Talbot-Lau moire x-ray diagnostic for high energy density plasmas

Abstract

Phase-contrast x-ray diagnostics can detect density gradients in low-Z matter with the sensitivity and spatial resolution necessary to characterize High Energy Density Plasma (HEDP) experiments. Talbot-Lau interferometry measures x-ray beam angular deviations due to refraction index gradients along its path and can simultaneously provide x-ray attenuation, refraction, and scatter images of an object. We have extended the Talbot-Lau method from the low magnification and high energy (30–100 keV) setup used in medical applications, to the high magnification and low energy (8–20 keV) setup HEDLP experiments require. We also developed single image based phase-retrieval techniques such as Talbot-Lau Moire deflectometry. The results obtained using low-Z test objects suggest a clear advantage of Talbot-Lau Moire deflectometry over conventional radiography for density diagnostic in HEDP. The Moire technique can detect with good spatial resolution both sharp and smooth density gradients, and can use incoherent, extended x-ray sources emitting either lines or continuum, thus allowing for a wide range of backlighters.