Development of a Sub-mK Continuous Nuclear Demagnetization Refrigerator
- 87 Downloads
We present the development of a two-stage PrNi\(_5\) continuous demagnetization refrigerator at the Institut Nel/CNRS and numerical simulations of its performance. The thermal model used in the simulations is discussed in detail including the likely sources of heating. We demonstrate the effects of the critical thermal links including superconducting heat switches as well as the heat conductivity of the PrNi\(_5\), accounting for the dependence of cooling power on the PrNi\(_5\) rod diameter. Our simulations show that if care is taken to minimize the thermal resistance between the nuclear stages, a sample temperature of 1 mK can be maintained under a 20-nW heat load.
KeywordsUltra-low temperatures Adiabatic nuclear demagnetization Continuous refrigeration techniques PrNi\(_5\)
We acknowledge support from the ERC StG Grant UNIGLASS No. 714692 and ERC CoG Grant ULT-NEMS No. 647917.
- 2.O.V. Lounasmaa, Experimental Principles and Methods below 1 K (Academic Press, London, 1974)Google Scholar
- 4.D. Schmoranzer, S. Kumar, A. Luck, E. Collin, A. Fefferman, X. Liu, T. Metcalf, G. Jernigan, Submitted to QFS2018 proceedingsGoogle Scholar
- 10.H.C. Meijer, G.J.C. Bots, H. Postma, The thermal conductivity of PrNi5; electroplating of PrNi5. Physica 107B, 607–608 (1981)Google Scholar
- 12.M. Kubota, H.R. Folle, C. Buchal, R.M. Mueller, F. Pobell, Nuclear magnetic ordering in PrNi5 at 0.4 mK. Phys. Rev. Lett. 45(20), 1812 (1981)Google Scholar
- 13.T. Shigematsu, M. Maeda, M. Takeshita, Y. Fujii, M. Nakamura, M. Yamaguchi, T. Shigi, H. Ishii, in Proceedings of the Sixteenth International Cryogenic Engineering Conference/International Cryogenic Materials Conference, (1997), p. 621–624Google Scholar