Excitation of electrostatic plasma waves using a dielectric covered metallic electrode

Abstract

Plasma response to high positive and negative voltage pulses is studied using pulsed capacitive excitation in a uniform and unmagnetized plasma. The positive or negative voltage pulse is applied to a metallic electrode, covered by a dielectric (Kapton) film, immersed in a low pressure argon plasma. The pulse magnitude is much greater than the electron temperature (U0 ≫ kTe/e). Experiments are carried out for different plasma parameters, to find how the plasma perturbations propagate for various applied pulse widths in comparison to ion plasma period ( fi-1). Plasma perturbations are studied by varying the thickness of the dielectric. For positive pulse bias, depending on the dielectric thickness, excitation of solitary electron holes, or solitary ion holes are observed. For negative pulse bias, varying the dielectric thicknesses, only ion rarefaction waves are excited.