Progress of Theoretical Physics
Superfluid Vortex, Trapping Neutral Impurities
Tetsuo Ohmi, Tunemaru Usui
Abstract
Structure and energy of a superfluid vortex line and a neutral impurity (He3) trapped by it are investigated in the Hartree-Fock approximation. In dilute gas the shape of the impurity is prolate along the vortex line, while in dense gas it becomes more spherical. In liquid helium the ratio of the axes is estimated at √0.842 and the binding energy at 3.5°K. A rough estimate of the saturation density is given. It is pointed out that at this density the tension has decreased to 60% of that in pure He4.