Simultaneous simulation of microhollow cathode discharge and its sustained discharge with split third electrodes

Simultaneous simulation of microhollow cathode discharge (MHCD) and its sustained discharge in argon is attempted with a two dimensional, self-consistent, continuum fluid model. Bell-shape enlarged volume discharge is simulated with a single third electrode, and further expansion in the discharge volume of the sustained discharge is demonstrated with split third electrodes. In the sustained discharge region, monomer metastable is a dominant species and the number density of dimer ions is higher than that of monomer ions. The expansion in the sustained discharge does not alter the characteristics of the MHCD observed with a single electrode. But electrons and metastables in the sustained discharge region are expanded when the third electrodes are turned on. The simulated distribution of metastable species shows a rake-like structure that is also observed in experiments. As the pressure increases, a ratio of dimer-to-monomer metastable number density increases.