryogenic thermal switch operates based on the principle of differential coefficients of thermal expansion of differing materials. A small gap is either closed or opened, dependant upon the relative dimensions of two pieces of differing materials. As the temperature of the pieces is raised, the piece having the greater coefficient of thermal expansion (CTE) increases its dimensions at a greater rate, causing a gap to open up. Conversely, when the temperature of the pieces is lowered, the piece having the greater CTE shrinks proportionally faster, thereby closing the gap. The present invention makes use of a reliable flat-faced geometry for the two sides of the gap.

Abstract: A cryogenic cooler and a dewar assembly including a cooled surface; a cooling surface for removing thermal energy from said cooled surface; and an adapter disposed between said cooling surface and the cooled surface for conducting thermal energy therebetween. A first fluid is disposed between the cooled surface and the adapter for conducting thermal energy from the cooled surface to the adapter. A second fluid is disposed between the cooling surface and the adapter for conducting thermal energy from the adapter to the cooling surface whereby the cooling surface remains free to move axially relative to the adapter at a temperature of the cooling surface at which the first fluid is susceptible to freezing. This allows for movement of the cold finger relative to the dewar and adapter, due to differential thermal coefficients of expansion or support structure motion, without adversely affecting the communication of thermal energy from the load.

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: Disclosed is a beverage cooling appliance (10) comprising a base (18) that holds a battery pack (20), a on/off switch (120), and a pair of upright supports (116 and 118). A framework (30) that is able to swivel upward or downward on a pair of hinge pins (112 and 114), near the top of the upright supports (116 and 118), that holds a pair of drive rollers (26 and 28) with motor/gearbox units (22 and 24) inside the drive rollers (26 and 28) mounted on the framework (30) swing downward to contact a beverage container (12) lying on a bed of ice (14) in a ice tray (16) fixed atop the base (18).

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: Apparatus and method for sub-ambient cooling using thermoelectric element dynamics in conjunction with pulsed electrical power and multiple selectively enabled thermal switches. In one form, Peltier devices are dynamically enabled using pulses of electrical power while the thermal paths, between the cold and hot sides of the device are selectively switched conduction state responsive to the temperature dynamics within the Peltier device. Switched coupling of the thermal connections in relative synchronism to the Peltier device electrical and thermal dynamics materially improves efficiency by decoupling Joule heating and conductive heat transfer losses otherwise affecting the net heat transfer. Preferable implementations utilizes MEMS to accomplish the selective switching, whereby sub-ambient cooling capacity is increased by parallel operation of multiple Peltier devices and MEMS switches.

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 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: Sample analysis in a portable analytical instrument, preferably in the form of a gas chromatograph, benefits from temperature control of one or more thermal zones in the instrument by way of a thermal isolation system that includes a novel pumping assembly to effect a selective amount of thermal isolation of the thermal zone. The pumping assembly includes a pumping element in the form of a tubular or planar palladium structure. The pumping assembly makes use of the unique properties of palladium to allow selective control of a nominal gas pressure within a vacuum cavity. A component system, which may include a separation column and a thermal device for heating and/or cooling the component system, may be provided within the vacuum cavity. The thermal device and the pumping assembly are individually controlled by a control system.

Abstract: A cryogenic cooling apparatus is provided, wherein the degree of freedom of installation and use is increased without deteriorating the reliability or stability and the range of uses of the apparatus is also increased. A coil unit and a refrigeration unit are positioned such that a second heat conductive member disposed on an extendible wall of a vacuum container and a fourth heat conductive member disposed on an extendible wall of another vacuum container face each other coaxially. In this state, the coil unit and refrigeration unit are relatively moved to approach each other, and thus the second heat conductive member and fourth heat conductive member come in contact. If the coil unit and refrigeration unit are further moved, the extendible wall extends and consequently the second heat conductive member comes in contact with a first heat conductive member. In addition, the extendible wall contracts and consequently the fourth heat conductive member comes in contact with a third heat conductive member.

Abstract: In a "permanent" magnet system based on high-temperature superconductors, a superconducting magnet is cooled to a temperature below its critical temperature with a cooler. The magnet is coupled to a cold body of solid nitrogen which is insulated to minimize heat input to the system. The superconducting magnet is energized to generate a magnetic field and the cooler is removed. Unlike conventional superconducting magnets in which the magnet operating temperature is maintained at a fixed point, in the system of the present invention the operating temperature is allowed to rise from an initial value of approximately 20 K to as high as 63 K (the melting point of nitrogen), enabling operation over an extended period without the aid of direct cooling. The superconducting magnet is recooled periodically to lower its temperature to approximately 20 K. The magnetic field is maintained and the system is fully operable during the recooling process.

Abstract: A device for receiving thermal conduit comprising a thermally conductive material for coupling between an end of a conducting element of the thermal conduit and an end of an outer shell of the thermal conduit. The thermally conductive material is arranged to physically define a best thermal path from the end of the conducting element to the end of the outer shell such that substantially all thermal energy dissipated from the conducting element to the outer shell flows along the best thermal path. The length of the best thermal path is significantly greater than a nearest distance between the conducting element and the outer shell, and the conductive material is thin and manufactured of a poor thermal conductor such that the total energy dissipated along the best thermal path is reduced.

Abstract: A demountable thermal coupling for engaging a refrigeration unit with a cryogenic device includes a collet assembly which is slidingly mounted against a retainer ring in the passageway of a sleeve assembly. When the refrigeration unit is engaged with the sleeve assembly, the collet assembly closes onto a cooling probe of the refrigeration unit to establish a thermal contact between the cooling probe and the collet assembly. An interconnect between the collet and the superconducting device then allows the cooling probe to cool the superconducting device. Withdrawal of the cooling probe from the collet disengages the refrigeration unit from the superconducting device.

Abstract: A ceramic composite is provided comprising ceramic fibers and microparticles bound together as a porous matrix with a ceramic binder. The ceramic composite is particularly useful for transporting cryogenic fluids.

Abstract: A ceramic composite is provided comprising ceramic fibers and microparticles bound together as a porous matrix with a ceramic binder. The ceramic composite is particularly useful for transporting cryogenic fluids.