Design evaluation of serial and parallel sub-mK continuous nuclear demagnetization refrigerators. (September 2020)

• Record Type: Journal Article
• Authors: Schmoranzer, David; Butterworth, James; Triqueneaux, Sébastien; Collin, Eddy; Fefferman, Andrew
• Is Part Of: Cryogenics. Volume 110(2020)
• Publication Date: 2020-09
• Subjects: Ultra low temperatures -- Adiabatic nuclear demagnetization -- Continuous refrigeration techniques -- PrNi5; Low temperature engineering -- Periodicals; Low temperature research -- Periodicals; 536.56
• DOI: 10.1016/j.cryogenics.2020.103119
• Languages: English
• ISSNs: 0011-2275

Abstract

Highlights: Development of novel refrigerators for ultra-low temperatures. Simulations of the performance of Continuous Nuclear Demagnetization Refrigerators. Comparison of serial and parallel design options with two demagnetization stages. Serial arrangement yields higher cooling power and lower final temperature. Abstract: We present the evaluation of two different design configurations of a two-stage PrNi5 continuous nuclear demagnetization refrigerator. Serial and parallel configurations of the two stages are considered, with emphasis on the attainable cooling power at sub-mK temperatures and the impact of the design choices on the operation of the refrigerator. Numerical simulations of heat transfer in the setup are used to evaluate the performance of the refrigerator as well as the technological requirements for the essential thermal links. In accord with similar findings for adiabatic demagnetization refrigerators (Shirron, 2014), our simulations show that the performance of both configurations improves as the thermal links improve, and that the parallel configuration yields a higher cooling power than the series design for a given thermal link resistance and sample temperature.