NONLINEAR COUPLING BETWEEN UPPER-HYBRID AND MAGNETOACOUSTIC WAVES IN PARTIALLY-IONIZED GASES

The nonlinear coupling between finite amplitude upper-hybrid and magne toacoustic perturbations in weakly ionized plasmas has been considered . The interaction is governed by a set of equations comprising the non linear Schrodinger equation for the upper-hybrid wave envelope and a p air of driven equations for magnetosonic perturbations. The latter are described by the magnetoacoustic-hydrodynamic (MAD) equations in the presence of the upper-hybrid ponderomotive force. The modulational ins tabilities and envelope upper-hybrid solitons are examined The relevan ce of our investigation to space and laboratory plasmas has been point ed out.