Transmission of sound at the liquid-solid interface of helium under growth

Abstract

With the help of a simple one-dimensional continuum model we establish basic matching conditions of chemical potential and pressure at a growing interface, taking into account interfacial kinetic energies. Using these matching conditions we calculate the sound transmission coefficient under normal incidence when the interface undergoes steady growth. We predict a large correction to the transmission coefficient when the interface mobility is large. We also suggest experiments that might display the effect of steady growth and give direct access to the interface mobility