Oxidation of metals by a plasma formed as a result of low-threshold breakdown of air

The characteristics of the oxidation of copper, aluminum, and titanium were determined in the case when breakdown of air was initiated by CO₂ laser pulses incident on targets made of these metals. A study was made of the influence of surface oxide films on the threshold radiation intensity necessary to produce a plasma. The dependence of the efficiency of the thermal interaction of an optical-breakdown plasma on the magnitude and sign of the charge carried by the surface of a metal target was investigated for the first time in the specific case of titanium.