Excitation and the propagation of ion acoustic solitons in nonideal plasmas

Ion-acoustic soliton propagation in non-ideal plasmas is investigated experimentally and theoretically by modifying the KdV equation and/or using the Kadomstev-Petviashvili (KP) equation. The evolution of the frequency spectrum of a velocity modulated bursts of ions from a fine mesh grid in a plasma is measured and interpreted. Experiments on the propagation of an ion-acoustic soliton into a region of inhomogeneous plasma density are described. It is found that the local amplitude and velocity decrease and the width increases as the soliton propagates into a region of lower density. The propagation of an ion-acoustic soliton from a quiescent plasma region into a localized nonquiescent region is experimentally examined. The soliton properties are preserved although the soliton undergoes an enhanced damping as it propagates in the noisy plasma. The effects of small transverse perturbations are studied by launching solitons from the nonplanar geometries and interpreted using the KP equation