Filters
Results 1 - 1 of 1
Results 1 - 1 of 1.
Search took: 0.016 seconds
AbstractAbstract
[en] We present experimental results on the condensation of 4He atoms on the surface of liquid 4He. We show that there is quantum condensation with the creation of phonons and R+rotons in one-to-one processes as atoms go into the Bose-Einstein condensate. These phonon and R+roton signals can be recognized by their time of flight, their angular distribution and their dependence on the ambient temperature. Condensing atoms also create ripplons with a high probability. We derive rate equations for the growth of the ripplon density and the ripplon decay by the creation of bulk phonons. During the atom pulse a dynamic equilibrium is established. The low-energy phonons that are created by ripplon-ripplon scattering can easily be detected and distinguished from the phonons created by quantum condensation. From measured data, estimates are made of the probabilities of creating phonons, R+rotons and ripplons in condensation processes as well as estimates of the quantum evaporation probabilities of phonons and rotons. We clearly detect R+rotons directly with a bolometer in the liquid 4He and show why the signal of R+rotons is obscured by the low-energy phonon signal when both the source and detector are in the liquid helium. Values of the Kapitza conductance for the Zn bolometers are derived
Secondary Subject
Source
S0953-8984(03)60159-1; Available online at http://stacks.iop.org/0953-8984/15/4717/c32706.pdf or at the Web site for the Journal of Physics. Condensed Matter (ISSN 1361-648X) http://www.iop.org/; Country of input: International Atomic Energy Agency (IAEA)
Record Type
Journal Article
Journal
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue