The propagation of an ion-acoustic soliton from a quiescent plasma region into a localized non-quiescent region (An n/sol,ion z An ninobrc) is experimentally examined. Sekeral of the soliton properties are preserved although the soliton undergoes an enhanced damping as it propagates in the noisy plasma.

Experiments on the propagation of an ion-acoustic soliton from an isotropic plasma into a region containing a weak mirror magnetic field are described. An anomalous focusing of the soliton is detected. The magnetic field also allows us to separately observe reflected ions from the soliton and the ions involved in the excitation of the soliton.

The evolution of the frequency spectrum of a velocity modulated burst of ions from a fine mesh grid in a plasma is measured and interpreted. Initial frequency modulation close to the grid indicates a ‘‘klystron bunching’’ of the ions. The measured spectrum far from the grid indicates the excitation of an ion-acoustic soliton.

Experiments on the propagation of an ion-acoustic soliton from an isotropic plasma into a region where a localized magnetic field exists are described. The solitons propagate in a direction that is almost perpendicular to the magnetic field. The strength of the field is sufficient to magnetize the electrons but leave the ions unmagnetized.