Dynamics of the development of breakdown near the surface of infrared optics elements in gaseous media

An experimental investigation was made of the influence of the pressure of the ambient gas on the shape of CO₂ laser pulses transmitted by an NaCl sample after breakdown on its surface. A study was made of the dynamics of formation of a breakdown plasma initiated by surface breakdown in various gases: it was carried out in a wide range of gas pressures and incident radiation intensities. Measurements were made of the dependences of the velocity and maintenance threshold of optical detonation waves on the pressure of air when CO₂ laser radiation was used. The absence (in some cases) of the visible traces of damage as a result of this breakdown and the opacity of the surfaces of infrared optics materials in gaseous media was attributed to the screening of the surface by an optical detonation wave.