Phase imaging of irradiated foils at the OMEGA EP facility using phase-stepping X-ray Talbot–Lau deflectometry

• Published in: High power laser science and engineering 2023-01, Vol.11, Article e49
• Main Authors: Pérez-Callejo, G., Bouffetier, V., Ceurvorst, L., Goudal, T., Klein, S. R., Svyatskiy, D., Holec, M., Perez-Martin, P., Falk, K., Casner, A., Weber, T. E., Kagan, G., Valdivia, M. P.
• Format: Article
• Language: English
• Subjects: Ablation; deflectometry; Dense plasmas; Experiments; Image resolution; Interferometry; Laboratories; Laser ablation; Laser plasmas; Lasers; Medical imaging; Metal foils; OMEGA EP; Phase stepping; phase-contrast imaging; Plasma; Polystyrene resins; Power; Radiation; Short pulses; Talbot–Lau; X-ray interferometry; X-ray radiography
• ISSN: 2095-4719; 2052-3289
• DOI: 10.1017/hpl.2023.44

Diagnosing the evolution of laser-generated high energy density (HED) systems is fundamental to develop a correct understanding of the behavior of matter under extreme conditions. Talbot–Lau interferometry constitutes a promising tool, since it permits simultaneous single-shot X-ray radiography and phase-contrast imaging of dense plasmas. We present the results of an experiment at OMEGA EP that aims to probe the ablation front of a laser-irradiated foil using a Talbot–Lau X-ray interferometer. A polystyrene (CH) foil was irradiated by a laser of 133 J, 1 ns and probed with 8 keV laser-produced backlighter radiation from Cu foils driven by a short-pulse laser (153 J, 11 ps). The ablation front interferograms were processed in combination with a set of reference images obtained ex situ using phase-stepping. We managed to obtain attenuation and phase-shift images of a laser-irradiated foil for electron densities above ${10}^{22}\;{\mathrm{cm}}^{-3}$ . These results showcase the capabilities of Talbot–Lau X-ray diagnostic methods to diagnose HED laser-generated plasmas through high-resolution imaging.