Wolter-like high resolution x-ray imaging microscope for Rayleigh Taylor instabilities studies

In the context of the inertial confinement fusion, experiments have been carried out on the Phebus laser facility to study the Rayleigh–Taylor instabilities (RTIs) at the ablation front. Premodulated brominated plastic targets (25μm thick) with a modulation wavelength between 12 and 50μm were accelerated with a temporally shaped soft x-ray pulse emitted from a hohlraum with a maximum radiation temperature of about 115eV. The RTI growth was measured by face-on radiography using a microscope coupled with an x-ray streak camera, which has spatial and temporal resolutions of about 5μm and 50ps, respectively. The acceleration was derived from side-on velocity measurements. The microscope we have developed is a Wolter-like microscope which consists of two toroïdal mirrors. We will present the experimental and theoretical potentialities of this microscope: characterization with an x-ray generator and plasma laser x-ray source (Phebus facility) for two-dimensional (2D) and 1D time-resolved imaging studies. Spatial resolution of about 4μm was achieved in the 1–5keV range. The Wolter-like constitutes an interesting device for laser plasma diagnostics and will be very useful in the Laser Mégajoules experiments conducted with more powerful lasers.