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 (25 mu m thick) with a modulation wavelength between 12 and 50 mu m were accelerated with a temporally shaped soft x-ray pulse emitted from a hohlraum with a maximum radiation temperature of about 115 eV. 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 5 mu m and 50 ps, respectively. The acceleration was derived from side-on velocity measurements. The microscope we have developed is a Wolter-like microscope which consists of two toroidal 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 4 mu m was achieved in the 1-5 keV range. The Wolter-like constitutes an interesting device for laser plasma diagnostics and will be very useful in the Laser Megajoules experiments conducted with more powerful lasers. (c) 2005 American Institute of Physics.