Nonlinear excitation of large-amplitude ion acoustic solitary waves in a multispecies warm ion plasma with ultra-relativistic degenerate electrons

Abstract

Large-amplitude ion acoustic solitons (IASs) in an ultra-relativistic degenerate quantum plasma consisting of non-degenerate warm light nuclei, stationary heavy nuclei and relativistically degenerate electrons are investigated. The Sagdeev’s pseudo-potential approach is adopted to obtain the energy integral equation for the study large-amplitude IASs. The Mach number domain $\left( {M_{l} \le M \le M_{h} } \right)$ is determined numerically in term of various parameters. Our numerical investigation shows that only compressive solitary waves can propagate in present plasma systems. The effect of different plasma parameters, such as the number density ($\mu_{e}$), degenerate electron density ($k$), relativistic factor ($\gamma$), temperature ratio ($\sigma$) and Mach number ($M$), on the characteristic properties of solitary waves are reported. The corresponding phase trajectory is also drawn for the existing domain. The present theoretical study recovers the results from a previously published article (Sultana and Schlickeiser, Phys. Plasmas 25: 022110, 2018) for a cold multi-ion quantum plasma. Our result may be helpful to understand the basic characteristic of nonlinear solitary waves propagating in a quantum plasma, in which the non-degenerate warm light nuclei, stationary heavy ions and relativistic degenerate electrons are present. Plasmas with the given composition are found in astrophysical object such as white dwarfs, neutrons stars, etc.