On the evolution of ion cyclotron waves in magnetized pair ion-electron plasmas

Abstract The evolution of low frequency, electrostatic ion cyclotron waves (ICWs) in response to weak perturbation is analytically studied in a magnetized pair ion plasma with isothermal electrons distributed according to the Maxwell-Boltzmann law. Excited ICWs travel perpendicular (nearly) to the direction of the applied magnetic field. To deal with the intrinsic nonlinearity and pair-ion dynamics, a simple perturbation technique is used to solve the governing fluid and Maxwell's equations. The stationary wave solutions show that excited ICWs slowly lose coherence nature due to the mixing of phases of adjacent particles. Wave frequency becomes space-dependent under the influence of nonlinear ponderomotive force which is self-consistently generated as the mode evolves in time. Relevant mode breaks in due course failing to maintain coherency. An approximate time is obtained when the mixing of the phases starts. The effects of the concerned parameters are discussed. Phase-mixing also mediates irreversible wave-particle energy transfer causing collisionless damping of ICWs. Obtained results can be useful in understanding the behavior of nonlinear ICWs in laboratory produced pair plasmas.