Ion-acoustic solitary waves in ion-beam plasma with Boltzmann electrons

Abstract

Particle simulations and a pseudopotential method were used to study ion-acoustic solitary waves in a plasma composed of Boltzmann electrons and kinetic beam ions. Pseudopotential theory was first applied to determine how ion-acoustic solitary waves can exist in a two-component plasma. Then, particle simulations were carried out, wherein ion-acoustic solitary waves were excited by modulating the bias grid voltage in a double plasma model. For the modulation, the potential of the grid bias was rapidly decreased, such that hump-type ion-acoustic solitary waves with good Gaussian shape were excited one after another, forming a train of waves. The simulation also showed that the phase velocities of ions decrease sharply when the solitary wave occurs, which indicates that the solitary ion-acoustic wave is excited via the inverse Landau damping process.