Dynamic Gas Anisotropy under Optomechanical Parametric Resonance

摘要

An approximate kinetic equation describing a gas of two-or three-level atoms in an external laser field is found under conditions of optomechanical parametric resonance, which causes atomic oscillations along the field wave vector. The approximation is appliable to a gas of cylindrical particles whose axes retain their spatial orientation, making the gas anisotropic. The closed set of equations for macroparameters allows for a numerical solution. Expressions for direction-dependent transfer coefficients such as diffusion, viscosity, and thermal conductivity are derived phenomenologically. A two temperature medium is shown to arise if a fluid consists of several gases with the optomechanical parametric resonance conditions satisfied for one of them.