Phonons Created in Superfluid Helium by a Thin Film Gold Heater
| 详细信息 | 推荐本文 | |
- 作者：I. N. Adamenko ; K. E. Nemchenko ; V. A. Slipko and A. F. G. Wyatt
- 关键词：Kapitza conductance ; Superfluid helium ; Phonons
- 刊名：Journal of Low Temperature Physics
- 出版时间：December, 2009
- 出版年：2009
- 期刊代码：20_00222291
- 类别：law
- 卷：157
- 期：5-6
- 页码：509-526
- 数据来源：sp
摘要
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.