Tuesday, June 19, 2012

1206.3676 (I. N. Adamenko et al.)

Pressure of thermal excitations in superfluid helium    [PDF]

I. N. Adamenko, K. E. Nemchenko, I. V. Tanatarov, A. F. G. Wyatt
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.
View original: http://arxiv.org/abs/1206.3676

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