Excitation of multiple ion-acoustic shocks

Multiple electrostatic ion-acoustic shock-like density perturbations are observed experimentally to be launched from a large plate in a quiescent collisionless plasma. The formation of the fastest shock is due to ions expelled from the edge of the ’’transient sheath’’ surrounding the plate. The second shock then evolves as a result of the surrounding ions filling in the region of density depression created by the first shock. Reflected ions and turbulent ion-acoustic noise at the shock front and amplitude modulation in the trailing dispersing oscillations are only observed for the leading shock.