Abstract: A heat exchanger comprises a glass body having a first flat face and a second flat face on opposing ends, and defining a longitudinal axis therebetween. A plurality of holes in the glass body are elongated along the longitudinal axis by extending from said first flat face to said second flat face. The plurality of holes are configured to receive and direct a gas therethrough, to exchange heat between the gas and the glass body.

Abstract: An apparatus includes a glass body having a first face and a second face on opposing ends and defining a longitudinal axis between the opposing ends. The glass body includes an exterior surface continuously extending from the first face to the second face. The glass body also includes an interior surface surrounding an aperture, the aperture extending longitudinally from the first face to the second face. The glass body further includes a plurality of holes surrounding the aperture, where the holes are disposed within the glass body and extend longitudinally from the first face to the second face. The holes are configured to receive and direct a gas through the holes to exchange heat between the gas and the glass body.

Abstract: A heat exchanger comprises a glass body having a first flat face and a second flat face on opposing ends, and defining a longitudinal axis therebetween. A plurality of holes in the glass body are elongated along the longitudinal axis by extending from said first flat face to said second flat face. The plurality of holes are configured to receive and direct a gas therethrough, to exchange heat between the gas and the glass body.

Abstract: A heat exchanger includes a glass body having a first flat face and a second flat face on opposing ends, and defining a longitudinal axis therebetween. A plurality of holes in the glass body are elongated along the longitudinal axis by extending from said first flat face to said second flat face. The plurality of holes are configured to receive and direct a gas therethrough, to exchange heat between the gas and the glass body.

Abstract: Described herein is a Stirling cycle cryogenic cooler comprising: a first magnetic circuit and a second magnetic circuit for generating a field of magnetic flux; the first magnetic circuit and the second magnetic circuit having a shared magnetic gap and the first magnetic circuit further having an additional magnetic gap; a first coil disposed in the shared magnetic gap; and a second coil disposed in the additional magnetic gap, said second coil being mounted for independent movement relative to said first coil. Also described herein is a method of cooling using the Stirling cycle cryogenic cooler.

Abstract: A vibration control system includes a mechanical system which generates vibration; a sensor configured to measure the vibration and generate a vibration signal thereof, and a processor configured: (a) receive a vibration signal from a sensor in a mechanical system; (b) model the vibration signal using a time-domain function; (c) adjust one of an amplitude coefficient and a phase coefficient of the modeled vibration signal; (d) output a control signal corresponding to the modeled vibration signal to the mechanical system so as to reduce the vibration; and (e) receive another vibration signal from the sensor. Steps (c)-(e) are repeated when the average value of the vibration signal is greater than a predetermined value. A method for vibration control is also disclosed.

Abstract: A thermal-cycle cryocooler, such as a Stirling-cycle cryocooler, has a single working volume that is utilized by both the compressor and the displacer. The compressor and the displacer have respective movable parts, one of which is surrounded by the other. One of the parts may be a piston, a portion of which moves within a central bore or opening in a cylinder that is the other movable part. The piston may be a component of the compressor and the cylinder may be a component of the displacer, or vice versa. The working volume is located in part in a bore of the cylinder, between the piston and a regenerator that is coupled to the cylinder. Movements of either the piston or the cylinder can directly (i.e. without the use of a gas transfer line or flow passage) cause compression or expansion of the working gas in the working volume.

Abstract: In one embodiment, a compressor includes a motor assembly configured to compress a gas within a compression volume, the motor assembly including: a stationary coil assembly; a moving assembly having at least one magnet, and a gap located between the stationary coil assembly and the moving assembly; wherein the moving assembly is configured to reciprocate axially with respect to the stationary coil assembly when electrical current is applied to the stationary coil assembly, and to change the width of the gap between the stationary coil assembly and the moving assembly so as to provide magnetic axial stiffness against motion of the moving assembly. One or more embodiments may be used in a cryocooler assembly.

Abstract: A heat exchanger comprises a glass body having a first flat face and a second flat face on opposing ends, and defining a longitudinal axis therebetween. A plurality of holes in the glass body are elongated along the longitudinal axis by extending from said first flat face to said second flat face. The plurality of holes are configured to receive and direct a gas therethrough, to exchange heat between the gas and the glass body.

Abstract: In one embodiment, a compressor includes a moving assembly configured to compress a gas within a compression volume; a guide rod connected to the moving assembly which reciprocates axially with the moving assembly; and a bellows seal positioned between the moving assembly and a stationary housing which at least partially defining the compression volume. In another embodiment, a compressor includes a motor assembly configured to compress a gas within a compression volume, the motor assembly including: a stationary coil assembly; a moving assembly having at least one magnet, and a gap located between the stationary coil assembly and the moving assembly; wherein the moving assembly is configured to reciprocate axially with respect to the stationary coil assembly when electrical current is applied to the stationary coil assembly, and to change the width of the gap between the stationary coil assembly and the moving assembly so as to provide magnetic axial stiffness against motion of the moving assembly.

Abstract: A vibration control system includes a mechanical system which generates vibration; a sensor configured to measure the vibration and generate a vibration signal thereof, and a processor configured: (a) receive a vibration signal from a sensor in a mechanical system; (b) model the vibration signal using a time-domain function; (c) adjust one of an amplitude coefficient and a phase coefficient of the modeled vibration signal; (d) output a control signal corresponding to the modeled vibration signal to the mechanical system so as to reduce the vibration; and (e) receive another vibration signal from the sensor. Steps (c)-(e) are repeated when the average value of the vibration signal is greater than a predetermined value. A method for vibration control is also disclosed.

Abstract: A cryocooler in which two independently moving flexure systems are split across a single magnetic structure, decreasing package size and increasing resistance to cantilevered mass sag due to external forces. A series of concentrically oriented flexure coupling shafts are provided that allow two independently moving flexure assemblies to be split across a single motor. A series of connectors are included on the forward side of the motor that pass through the outer shaft and allow the inner connecting shaft to be mounted to its flexures without interference. A series of close-out connections are included on the aft flexure stacks that makes assembly possible, providing firm mechanical connections without interference.

Abstract: A multi-stage cryocooler has three or more stages, including an active first stage and passive second and third stages. The active stage may include a Stirling expander, and the passive second and third stages may be pulse tube coolers. The cryocooler may provide cooling at three different temperatures. The coldest cooling temperature may be at or below 10 K, and may be at or below 5 K. The system may provide cooling at such low temperatures while still operating at a relatively high frequency, for example, at a frequency of at least about 20 Hertz.

Abstract: Disclosed are a low vibration cryocooler and a method of reducing vibration in a cryocooler. The cryocooler can be a Stirling class cryocooler includes at least one motor that drives a mass, the motor having a main drive winding and a separate trim winding. A motor controller outputs a main drive signal that is coupled to the main drive winding and a separate vibration reducing signal that is coupled to the trim winding.

Abstract: A system and method for sensing position of an oscillating moving element. The inventive position sensor includes a first arrangement for sampling the position of the element at first positions thereof and providing samples in response thereto and a second arrangement for calculating other positions of the element using the sample of the first position. In the illustrative application, the first arrangement includes an LED and a photodiode and the moving element is a piston of a long-life cryogenic cooler. A processor receives samples from the photodiode and solves an equation of motion therefor. The equation of motion is P(t)=A·sin(?t+?)+B, where P(t)=the position of the element; A=position waveform amplitude; B=position waveform DC Offset; ?=angular frequency of operation; t=time; and ?=position waveform phase.

Abstract: A thermal-cycle cryocooler, such as a Stirling-cycle cryocooler, has a single working volume that is utilized by both the compressor and the displacer. The compressor and the displacer have respective movable parts, one of which is surrounded by the other. One of the parts may be a piston, a portion of which moves within a central bore or opening in a cylinder that is the other movable part. The piston may be a component of the compressor and the cylinder may be a component of the displacer, or vice versa. The working volume is located in part in a bore of the cylinder, between the piston and a regenerator that is coupled to the cylinder. Movements of either the piston or the cylinder can directly (i.e. without the use of a gas transfer line or flow passage) cause compression or expansion of the working gas in the working volume.

Abstract: A method and mechanism for eliminating one of the magnetic circuits in a conventional two motor Stirling cryocooler. The inventive cooler is a Stirling cycle cryogenic cooler with a magnetic circuit for generating a field of magnetic flux in two separate magnetic gaps; a first coil disposed in the flux field of one gap; and a second coil disposed in the flux field of the second gap. The second coil is mounted for independent movement relative to the first coil. In a specific embodiment, the first coil is a compressor coil and the second coil is a displacer coil. The coils are energized with first and second variable sources of electrical energy in response to signals from a controller.

Abstract: A cryocooler in which two independently moving flexure systems are split across a single magnetic structure, decreasing package size and increasing resistance to cantilevered mass sag due to external forces. A series of concentrically oriented flexure coupling shafts are provided that allow two independently moving flexure assemblies to be split across a single motor. A series of connectors are included on the forward side of the motor that pass through the outer shaft and allow the inner connecting shaft to be mounted to its flexures without interference. A series of close-out connections are included on the aft flexure stacks that makes assembly possible, providing firm mechanical connections without interference.

Abstract: A system and method for sensing position of an oscillating moving element. The inventive position sensor includes a first arrangement for sampling the position of the element at first positions thereof and providing samples in response thereto and a second arrangement for calculating other positions of the element using the sample of the first position. In the illustrative application, the first arrangement includes an LED and a photodiode and the moving element is a piston of a long-life cryogenic cooler. A processor receives samples from the photodiode and solves an equation of motion therefor. The equation of motion is P(t)=A·sin(?t+?)+B, where P(t)=the position of the element; A=position waveform amplitude; B=position waveform DC Offset; ?=angular frequency of operation; t=time; and ?=position waveform phase.