• The structure of ion-acoustic waves in a low-frequency three-component electron–ion space plasma with two-electron populations

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      https://www.ias.ac.in/article/fulltext/pram/091/01/0007

    • Keywords

       

      Ion-acoustic solitary waves; magnetosphere; ion cyclotron frequency; quasineutrality; space plasmas; wave dispersion

    • Abstract

       

      Low-frequency ion-acoustic waves are analysed on the ion time-scale, in a three-component electron–ion space plasma. The solitary waves propagate in the positive $x$ direction relative to an ambient magnetic field $\overrightarrow{B}_{0}$ which forms static background for a configuration consisting of cool fluid ions and both warm and hot Boltzmann distributed electrons with temperatures $T_{ic}$, $T_{ew}$ and $T_{eh}$, respectively. We derive linear dispersion relation for the waves by introducing first-order density, pressure and velocity perturbations into the ion fluid equations. Additionally, the variation in the nonlinear structure of the waves are investigated by carrying out a full parametric analysis utilising our numerical code. Our results reveal that ion-acoustic waves exhibit well-defined nonlinear spikes at speeds of $M \geq 2.25$ and an electric field amplitude of $E_{0} = 0.85$. It is also shown that low wave speeds ($M \leq 2$), higher densities of the hot electrons, antiparallel drifting of the cool fluid ions, and increased ion temperatures all lead to significant dispersive effects. The ion-acoustic plasma waves featured in this paper have forms that are consistent with those classified as the type-A and type-B broadband electrostatic noise (BEN) observed in the data obtained from earlier satellite missions.

    • Author Affiliations

       

      G GOVENDER1 S MOOLLA2

      1. Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
      2. School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
    • Dates

       
  • Pramana – Journal of Physics | News

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