Modulational instability of ion acoustic waves in a multi-species collisionless magnetized plasma consisting of nonthermal and isothermal electrons

Abstract

We have used the Sagdeev pseudo-potential technique to investigate the arbitrary amplitude ion acoustic solitons, double layers and supersolitons in a collisionless magnetized plasma consisting of adiabatic warm ions, isothermal cold electrons and nonthermal hot electrons immersed in an external uniform static magnetic field. We have used the phase portraits of the dynamical system describing the nonlinear behaviour of ion acoustic waves to confirm the existence of different solitary structures. We have also investigated the transition of different solitary structures: soliton (before the formation of double layer) → double layer → supersoliton → soliton (soliton after the formation of double layer) by considering the variation of θ only, where θ is the angle between the direction of the external uniform static magnetic field and the direction of propagation of the wave.

Modulation instability of obliquely propagating ion acoustic waves in a collisionless magnetized plasma consisting of nonthermal and isothermal electrons

“…• The NLSE obtained in the present paper for describing the amplitude modulation of IA waves propagating along any arbitrary direction to the direction of the magnetic field is exactly same as that of Dalui et al [23] if we put θ = 0 and if we ignore the perpendicular dispersive terms of the NLSE equation of Dalui et al [23], i.e., if we ignore the weak dependence of the spatial coordinates perpendicular to the direction of the magnetic field.…”

“…This dispersion relation can be easily obtained by linearizing the equations (1), (2), (3), (4) and (5) with respect to the perturbed dependent variables, and finally, assuming space-time dependence of the perturbed dependent variables to be of the form exp[i(k z − ωt)]. The dispersion relation (12) is exactly same as the dispersion relation (15) of Dalui et al [23] with slight modification in notations only. The dispersion relation (12) or the dispersion relation (15) of Dalui et al [23] is free from the effect of magnetic field.…”

“…In the present paper, we have investigated the MI of obliquely propagating IA waves in a collisionless magnetized plasma consisting of nonthermal and isothermal electrons, whereas Dalui et al [23] have investigated the MI of IA waves propagating along the direction of the magnetic field in the same plasma system. So, here the IA wave is propagating along a direction making an angle θ with the external uniform static magnetic field, whereas in Dalui et al [23], the value of θ is equal to 0.…”

“…Dalui et al [23] have discussed the MI of IA waves propagating along the direction of the magnetic field (B = B 0ẑ ) in a collisionless magnetized plasma. The linear dispersion relation of the IA wave propagating along the direction of the magnetic field (B = B 0ẑ ) can be written as…”

Modulational Instability of Ion Acoustic Waves in a Magnetized Plasma Consisting of Isothermally Distributed Hot and Cold Electrons

“…On the basis of laboratory experiments [12,13,14,15], we can say that two different temperatures (e.g., hot and cold) of electrons in plasma are also a very interesting field of research. Several authors [16,17,18,19,20,21,22,23,24,25,26,27,28] investigated the nonlinear properties of arbitrary amplitude ion acoustic (IA) solitary waves in an unmagnetized/magnetized plasma consisting of Maxwell-Boltzmann distribution of hot electrons and Maxwell-Boltzmann distribution of cold electrons.…”