Analysis of the species created by corona discharges and of their interactions with surfaces

Electrical discharges in various gases may produce chemical species which can cause damage to solide surfaces of different materials. In air, for example, ozone, metastable states of molecular oxygen, atomic oxygen and nitrogen oxides are produced. Furthermore, in the case of corona discharges,those species are pushed in preferred directions by electrical wind. As a matter of fact, in the case of corona discharges, there is an electrical wind ¹ resulting from the momentum given to the gas molecules by impact or drag of the ions as they move out of the high field region. The particles of the gas are swept away by this electrical wind towards low field regions and flow around encountered surfaces. The experiments presented in this paper were made with a point to plane system.