Numerical Investigation of Propagation and Decay of Fast Ionization Waves Generated by Nanosecond Pulsed Discharge

Fast ionization waves (FIW) are an effective tool for studying plasma kinetics in nanosecond pulsed discharges. A numerical investigation of FIWs in air having high energy deposition was conducted in capillary tubes having different diameters using a two dimensional model. Continuity equations for charged and neutral species, the electron energy equation and Poisson's equation were implicitly integrated together with a propagator model for photoionization which includes both ionizing and non-ionizing absorption. The species and reactions included in the study were selected on the basis of a sensitivity analysis. The main goals of this work are to quantify how system parameters (e.g., pressure, voltage and specific energy deposition) affect the properties of the plasma in the early afterglow (tens to hundreds of nanoseconds) following the FIW.