Effect of dust charging and trapped electrons on nonlinear solitary structures in an inhomogeneous magnetized plasma

Abstract

Main concerns of the present article are to investigate the effects of dust charging and trapped electrons on the solitary structures evolved in an inhomogeneous magnetized plasma. Such a plasma is found to support two types of waves, namely, fast wave and slow wave. Slow wave propagates in the plasma only when the wave propagation angle θ satisfies the condition θ≥tan-1{(1+2σ)-[(ndlh(γ1-1))/(1+ndlhγ1)]-v0u0}, where v0(u0) is the z- (x-) component of ion drift velocity, σ = Ti/Teff, ndlh = nd0/(nel0 + neh0), and γ1=-1Φi0[1-Φi01+σ(1-Φi0)] together with Ti as ion temperature, nel0(neh0) as the density of trapped (isothermal) electrons, Φi0 as the dust grain (density nd0) surface potential relative to zero plasma potential, and Teff=(nelo+neho)TelTeh/(neloTeh+nehoTel), where Tel(Teh) is the temperature of trapped (isothermal) electrons. Both the waves evolve in the form of density hill type structures in the plasma, confirming that these solitary structures are compressive in nature. These structures are found to attain higher amplitude when the charge on the dust grains is fluctuated (in comparison with the case of fixed charge) and also when the dust grains and trapped electrons are more in number; the same is the case with higher temperature of ions and electrons. Slow solitary structures show weak dependence on the dust concentration. Both types of structures are found to become narrower under the application of stronger magnetic field. With regard to the charging of dust grains, it is observed that the charge gets reduced for the higher trapped electron density and temperature of ions and electrons, and dust charging shows weak dependence on the ion temperature.