Electrical and Optical Properties of AC Microdischarges in Porous Ceramics

Abstract Generation of microdischarges inside porous ceramics by AC high voltage was explored. The physical properties of the microdischarges were investigated by electrical measurements, photographic visualization, and optical emission spectroscopy. The effects of pore size, discharge power, and gas mixture composition on the discharge properties and its development are described. The optimum generation and distribution of the microdischarges was observed with pore sizes of 50 and 80 µm. The emission spectra of the microdischarges indicated their strongly non‐equilibrium character. A theoretical analysis of the microdischarge mechanism is provided, accounting for the pore size and the elementary processes such as ionization, recombination, and ambipolar diffusion. magnified image