Quantitative density retrieval of gas jets for high harmonic generation EUV sources with a compact schlieren imaging system

We demonstrate the implementation of a compact schlieren imaging technique for quantitatively measuring atomic density profiles in a gas jet-based high harmonic generation EUV source. This technique compares high harmonic generation light sources and optimization, considering different nozzle geometries, backing pressures, and vacuum systems. The simplicity of schlieren imaging could make it a suitable standardized inspection tool for gas jet-based high harmonic generation sources. Several gas jet profiles at different backing pressures were analyzed, enabling the retrieval of the peak pressure within the gas jet and the impact of the vacuum system on the jets' shape.