Administration of EMP-related Publications
year | 2014 |
author(s) | Todoshchenko, I., Kaikkonen, J.-P., Blaauwgeers, R., Hakonen, P. J. and Savin, A. |
title | Dry demagnetization cryostat for sub-millikelvin helium experiments: Refrigeration and thermometry |
document type | Paper |
source | Review of Scientific Instruments, 85, 085106 (2014) |
doi | 10.1063/1.4891619 |
EMP/Horizon2020 | This publication does not include a EMP/Horizon2020 acknowledgement. |
abstract | We demonstrate successful “dry” refrigeration of quantum fluids down to T = 0.16 mK by using copper nuclear demagnetization stage that is pre-cooled by a pulse-tube-based dilution refrigerator. This type of refrigeration delivers a flexible and simple sub-mK solution to a variety of needs including experiments with superfluid 3He. Our central design principle was to eliminate relative vibrations between the high-field magnet and the nuclear refrigeration stage, which resulted in the minimum heat leak of Q = 4.4 nW obtained in field of 35 mT. For thermometry, we employed a quartz tuning fork immersed into liquid 3He. We show that the fork oscillator can be considered as self-calibrating in superfluid 3He at the crossover point from hydrodynamic into ballistic quasiparticle regime. |