title: Thermal diffusion shock waves.
abstract: The Ludwig-Soret effect or thermal diffusion, which refers to the separation of liquid mixtures in a temperature gradient, is governed by a nonlinear, partial differential equation in space and time. It is shown here that the solution to the nonlinear differential equation for a binary mixture predicts the existence of shock waves completely analogous to fluid shocks and obeys an expression for the shock velocity that is an exact analogue of the Rankine-Hugoniot relations. Direct measurements of the time dependent, spatial absorption profile of a suspension of nanometer sized particles subjected to a sinusoidal temperature field generated by a pair of continuous laser beams, as well as self-diffraction experiments, show motion of the particles in agreement with the predictions of nonlinear theory.
authors.affiliation: Department of Physics, Brown University, Providence, RI 02912, USA.
authors.forename: Sorasak
authors.initials: S
authors.lastname: Danworaphong
authors.forename: Walter
authors.initials: W
authors.lastname: Craig
authors.forename: Vitalyi
authors.initials: V
authors.lastname: Gusev
authors.forename: Gerald J
authors.initials: GJ
authors.lastname: Diebold