On the influence of surface condition on air plasma formation near metals irradiated by microsecond TEA CO2laser pulses

Abstract
A systematic electron microscopy analysis is performed of the defects on metallic surfaces, either pre-existing or introduced by processing or as a result of powerful laser irradiation. Metallic and nonmetallic defects were revealed with a vaporisation threshold lower than that of an ideal plane metallic surface. This lower threshold might lead to a lowering of the breakdown threshold of a gas in the neighbourhood of the metallic target.