Excitation of ion acoustic solitary waves and shock waves in decaying plasma between biased parallel-plate electrodes

In this study, we explore the excitation of ion acoustic solitary waves and shock waves in a decaying plasma confined between biased parallel-plate electrodes using one-dimensional particle-in-cell simulations. Our findings demonstrate that the oscillating electric field at the sheath edge generates a sequence of ion acoustic solitary waves, which exhibit characteristics consistent with the Korteweg–de Vries (KdV) equations. We observe that as the electron temperature decreases, the intervals between adjacent wave pulses shorten progressively, leading to the eventual formation of a coherent shock wave structure. These findings highlight the critical role of kinetic simulations in elucidating the dynamics of plasma decay processes.