Dynamics of the vapor breakdown plasma accompanying the irradiation of metals by cw CO2 laser radiation

An experimental investigation was made of the dynamics of the vapor breakdown plasma formed from a metal (low-carbon steel) during irradiation by a 500-W cw СО₂ laser in the intensity range 2–4.5 MW/cm². The plasma behaved in a self-oscillatory manner. The breakdown plasma was found to be inhomogeneous within one self-oscillations period and it consisted of a system of striations parallel to the metal surface. A qualitative explanation of this phenomenon is presented.