Testing Talbot--Lau X-Ray Moir\'{e} Fringe Deflectometry with a Laser Backlighter*

Moir\'{e} fringe deflectometry is a simple and robust density diagnostic method, based on light refraction caused by electron density gradients. The Talbot-Lau (TL) grating interferometer could make it possible to apply this method for density diagnostics in high-energy-density plasmas using hard x rays from conventional backlighters. When compared to conventional radiography, the TL interferometer offers more sensitivity to refraction and is therefore less dependent on modeling. We adapted the TL interferometer to the high-energy-density-physics requirements by extending its operation to high magnification, 8 to 17 keV x-ray energy, and single-shot phase retrieval. The next step of development is to test its operation close to a high power laser backlighter. We designed an experiment on the Multi-Terawatt laser aimed at studying grating survival as a function of distance from the backlighter as well as demonstrating Moir\'{e} fringe production with 8-keV x rays. The possibility of directly using a microperiodic backlighter instead of a ``source'' grating is also discussed.