DEVELOPMENT OF SUPERMIRRORS FOR HIGH RESOLUTION X-RAY LMJ MICROSCOPES

摘要

With regards to the future Laser Megajoules french facility (LMJ), our laboratory is developing advanced time-resolved High Resolution X-ray Imaging (HRXI) systems to diagnose laser produced plasma. Shrapnel and X-ray loading on this laser imposes to place any HRXI as far away from the source as possible. Grazing incidence X-ray microscopes are the best solution to overpass this limitation. These imagers combine therefore grazing X-ray microscope and camera. We designed imaging diagnostics, mainly with a long working distance (> 50 cm) and high spatial resolution. All of them are composed of single or multi-toroidal(s) mirror(s).To increase the bandwidth of reflectivity of all these mirrors, multilayer coatings have been deposited. We present mainly microscopes using non-periodic W/SiC multilayer coatings (Supermirrors), developed in collaboration with Institut d'Optique.Supermirrors were designed for a first set of diagnostics to work at 0.7° grazing incidence. Secondly, we have implemented this supermirror on a Wolter-type microscope used at a smaller grazing incidence (0.6° angle) in order to increase the bandwidth of reflectivity up to 12 keV. Metrology for x-ray reflectance in the whole range on the synchrotron radiation facility BESSY II is also presented.