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arXiv · 1206.3676

Pressure of thermal excitations in superfluid helium

I. N. Adamenko·K. E. Nemchenko·I. V. Tanatarov·A. F. G. Wyatt
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Abstract

We find the pressure, due to the thermal excitations of superfluid helium, at the interface with a solid. The separate contributions of phonons, $R^-$ rotons and $R^+$ rotons are derived. The pressure due to $R^-$ rotons is shown to be negative and partially compensates the positive contribution of $R^+$ rotons, so the total roton pressure is positive but several times less than the separate $R^-$ and $R^+$ roton contributions. The pressure of the quasiparticle gas is shown to account for the fountain effect in $HeI I$. An experiment is proposed to observe the negative pressure due to $R^-$ rotons.

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I. N. Adamenko, K. E. Nemchenko, I. V. Tanatarov, A. F. G. Wyatt. 2012-06-16. Pressure of thermal excitations in superfluid helium. https://doi.org/10.1088/0953-8984%2F20%2F24%2F245103

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