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EPSRC Reference: GR/M35680/01
Title: CREATION AND DECAY OF TOPOLOGICAL DEFECTS IN SUPERFLUID HELIUM-4 AND THE EARLY UNIVERSE
Principal Investigator: McClintock, Professor P
Other Investigators:
Researcher Co-Investigators:
Project Partners:
Department: Physics
Organisation: Lancaster University
Scheme: Standard Research (Pre-FEC)
Starts: 01 October 1998 Ends: 30 September 2001 Value (£): 214,103
EPSRC Research Topic Classifications:
Quantum Fluids & Solids
EPSRC Industrial Sector Classifications:
No relevance to Underpinning Sectors
Related Grants:
Panel History:  
Summary on Grant Application Form
It is proposed to investigate the creation and decay of quantised vortices in isotropically pure He II. The work will be done in two parts:1. Pioneering investigations of the free decay of quantised turbulence in the mechanical vacuum below 100 mK will be conducted in the new dilution refrigerator recently provided by EPSRC. The decay mechanism in this regime, where damping is almost absent, is currently unknown. But if it is attributable to thermal phonons within some temperature range, we can hope to measure the temperature dependence of the vortex-phonon scattering cross-section for comparison with a theoretical prediction.2. Evidence for the creation of vortices via the Kibble mechanism will be sought through measurements of second sound attenuation immediately following expansions of a small volume of liquid helium-4 through the lambda transition. The results will be compared with theoretical predictions, and are expected to shed light on the production of cosmic strings in the symmetry-breaking GUT phase transition of the early universe. Even if vortices cannot be observed, it will be possible to reduce the upper bound of the created vortex density by at least a factor of 10 from its present value.
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Organisation Website: http://www.lancs.ac.uk