A specific property of electromagnetic waves interacting with dust-laden plasma

Abstract

The propagation pattern of electromagnetic waves EMWs in dusty plasmas is quite different from that in electron-ion plasmas. For instance, here the ponderomotive force acts on dust grains as a negative pressure, and a nonlinear Schrödinger equation with an additional nonlinear term is obtained. Based on this equation, the modulation instability is examined and it is shown that the growth rate becomes maximum when that additional term compensates the diffraction term. The main part of this work is devoted to the localization of the grains by the EMW. Considering both subsonic and supersonic regimes, it has been shown that under certain conditions the grains are localized and the ions circumnavigate the grains, whereas the electrons escape from the region of localization. Further, the localization of grains by the EMW is found to be shape-dependent of the pulse. Comparing pancake and light bullet shaped pulses in the supersonic regime, and it is shown that only the light bullet shape leads to the compression of grains. Finally, investigating nonstationary solution, it is shown that for some parameters, the nonlinear wave breaking and the formation of a shock wave can take place. © 2006 American Institute of Physics