Abstract: A magnetic refrigerant material exhibits sufficiently great magnetocaloric effect at or near room temperature. The magnetic refrigerant material has an NiAs type hexagonal structure in a ferromagnetic phase. The magnetic refrigerant material includes a first element Mn, a second element As and a third element to substitute for a portion of the second element, and exhibits a magnetic phase transition in a temperature range from about 230 K to less than about 318 K.

Abstract: A solid state thermal control device contains a substrate and a plurality of solid state thermal elements on the substrate. The thermal elements are adapted to provide thermal control to a device under test (DUT). Each solid state thermal element contains at least one solid state heater and an active control circuit adapted to control a thermal output of the heater. Optionally, the each thermal element may also include a solid state temperature sensor.

Abstract: The magnetic composite material of the present invention is used as a working substance in the magnetic refrigeration system and comprising at least two phases, including, a first phase composed of an intermetallic compound represented by a general formula: La(Fe(Co, Ni)Si)13, having an NaZn13 type crystal structure, and a second phase is composed of an iron alloy containing Si. The first phase is precipitated in an expansion size of 100 &mgr;m or less in average. Preferably, the magnetic composite material contains Fe as a principal component, La in an amount from 4 atomic % to 12 atomic %, Si in an amount from 2 atomic % to 21 atomic %, and Co and Ni in a total amount from 0 atomic % to 11 atomic %, and the total amount of Fe, Co and Ni being from 75 atomic % to 92 atomic %.

Abstract: To provide a temperature control device and a temperature control method, which are capable of applying temperature control with high accuracy to an object of temperature control and facilitating removal of the object of temperature control to reduce cost at the time of replacement, and an ink-jet recording apparatus.

Abstract: A compact portable transport unit for shipping hyperpolarized noble gases and shielding same from electromagnetic interference and/or external magnetic fields includes a means for shifting the resonance frequency of the hyperpolarized gas outside the bandwidth of typical frequencies associated with prevalent time-dependent fields produced by electrical sources. Preferably the transport unit includes a magnetic holding field which is generated from a solenoid in the transport unit. The solenoid includes a plurality of coil segments and is sized and configured to receive the gas chamber of a container. The gas container is configured with a valve, a spherical body, and an extending capillary stem between the valve and the body. The gas container or hyperpolarized product container can also be formed as a resilient bag.

Abstract: A magnetocaloric refrigeration device, placed in a controllable magnetic field, includes a heat release/absorption module. The heat release/absorption module includes a magnetocaloric working unit and at least one heat pipe. The magnetocaloric working unit is made of a magnetocaloric material. The temperature of the unit changes as the magnetic field is applied or removed. The heat pipe includes evaporation and condensation portions respectively extending from top and bottom of the magnetocaloric working unit. When a magnetic field is applied to the magnetocaloric working unit to absorb heat, the lower condensation portion of the heat pipe transfers heat upward to the magnetocaloric working unit. When the magnetic field is removed from the magnetocaloric working unit to release heat, the heat from the magnetocaloric working unit is transferred to the outside through the upper heat release portion. The magnetocaloric refrigeration device has advantages of simple structure, low production cost, and small size.

Abstract: Solid state thermioninc refrigerators with elements having at least one barrier segment connected to wire-equivalent segments. The barrier segment has solid state regions that establish a potential energy barrier to electric carriers. This barrier is such that the circulation of a negative electrical charge from one of such regions to another region experiences an increasing potential energy. Elements can be superconducting or nonsuperconducting. Elements can also include an inverse barrier.

Abstract: The invention relates to thermal physics, in particular to a method and apparatus for cooling a working medium and a method for generating microwave radiation. The object is to reduce the power consumed in the cooling process and in the conversion of electric power into electromagnetic radiation energy.

Abstract: A slush hydrogen production device (10) utilizes a hydrogen slushifier magnetic refrigerator (30) having a wheel (50) of material exhibiting the magnetocaloric effect. The wheel is rotated through a magnetic field of varying intensity around the circumference of a wheel housing (36) created by the windings of superconductive magnets (56). The material of the wheel (50) follows a magnetic Carnot cycle as the wheel rotates (36) through regions of low temperature heat transfer and high temperature heat transfer. Liquid hydrogen is supplied to the regions of low and high temperature heat transfer through inlet pipes (39 and 42). Gaseous hydrogen is produced in the high temperature heat transfer region and vented away by an outlet pipe (48). Solid hydrogen is produced in the low temperature heat transfer region by direct solidification upon the magnetic wheel (50); and is removed by scrapers (76) and deposited in a compartment (26) where it mixes with liquid hydrogen to form slush hydrogen.

Abstract: A surface cleaning apparatus comprising a chamber, and a thermal transfer device. The chamber is capable of holding a semiconductor structure therein. The thermal transfer device is connected to the chamber. The thermal transfer device has a surface disposed inside the chamber for contacting the semiconducting structure and controlling a temperature of the semiconductor structure in contact with the surface. The thermal transfer device has a thermal control module connected to the surface for heating and cooling the surface to thermally cycle the surface. The thermal control module effects a substantially immediate thermal response of the surface when thermally recycling the surface.

Abstract: A method and apparatus is provided for generating an artificial heat sink below ambient temperature for a cryogenic condenser by isothermally magnetizing a paramagnetic fluid and removing the magnetic field thereby creating a temperature drop in the fluid by the magentocaloric effect. The heat of magnetization is converted into mechanical work by initially placing the fluid inside a sealed chamber with a door that opens to a conduit leading into the bore of a superconducting solenoid. When the solenoid is energized with current, it creates a strong axial magnetic field that exerts magnetic attractive forces on the fluid inside the chamber. When the fluid is released by opening the door, it is accelerated through the conduit toward the superconducting solenoid where it becomes magnetized by the increasing strength of the magnetic field.

Abstract: An apparatus and a method for providing a magnetic holding field about a chamber for accumulating frozen 129Xe. The apparatus includes a magnetic field source and a yoke for supporting the magnetic field source about the chamber. The magnetic field source provides a magnetic holding field having a field strength of greater than 2 kiloGauss. The apparatus may further include yoke for coupling the magnetic holding field through a portion of the chamber.

Abstract: An apparatus for performing a thermodynamic cycle comprising: a sample having a ferromagnetic phase transition temperature; means to magnetise the sample above the ferromagnetic phase transition temperature of the sample; and means to cool the sample to a temperature that is below the ferromagnetic phase transition temperature thereof, wherein the demagnetisation of the sample whilst the sample is below the ferromagnetic phase transition temperature thereof causes the generation of an independent magnetic flux.

Abstract: The invention relates to a method and apparatus for cooling multilevel entities such as atoms, ions or molecules as well as entities with no apparent internal structure. Cooling is achieved by coherent scattering, where the frequency of the emitted radiation exceeds the frequency of the illumination radiation. Such coherent scattering is achieved by placing the entities in a resonator containing in which the cavity length and mirror coating are selected to support a resonant radiation. The entities are illuminated with an illumination radiation whose energy is lower than that of the resonant radiation supported by the resonator by a certain detuning energy selected such that coherent scattering of resonant radiation from the entities at a higher frequency than that of the illumination radiation is promoted by the resonator. As a result of the coherent scattering energy is carried away from the entities and they are cooled.

Abstract: The magnetic material for magnetic refrigeration of the present invention is characterized by exhibiting, in a certain temperature region, preferably, only in part of a temperature region from 200 K to 350 K, an inflection point at which a second order differential coefficient of a magnetization curve changes from positive to negative with respect to a magnetic field, within the range of this magnetic field formed using a permanent magnet unit. This magnetic material of the present invention can generate a low temperature by using a relatively low magnetic field, by transferring the entropy between the electron spin system and the lattice system near the temperature at which an inflection point appears on the magnetization curve. Examples of the magnetic material meeting this condition are La(Fe,Si)13, (Hf,Ta)Fe2, (Ti,Sc)Fe2, and (Nb,Mo)Fe2, each containing 50 to 60 atomic % of transition metals such as Fe.

Abstract: A magnetic refrigeration apparatus has an annular container including a plurality of magnetic regenerator compartments containing magnetocaloric material, and a magnet mounted for rotation around the annular container, whereby the motion of the magnet produces a variation of magnetic field strength in the magnetic regenerator compartments, which in term leads to a variation in temperature of the magnetocaloric material in the magnetic regenerator compartments. Heat transfer fluid is propelled by a pump, and directed to and from the regenerator compartments and hot and cold heat exchangers by valves. Each valve includes an axial port and a plurality of radial ports.

Abstract: The invention relates to a polarizer for noble gases comprising a glass sample cell and a pressure chanter in which the sample cell is located. High pressure and accompanying broadband or narrow-band lasers can be similarly provided in an optimal manner. To this end, the polarizer is operated at pressures of 30 bar and higher.

Abstract: A vapor compression apparatus and a method for operating a vapor compression system are provided. A working fluid is conveyed through a vapor compression system having a fluid line. A magnetic field generator is connected to the fluid line to direct a magnetic field through the working fluid. The magnetic field is operable to disrupt intermolecular forces and weaken intermolecular attraction to enhance expansion of the working fluid to the vapor phase, increasing the capacity, performance and efficiency of the system components, and reducing system cycling, mechanical wear and energy consumption.

Abstract: A portable thermoelectric cooling and heating appliance device and associated method of using the device are disclosed. The device comprises: a generally rectangular box, a hinge, a generally rectangular lid, a locking means, and a power cord. The box has a divider wall which defines a partition between a left and a right chamber within the box. The box further includes: an outer shell; an insulation layer; a inner shell; a power input plug; a first heat transfer unit; a first network of cooling/heating coils; a first control knob having a first voltage regulator and a first thermostat operationally connected to each other; a first spigot having a first button and a first drain; a second heat transfer unit; a second network of cooling/heating coils; a second control knob having a second voltage regulator and a second thermostat operationally connected to each other; and a second spigot having a second button and a second drain. The hinge is attached to the outer shell of the box.

Abstract: A transport unit includes a plurality of permanent magnets arranged to provide a magnetic holding field for protecting hyperpolarized gas during storage and/or transport. The permanent magnets are configured in a relatively light weight manner to project a substantially cylindrical magnetic holding field or spherical holding field in space. The magnet arrangements can include primary magnets and field shaping secondary magnets which act to enlarge the region of homogeneity. The permanent magnet arrangement can also be provided with a cylindrical shaped flex sheet magnetically activated to provide the magnetic holding field. The permanent magnet arrangements do not require disassembly to insert or remove one or more containers of hyperpolarized gas in or out of the transport unit.

Abstract: The invention relates to a novel cooling system (100) in which waste heat to be dissipated is first absorbed by an electron emission layer (15). The heat induces a discharge of electrons (13) from the surface of the electron emission layer, whereby the electrons are drawn off by a suction electrode (10) which is located on a positive potential located opposite the emission layer (15). The thermal energy carried along by the electrons (13) induce a heat transfer from the electron emission layer (15) to the suction electrode (10). The intensity of the electron flow can be controlled by the bias voltage of a grid (12) which is arranged between the electron emission layer (15) and the suction electrode (10). The surface of the electron emission layer (15) is preferably composed of alkaline earth metals such as barium or cesium.

Abstract: A vapor compression apparatus and a method for operating a vapor compression system are provided. A working fluid is conveyed through a vapor compression system having a fluid line. A magnetic field generator is connected to the fluid line to direct a magnetic field through the working fluid. The magnetic field is operable to disrupt intermolecular forces and weaken intermolecular attraction to enhance expansion of the working fluid to the vapor phase, increasing the capacity, performance and efficiency of the system components, and reducing system cycling, mechanical wear and energy consumption.

Abstract: Described herein is a temperature control system for cooling magnetic elements (14) in MRI apparatus (10). The control system comprises a wax (16) in contact with the elements (14) which is substantially maintained at its phase transition temperature between a solid state and a liquid state, but in a substantially solid state. A sensor (18) is immersed in the wax (16) and operates to provide a signal on the change of state of the wax (16). The sensor (18) is connected to a controller (20) which controls the operation of a heating element (26) also immersed in the wax (16) to control the temperature thereof. When the MRI apparatus is operational, heat is generated by the magnetic elements (14) is used to change the wax (16) to a liquid, this change being detected by the sensor (18) which sends signals to the controller (20) to turn off the heating element (26).

Abstract: The invention relates to a method and apparatus for cooling multilevel entities such as atoms, ions or molecules as well as entities with no apparent internal structure. Cooling is achieved by coherent scattering, where the frequency of the emitted radiation exceeds the frequency of the illumination radiation. Such coherent scattering is achieved by placing the entities in a resonator containing in which the cavity length and mirror coating are selected to support a resonant radiation. The entities are illuminated with an illumination radiation whose energy is lower than that of the resonant radiation supported by the resonator by a certain detuning energy selected such that coherent scattering of resonant radiation from the entities at a higher frequency than that of the illumination radiation is promoted by the resonator. As a result of the coherent scattering energy is carried away from the entities and they are cooled.

Abstract: The present invention discloses a miniature thermodynamic device that can be constructed using standard micro-fabrication techniques. The device can be used to provide cooling, generate power, compress gases, pump fluids and reduce pressure below ambient (operate as a vacuum pump). Embodiments of the invention relating to the production of a cooling effect and the generation of electrical power, change the thermodynamic state of the system by extracting energy from a pressurized fluid. Energy extraction is attained using an expansion process, which is as nearly isentropic as possible for the appropriately chosen fluid. An isentropic expansion occurs when a compressed gas does work to expand, and in the disclosed embodiments, the gas does work by overcoming either an electrostatic or a magnetic force.

Abstract: Apparatus and methods for performing switching of heat flow in magnetic refrigeration systems are provided. In one embodiment, microelectromechanical (MEM) switches are provided for switching from a heat absorption phase and a heat rejection phase of a magnetic refrigeration cycle. In other embodiments, these MEM switches are replaced by thermoelectric switches. The thermoelectric switches operate such that an “on” state is defined as heat flow being allowed by virtue of the thermal conductivity of the thermoelectric switch. An “off” state is defined as a net zero heat flow through the thermoelectric switch obtained by providing a current that is just sufficient to offset the heat flow through the thermoelectric switch due to its thermal conductivity. In some embodiments, the thermoelectric switches are “directly coupled” thermoelectric switches, meaning that they are energized by a direct electrical coupling to a current source.

Abstract: In heating and cooling apparatus, molecules of working gas are excited by light irradiation and thereby cooled as the gas flows through a mirrored cooling cell. In a closed loop embodiment, the gas then flows by means of a fan or compressor to a first heat exchanger where heat from the matter being cooled is transferred to the gas; and, then to a second heat exchanger where heat is transferred from the gas to a heat sink. The apparatus may be used either like a heat pump or air conditioner. In an open-end cooling apparatus embodiment, the gas flows from the cooling cell, through the first heat exchanger, and to atmosphere. The light source may be a 10.6 micron laser; or a 9-11 micron electric arc, a hot filament or the Sun. Working gases comprise N2 and C02; exhaust gases of engines or fuel cells; and gases which comprise different molecular composition gases or different isotopic species of the same molecular composition gas.

Abstract: Apparatus and methods for performing switching of heat flow in magnetic refrigeration systems are provided. In one embodiment, microelectromechanical (MEM) switches are provided for switching from a heat absorption phase and a heat rejection phase of a magnetic refrigeration cycle. In other embodiments, these MEM switches are replaced by thermoelectric switches. The thermoelectric switches operate such that an “on” state is defined as heat flow being allowed by virtue of the thermal conductivity of the thermoelectric switch. An “off” state is defined as a net zero heat flow through the thermoelectric switch obtained by providing a current that is just sufficient to offset the heat flow through the thermoelectric switch due to its thermal conductivity. In some embodiments, the thermoelectric switches are “directly coupled” thermoelectric switches, meaning that they are energized by a direct electrical coupling to a current source.

Abstract: Apparatus and methods for performing switching of heat flow in magnetic refrigeration systems are provided. In one embodiment, microelectromechanical (MEM) switches are provided for switching from a heat absorption phase and a heat rejection phase of a magnetic refrigeration cycle. In other embodiments, these MEM switches are replaced by thermoelectric switches. The thermoelectric switches operate such that an “on” state is defined as heat flow being allowed by virtue of the thermal conductivity of the thermoelectric switch. An “off” state is defined as a net zero heat flow through the thermoelectric switch obtained by providing a current that is just sufficient to offset the heat flow through the thermoelectric switch due to its thermal conductivity. In some embodiments, the thermoelectric switches are “directly coupled” thermoelectric switches, meaning that they are energized by a direct electrical coupling to a current source.

Abstract: Method of making an active magnetic refrigerant represented by Gd5(SixGe1−x)4 alloy for 0≦x≦1.0 comprising placing amounts of the commercially pure Gd, Si, and Ge charge components in a crucible, heating the charge contents under subambient pressure to a melting temperature of the alloy for a time sufficient to homogenize the alloy and oxidize carbon with oxygen present in the Gd charge component to reduce carbon, rapidly solidifying the alloy in the crucible, and heat treating the solidified alloy at a temperature below the melting temperature for a time effective to homogenize a microstructure of the solidified material, and then cooling sufficiently fast to prevent the eutectoid decomposition and improve magnetocaloric and/or the magnetostrictive and/or the magnetoresistive properties thereof.

Abstract: The present invention relates to a method of hyperpolarizing a gas sample. The method cryogenically forming a solidified gas structure from the sample gas, the solidified gas structure being surrounded by 3He. A magnetic field is then to the solidified gas structure and the 3He to thereby polarize the solidified gas structure, before the 3He is removed to thereby leave a solidified gas structure of hyperpolarized sample gas.

Abstract: A normal-insulator-superconductor (NIS) microrefrigerator in which a superconducting single crystal is both the substrate and the superconducting electrode of the NIS junction. The refrigerator consists of a large ultra-pure superconducting single crystal and a normal metal layer on top of the superconducting crystal, separated by a thin insulating layer. The superconducting crystal can be either cut from bulk material or grown as a thick epitaxial film. The large single superconducting crystal allows quasiparticles created in the superconducting crystal to easily diffuse away from the NIS junction through the lattice structure of the crystal to normal metal traps to prevent the quasiparticles from returning across the NIS junction. In comparison to thin film NIS refrigerators, the invention provides orders of magnitude larger cooling power than thin film microrefrigerators.

Abstract: A magnetic refrigeration apparatus has an annular container including a plurality of magnetic regenerator compartments containing magnetocaloric material, and a magnet mounted for rotation around the annular container, whereby the motion of the magnet produces a variation of magnetic field strength in the magnetic regenerator compartments, which in term leads to a variation in temperature of the magnetocaloric material in the magnetic regenerator compartments. Heat transfer fluid is propelled by a pump, and directed to and from the regenerator compartments and hot and cold heat exchangers by valves. Each valve includes an axial port and a plurality of radial ports.

Abstract: A system, method, and computer program products and associated apparatus, to monitor and determine the polarization level of a quantity of hyperpolarized gas during transport. A portable device is configured to transmit an excitation pulse and analyze a response signal in transit to provide a polarization level corresponding to the hyperpolarized gas. Preferably, the monitoring system can provide magnetic field fluctuation feedback to the transport unit and adjust operating current to a solenoid. The system also can compensate for NMR frequency shifts that may appear in the measured response signal to provide a more accurate polarization level or “real” T1 for the hyperpolarized gas.

Abstract: Methods of extracting and removing hyperpolarized gas from a container include introducing an extraction fluid into the container to force the hyperpolarized gas out of an exit port. The hyperpolarized gas is forced out of the container separate and apart from the extraction fluid. Alternatively, if the fluid is a gas, a portion of the gas is mixed with the hyperpolarized gas to form a sterile mixed fluid product suitable for introduction to a patient. An additional method includes engaging a gas transfer source such as a syringe to a transport container and pulling a quantity of the hyperpolarized gas out of the container in a controlled manner. Another method includes introducing a quantity of liquid into a container and covering at least one predetermined internal surface or component with the liquid to mask the surfaces and keep the hyperpolarized gas away from the predetermined internal surface, thereby inhibiting any depolarizing affect from same.

Abstract: A rotating magnetic refrigeration apparatus has magnetic regenerator beds arranged in a ring that is mounted for rotation about a central axis, such that each bed moves into and out of a magnetic field provided by a magnet as the ring rotates. Heat transfer fluid is directed to and from the regenerator beds by a distribution valve which is connected by conduits to the hot and cold ends of the beds and which rotates with the ring of beds. The distribution valve has a stationary valve member which is connected by conduits to a hot heat exchanger and to a cold heat exchanger. The beds include magnetocaloric material that is porous and that allows heat transfer fluid to flow therethrough.

Abstract: Solid state thermioninc refrigerators with elements having at least one barrier segment connected to wire-equivalent segments. The barrier segment has solid state regions that establish a potential energy barrier to electric carriers. This barrier is such that the circulation of a negative electrical charge from one of such regions to another region experiences an increasing potential energy. Elements can be superconducting or nonsuperconducting. Elements can also include an inverse barrier.

Abstract: The invention relates to a novel cooling system (100) in which waste heat to be dissipated is first absorbed by an electron emission layer (15). The heat induces a discharge of electrons (13) from the surface of the electron emission layer, whereby the electrons are drawn off by a suction electrode (10) which is located on a positive potential located opposite the emission layer (15). The thermal energy carried along by the electrons (13) induce a heat transfer from the electron emission layer (15) to the suction electrode (10). The intensity of the electron flow can be controlled by the bias voltage of a grid (12) which is arranged between the electron emission layer (15) and the suction electrode (10). The surface of the electron emission layer (15) is preferably composed of alkaline earth metals such as barium or cesium.

Abstract: In heating and cooling apparatus, molecules of working gas are excited by light irradiation and thereby cooled as the gas flows through a mirrored cooling cell. In a closed loop embodiment, the gas then flows by means of a fan or compressor to a first heat exchanger where heat from the matter being cooled is transferred to the gas; and, then to a second heat exchanger where heat is transferred from the gas to a heat sink. The apparatus may be used either like a heat pump or air conditioner. In an open-end cooling apparatus embodiment, the gas flows from the cooling cell, through the first heat exchanger, and to atmosphere. The light source may be a 10.6 micron laser; or a 9-11 micron electric arc, a hot filament or the Sun. Working gases comprise N2 and C02; exhaust gases of engines or fuel cells; and gases which comprise different molecular composition gases or different isotopic species of the same molecular composition gas.

Abstract: A cryogenic rectification system wherein some or all of the refrigeration necessary to drive the rectification is generated by periodically magnetizing and demagnetizing a bed of magnetizable material, passing refrigerator gas through the bed to produce cold refrigerator gas, and passing refrigeration from the cold refrigerator gas into the rectification system.

Abstract: A cooling apparatus for power semiconductors, which apparatus is essentially box-shaped, has two extruded cooling sections (14, 15) joined to each other. One of the cooling profiles (14) forms a first heat-conducting side wall (16), and the other cooling profile (15) forms a second heat-conducting side wall (17), opposite the first side wall (16), of the cooling apparatus (1). The side walls (16, 17) have cooling partitions (18, 19) formed on the inner sides of the latter, which cooling partitions bound cooling channels through which a cooling fluid can be conducted. Power semiconductors (4, 5) are to be attached to the outer sides of the side walls (16, 17) in a heat-conducting manner. In order to achieve the largest possible cooling surface of the cooling apparatus, the cooling partitions (18) formed on the first side wall (16) project between the cooling partitions (19) formed on the second side wall (17).

Abstract: Methods of extracting and removing hyperpolarized gas from a container include introducing an extraction fluid into the container to force the hyperpolarized gas out of an exit port. The hyperpolarized gas is forced out of the container separate and apart from the extraction fluid. Alternatively, if the fluid is a gas, a portion of the gas is mixed with the hyperpolarized gas to form a sterile mixed fluid product suitable for introduction to a patient. An additional method includes engaging a gas transfer source such as a syringe to a transport container and pulling a quantity of the hyperpolarized gas out of the container in a controlled manner. Another method includes introducing a quantity of liquid into a container and covering at least one predetermined internal surface or component with the liquid to mask the surfaces and keep the hyperpolarized gas away from the predetermined internal surface, thereby inhibiting any depolarizing affect from same.

Abstract: Methods and apparatus for magnetically cooling and liquefying a process stream include a plurality of active magnetic regenerative refrigerators (AMRRs) configured in parallel or in series and parallel. Active magnetic regenerative liquefiers (AMRLs) include such AMRRs and are configured to liquefy, for example, natural gas or hydrogen. In specific embodiments, a magnetic field is produced by hexagonally arrayed solenoids and magnetic refrigerants are selected to provide a thermal mass that is dependent on an applied magnetic field.

Abstract: A cryogenic vessel system for containing cryogenic fluid wherein refrigeration is generated by applying and withdrawing a magnetic field to a bed of magnetizable particles, and the refrigeration is provided to the vessel interior to counteract heat leak into the vessel.

Abstract: A magnetic refrigeration system uses high-temperature side thermal diode modules with magnetocaloric material placed inside of hermetically sealed module containers. The material in the form of a porous matrix. The material comes into direct thermal contact with or is submerged in a hest transfer fluid, and a radical increase in heat transfer is obtained due to large surface area and pores in the material, which serve as nucleation sites and develop thin meniscus evaporating layers. These modules also contain special condensing surfaces and a means for return of condensed fluid to the evaporator. Various combinations with low-temperature side modules are also disclosed. A refrigeration system using the modules includes a rotatable disk on which a plurality of modules disposed radially on the disk are carried, and the disk is rotated in proximity to a magnetic field generator so that the material in the modules is intermittently magnetized and thereby heated.

Abstract: A system for providing refrigeration to a heat load, especially over a larger temperature range and at a cryogenic temperature, wherein magnetic refrigeration cools a heat transfer medium to provide higher level refrigeration to a refrigeration fluid, and lower level refrigeration is provided to the fluid using a nonmagnetic system.

Abstract: A rotating magnetic refrigeration apparatus has magnetic regenerator beds arranged in a ring that is mounted for rotation about a central axis, such that each bed moves into and out of a magnetic field provided by a magnet as the ring rotates. Heat transfer fluid is directed to and from the regenerator beds by a distribution valve which is connected by conduits to the hot and cold ends of the beds and which rotates with the ring of beds. The distribution valve has a stationary valve member which is connected by conduits to a hot heat exchanger and to a cold heat exchanger. The beds include magnetocaloric material that is porous and that allows heat transfer fluid to flow therethrough.

Abstract: Optical refrigerators using semiconductor material as a cooling medium, with layers of material in close proximity to the cooling medium that carries away heat from the cooling material and preventing radiation trapping. In addition to the use of semiconducting material, the invention can be used with ytterbium-doped glass optical refrigerators.

Abstract: Methods and apparatus for magnetically cooling and liquefying a process stream include a plurality of active magnetic regenerative refrigerators (AMRRs) configured in parallel or in series and parallel. Active magnetic regenerative liquefiers (AMRLs) include such AMRRs and are configured to liquefy, for example, natural gas or hydrogen. In specific embodiments, a magnetic field is produced by hexagonally arrayed solenoids and magnetic refrigerants are selected to provide a thermal mass that is dependent on an applied magnetic field.

Abstract: A heat regenerative material including AMz, where A is at least one rare earth element selected from the group consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb; M is at least one metal selected from the group consisting of Ni and Co; and z is 0.001 to 9.0; the heat regenerative material being formed of particles with an average diameter of 1-2,000 &mgr;m or filaments with an average diameter of 1-2,000 &mgr;m.