Helium - from matter waves to quantum fluid clusters

Oleg Kornilov, Jan Peter Toennies

Steven W. Van Sciver

Nobuo Wada, Milton W. Cole

Ivan A. Pshenichnyuk, Natalia G. Berloff

We study inelastic interactions of particles with quantized vortices in superfluids by using a semiclassical matter wave theory that is analogous to the Landau two-fluid equations, but allows for the vortex dynamics. The research is motivated by recent experiments on xenon-doped helium nanodroplets that show clustering of the impurities along the vortex cores. We numerically simulate the dynamics of trapping and interactions of xenon atoms by quantized vortices in superfluid helium and the obtained results can be extended to scattering of other impurities by quantized vortices. Different energies and impact parameters of incident particles are considered. We show that inelastic scattering is closely linked to the generation of Kelvin waves along a quantized vortex during the interaction even if there is no capture. The capture criterion of an impurity is formulated in terms of the binding energy.

M. V. Rama Krishna, K. Birgitta Whaley

J. Gspann, G. Krieg, Hans-Peter Vollmar

The recently accomplished generation of 3He-clusters using nozzle sources with internal recycling of the nozzle feed gas is described. Measured cluster sizes are in the same range of some millions of atoms per cluster as in the case of 4He-clusters generated with the same nozzle. Cesium atomic beam scattering by 4He-clusters beams is studied as a means of investigating the atomic interaction with helium clusters which are unique in being certainly liquid due to the quantum fluid properties of helium.