Effect of Electrode Spacing in a Single-Gap Multi-Aperture Pseudospark Switch

In this study, an experimental and simulation investigation of the discharge characteristics of demountable single-gap multi-aperture pseudospark switch (SGMA-PSS) has been carried out with hydrogen gas by applying dc high voltage. The study shows the importance of facing electrode gas gap (FEGG) on the discharge characteristics of SGMA-PSS. The breakdown voltage of SGMA-PSS has been measured for a wide range of gas pressures at several FEGGs during the experiment. Further, the 2-D axis-symmetric kinetic simulation tool COMSOL Multiphysics has also been used for better understanding of discharge characteristics and analysis of the effect of FEGG on the penetrating potential. Both the experimental and the simulation studies have indicated that the breakdown potential is decreasing with increasing FEGG at constant pressure. The obtained results validate the breakdown mechanism as per the left side of Paschen's curve. The results have clearly shown that 2.4 mm electrode spacing has higher breakdown as well as larger penetrating potential which corresponds to the higher discharge current. The proposed investigation is very much useful for analyzing the impact of electrode spacing on the performance of the SGMA-PSS and the development of suitable switches for fast pulsed power applications.