Mathematical Modeling of the Gas-Jet Target for Extreme Ultraviolet Laser

The formation of a supersonic gas target for lasers that operate in the extreme ultraviolet wavelengths is considered. The gas target is generated in the interaction zone of two opposite supersonic gas jets. The emission properties of inert gas targets were investigated experimentally. The distributions of the emission radiation intensity for argon, krypton and carbon dioxide were obtained and the shapes of the emission zone were detected.
The experimental conditions were reproduced in numerical experiments. The mathematical model of viscous compressible gas was used to model the gas dynamics of supersonic gas jets. The problem was solved in a two-dimensional axisymmetric setting for argon. The obtained distributions of the main gasdynamic quantities made it possible to detail the flow features and estimate the size of the emission zone, as well as the density level corresponding to this zone. It was demonstrated that the results of calculations qualitatively agree with the experimental data. In addition, it was found that the density level of the emission region with the required extreme ultraviolet intensity factor can be obtained by monitoring the total pressure.