Optical breakdown of molecular nitrogen in a wide range of pressures near a solid target

An investigation was made of the conditions for the formation and evolution of a laser plasma near a metal surface in nitrogen at pressures of 1–140 atm. A neodymium laser (λ = 1.06μ) operating in the spiky regime with an average power density G = 1–10 MW/cm² was used in the experiments. A numerical analysis was made of the characteristics of optical breakdown of molecular nitrogen in the pressure range 10–200 atm. The experimental data were interpreted on the basis of the results of numerical modeling.