Mass Coupling and Q−1 of Impurity-Limited Normal 3He in a Torsion Pendulum
- 56 Downloads
We present results of the Q−1 and period shift, ΔP, for 3He confined in a 98% nominal open aerogel on a torsion pendulum. The aerogel is compressed uniaxially by 10% along a direction aligned to the torsion pendulum axis and was grown within a 400 μm tall pancake (after compression) similar to an Andronikashvili geometry. The result is a high Q pendulum able to resolve Q−1 and mass coupling of the impurity-limited 3He over the whole temperature range. After measuring the empty cell background, we filled the cell above the critical point and observe a temperature dependent period shift, ΔP, between 100 mK and 3 mK that is 2.9% of the period shift (after filling) at 100 mK. The Q−1 due to the 3He decreases by an order of magnitude between 100 mK and 3 mK at a pressure of 0.14±0.03 bar. We compare the observable quantities to the corresponding calculated Q−1 and period shift for bulk 3He.
KeywordsImpurity limited transport Normal 3He
Unable to display preview. Download preview PDF.
- 12.V.V. Dmitriev, D.A. Krasnikhin, N. Mulders, V.V. Zavjalov, D.E. Zmeev, JETP Lett. 86, 681 (2007) Google Scholar
- 19.J.M. Parpia, D.J. Sandiford, J.E. Berthold, J.D. Reppy, J. Phys. Colloq. C6 39, 35 (1978) Google Scholar
- 21.J.M. Parpia, The viscosity of normal and superfluid helium three, Ph.D. Thesis, Cornell University, Unpublished, 1979 Google Scholar