Twisted positron-acoustic wave in quantum plasmas

Abstract

In this paper, we explore the existence of positron-acoustic wave (PAW) carrying orbital angular momentum (OAM) in a quantum electron-positron-ion (EPI) plasma system containing electrons, two-temperature positrons, and immobile ions as a neutralizing background. To achieve this aim, we employ the quantum hydrodynamic approach to obtain the evaluation equation of cold positrons density. By solving this equation in the paraxial limit, the Laguerre–Gaussian (LG) modes of positron perturbation are derived, and their corresponding angular momentum densities are calculated. In the following, based on numerical analyses it is found that the evolution of LG potentials and cold positrons density oscillations are greatly affected by variation of radial and angular mode numbers, relative Fermi temperature of hot species, positrons concentration, and azimuthal phase value. It is expected that the results of this study will give more insight into the positrons dynamics in dense astrophysical and laboratory plasmas.

Head-on collision of dust-ion acoustic solitary waves in a plasma with a nonextensive electron

“…Research around the linear and nonlinear wave phenomena in multi component plasmas has attained a significant popularity during the last decades [1][2][3][4]. This amount of attention can be originated from their frequent attendance in active galactic nuclei [5], pulsar magnetosphere [6][7], solar atmosphere [8] and in the inner regions of the accretion disks surrounding the central black holes [9][10].…”