Reflection dissipation of an ion‐acoustic soliton

The dynamic interaction between an ion‐acoustic soliton and adiabatically reflected particles is investigated. A perturbed Korteweg–de Vries (KdV) equation for the wave electric potential is derived from the Vlasov–Poisson equations and solved in the adiabatic soliton approximation. The soliton attenuation/amplification rate is found to be proportional to χi‖Φm‖1/2, where Φm is the initial soliton amplitude, and χi is the imaginary part of the linear susceptibility of ions/electrons when the wave is compressive/rarefactive mode. The amplitude variation is caused by momentum exchange between the soliton and reflected particles, as viewed from the soliton reference frame.