Temperature Dependence of the Superfluid Healing Length

The reduction in superfluid mass of helium contained in restricted geometries has been studied as a function of temperature. The results are discussed in terms of a superfluid healing length ${\xi }_s$. Near $T_{\lambda }$, ${\xi }_s$ can be described by a power law, ${\xi }_s={\xi }_{s,0\mathrm{}}{(1-\frac{T}{T_{\lambda }})}^{-\nu }$, where $\nu =0.67\mathrm{}\pm 0.04$. A value for ${\xi }_{s,0\mathrm{}}=4.0\mathrm{}\pm 0.5$ Å is obtained from the analysis of superfluid flow through a slit of known geometry.