X-ray imaging of Rayleigh-Taylor instabilities using Fresnel zone plate at the National Ignition Facility

Being able to provide high-resolution x-ray radiography is crucial in order to study hydrodynamic instabilities in the high-energy density regime at the National Ignition Facility (NIF). Current capabilities limit us to about 20 mu m resolution using pinholes, but recent studies have demonstrated the high-resolution capability of the Fresnel zone plate optics at the NIF, measuring 2.3 mu m resolution. Using a zinc He-alpha line at 9 keV as a backlighter, we obtained a radiograph of Rayleigh-Taylor instabilities with a measured resolution of under 3 mu m. Two images were taken with a time integrated detector and were time gated by a laser pulse duration of 600 ps, and a third image was taken with a framing camera with a 100 ps time gate on the same shot and on the same line of sight. The limiting factors on image quality for these two cases are the motion blur and the signal to noise ratio, respectively. We also suggest solutions to increase the image quality.

Automated summary

The ability to provide high-resolution X-ray radiography is essential for studying hydrodynamic instabilities in high-energy density regimes at the National Ignition Facility. Recent studies have demonstrated the high-resolution capability of Fresnel zone plate optics, achieving a resolution of 2.3 µm. Challenges in improving image quality include motion blur and signal to noise ratio limitations.