Solitary waves dissipation in pair-ion plasmas for (r, q)-distributed electrons

Solitary waves in a symmetric pair-ion plasma are studied as affected by various plasma parameters, e.g., electron density, collision frequency, ion temperatures, ( r, q)-distributed electrons. In this regard, plasma fluid equations have been used to simulate the plasma system for which a reductive perturbation technique is applied to derive the relevant damped Korteweg–de Vries equation. The effects of spectral indices, collision frequency, ion-electron temperature ratios, and density on the time evolution of perturbed potential profile have been illustrated and benchmarked with Boltzmann distributed electrons. It is observed that the nonthermal population significantly affects the soliton amplitude, which increases with r and q. Furthermore, it also grows with electron density and ion temperature; however, there is a in the slowing down rate in the case of the latter. An increase in the collision frequency leads to faster damping in both the amplitude and speed of the solitary potential profiles. This work will be useful in the determination of plasma dynamics for pair-ion plasma systems containing nonthermal electrons, especially with flat-topped distribution functions, e.g., as found in Earth's magnetosheath and magnetotail, as well as in laboratory experiments with the fullerene plasma. To the best of our knowledge, a general description for pair ion plasmas using (r, q) distribution has never been reported. This study can explore a huge variety of velocity distribution functions—via the two index nonthermal parameters, in contrast to single index counterparts.