From the Langer and Fisher thermal-fluctuation theory we have determined the pressure-velocity dependence for pressure-driven intrinsic superfluid helium flow to be $p\propto \exp \left(\frac{-\beta {\rho }_s}{\rho v_s\mathrm{kT}}\right)$. Experiments of pressure-driven intrinsic flow through submicron pores in porous mica are in agreement with this relation.

• Received 1 April 1969

DOI:https://doi.org/10.1103/PhysRevLett.22.1240