Generation of whistler wave by parametric decay of lower hybrid wave in a complex plasma

Abstract

The effect of fluctuations of dust grains on the parametric up conversion of lower hybrid waves into a whistler wave in a complex plasma is studied. In a complex plasma, which contains ambient magnetic field, the lower hybrid pump possessing a large amplitude decays into two modes: a whistler wave mode and a lower hybrid wave mode having low frequency. Furthermore, a ponderomotive force is exerted by the lower hybrid pump and whistler side bands on the existing electrons, which drives the lower hybrid decay mode. Furthermore, the coupling of v⃗1, the oscillatory velocity of low-frequency lower hybrid waves, along with the density perturbations, produces a nonlinear current, which drives the whistler mode. The growth rate Γ (sec−1) of lower hybrid waves scales linearly with the amplitude of the pump waves, and it increases as the amplitude of the lower hybrid pump waves increase. Moreover, the dust grain charges influence the instability appreciably. Our theoretically observed growth rate decreases with the increase in the relative density d=n0i/n0e of negatively charged dust grains, while it decreases with the size of dust grains a (μm). The growth rate varies inversely to the electron cyclotron frequency ωce, and it decreases as ωce increases. The results presented in the article are efficiently able to elaborate the basics of the whistler wave excitation in complex plasmas, space plasmas, processing in solid state plasmas, fusion plasmas, and laboratory plasmas as well as industrial plasmas.