"The transportation of liquid helium, which was such a cumbersome task in the past, now only requires the press of a switch, with no troubles at all."

The GM refrigerator was developed by Guilford and MacMahon in 1959. An air conditioner compressor unit was modified for this purpose. It is one of the most popular refrigerators in use even today, as it has a simple structure and high reliability.

The pulse tube refrigerator was developed by Guildford in 1963 and it is comprised of a compressor unit, a cold storage unit and a simple tube that is referred to as the pulse tube.


Notes on refrigerators

Refrigerators operate to lower the temperature of an object using a refrigerant. Refrigerators lower the temperature basically through compression and expansion and there are a number of types that vary in the refrigerating cycles and the principles used.

GM refrigerator
This is a mechanical refrigerator in which the cooling agent moves back and forth inside a cylinder to perform adiabatic expansion of the refrigerant gas to generate a chill. The method used to move the cooling agent back and forth inside our GM refrigerator is by converting the motor rotating movement to a back and forth motion using a crank mechanism and therefore there is no restriction on the orientation of the refrigerator for installation. Furthermore, for the first time in the world we devised seals for the two-stage cooling agent and resolved problems relating to the limitation of the orientation for installing the 4k refrigerator.
Pulse tube refrigerator
The pulse tube refrigerator is a refrigerator comprised of a compressor unit, cold storage unit and a simple tube referred to as a pulse tube. The most significant difference from the GM refrigerator is that there are no back and forth motions of the cooling agent inside the cylinder, with the result that vibrations generated by the operation of the refrigerator are minute. Furthermore, since the cooling agent is fixed and as there are fewer drive components when compared to the GM refrigerator, the frequency of maintenance is lower. A characteristic of our pulse tube refrigerators is that the double-step refrigeration capacity can be used effectively, since the amount of heat intrusion from the outside is reduced, due to the seals we devised to increase the first stage refrigeration performance.
GM-JT refrigerator
This 4k GM refrigerator is based on the two-stage GM refrigerator with a Joule Thomson (JT) adiabatic expansion section. The refrigerating capacity of 4k is delivered using the latent heat of helium and one of the features is that it offers extremely superior efficiency in comparison with expansion type refrigerators (such as GM refrigerators and pulse tube refrigerators). Another feature is that theoretically it also has extremely small temperature fluctuations, since latent heat is used. We are at the present time the only refrigerator manufacturer capable of offering GM-JT refrigerators to the market.

Applications of refrigerators

GM refrigerator
This product features freedom of orientation for installation, which is utilized in astronomical observations, with installations in the "Subaru telescope" and the "ALMA telescope", whereas for industrial products it is used with superconductive magnets for MRI systems.
Pulse tube refrigerator
Since the vibration of the refrigerator is comparatively small, it is used with magnets for NMR and dilution refrigeration precoolers.
GM-JT refrigerator
This is used primarily with superconductive magnets for accelerators, because of its superior efficiency, and for the cooling of sensors that must be kept away from thermal noise due to low temperature fluctuations.

The global network includes sites in the United States (three locations), United Kingdom, Germany, Korea and China, where sales and service operations are conducted. We are about to establish a support framework for the growing Asian market as well.

Product lines

4k GM refrigerator
  • Refrigerating capacity does not depend on orientation
  • Stability of temperature in the second stage
Pulse tube refrigerator
  • Low vibration
  • Long-term stability
4k GM-JT refrigerator
  • Maximum capacity for 4k refrigerators (the only manufacturer)
  • Low vibration
  • Low electric power consumption

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