341 results about "Cryocooler" patented technology

A transceiver architecture for wireless base stations wherein a broadband radio frequency signal is carried between at least one tower-mounted unit and a ground-based unit via optical fibers, or other non-distortive media, in either digital or analog format. Each tower-mounted unit (for both reception and transmission) has an antenna, analog amplifier and an electro-optical converter. The ground unit has ultrafast data converters and digital frequency translators, as well as signal linearizers, to compensate for nonlinear distortion in the amplifiers and optical links in both directions. In one embodiment of the invention, at least one of the digital data converters, frequency translators, and linearizers includes superconducting elements mounted on a cryocooler.

A vertical support rigidly mounted to a planar base positions and supports a cryocooler expander unit off axis and away from a sample to be examined. The sample support is likewise rigidly mounted to the planar base with a rigidly mounted sample housing therein. The cryocooler expander unit is suspended in the vertical support by spring dampening bearings. A pair of opposing flexible vacuum bellows connects the cryocooler expander unit to the sample housing and vertical support. This configuration isolates the sample from vibration. Flexible thermal links associated with an predictive electronic closed loop control sequence maintains sample temperature.

A compact optical payload for an unmanned aircraft includes two infrared cameras for wide and narrow field viewing, a daylight color camera, a laser pointer and a laser range finder.

A closed-cycle refrigerator provides cooling to extremely low temperatures, particularly in the range of 0.5 K to 2.0 K. A 4 K pulse-tube cryocooler cold head or G-M cryocooler cold head liquefies helium in a first cooling chamber at a pressure at approximately 1 atmosphere. Liquid helium flows from the first cooling chamber, through a Joule-Thomson valve, and into a second cooling chamber under a pressure differential created by a pump. Helium vapor extracted from the second cooling chamber by the pump is routed back to the first cooling chamber to be re-condensed. This closed-cycle design provides continuous cooling below 2 K. Cryocooler cold head cold sections have no physical contact with subsequent cooling elements, such as the first and second cooling chambers to reduce vibration transfer. In some embodiments the cryocooler cold head is connected to a vacuum chamber via a vibration damping coupler to further reduce vibration transfer.

A superconducting magnet assembly and method of cooling a superconducting magnet assembly. An embodiment of the method of manufacturing a superconducting magnet assembly includes: providing a housing configured about a vacuum reservoir; forming a coil former; surrounding the coil former with a thermal shield; locating the thermal shield in the vacuum reservoir; positioning a superconducting magnet about the coil former, wherein the superconducting magnet is configured about a central core to receive an object; providing a second vacuum reservoir having a cryogen reservoir therein; providing two two-phase heat transfer devices wherein each comprises tubing having an evaporator region and a condenser region; thermally connecting the evaporator region of one of the heat transfer devices with the coil former and/or the superconducting magnet and the evaporator region of the other two-phase heat transfer device with the thermal shield; and thermally connecting a cryocooler to the cryogen reservoir and to the condensing region of both heat transfer devices.

A cryostat configuration for keeping cryogenic fluids in at least one cryocontainer, comprising an outer shell and a neck tube containing a cold head of a cryocooler, wherein the coldest cold stage of the cold head is disposed in a contact-free manner relative to the neck tube and the cryocontainer, and wherein a cryogenic fluid is located in the neck tube, is characterized in that the neck tube is disposed between the outer shell and a cryocontainer and/or the radiation shield, the neck tube is closed in a gas-tight manner at the end facing the cryocontainer and/or the radiation shield, the neck tube is coupled to the cryocontainer and/or a radiation shield disposed between the cryocontainers or a cryocontainer and the outer shell, via a connection having a good thermal conductivity, the neck tube comprising a fill-in device at an end located at ambient temperature. This permits efficient heat transfer between the cryocooler and the cryocontainer with little vibration, while simultaneously ensuring great safety during maintenance work without discharging the magnet.

An NMR apparatus comprising a superconducting magnet coil system, in particular, an NMR spectrometer, with a cryostat which comprises an outer shell and a helium tank which contains the magnet coil system, and with an NMR probe head which is disposed in a room temperature bore of the cryostat and which contains a cooled RF resonator for receiving NMR signals from a sample to be examined and is cooled, together with the NMR probe head, by a cold head of a common, multi-stage, compressor-operated refrigerator, is characterized in that the cold head of the refrigerator is disposed in a neck tube, the upper end of which is connected to the outer shell of the cryostat and the lower end of which is connected to the helium tank in such a manner that the neck tube and the helium tank delimit a helium space, with at least one cooling circuit with thermally insulated transfer lines being provided between the helium space and the NMR probe head, wherein the cryogenic helium in the helium space is used as coolant for the cooling circuit. This produces an NMR apparatus which cools a plurality of elements at different temperature levels using only one single cryocooler to optimally utilize the cooling resources of the refrigerator.

Cryogenic refrigeration employs a pulse tube cryo-cooler and a dilution refrigerator to provide very low temperature cooling, for example, to cool superconducting processors. Continuous cryogenic cycle refrigeration may be achieved using multiple adsorption pumps. Various improvements may include multiple distinct thermal-linking points, evaporation pots with cooling structures, and/or one or more gas-gap heat switches which may be integral to an adsorption pump. A reservoir volume may provide pressure relief when the system is warmed above cryogenic temperature, reducing the mass of the system. Additional heat exchangers and/or separate paths for condensation and evaporation may be provided. Multi-channel connectors may be used, and/or connectors formed of a regenerative material with a high specific heat capacity at cryogenic temperature. Flexible PCBs may provide thermal links to components that embody temperature gradients. Various components may be pre-cooled, for example via a switchable thermalization system.

A cryocooler for liquefying gas in which the neck of the dewar or cryostat includes a cold end of a cryocooler with the first stage cooling station, the first stage regenerator, the second stage cooling station, the second stage regenerator, and a condenser thermally coupled to the second cooling station. Radiation baffles are also present within the neck portion of the dewar between the storage portion for the dewar and the condenser, such that when the cryocooler is turned off, the radiation baffles reduce heat radiation on the cryogen in the storage section of the dewar.

A cryogenic system includes a space formed between a cooling stage of a cryocooler unit and an element to be cooled, and a thermal joint placed in the space, wherein the thermal joint is composed of a substance that has a melting point higher than the cooling temperature of the element to be cooled and that is in a liquid or gaseous state at room temperature and atmospheric pressure. The cryogenic system can achieve reproducible and excellent thermal contact at a cooling stage without applying a large mechanical stress to a cryocooler unit structure.

A cryocooler is located on a spacecraft bus, such as a bus box, separate from the cryogenic propellant tanks disposed on a separable and distinct propellant cartridge system spacecraft docked to the spacecraft bus. In operation, propellant may be continuously pumped from the tanks through the cryocooler cold heat exchanger and then back to the tanks on the separable propellant cartridge system spacecraft through temporarily couplable lines. After the propellant tanks are depleted, the propellant cartridge system is then undocked from the bus and typically discarded. A new propellant cartridge system spacecraft comprising a full set of tanks may then be docked to the bus and the cryocooler supply/return lines coupled. The remote cryocooler may function as part of a larger space depot for spacecraft resupply, although it is not limited to such applications.

A system and method for a magnetic resonance (MR) imaging system includes a coil form, at least one magnet positioned about the coil form and configured to generate a magnetic field, at least one gradient coil for manipulating the magnetic field generated by the at least one magnet by way of a gradient field, and a heat pipe thermally connected to the coil form and having a cryogen therein. The MR imaging system also includes a cryocooler connected to the heat pipe to cool the heat pipe and the cryogen, wherein the coil form is comprised of a thermally conductive material in which eddy currents are substantially reduced during operation of the at least one gradient coil. The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.

A spacecraft instrument thermal control method and system providing scalable thermal control of on-board instrument temperature. Adapted for a spacecraft with bus supporting instrumentation and thermal radiator panels, cooling is carried out by one or more active coolers, such as cryocoolers, each mounted to the spacecraft at a radiator spatially separated from the instrument, with cold side of the cooler being thermally coupled to an instrument focal plane or other instrument location requiring cryogenic cooling and the warm side coupled to the radiator. A closed loop temperature control system measures the temperature of the controlled portion of the instrument, and adjusts active cooler drive signals to maintain a specified set point temperature.

Apparatus and method for separating oxygen directly from air, operating at substantially atmospheric pressure and recuperating energy used for cooling incoming air. An ambient air input leads from the atmosphere to a vessel for confining gases. A cryocooler has a cooled surface in the vessel for directly condensing oxygen from the air at substantially atmospheric pressure. The cryocooler cools the cold surface to a temperature greater than the boiling point temperature of nitrogen and not greater than the boiling point temperature of oxygen for condensing oxygen. A liquid/gas separator separates the liquid oxygen from residual gases which both flow out through separate outputs. Air is propelled through the system at substantially atmospheric pressure by an air impeller. A heat exchanger recovers cooling energy and dehumidifies incoming air by transferring heat from the incoming air to outgoing gases.

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.

A high temperature superconducting (HTS) magnet coil disposed within a cryostat is configured with a thermo-siphon cooling system containing a liquid cryogen. The cooling system is configured to indirectly conduction cool the HTS magnet coil by nucleate boiling of the liquid cryogen that is circulated by the thermo-siphon in a cooling tube attached to a heat exchanger bonded to the outside surface of the HTS magnet coil. A supply dewar is configured with a re-condenser cryocooler coldhead to recondense boiloff vapors generated during the nucleate boiling process.

A cryostat configuration for keeping liquid helium comprises an outer jacket (1) surrounding a helium container (2) connected at at least two suspension tubes (3) to the outer jacket (1), and with a neck tube (4) whose upper warm end (5) is connected to the outer jacket (1) and whose lower cold end (6) is connected to the helium container (2) and into which a multi-stage cold head of a cryocooler (7) is installed, wherein the outer jacket (1), the helium container (2), the suspension tubes (3) and the neck tube (4) delimit an evacuated space, and the helium container (2) is surrounded by at least one radiation shield (8) which is connected in a heat-conducting fashion to the suspension tubes (3) and also to a contact surface (9) on the neck tube (4) of the helium container (2). The cryostat configuration is characterized by a gas gap (13) between one or more cold stages of the cold head (7) and one or more contact surfaces (9) in the neck tube (4) which are each connected in a heat-conducting manner to a radiation shield (8) via a fixed, rigid or flexible thermal bridge (12), heat being transferred through the gas gap (13) from the respective radiation shield (8) to the corresponding cold stage of the cold head (7). A cryostat configuration of this type ensures that no vibrations of the cold head (7) stages pass detectably into the cryostat configuration, wherein the quality of the thermal connection between the cold head (7) and the radiation shield(s) (8) is nevertheless sufficient.

A superconducting magnetizer includes a thermal shield disposed within a vacuum chamber. A superconducting magnet is disposed within the thermal shield and configured to generate a magnetic field in response to an electric current supplied to the superconducting magnet. A heat transfer device comprising at least one of a thermal conduction device, and a heat pipe is disposed contacting the superconducting magnet. A cryocooler is coupled to the heat transfer device and configured to cool the superconducting magnet via the heat transfer device.

Method of controlling a pulse tube cryocooler in which the power input to the acoustic source is varied to maintain temperature of a refrigeration load or a temperature that is at least referable to the temperature of the refrigeration load, at a set point temperature. Additionally, the impedance of an inertance network of the pulse tube cryocooler is also adjusted to obtain a maximum cooling power to the refrigeration load at the particular temperature as sensed and the particular power that is being supplied to the acoustic source.