Thermodynamic parameters of a nanosecond plasma formed on a solid target in the radiation field of harmonics of a high-power neodymium laser emitting pulses with a steep leading edge

Measurements of the plasma pressure on an aluminium target in vacuum were made in the radiation field of harmonics of a gigawatt neodymium laser. The results were combined with measurements of the plasma temperature to find the plasma density in the region of its one-dimensional expansion near the target. The plasma was found to be close to equilibrium and near-ideal. Its density, like its temperature, was governed by the laser radiation intensity and was independent of the radiation frequency.