Experimental study of electron trapping in an ion acoustic soliton

Abstract

Electron-trapping in ion-acoustic solitons is experimentally investigated by means of « instantaneous » probe characteristics in the soliton, obtained by fast sampling of the probe current; the probe is biased via a D.A.C. and the data can be processed by a signal-averager. The measured relationship between density and potential fluctuations is not the Boltzmann distribution. This may be explained by the existence of a trapped electron population. The trapping efficiency is estimated using Schamel's theory