Cascading bifurcations to chaos in a current-carrying ion sheath

Recently, cascading bifurcations followed by the onset of chaos were observed in a current-carrying plasma sheath when an external periodic oscillation was applied to a fine-meshed grid which divided the plasma produced by dc discharge. In this experimental set-up, the potential at the grid is negatively biased to the extent that electrons cannot penetrate up to the grid and, therefore, the resultant sheath is an ion sheath which is detached from the plasma by an ordinary sheath. The ion sheath on both sides of the grid forms a potential well in which the ions oscillate to induce a primary motion responding to the external oscillation. (author) 2 figs