4 K Closed Cycle Refrigerators from Janis and SHI

Why should I consider using a 4 K cryocooler?

4 K cryocoolers allow you to cool samples, devices and/or equipment without the inconvenience and expense of liquid helium. They can be applied to a broad range of applications in both research and industry. Some typical uses include materials research, superconductivity, cryopumps, shield cooling, and helium recondensing.

How do 4 K cryocoolers work?

Two-stage Gifford-McMahon (G-M) refrigerator systems have been in widespread use for several decades. Room temperature helium gas is first compressed, and then supplied to the refrigerator via flexible gas lines. The compressed helium is cooled by expansion, and provides cooling to two heat stations on the refrigerator. After cooling the refrigerator, the gas is returned to the compressor to repeat the cycle.

Pulse Tube (PT) refrigerator systems use a similar compression/expansion cycle, but eliminate the moving regenerator found in G-M cryocoolers. PT cryocoolers often have reduced vibration levels at the vacuum interface flange as compared with G-M systems. Click here to see the three main differences between PT cryocoolers and G-M cryocoolers.

Sumitomo Heavy Industries (SHI) 4 K cryocoolers are available in both modified G-M cycle and PT configurations, employing rare earth heat exchanger materials. These materials retain useful heat capacity to temperatures below 4 K, resulting in base temperatures previously unobtainable in a two-stage cryocooler.

Is a 4 K cryocooler economically practical?

Prior to the introduction of 4 K cryocoolers, liquid helium was most commonly used to cool equipment and experiments to 4 K. The following chart shows the operating cost of a typical liquid helium cooled apparatus (not including storage dewar evaporative losses). In some cases, the entire cost of a 4 K refrigerator can be recovered in the first year!

Chart of annual liquid helium costs at one liter per hour. 

Why should I choose Janis Research?

Janis Research Company is a distributor of 4 K G-M refrigerators manufactured by the Cryogenic Department of SHI. More than just a distributor, Janis is a preferred cryostat partner of SHI, and has been manufacturing cryogenic equipment for over 50 years. Our team of engineers and designers includes many with advanced degrees, with over 200 years of combined experience in the field of cryogenics! This experience and innovation was rewarded with a 1998 R&D 100 award, as well as two of NASA’s Public Service Group Achievement Awards.

What does our experience mean for you?

It has enabled us to create system designs that are sophisticated, yet simple to operate, and customized to meet your specific application requirements. We can guide you through the range of available options, and help you choose the 4 K cryocooler or complete system that is right for you. Read on and you will find a wide range of cryocooler possibilities. Then contact a Janis sales engineer for help selecting the one that is right for your application and budget.


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