Abstracto

Electron Inertia Induce Nonlinear Acoustic Modes Near the Transonic Region in a Multispecies Plasma

Utpal Deka, Nayan Kamal Bhattacharyya, Prem Das Chettri

In presence of multicomponent ionic plasma, more than one plasma sound waves are possible depending on the number of ions. In this work, we considered the presence of a negative ion along with the normal positive ion. Here we show that finite but weak electron inertial delay effect causes a resonant excitation of the ion acoustic solitons near the transonic zone, which depends on e � i1,2 � m m� ratio. It has been seen that under such situation near the plasma sheath transonic zone, the KdV equations have complex coefficients. We have shown that even in presence of the complex coefficients soliton like solution can be derived only for infinitely long wavelength source perturbation. It is seen that when the negative ions mass becomes equal to that of a dust particle then similar excitation situation as in case of colloidal plasma can be retrieved. It is plausible that such kind of a resonant excitation may lead to acoustic turbulence near the plasma sheath edge. A detailed discussion of the nonlinear acoustic mode analyses in the transonic regime with negative ionic impurity using a hydrodynamic approach is presented