  Microcavity plasma arrays of inverse pyramidal cavities have been fabricated
in p-Si wafers. Each cavity acts as a microscopic dielectric barrier discharge.
Operated at atmospheric pressure in argon and excited with high voltage at
about 10 kHz, each cavity develops a localized microplasma. Experiments have
shown a strong interaction of individual cavities, leading to the propagation
of wave-like optical emission structures along the surface of the array. This
phenomenon is numerically investigated using computer simulation. The observed
ionization wave propagates with a speed of about 5 km/s, which agrees well the
experimental findings. It is found that the wave propagation is due to
sequential contributions of a drift of electrons followed by drift of ions
between cavities seeded by photoemission of electrons by the plasma in adjacent
cavities.
