Onset of Superfluid Flow inHe4Films Adsorbed on Mylar

Abstract
Detailed studies of the thermal conductance of a Mylar strip on which an adsorbed film of He4 resides have been made at several temperatures as a function of the thickness of the helium film. The conductance in the vicinity of the superflow onset transition is observed to rise in a manner consistent with the predictions of Ambegaokar et al.