Thermal phenomena in the flow of superfluid 3He through a weak link

Abstract

We report on experiments performed with a weak link which was the only flow connection between two volumes of 3He. The deflection of a flexible wall between the volumes was measured to monitor the flow through the weak link as well as to measure the pressure difference across it. The temperature of the main volume was changed in steps of approximately 0.2 mK. After these temperature steps a fountain pressure developed and decayed on a time scale of several hundred seconds. This thermomechanical effect was found in normal and in superfluid 3He. We did not observe any influence of the quantum phase difference on the heat conductivity.