Three dimensional ion-acoustic rogons in quantized anisotropic magnetoplasmas with trapped/untrapped electrons

M Irfan; S Ali; S A El-Tantawy; Sherif M E Ismaeel

doi:10.1063/1.5109157

Three dimensional ion-acoustic rogons in quantized anisotropic magnetoplasmas with trapped/untrapped electrons

Chaos. 2019 Oct;29(10):103133. doi: 10.1063/1.5109157.

Authors

M Irfan¹, S Ali², S A El-Tantawy³, Sherif M E Ismaeel⁴

Affiliations

¹ Department of Physics, University of Malakand, Chakdara Dir (Lower), Khyber Pakhtunkhwa 18800, Pakistan.
² National Centre for Physics at QAU Campus, Shahdra Valley Road, Islamabad 44000, Pakistan.
³ Research Center for Physics (RCP), Department of Physics, Faculty of Science and Arts, Al-Baha University, Al-Mikhwah 1988, Saudi Arabia.
⁴ College of Sciences and Humanities Studies Al-Kharj, Physics Department, Prince Sattam Bin Abdulaziz University, Al Kharj 11942, Saudi Arabia.

PMID: 31675836
DOI: 10.1063/1.5109157

Abstract

Three-dimensional (3D) modulational instability (MI) and ion-acoustic (IA) envelopes are studied in a quantized degenerate magnetoplasma, whose constituents are the trapped/untrapped electrons and anisotropic positive ions. By using quantum hydrodynamic equations and the multiscale reductive perturbation technique, a 3D nonlinear Schrödinger equation is derived to account for electron quantization and ion pressure anisotrophy effects. The potential excitations are shown stable (unstable) against the perturbations for K_c<0(K_c>0), where K_c is a critical parameter that accounts for the longitudinal (transverse) dispersion(s) and nonlinearity effects. Numerically, the nonlinear evolution of IA wavepackets into a 3D MI may be revealed in the ranges of low and high frequencies 0<ω≤0.05 and 0.75≤ω≤1.1. The quantizing magnetic field reduces (enhances) the group speed (wave frequency) of IA excitations, concentrating the wave energy to favor the modulational instability. Finite electronic temperature (viz.,T_e≤10keV) enhances the untrapped electrons and significantly widens the instability domain K_c>0. The ionic pressure anisotropy increases the wave frequency (ω), piles up the harmonics under K_c>0, and give rise to modulational instability. The quantized magnetic field and anisotropic pressure reduce the amplitude and spatial extension of the IA rogons. This study is important for understanding the 3D MI and unstable excitations in degenerate plasmas, relevant to white dwarfs, neutron stars, and high-energy density experiments, where strong magnetic field quantizes the dynamics of trapped/untrapped electrons.