Simultaneous measurement of the heat capacity and superfluid density of 4He films in vycor glass

Abstract

A simultaneous measurement of the heat capacity and superfluid density of thin 4He films on Vycor glass has been made. We have conclusively established the 3D nature of the critical region by the observation of a heat capacity peak coincident with Tc of the film. In addition, we find reasonable agreement when two scale factor universality is used to compare the critical region of the film transition to that of the bulk lambda transition.