Nonlinear particle trapping by coherent waves in thermal and nonthermal plasmas

Abstract

We perform a test particle simulation to study the resonant interaction of electrons with a stationary electrostatic wave. In the simulation, we use a new method to generate nonthermal particle distributions efficiently. This method utilizes inverse cumulative distribution function, and compared with the existing methods in the literature, found to have a negligible deviation from the analytical form of the distribution, particularly in the tail side, where nonthermal particles are situated. The simulation revealed that the trapped particle density varies highly with the width (≈10%–60%) and amplitude (≈13%–19%) of the wave potential. The particle trapping is found to be more efficient in nonthermal plasmas than thermal plasma. It implies that particle transport through waves could be more effective in nonthermal plasmas than thermal plasmas. In addition, the simulation sheds light on the particle trapping time and its relation to the characteristics of the wave potential. Overall, the present study will be helpful to understand the particle trapping by the coherent waves, which are frequently seen in space and astrophysical plasmas.