Mechanism of energy transfer from an optical-breakdown plasma to a metal surface

A two-dimensional theoretical model is developed for the description of the transfer of energy from a surface-breakdown plasma, maintained by CO₂ laser radiation, to a target. An investigation is reported of the efficiency of the interaction of laser radiation with a target as a function of the radiation intensity and spot size. A strong localization of the laser interaction is shown to be due to a heat-conduction energy flux, whereas the energy deposited outside the irradiation spot is due to radiative energy transfer at ultraviolet frequencies.