Phonons Created in Superfluid Helium by a Thin Film Gold Heater
| Autor: | Adrian F. G. Wyatt, I. N. Adamenko, K. E. Nemchenko, V. A. Slipko |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Materials science
Condensed matter physics Phonon Liquid helium Detector Energy flux Condensed Matter Physics Atomic and Molecular Physics and Optics Computer Science::Other law.invention Physics::Fluid Dynamics Condensed Matter::Materials Science law Condensed Matter::Superconductivity Sapphire General Materials Science Thin film Superfluid helium-4 Bar (unit) |
| Zdroj: | Journal of Low Temperature Physics. 157:509-526 |
| ISSN: | 1573-7357 0022-2291 |
| DOI: | 10.1007/s10909-009-0011-z |
| Popis: | We show that a thin film gold heater, on polished sapphire, radiates phonons into liquid helium by both the acoustic and background channels. To analyse the measured angular distributions of phonons, at a pressure of 24 bar, we derive an expression for the phonon flux incident on a detector for a general spatial arrangement of heater and detector, when the phonons travel ballistically. We then develop an expression for the particular geometry of the experiments. We find that most of the energy flux, from the heater to the liquid helium, is transmitted by the background channel and this fraction increases with heater power. We discuss the implications for the Kapitza conductance problem. |
| Databáze: | OpenAIRE |
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