Characteristics of ion–acoustic soliton in hydrodynamic description of plasma electrons and their comparison with kinetic theory

The characteristics of an ion–acoustic soliton are considered analytically and numerically within the framework of hydrodynamic equations for electrons. For the first time, analytical expressions for the velocity and current of electrons, as well as the total current, were obtained in the soliton localization region. It is shown that the total current in the region of the maximum potential of the ion–acoustic soliton flows in the direction of its movement. Numerical solution of the hydrodynamic equations demonstrates that the ion–acoustic soliton moves at a constant velocity and does not change its shape over time. It has also been numerically established that when two solitons interact, their shape does not change. A comparison of the ion–acoustic soliton characteristics obtained within the framework of hydrodynamic equations with the results of kinetic theory was carried out.