Construction and Characterization of Pseudospark High Power Plasma Switch

Discharge can be created by applying a potential difference between two electrodes in a gaseous medium. Electric field generated between these two electrodes (anode and cathode) causes ionization of neutral gas particles and creates a conducting path. This phenomenon is called breakdown of the gaseous medium [1]. Electric field lines between the anode and the cathode depend on the geometry of the electrodes. The simplest configuration, where the electric field is almost uniform, is two plane electrodes with a small gap in between compared to the size of electrodes. Figure 1.1 shows voltage-current characteristics of a DC low pressure electrical discharge with plane electrodes [1,2]. Dark discharge region is where discharge formation begins, however the discharge does not contain enough energized particles to lead to breakdown formation. This discharge is dark because there are no energy level transitions of electrons causing visible light emission. During background ionization regime of the dark discharge, individual ions and electrons created by cosmic rays and other forms of natural ionizing radiation are swept out by increasing voltage; during saturation regime, all the background ionized charged particles are removed
and moreover electrons do not have enough energy to cause ionization [3].