VORTEX RINGS IN A BOSE FLUID

摘要: Vortex rings are considered as flow patterns of a phenomenological Hartree-type fluid with parameters fitted to the observed phonon-roton spectrum. The basis calculations is variational, and density which constant except in vortex cores employed. energy lines expressed terms core radius $c$, defined distance from singular line point half asymptotic density. size determined by minimizing found be independent ring when latter larger than ten times radius. Comparing results data Rayfield Reif, one finds $c=1.7$ \AA{}, while model yields this value. critical velocity associated formation channel following Fetter's earlier calculation. In present calculation it possible incorporate Fineman-Chase analysis wall effects. Agreement experiment considerably improved.