Interferometric investigation of shock waves induced by a TEA-CO2 laser-produced plasma in air in front of a solid target

The shock waves induced in the surrounding atmosphere by an air plasma were investigated by laser interferometry. The air-breakdown plasma was produced by a TEA-CO2 laser in front of a solid target. The results were compared to the predictions of the theory of intense explosions in gases and a good agreement was inferred. It was also determined that the symmetry of the expansion of the initial shock wave is determined by the plasma-source shape and, accordingly, depends on the laser power density incident on the target surface. However, for further stages all the shock waves expand spherically.