Dynamics of theHe3 ABPhase Boundary

Abstract
We investigate the friction coefficient of the moving boundary. At not too low temperatures the friction is ascribed primarily to transmission and Andreev reflection of quasiparticles; the resulting theoretical value of the terminal velocity vAB is in reasonable agreement with the data of Buchanan, Swift, and Wheatley. At lower temperatures we predict a saturation of vAB and underdamped oscillations of the pinned boundary.