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.

This invention relates generally to oil lubricated helium compressor units for use in cryogenic refrigeration systems, operating on the Gifford McMahon (GM) cycle. This invention provides redundancy between water cooling and air cooling if there is a blockage in the water or air supply by having air and water cooled after-coolers in series or parallel.

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.

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 Gifford-McMahon (GM) type double-inlet pulse tube system providing cooling at cryogenic temperatures is provided. The system has a co-axial double-inlet valve that includes a base having an adjustable port, a fixed needle partially engaged in one end of the adjustable port, an adjustable needle partially engaged in another end of said adjustable port, and a body for housing the base, the fixed needle and the adjustable needle. The base is configured to be adjustable along an axial direction. The adjustable needle is arranged co-axially with the fixed needle. The adjustable port and the adjustable needle are configured to control an alternating current (AC) flow and a direct current (DC) flow between the stem port and the end port and to produce the DC flow in either direction between the stem port and the end port.

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.

A cryogenic refrigerator includes a pulse tube cryocooler including a pulse tube, and a pulse tube cryocooler rotating mechanism that rotatably supports the pulse tube cryocooler allowing it to be changed from a cooling posture to a heating posture. When the pulse tube cryocooler is in the cooling posture, an inclination angle formed between a vertical line and a center axis of the pulse tube is a first angle, and when the pulse tube cryocooler is in the heating posture, the inclination angle is a second angle. In a case where the inclination angle formed when a cold end of the pulse tube faces vertically downward is defined as zero degrees and the inclination angle formed when the cold end of the pulse tube faces vertically upward is defined as 180 degrees, the second angle is larger than the first angle.

A thermoacoustic device includes a loop tube in which a working gas is sealed; a stack in which a temperature gradient is generated in a tube axis direction of the loop tube, the stack being provided in the loop tube; and a diaphragm structure including a diaphragm provided in the loop tube and an operation unit, the diaphragm having a surface extending in a direction intersecting the tube axis direction and being configured to vibrate with a component of vibration in the tube axis direction, and the operation unit being configured to apply a physical quantity that is required, to the diaphragm to change a rigidity of the diaphragm in the tube axis direction.

There is provided a starting method for a cryocooler, the cryocooler including a compressor, a cold head, a high pressure line, and a low pressure line, the method including increasing a volume of the high pressure line when the cold head is at a room temperature, cooling the cold head from the room temperature to a cryogenic temperature while controlling an operation frequency of the compressor based on a pressure of the high pressure line or a differential pressure between the high pressure line and the low pressure line, after the volume of the high pressure line has been increased, decreasing the volume of the high pressure line after the cold head has been cooled to the cryogenic temperature, and maintaining the cold head at the cryogenic temperature after the volume of the high pressure line has been decreased.

Techniques facilitating mechanical vibration management for cryogenic environments are provided. In one example, a system can comprise a processor that executes computer executable components stored in memory. The computer executable components can comprise a linearization component and a drive component. The linearization component can translate data indicative of a nonlinear drive signal into a linear drive signal. The drive component can dynamically control operation of a compressor of a cryocooler using the linear drive signal. The cryocooler can provide cooling capacity for a cryogenic environment.