Dependence of pre-breakdown time on ionization processes in a pseudospark discharge

The formation and development of pseudospark discharge, especially the onset of thebreakdown, are of great technological interests in multiple applications due to theirinfluences on the limits of current rising and fast switching performances of the devices.In this work, the development of pseudospark discharge in the pre-discharge and hollowcathode phases in a single-gap device are investigated by a time-dependent model tocalculate the temporal development of total ionization cross section in varying times andregions. The simulations in our work are performed using the two-dimensional kineticplasma simulation code XOOPIC. The time-dependent evolutions of the ionization crosssection in pre-discharge and hollow cathode phases are presented under varying electricfields and hollow cathode configurations. Thus the electron multiplications and plasmageneration processes by ionizing collisions in varying phases are examined and theirdependences on a variety of external parameters are determined in different regions in thepseudospark device. A sequence of physical events and their influences in differentregions are also identified via the quantitative analysis of time-dependent ionizationcross section. The discharge formation time shows highest dependences on the cathodeaperture diameters and anode voltages. Additionally, a linear dependence of thepseudospark breakdown time on the time-averaged ionization cross section is illustratedunder varying external parameters. It indicates that the influences of the externalparameters on the discharge performances can be determined and estimated via the total andaverage ionization cross sections under varying external conditions. In this work, both aqualitative understanding of the pseudospark onset mechanism and a quantitative approachto estimate the formation time in a pseudospark device with varying parameters aredeveloped via this model