Abstract: A thermoacoustic apparatus capable of reducing the time elapsed until an acoustic wave is generated and improving the energy conversion efficiency significantly is provided. In order to solve the above-described issues, in a thermoacoustic apparatus 1 including a pair of heat exchangers 41 and 43 separately set on the high temperature side and on the low temperature side, a second stack 42 which is sandwiched between the heat exchangers 41 and 43 and which has a plurality of transmission paths in the inside, and a loop tube 2 provided with the heat exchangers 41 and 43 and the stack 42, the thermoacoustic apparatus converting acoustic energy generated in the loop tube 2 with an acoustic wave generator 3 to thermal energy by using the heat exchangers 41 and 43 and the stack 42, a narrow portion 21 in which the inner diameter is relatively reduced is disposed at a position at which the particle velocity of a standing wave generated in the loop tube 2 is in the vicinity of a maximum.

Abstract: A cooling device for Stirling circulated dry storage container, which is mainly to make an accommodation space with opening within an external shield, and at the peripherals of the accommodation space, it is installed with a plurality of air flow inlets and air flow outlets that are connected to the external side. In addition, a shield cover is used to cover the opening of the accommodation space, and a nuclear waste storage container is installed within the accommodation space of the external shield, and the peripheral of the accommodation space and the nuclear waste storage container forms an air flow channel.

Abstract: Methods and apparatuses for generating hyperpolarized materials are disclosed. In one embodiment, a flexible fluid path is provided for use in a polarizer system. In a further embodiment, a polarizer system is provided with an electromechanical assembly for controlling the movement of a fluid path, when present, within a sample path of the polarizer system. In a further embodiment, a polarizer system is provided having a sample path entry point at a convenient height for use by a user standing on the ground.

Abstract: An integral compressor-expander assembly, including a cryogenic expander positioned in an overhung configuration on a central shaft; a multi-stage centrifugal compressor supported on the central shaft between at least two bearings; and a device coupled to the central shaft and configured to either supply rotational power to the central shaft or generate power from rotation of the central shaft, depending upon a current operational mode of the multi-stage compressor.

Abstract: A two-stage pulse tube refrigerator having a compact design, low vibration and low heat loss is provided where at least the 2nd stage is co-axial but preferably, both stages are co-axial with the second stage pulse tube being central and the first stage pulse tube occupying the annular space between the second stage pulse tube and the first stage regenerator. Convection losses associated with different temperature profiles in the pulse tubes and regenerators are minimized by shifting the thermal patterns in the pulse tubes relative to the regenerators by one or more of spacers in the regenerators, physical differences in length with gas channel connections, adjustment of dc flow, and thermal bridges.

Abstract: An air cycle machine includes two turbines and a compressor mounted on an integral shaft. The integral shaft includes a plurality of shaft sections that are welded together and machined in a single set-up process into a desired shaft shape to provide highly aligned bearing surfaces. The shaft includes three stops that cooperate with three fasteners to secure the two turbines and the compressor on the shaft.

Abstract: A disclosed device cryogenic refrigerator includes a first stage displacer; a first stage cylinder configured to form a first expansion space between the first stage cylinder and the first stage displacer; a second stage displacer connected to the first stage displacer; and a second stage cylinder configured to form a second expansion space between the second stage cylinder and the second stage displacer, wherein the second stage displacer includes a helical groove formed on an outer peripheral surface of the second stage displacer so as to helically extend from the second expansion space, a flow resistor communicating with a side of the first stage displacer in the helical groove, and a flow path connecting the flow resistor to a side of the first expansion space, wherein the flow resistor is always positioned on a side of the second expansion space relative to the first expansion space.

Abstract: A two-stage GM cryogenic refrigerator includes a displacer having a low-temperature side and a high-temperature side and a motor configured to drive the displacer. The motor is configured to be rotatable forward in cooling and backward in increasing a temperature. The cryogenic refrigerator further includes a resin provided on an outer circumferential surface of the displacer. A thickness of the resin is thinner on the high-temperature side than on the low-temperature side.

Abstract: A cryogenic refrigerator has a refrigeration cylinder and at least two displacers. Each displacer reciprocates in the refrigeration cylinder and moves refrigeration gas through the refrigeration cylinder. A regenerator cools the refrigeration gas, and gas control valves admit high pressure gas into the refrigeration cylinder and exhaust gas from the refrigeration cylinder. The refrigerator also has linear motors operatively connected to displacers, and the linear motors drive the displacers in reciprocating movement. A position sensor is provided to determine a parameter of the displacers during reciprocation. A controller is operatively connected to the linear motors to control the linear motors. The controller controls a parameter of the two displacers during reciprocation. The parameter can be stroke length, stroke speed, stroke phase or another parameter of the displacer for temperature control of the cryogenic refrigerator. The cryogenic refrigerator may also include a device to remove vibration.

Abstract: A refrigeration device of an embodiment includes: a heat-insulating vacuum chamber; a refrigerator cryogenic unit that is provided in the heat-insulating vacuum chamber and is cooled to a lower temperature than 195 K; a catalytic electrode that is provided in the heat-insulating vacuum chamber and contains a transition metal at least in part of a surface thereof; a power supply that applies a voltage to the catalytic electrode; and a heating unit that is provided in the heat-insulating vacuum chamber and heats the catalytic electrode. In this refrigeration device, the catalytic electrode is insulated from the heat-insulating vacuum chamber and the heating unit, and the heating unit is insulated from the heat-insulating vacuum chamber and the catalytic electrode.

Abstract: A cryogenic refrigerator includes a refrigerator body configured to produce cold temperatures by expanding a refrigerant gas; a compressor connected to a first pipe for feeding the refrigerant gas of a first pressure to the refrigerator body, and connected to a second pipe for collecting the refrigerant gas of a second pressure lower than the first pressure from the refrigerator body; a buffer tank configured to store the refrigerant gas; a first valve provided in a first connecting pipe connecting the buffer tank and the refrigerator body; a second valve provided in a second connecting pipe connecting the buffer tank and the first pipe; and a third valve provided in a third connecting pipe connecting the buffer tank and the second pipe.

Abstract: Various embodiments are directed to pulse tube coolers having flow resistance devices that are variable within the thermodynamic cycle of the pulse tube. An example pulse tube may comprise a compressor, a regenerator, a reservoir and a pulse tube. A working fluid may be positioned within the regenerator, pulse tube and reservoir. Further, a variable phase control device may be positioned in a fluid path between the pulse tube and the reservoir. The pulse tube cooler may also comprise a control circuit. The control circuit may be programmed to vary a characteristic of the variable phase control device based on the position of the pulse tube cooler in its thermodynamic cycle.

Abstract: A cryogenic refrigerator includes a cylinder, a displacer configured to be moved back and forth in the cylinder by a drive unit, an inlet valve configured to be opened in supplying a refrigerant gas into the cylinder, an exhaust valve configured to be opened in exhausting the refrigerant gas from the cylinder, and an expansion space formed in the cylinder and configured to generate a cooling by expanding the refrigerant gas caused by back and forth movement of the displacer. A moving speed of the displacer in the vicinity of a bottom dead center is set to be faster than the moving speed of the displacer in the vicinity of a top dead center.

Abstract: A cryogenic refrigerator includes a Scotch yoke mechanism including a Scotch yoke and a bearing movably engaged with the Scotch yoke, and a displacer caused to reciprocate in a cylinder by the Scotch yoke mechanism, so that a refrigerant gas inside an expansion space formed in the cylinder is expanded by the reciprocation of the displacer to generate cold temperatures. The Scotch yoke includes a concave part at a position corresponding to a top dead center of the displacer.

Abstract: A disclosed device cryogenic refrigerator includes a first stage displacer; a first stage cylinder configured to form a first expansion space between the first stage cylinder and the first stage displacer; a second stage displacer connected to the first stage displacer; and a second stage cylinder configured to form a second expansion space between the second stage cylinder and the second stage displacer, wherein a helical groove is formed on an outer peripheral surface of the second stage displacer so as to helically extend from a side of the second expansion space toward the first stage displacer, wherein the second stage cylinder includes a first flow resistor communicating with a side of the first stage displacer in the helical groove, and a buffer portion communicating with a side of the first stage displacer in the first flow resistor.

Abstract: A cryostat (1) with a magnet coil system including superconductors for the production of a magnet field B0 in a measuring volume (3) has a plurality of radically nested solenoid-shaped coil sections (4, 5, 6) and which are electrically connected in series, at least one of which being an LTS section (5, 6) with a conventional low temperature superconductor (LTS) and at least one of which being an HTS section (4) including a high temperature superconductor (HTS), wherein the magnet coil system is located in a helium tank (9) of the cryostat (1) along with liquid helium at a helium temperature TL<4 K. The apparatus is characterized in that heating means are provided which always keep the HTS at an increased temperature TH>TL and TH>2.2 K. The cryostat in accordance with the invention can maintain the HTS section over a long period of time in a reliable manner.

Abstract: A disclosed cryogenic refrigerator includes a first stage displacer; a first stage cylinder configured to form a first expansion between the first stage cylinder and the first stage displacer; a second stage displacer connected to the first stage displacer; and a second stage cylinder configured to form a second expansion space between the second stage cylinder and the second stage displacer, wherein a helical groove is formed on an outer peripheral surface of the second stage displacer so as to helically extend from a side of the second expansion space toward the first stage displacer, the helical groove communicates with the first expansion space, and a cross-sectional area of the helical groove becomes smaller from a side of the second expansion space to a side of the first expansion space.

Abstract: Various embodiments are directed to pulse tube coolers and components thereof. A pulse tube cooler may comprise a compressor, a regenerator, a pulse tube and a reservoir. A network of phase control devices may be placed in a fluid path between a hot end of the pulse tube and the reservoir. The network of phase control devices may have at least one flow resistance device and at least one inertance device.

Abstract: An integrated Stirling refrigerator is composed of two parts: a compressor and an expander. The compressor is composed of a shell (1), a piston (4), a leaf spring (8), a magnet (9), a coil (10), a bracket (14) and a support shelf (15). The shell (1) of the compressor includes two cylinders (11, 12), one of which is set inside the other to form a compression chamber (3). The piston (4) is connected with the leaf spring (8). The coil (10) is fixed between the inside of the shell (1) and the bracket (14), and the magnet (9) is fixed between the bracket (14) and the support shelf (15), wherein the bracket (14) and the support shelf (15) are respectively connected with the shell (1). The inside of the expander is divided into two chambers by a small piston and a regenerator (7) fixed together, that is, an expansion chamber (6) and a pneumatic chamber, and a cylindrical spring (16) is provided on the bottom of the expander.

Abstract: A system and a method for liquefaction of gases which are utilized in their liquid state as refrigerants in applications that require low temperatures, throughout various pressure ranges, from slightly above atmospheric pressures to pressures near the critical point. The system and method are based on closed-cycle cryocoolers and utilize the thermodynamic properties of the gas to achieve optimal liquefaction rates.

Abstract: A reliquifier using a cryocooler in which an insulated sleeve surrounds a portion of the cold head, a first stage cooling station, and a second stage cooling station, including a condenser. Gas is conveyed from a cryostat to the insulated sleeve, where it is liquefied as it passes over the cold head. An end of the insulated sleeve is connected to a liquid transfer tube for conveying condensed fluid back to the cryostat.

Abstract: In a thermoacoustic refrigerator, operating temperatures, ambient temperature, and selected user input are utilized to control frequency and/or input power in order to optimize the efficiency of the thermoacoustic refrigerator operation. In a thermoacoustic heat engine, operating temperatures, ambient temperature, and selected user input are utilized to control impedance of a load to optimize the efficiency of the thermoacoustic heat engine operation.

Abstract: A travelling wave thermoacoustic piezoelectric apparatus capable of generating electrical energy from heat energy is provided. The travelling wave thermoacoustic piezoelectric apparatus includes a hosing with two ends connected by an inertance component, a porous stack, a resonator, and a piezoelectric bimorph. The housing comprises a compressible fluid and has a first portion and a second portion. The first portion receives heat energy from a heat source for creating a temperature gradient between the first portion and the second portion. A cold heat exchanger within the second portion is positioned at one end of the porous stack. The compressible fluid traverses between the first portion and the second portion through the porous stack and the inertance component to generate travelling acoustic waves. The travelling acoustic waves resonate with the resonator for generating acoustic energy.

Abstract: A standing wave thermoacoustic piezoelectric apparatus capable of generating electrical energy from heat energy is provided. The standing wave thermoacoustic piezoelectric apparatus includes a housing, a porous stack and a piezoelectric bimorph. The housing comprises a compressible fluid and has a first portion and a second portion. The second portion receives the heat energy from a heat source for creating a temperature gradient between the first portion and the second portion. A cold heat exchanger within the first portion is positioned at one end of the porous stack. The compressible fluid traverses between the first portion and the second portion through the porous stack to generate standing acoustic waves for generating acoustic energy. The piezoelectric bimorph positioned at an end of the first portion opposite to an end of the first portion having the cold heat exchanger, oscillates based on the acoustic energy for generating the electrical energy.

Abstract: A cryogenic refrigerator includes a cylinder configured to be fed with a refrigerant gas, a displacer configured to reciprocate in the cylinder, a drive unit configured to cause the displacer to reciprocate in the cylinder, and a connecting mechanism connecting the drive unit and the displacer. The connecting mechanism includes an output shaft extending from the drive unit toward the displacer, an engagement pin provided through the output shaft to extend in directions to cross the reciprocating directions of the displacer, a rotation prevention mechanism configured to engage with the engagement pin to prevent a further rotation of the displacer when the displacer rotates, and a lid body fixed to an end portion of the displacer and engaging with the output shaft.

Abstract: In one embodiment, as cryocooler is provided that includes: a regenerator piston; a drive coupler; and a link flexure having a proximal end coupled by a first pin to the drive coupler and having a distal end coupled by a second pin to the regenerator piston, wherein the link flexure forms a vane having flattened opposing faces that are orthogonal to a longitudinal axis for the first and second pin.

Abstract: A rotary valve includes a valve body and a valve plate. The valve body has a body-side passage formed therein, and includes a first slide surface. The valve plate has a plate-side passage formed therein, and includes a valve plate body and a resin valve slide body. The valve plate body is formed of a non-magnetic material and includes an accommodation room. The resin valve slide body is accommodated in the accommodation room of the valve plate body. The resin valve slide body includes a second slide surface in close contact with the first slide surface of the valve body. The valve plate rotates to switch a state of connection of the body-side passage and the plate-side passage.

Abstract: Overhung axial compressor, chemical reactor and method for compressing a fluid. The overhung axial compressor includes a casing configured to be vertically split along a vertical axis for access to an inside of the casing and a removable cartridge. The removable cartridge is configured to fit inside the casing and to be detachably attached to the casing. The removable cartridge includes a shaft disposed along a horizontal axis, the shaft being configured to rotate about the horizontal axis, a bearing system attached to the removable cartridge and configured to rotationally support a first end of the shaft, and plural blades disposed toward a second end of the shaft such that the second end is overhung inside the casing. The compressor also includes a guide vane mechanism configured to connect to the removable cartridge, the guide vane mechanism being configured to adjust a flow of a fluid to the plural blades.

Abstract: In an electron paramagnetic resonance spectrometer, a closed cycle cryocooler is used to cool gaseous helium, which is then circulated around a sample to cool the sample by direct convection. Since the sample is not mechanically connected to the refrigerator, no vibrations are transmitted from the refrigerator to the sample and the sample can be quickly removed and replaced. The cooled helium can be passed through a Joule-Thomson expansion device before circulating the cooled helium around the sample to further cool the helium. In addition, a vacuum pump can be connected to the helium outlet after circulating the cooled helium around the sample to increase the pressure differential across the Joule-Thomson expansion device and further cool the helium. In order to raise the temperature of the cooled helium, a heater can be placed about the cooled helium line upstream from the sample.

Abstract: A liquefier includes a Dewar having a storage portion and a neck portion extending therefrom. A hermetically isolated liquefaction chamber is disposed within the neck of the Dewar. One or more control components including a temperature and pressure sensor are coupled to a CPU and disposed within the liquefaction chamber for dynamic control of liquefaction conditions. A gas flow control is coupled to the CPU for regulating an input gas flow into the liquefaction chamber. A volume surrounding the liquefaction chamber may be adapted to provide a counter-flow heat exchange. These and other features provide improved liquefaction efficiency among other benefits.

Abstract: A method for the pulsating load refrigeration of a component of a Tokamak, said method using a refrigeration device subjecting a working fluid such as helium to a working cycle, the Tokamak comprising at least one operating mode called “periodic and symmetrical,” according to the method, the refrigerating power produced by the refrigeration device being increased to a relatively high level when the Tokamak is in a plasma generating phase (Dp) whereas the refrigerating power produced by the refrigeration device is reduced to a relatively low level when the Tokamak is no longer in a plasma generating phase (Dnp), characterized in that during the “periodic and symmetrical” operating phase of the Tokamak, the refrigerating power of the refrigeration device is regulated according to a forced variation also of the “periodic and symmetrical” type, that is one wherein the respective durations of generation of a high level of refrigeration and of generation of a low level of refrigerating power differ at most by 30%,

Abstract: A supersonic cooling system operates by pumping liquid. Because the supersonic cooling system pumps liquid, the compression system does not require the use of a condenser. The compression system utilizes a compression wave. An evaporator of the compression system operates in the critical flow regime where the pressure in an evaporator tube will remain almost constant and then ‘jump’ or ‘shock up’ to the ambient pressure.

Abstract: The present invention is an apparatus to confine a plurality of charged particles that include a plurality of coil heads that includes a plurality of superconducting coils, a bobbin and a plurality of insulation material and a plurality of support legs that include 2 support legs that are in conductive contact with each coil head and 2 support legs that are in physical contact with each coil head. The apparatus includes a base with a cryocooler inlet and a vacuum flange and a conductive cold element that is in the interior of the base, the conductive cold element is attached to the conductive rods of the 2 support legs that are in conductive contact with each coil head and the superconducting coils.

Abstract: A disclosed displacer to be inserted into a cylinder to expand a compressed working fluid inside the cylinder by reciprocation of the displacer inside the cylinder includes a cylindrical member; and a regenerative material included inside the cylindrical member, wherein a groove is formed on an outer peripheral surface of the cylindrical member, the outer peripheral surface facing the cylinder, and a sealing film is continuously formed on the outer peripheral surface and the groove over an area where the groove is formed in a longitudinal direction.

Abstract: A helium-cooling type regenerator configured to retain cold temperatures of working gas includes a first section through which the working gas flows, a second section configured to accommodate helium gas as a regenerator material, and a regenerator material pipe connected to the second section and to a helium source.

Abstract: A disclosed regenerative type refrigerator includes a cylinder expanding a refrigerant gas; a regenerator accumulating cold thermal energy and being provided inside the cylinder so as to be reciprocate inside the cylinder; a rotary drive portion generating driving force; a rotary member being rotated by the rotary drive portion; and a bearing member supporting the rotary member and including an inner wheel, an outer wheel, and two sealing members encapsulating a lubricant agent and being provided on sides of the outer wheel and the inner wheel, wherein the sealing members are fixed to one of the inner wheel member and the outer wheel member, and a gap is formed between the two sealing members and another one of the inner wheel member and the outer wheel member.

Abstract: A refrigerator includes two displacers which are longitudinally adjacent to each other and the high temperature displacer includes a main compartment and an auxiliary compartment for a regenerator material. A direct passage for operating gas is formed between the two displacers. A cryopump includes a low temperature cryopanel, a radiation shield which is cooled to a higher temperature than that of the low temperature cryopanel, and the refrigerator.

Abstract: The present invention provides a cryostat comprising a cryogen vessel (1), a thermal radiation shield (2), and a sleeve (5) for accommodating a cryogenic refrigerator. Also provided is a first thermal contact for thermally and mechanically connecting a first stage of a cryogenic refrigerator to the radiation shield for cooling thereof. A secondary recondensing chamber is provided (8) for accommodating a second stage of a cryogenic refrigerator, and means (10; 24) are provided for thermally connecting the secondary recondensing chamber to a recondensing surface (11a; 44) exposed to the interior of the cryogen vessel. The cryostat further comprises a pressure control arrangement (100) for controlling the pressure of a gas within the secondary recondensing chamber.

Abstract: A helium-cooling type regenerator includes first and second storage spaces. The first storage space is disposed in a region on a high-temperature side, and accommodates the regenerator material whose pressure is P1. The second storage space is disposed in a region on a low-temperature side, and accommodates the regenerator material whose pressure is P2, which is less than P1. A specific heat in the case where a pressure of the regenerator material accommodated in the first storage space is P2 is less than that in the case where the pressure of the regenerator material is P1, and a specific heat in the case where a pressure of the regenerator material accommodated in the second storage space is P1 is less than that in the case where the pressure of the regenerator material is P2.

Abstract: A superconducting magnet system with a superconducting magnet coil system disposed in a cryogenic fluid tank (2) of a cryostat (1), and a refrigerator (6) for cooling the cryogenic fluid that cools the magnet, is characterized in that a radiation shield (5; 21; 31; 41; 51) is provided which separates a refrigerator space (4) from the cryogenic fluid tank (2), wherein the entire cooling region (9) of the refrigerator (6) is disposed in the refrigerator space (4), and wherein the radiation shield (5; 21; 31; 41; 51) has openings (11; 22; 44, 45; 53) for gas or fluid exchange between the refrigerator space (4) and the cryogenic fluid tank (2). Should the refrigerator fail, the thermal input into the cryostat is reduced, and the safety of the maintenance staff is improved in case of a quench.

Abstract: An expansion engine operating on a Brayton cycle which is part of a system for producing refrigeration at cryogenic temperatures that includes a compressor, a counter-flow heat exchanger, and a load that may be remote, which is cooled by gas circulating from the engine. The engine has a piston in a cylinder which has nearly the same pressure above and below the piston while it is moving. Low pressure on a piston drive stem provides a force imbalance to move the piston towards the warm end.

Abstract: A sample cooling apparatus capable of cooling and holding samples or wafers at a cryogenic temperature with no vibration or drift with respect to a measurement reference surface is disclosed. In the sample cooling apparatus, a sample holder is arranged in a vacuum vessel mounted on a housing having a table for forming a measurement reference surface to be supported by a thermal insulator. A frame is disposed within the housing to be supported by a first buffer. A refrigerating machine is disposed in the frame to be supported by a second buffer and has a head directed to the vacuum vessel. The cooling head of the refrigerating machine is connected to the sample holder by way of a flexible thermal conduction member.

Abstract: This motor includes: a translationally movable induction coil; a power-supply circuit adapted to deliver, to at least one induction coil, an AC power-supply current; a movable mass adopting a translational movement an induction coil arranged so as to move a respective movable mass between a first position and a second position where the movable mass can compress the fluid; a secondary circuit arranged to connect the terminals of at least one induction coil in short-circuit; The secondary circuit comprises a compensation component for producing a phase shift between the power-supply voltage and the power-supply current, so as to reduce the phase difference that the inductance of the induction coil produces.

Abstract: A cryopump and a regenerating method of the cryopump whereby temperatures of a first stage and a second stage can be securely increased to target temperatures and time required for regenerating can be shortened are provided. At the time of regenerating, the temperature of the second stage cooling stage is controlled based on the temperature detected by the second temperature detection part. In the case where the temperature of the first stage cooling stage reaches the limiting temperature, namely critical temperature, of the first stage displacer, the rotation in the reverse direction of the reversible motor is controlled or stopped and thereby the regenerating process is stopped for a while.

Abstract: A system and method to connect a cryocooler (refrigerator) to a superconducting magnet or cooled object allows for replacement without the need to break the cryostat vacuum or the need to warm up the superconducting magnet or other cooled object. A pneumatic or other type of actuator establishes a thermo-mechanical coupling. The mechanical closing forces are directed perpendicular (cross-axially) to the cryocooler axis and are not applied to the thin wall cryocooler body or to the thin cryostat walls or to the cooled object or to its shield. It is also possible that some of the compressive force be transferred to the cryocooler body. In that case, the extensions are designed so that the forces transferred to the cryocooler thermal stages do not exceed allowable stresses in the cryocooler stage.

Abstract: Cooling in the supersonic region of a compressible fluid is disclosed. The fluid is accelerated by a reciprocating piston to a velocity equal to or greater than the speed of sound in the fluid in an evaporator. No conventional mechanical pump is required to accelerate the fluid. A phase change of the fluid due to a pressure differential may be utilized to transfer heat from an element to be cooled.

Abstract: An open brayton cycle power generation system is enabled and improved by integration of an energy storage system utilizing cryogenic storage of atmospheric gas. A particular improved system is an open brayton cycle power generation system in which the heating source is Concentrating Solar Power. Multiple embodiments are described which permit various modes of operation and improved overall efficiency.

Abstract: A cryogenic refrigerator according to an embodiment of the present invention is used in cooling a superconducting magnet. The cryogenic refrigerator includes a crankpin bearing of a scotch yoke. The crankpin bearing is made of a cylindrical nonmagnetic resin material. The crankpin bearing includes a cylindrical inner wall and a cylindrical outer wall. The cylindrical inner wall supports a crankpin. The crankpin is eccentrically attached to an output shaft of a motor slidably in a circumferential direction. The cylindrical outer wall contacts with an inner wall of a window portion of the scotch yoke. The cylindrical inner wall is made of another nonmagnetic resin material different from the nonmagnetic resin material of the cylindrical outer wall. Hardness of the cylindrical inner wall is higher than hardness of the cylindrical outer wall.

Abstract: The invention provides a variable impedance device including a first bus bar refrigeration system, a first bus bar thermally connected to the first bus bar refrigeration system to be maintained at a target bus bar temperature by the first bus bar refrigeration system, a variable impedance component refrigeration system, a variable impedance component electrically connected to the first bus bar and thermally connected to the component refrigeration system, a variable impedance component may be at least partially made of a material that is superconducting below a critical temperature and may be maintained at a target component temperature, wherein the target bus bar temperature may be between the 300K and critical temperature and the target component temperature may be below the critical temperature and a second bus bar connected to the variable impedance component so that current flows between the first and second leads through the variable impedance component.

Abstract: A G-M refrigerator comprises a compressor (1), a gas inlet valve (2), an exhaust valve (3), a regenerator (4), a cylinder (5), a piston (6), a hot cavity (7), a cold cavity (8), a seal ring (9), a driving mechanism (10-12), an annular gap (13), a heat exchanger (14), an orifice valve (18) and a gas reservoir (19). By introducing a phase modulation mechanism, such as the orifice valve (18), the gas reservoir (19) and the like, the working way of gas in the annular gap (13) is changed to be the same with that of a pulse tube refrigerator with the phase modulation mechanism, expansion of the part of the gas is fully utilized for doing work so as to generate the cold effect, loss caused by gas leakage through the seal ring (9) is further eliminated and the performances of the G-M refrigerator are further improved.