There is provided a cryocooler including a cryocooler cylinder, a pressure switching valve that generates a periodic pressure fluctuation inside the cryocooler cylinder, and a sensor that measures a periodic deformation of the cryocooler cylinder, which is caused by the periodic pressure fluctuation inside the cryocooler cylinder.

A cryocooler includes an expansion chamber, a cooling stage thermally coupled to the expansion chamber, the cooling stage including a first heat transfer block provided with a surface exposed to the expansion chamber and a first heat exchange surface disposed outside the expansion chamber and a second heat transfer block provided with a second heat exchange surface facing the first heat exchange surface, a refrigerant supply port installed in the cooling stage outside the expansion chamber, a refrigerant discharge port installed in the cooling stage outside the expansion chamber, and a refrigerant path fluidically separated from the expansion chamber, the refrigerant path being formed between the first heat transfer block and the second heat transfer block such that a refrigerant flows from the refrigerant supply port to the refrigerant discharge port along the first heat exchange surface and the second heat exchange surface.

A GM cryocooler includes a compressor having a compressor discharge port and a compressor suction port, a displacer capable of reciprocating in an axial direction, a displacer cylinder accommodating the displacer, a drive piston connected to the displacer so as to drive the displacer in the axial direction, a drive chamber in which the drive piston is driven, a main pressure switching valve configured to alternately connect the displacer cylinder to the compressor discharge port and the compressor suction port, an auxiliary pressure switching valve configured to alternately connect the drive chamber to the compressor discharge port and the compressor suction port, and a buffer volume connected between the auxiliary pressure switching valve and the compressor.

A cryocooler includes a displacer, a cylinder that forms an expansion space, a Scotch yoke mechanism configured to drive the displacer in a reciprocating manner, a first rod that extends from the Scotch yoke mechanism, a housing that includes an assist chamber, a rotary valve configured to switch between a state in which the expansion space and a discharge side of a compressor are connected and the assist chamber and a suction side of the compressor are connected and a state in which the expansion space and the suction side of the compressor are connected and the assist chamber and the discharge side of the compressor are connected, a motor configured to drive the Scotch yoke mechanism and the rotary valve, and an on-off valve configured to open and close a gas flow path through which the rotary valve and the assist chamber are connected.

A thermo-acoustic device for transferring energy by an acoustic wave, includes a resonator; a source for generating the acoustic wave; a thermodynamic section that forms an acoustic network and includes a compliance volume, a thermo-acoustic core and a fluidic inertia. The thermodynamic section is situated between the resonator and the source. The thermo-acoustic core is within the thermodynamic section and includes a cold terminal, a hot terminal and a regenerator. The regenerator is positioned between the hot and cold terminals. The source includes a piston compressor. The compressor is arranged as a mechanical double acting reciprocating piston compressor with a first outlet for a pressure wave generated on one side of the piston and a second outlet for a pressure wave generated on the other side of the piston. The first outlet is coupled with a first thermodynamic section, and the second outlet coupled with a second thermodynamic section.

A pulse tube cryocooler includes a cold head including a pulse tube and a radiator thermally coupled to a high-temperature end of the pulse tube, and a forced cooler that forcedly cools the radiator in a cool-down operation of the pulse tube cryocooler from an ambient temperature to a cryogenic temperature.

A cryogenic cooler includes a housing, and first, second, and third actuators. The first actuator includes at least one first voice coil and at least one first magnetic circuit, the at least one first voice coil of the first actuator configured to drive a compressor piston, the first actuator causing vibrations to the housing when driving the compressor piston. The second actuator includes at least one second voice coil and at least one second magnetic circuit, the at least one second voice coil of the second actuator configured to reduce the vibrations to the housing caused by driving the compressor piston. The third actuator includes at least one third voice coil and at least one third magnetic circuit, the third actuator configured to drive a displacer piston. The compressor piston, balance mechanism, and displacer piston are concentrically formed within the cryogenic cooler.

This disclosure describes systems, methods, and apparatus for improving the cooldown time, or efficiency of cooling systems, for a low-frequency one or multi-stage pulse-tube refrigerator. More specifically, actuation is performed on the driving frequency of the oscillating pressure and flow, on flow resistance of valves in the acoustic network that terminate the LF-OPTR or LF-DIPTR, and/or on the asymmetric flow resistance of the bypass valves in a LF-DIPTR's flow network. The actuation of these parameters is informed by measurements of the output pressure or output-input differential pressure at the steady flow compressor, the temperature of each stage of the refrigerator, and the temperature difference between the final stage and upper stages of the refrigerator, to name a few non-limiting examples.

A thermo-acoustic device for transferring energy by an acoustic wave, includes a resonator; a source for generating the acoustic wave; a thermodynamic section that forms an acoustic network and includes a compliance volume, a thermo-acoustic core and a fluidic inertia. The thermodynamic section is situated between the resonator and the source. The thermo-acoustic core is within the thermodynamic section and includes a cold terminal, a hot terminal and a regenerator. The regenerator is positioned between the hot and cold terminals. The source includes a piston compressor. The compressor is arranged as a mechanical double acting reciprocating piston compressor with a first outlet for a pressure wave generated on one side of the piston and a second outlet for a pressure wave generated on the other side of the piston. the first outlet is coupled with a first thermodynamic section, and the second outlet coupled with a second thermodynamic section.

A cooling system is provided with a refrigerator using helium gas, a compressor that compresses the helium gas returned from the refrigerator and supplies the gas to the refrigerator, and a control unit. The control unit includes a measurement acquisition unit that acquires measurements of a plurality of different parameters representing a status of the refrigerator, or the compressor, or both, and an analysis unit that conducts multivariate analysis of the measurements acquired by the measurement acquisition unit.