Prebreakdown in the hollow cathode pseudospark discharge

Summary form only given. The ionization growth during the prebreakdown phase of a pseudospark discharge is numerically simulated within the hollow cathode region. A swarm model based on the local field approximation is applied. The continuity equations for electrons and ions are solved simultaneously with Poisson´s equation as a function of time in a two-dimensional axially symmetric geometry. The distortion of the electric field due to the hollow cathode geometry and due to space charge effects is incorporated. According to the simulations, the plasma density inside the hollow cathode region at first grows exponentially in time during several 100 ns, mainly because of electron impact ionization and photon emission releasing secondary electrons at the surfaces by photo effect. The electrons follow the electric field lines as a nearly incompressible fluid, resulting in a focusing towards the axis combined with an increase in velocity