Experimental investigations of the microconvective instability in optically induced gratings

A. Meżulis - E. Blūms

Insitute of Physics, University of Latvia, Salaspils-1, LV-2169, Latvia

Abstract
In the present work attention is paid to some notable effects in the Forced Rayleigh Scattering experiments with an applied magnetic field, ∇T ||H, which have not been analyzed before. The work deals with an idea that the experimentally observed effects are caused by a microconvection . The dimensionless numbers Cm and \Rm, which are responsible for the onset of microconvection, are calculated from the experiments as well as from the linear stability analysis in a Hele-Shaw approximation . In the framework of the performed experimental data processing, an original method is developed to define the values of diffusion and Soret coefficients and their field dependence. Figs 7, Refs 10.