QFS 2016 Book of Abstracts

Abstracts

O4.4 Observation of metastable solid and superfluid helium-4 around 1 K An Qu, A. Trimeche, J. Dupont-roc, J. Grucker, Ph. Jacquier Laboratoire Kastler Brossel, Paris, France In 2012, using an optical interferomertric method, we have successfully observed the metastable solid helium at the pressure 5bar below the melting pressure. This year, with the same technique, the homogeneous cavitation density of superfluid helium at T=0.96 K is measured and found to be ρcav = 0 . 1338 ± 0 . 0002 g ∗ cm − 3 . A well established equation of state for liquid helium at negative pressures converts this to the cavitation pressure P cav = − 5 . 1 ± 0 . 1 bar . This cavitation pressure is consistent with a model taking into account the presence of quantized vortices, but disagrees with previously published experimental values of P cav .

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