A cryocooler includes a first cylinder and a second cylinder, a first cooling stage, a second cooling stage, a radiation shield which is cooled by the first cooling stage, accommodates the second cooling stage, and shields the second cooling stage from radiant heat from an outside, and a temperature sensor which detects a temperature of the second cooling stage. A working gas is supplied into the first cylinder and the second cylinder to be expanded and is exhausted to the outside, an insertion hole through which an output cable of the temperature sensor passes through from an inside to an outside of the radiation shield is provided in the radiation shield, and the insertion hole is configured such that the radiant heat entering the radiation shield from the outside of the radiation shield is not directly radiated to the second cooling stage.

A cryocooler includes an expander that includes a cooling stage, an exhaust temperature sensor that measures an exhaust temperature which is a temperature of a working gas exhausted from the expander and outputs an exhaust temperature signal indicating the measured exhaust temperature, and a controller that compares, during execution of initial cooling in which the cooling stage is cooled from an initial temperature to a cryogenic temperature, the measured exhaust temperature to a reference temperature based on the exhaust temperature signal and completes the initial cooling in a case where a temperature difference between the measured exhaust temperature and the reference temperature is within a reference range.

The cryocooler includes an expander motor that operates an expander of the cryocooler, an inverter that is configured to control an operation frequency of the expander motor and is operable to drive the expander motor in the steady operation at an operation frequency lower than in the cool-down operation, a current sensor that measures a current supplied from the inverter to the expander motor, and outputs a motor current signal indicating the current; and a processor that monitors the expander motor on a basis of the motor current signal in at least the steady operation.

Provided is a thermoacoustic refrigerator including an air column pipe, a prime mover, a load, and a heat accumulation tank. An exhaust gas supplied to and discharged from the heat accumulation tank is supplied, as a heat source, to the prime mover disposed inside the air column pipe, so as to cause self-oscillation of a working gas filled in the air column pipe so that sound waves are generated. With the sound waves, the load disposed inside the air column pipe converts sound wave energy into heat energy, so as to output cold heat.

A dilution refrigerator is provided. The dilution refrigerator includes a plurality of thermalization plates configured to be cooled to a plurality of temperatures, and a first thermalization plate of the plurality of thermalization plates includes an integrated heat exchanger. The integrated heat exchanger includes channels formed in the first thermalization plate, and the channels are configured to allow helium to flow through the first thermalization plate during operation of the dilution refrigerator to improve heat exchange and cooling power of the dilution refrigerator.

The present disclosure relates to a cryogenic apparatus (300, 400, 500), comprising: at least one first temperature change mechanism (310, 410) connected to a sample stage (20) and configured to change a temperature at the sample stage (20); at least one second temperature change mechanism (320, 420, 520, 522) different from the at least one first temperature change mechanism (310, 410), wherein the at least one second temperature change mechanism (320, 420, 520, 522) is connected to the sample stage (20) and configured to change the temperature at the sample stage (20); and a controller. The controller is configured to: operate the at least one first temperature change mechanism (310, 410) in a first temperature range (A); operate the at least one second temperature change mechanism (320, 420, 520, 522) in a second temperature range (B) different from the first temperature range (A); and operate both the at least one first temperature change mechanism (310, 410) and the at least one second temperature change mechanism (320, 420, 520, 522) in a third temperature range (C) between the first temperature range (A) and the second temperature range (B).

A cryogenic cooler includes a cold region, a heat-transfer fluid circuit, the cold region being positioned in the circuit, and an application heat exchanger configured to exchange calories with a device to be cooled. The cooler includes at least one passive non-return valve fluidly connected to the cold region, the heat exchanger having at least one first fluid inlet positioned downstream of the non-return valve in the flow direction of the heat-transfer fluid, the heat-transfer fluid circulating from the end of the cold region.

A cryocooler includes a cold head including a displacer movable in an axial direction, a drive piston connected to the displacer to move the displacer in the axial direction, an expansion chamber formed with the displacer, a piston drive chamber formed with the drive piston, a spool valve including a valve drive chamber, a spool that moves between a first position and a second position in response to a pressure of the valve drive chamber, and a pressure control mechanism configured to control a pressure of the valve drive chamber so that the spool reciprocates between the first position and the second position, and to generate a pressure fluctuation having an opposite phase to the pressure fluctuation in the expansion chamber in the piston drive chamber in synchronization with the reciprocation of the spool.

Provided is a helium recondensation apparatus for a cryostat, which can stably recondense vapor of helium in the cryostat while preventing a pipeline for the recondensation from being clogged. A recondensation apparatus includes a freezer, a first heat exchanger, a first recondensing chamber, and a first connection part. The first heat exchanger stores heat-exchanging helium in a helium tank included in an NMR apparatus, and permits the heat-exchanging helium to evaporate owing to heat of vaporization taken from vapor of coolant helium in the helium tank, thereby permitting the coolant helium to recondense through heat exchange with the heat-exchanging helium. The first connection part is separated from the coolant helium in the helium tank and permits the heat-exchanging helium to flow between the first heat exchanger and the first recondensing chamber therethrough.

An improved cryogenic cooling system is disclosed. The cryogenic cooling system comprises a pressure sensing system disposed at or near the cryocooler to provide a more accurate representation of the pressure of the working gas within the cryocooler. By utilizing pressure measurements at the cryocooler, the thermal performance and net cooling capacity of the system may be improved. This may also improve the life of the cryocooler. Further, in some embodiments, pressure sensing systems are disposed at both the compressor and the cryocooler. In these embodiments, performance issues and potential failures may be monitored.