Wave excitation in a modified double plasma device

Abstract

A modified double plasma (MDP) device is newly developed and shown to be useful for basic plasma wave experiments. Further, the mechanism of wave excitation in the MDP device is experimentally clarified. From the results the peculiarity of the device is found, that ion-acoustic waves can be excited in plasmas essentially freely from the effects of stationary beam ions and other modes, such as ion-beam modes as far as linear waves are concerned. For nonlinear waves, however, ion-acoustic solitons or shocks with reflected ions ahead and slower wave-like signals behind are possibly excited just as in a conventional DP device.