Enhancing the predictive capability of modified Paschen curve models for direct current field emission assisted (FEA) microdischarges

Traditional plasma systems typically operate at low pressures and centimeter scale reactors. However, during the last decade or so, there is an active interest in the downscaling of devices and plasmas are no exception. Because of the popular pd (pressure times gap size) scaling, such plasmas have to operate at or near atmospheric pressure and are referred to as microplasmas or microdischarges. While downscaling the plasma device, field emission electrons from the field emission and their interaction with micro discharge due to high electric fields has shown to affect for both pre-and post breakdown. In this context, we are presenting the better understanding of field enhancement factor (β_eff) with electric field that able to predict the breakdown voltage in the microscale gap sizes. It is found that the β_eff is decreasing with increase in the electric field. The interpretation of experimental data using one-dimensional modified Paschen law indicates the similar electric field dependence. We have extracted the values of β_eff from different experimental datasets for microscale breakdown of different gases argon, hydrogen, Carbon-Dioxide and dry air analyze them and are shown to be consistent and an empirical dependence on electric field.