Spin Dynamics of 3He and 3He-4He Mixtures

Clubb, David (2003) Spin Dynamics of 3He and 3He-4He Mixtures. PhD thesis, University of Nottingham.

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Abstract

Experiments have been performed at high B/T to try to establish the existence and value of an anisotropy temperature (Ta) for pure 3He, and for 6.2% and 0.7% 3He-4He mixtures. The anisotropy of diffusion in dilute Fermi gases as the temperature T goes to zero has been predicted, though experimental evidence for such anisotropy has not been universally accepted.

Finite size effects have required careful analysis of the theory of the cell for the 6.2% mixture. This alters the result as determined by the usual Leggett-Rice formula. Further investigation, beyond the scope of this thesis, is currently underway for the case of pure 3He.

The possibility of using a quartz tuning fork as a viscometer has also been investigated. It is shown that tuning forks can be used field-inpendently above 3 mK in saturated 3He-4He mixtures, and to detect the superfluid A and B-phase transitions in pure 3He. It is strongly suggested from the data that the tuning fork has great potential as a high-field viscometer; however further experiments are required to fully appreciate its useful range, in both normal and superfluids.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Owers-Bradley, John
Keywords: ULT, ultra-low temperature, NMR, nuclear magnetic resonance, spin-dynamics, Helium-3, Helium mixtures, tuning fork viscometer, capactiance thermometer
Subjects: Q Science > QC Physics > QC170 Atomic physics. Constitution and properties of matter
Faculties/Schools: UK Campuses > Faculty of Science > School of Physics and Astronomy
Item ID: 10007
Depositing User: EP, Services
Date Deposited: 11 Jun 2003
Last Modified: 14 Sep 2016 23:59
URI: http://eprints.nottingham.ac.uk/id/eprint/10007

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