ABSTRACT
Dilution refrigerator is the most effective workhorse at temperatures of a few to a few dozens of milli-kelvin. This workhorse can also continously provide a few hundred microwatt to a few milli-watts of cooling power at 100 mK. After a brief review of the history the development of dilution refrigerator followed by detailed descriptions of the working priciples and the main components of the dilution refrigerator, special features and the operation of the cryogen-free dilution refrigerator were discussed.
While the cryogen-free dilution refrigerator became a mature commercial product, effort to achieve lower temperatures with a cryogen-free system is of great interest. Cryogen-free Nuclear Adiabatic Demagnetization Refrigerator (NADR) systems to reach sub-millikelvin has emerged from the horizon during the past few years. Example was introduced at the end this chapter (actually the end of the book) as one of the expectations for the new development of future cryogen-free cryogenic engineering and technologies:
