Advanced measurement of gas jet density using a wavefront sensor

We present a four-pass tomography setup for the characterization of the density distribution of a gas jet. The data acquired with a wavefront sensor is processed using a tomography algorithm, providing a 3D reconstruction of the gas density distribution. We applied this technique to characterize a supersonic gas jet produced by a de Laval nozzle and obstructed by a razor blade in ambient pressure, which are among the common targets used in high-repetition rate laser wakefield acceleration (LWFA) experiments. The results revealed the complex density distribution of the jet, including the formation of barrel shocks. The four-pass tomography setup with a wavefront sensor provides a valuable tool for the detailed characterization of gas jets, enabling the investigation of fundamental fluid mechanics phenomena and contributing to the development of advanced propulsion systems and LWFA gas targets.