The Talbot-Lau X-Ray Deflectometer: A Refraction-Based Plasma Diagnostic

Talbot-Lau X-ray Deflectometry (TXD) has been developed as an electron density diagnostic for High Energy Density (HED) plasmas. The diagnostic delivers refraction, attenuation, elemental composition, and scatter information from a single-shot Moire image. A Talbot-Lau interferometer was benchmarked using laser-target and X-pinch x-ray backlighters. Grating survival and electron density mapping were demonstrated for: a) 25–60 J, 8–30 ps laser pulses using copper targets and b) X-pinches driven by a ~350kA/350ns generator. X -ray backlighter quality was assessed in order to optimize areal electron density gradient retrieval and electron density mapping. TXD enabled accurate areal electron density detection with high contrast (>25%) and spatial resolution of
$\sim 50\mu \mathrm{m}$
in the high-power laser experiments, while a higher spatial resolution
$< 27\mu \mathrm{m}$
and lower contrast (<15%) were found in pulsed power experiments, thus demonstrating the potential of TXD as an electron density diagnostic for HED plasmas.