Phase-contrast imaging of irradiated foils through Talbot-Lau X-ray Deflectometry on OMEGA EP

Talbot-Lau X-ray Deflectometry (TXD) diagnostics for OMEGA EP can measure electron density gradients to characterize HED plasmas through phase-contrast. To optimize TXD, a suite of backlighter targets were studied on MTW considering source size and spectral quality within the 8 keV interferometer contrast curve. The EP-TXD diagnostic mapped the ablation front of a foil irradiated by 150 J, 1 ns laser pulse (\textgreater 2.4 x 10$^{\mathrm{17}}$ W/cm$^{\mathrm{2}})$. For the first time, a Moir\'{e} fringe pattern was recorded at 5 ns detecting refraction angles \textless 150 \textmu radians, equivalent to line-integrated electron density gradients of \textless 1.8 x 10$^{\mathrm{25}}$ cm$^{\mathrm{-3}}$. Additional Moir\'{e} images can help benchmark MHD codes and simulations by mapping the evolution of the ablation front near critical density. Further developments to the TXD platform will include monochromatic backlighting to improve fringe contrast and spatial resolution so that foils can be irradiated at higher intensities.