On Velocity Stopbands in Electrostatic Solitary Wave Propagation in Magnetospheric Plasma in the Presence of an Ion Beam—Application in the Solar Wind
Year: 2024
Type: article
Abstract: Satellite observations in the Earth’s magnetosphere suggest a coexistence of different types of ion populations, such as protons and heavier helium ions (alpha particles) transported by the solar wind. We have undertaken an investigation, from first principles, of the conditions for the occurrence of electrostatic solitary waves in such a multi-ion plasma environment. Nonlinear analysis has been employed to explore the effect of an ion beam on the occurrence of stopbands in a multicomponent plasma consisting of Boltzmann electrons and two ion species, modeled as cold and warm (adiabatic) ions. A “stopband” is an interval of pulse speed (mach (Mach number) values in which solitary waves cannot propagate. Such stopbands are known to exist in relation to fast ion-acoustic solitary waves (exclusively). Our parametric analysis reveals that the stopband widens over the range of cold ion charge density (values) upon increasing speed of a hot ion beam moving along the direction of wave propagation. However, the stopband becomes narrower in the case of a counterpropagating beam. Similarly, the streaming of a cold ion beam fluid along (or antiparallel) to the wave direction leads to the narrowing (or widening, respectively) of the stopband. The fast soliton existence (velocity) domain is characterized by two critical points (a crossover and a turning point), which are affected by the beam. Our study could be relevant to understanding energy dissipation processes in the fast solar wind associated with relative drifts between the major (protons) and minor (alpha particles) ions which results in the heating of both species.
Source: The Astrophysical Journal
Authors: S. K. Maharaj, R. Bharuthram, I. Kourakis
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Awards: G1101799216, G1430768255
OpenAlex ID: W4404194789
